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Effects of co-fermentation with Candida stellata and Saccharomyces cerevisiae on the aroma and composition of Chardonnay wine
Australian Journal of Grape and Wine Research
Abstract
Effects of several inoculation protocols using Saccharomyces cerevisiae strain AWRI 838 (an isolate of Lalvin EC11 18) and Candida stellata strain AWRI 1159 (CBS 2649) upon the aroma properties and chemical composition of Chardonnay wine were determined. An increase in the concentration of glycerol and acetic acid was observed when fermentation was performed with C. stellata AWRI 1159, which did not progress to dryness. Sensory descriptive analysis showed a substantial difference in aroma between the wines produced by monocultures of the two yeast species. The Candida stellata AWRI 1159 produced significantly more intense ‘honey’, ‘apricot’, and ‘sauerkraut’ aromas, and diminished the ‘lime’, ‘banana’‘tropical fruit’ and ‘floral’ aromas ascribed to S. cerevisiae AWRI 838. When C. stellata AWRI 1159 was co-inoculated at ten times the initial concentration of strain S. cerevisiae AWRI 838, the non- Saccharomyces yeast had only a minor impact upon wine aroma and composition despite maintaining a significant viable population of 5–10 times 106 colony forming units per mL throughout fermentation. Wine of a different aroma profile to either of the reference monoculture wines was produced by sequential fermentation, whereby C. stellata AWRI 1159 conducted the first half of fermentation, before inoculation with S. cerevisiae AWRI 838, and the subsequent completion of fermentation. This wine had ‘floral’, ‘banana’, ‘lime’, ‘tropical fruit’ and ‘sauerkraut’ aroma scores intermediate to the two reference monoculture wines, ‘apricot’ and ‘honey’ aroma ratings similar to the S. cerevisiae AWRI 838 wine, and ‘ethyl acetate’ aroma that exceeded that of both reference wines. These results suggest the potential of a reliable mixed culture fermentation strategy for exploiting unconventional, fermentation-impaired yeasts for producing greater flavour diversity in wine.
... Traditionally, crafting sour beers involves a complex interaction of multiple microbes and lengthy aging [11] while at the same time having to deal with finicky lactic acid bacteria that are sensitive to hops [12] and demand cross-contamination control. It is therefore of particular interest that strains producing high levels of lactic acid could potentially be used to make sour beer without adding bacteria, thus simplifying and shortening the process. ...
... In addition, the authors employed RNA high-throughput sequencing technology to unravel the transcriptome-level gene expression of S. cerevisiae and L. thermotolerans in a mixed fermentation environment. While delving deeper into the intriguing realm of yeast-yeast interactions, this technology can help to illuminate the research on the cellular adaptive responses of both yeasts, building upon previous genetic analyses of expression variations during beer fermentation [12][13][14]. Therefore, this study provides a framework for establishing the process and procedure of mixed-culture fermentation, which is expected to inspire the production of natural, fruity sour beer from industrial wort. ...
... Correlation analysis was performed using methylene blue staining method for micromonitoring analysis of cell mortality [12], and the yeast mortality Color process was determined by the methylene blue staining method. The EMA pretreatment conditions suit- able for the two yeast strains were determined as EMA concentration of 20 µmol/L upon placed in the dark for 10 min. ...
Increasingly high interest in yeast–yeast interactions in mixed-culture fermentation is seen along with beer consumers’ demands driving both market growth and requests for biotechnological solutions that can provide better sensory characteristics. In this study, Lachancea thermotolerans and Saccharomyces cerevisiae with a cell population ratio of 10:1 were inoculated for sour beer fermentation while the process conditions within the brewing industry remained unchanged. With L. thermotolerans producing lactic acid (1.5–1.8 g/L) and bringing down the pH to 3.3–3.4 whilst adding no foreign flavors herein, this study revealed a new natural, fruity sour beer with a soft, sour taste. In this study, the double-yeast mixed-culture fermentation produced more flavor substances than a single-culture process, and plenty of isobutyl acetate and isoamyl acetate enhanced the fruit aroma and balanced the sour beer with a refreshing taste. While playing a positive role in improving the beer’s quality, the double-yeast mixed-culture fermentation developed in this study helps to offer an alternative mass production solution for producing sour beer with the processes better controlled and the fermentation time reduced. The stress responses of the L. thermotolerans during the fermentation were revealed by integrating RNA sequencing (RNA-Seq) and metabolite data. Given that the metabolic flux distribution of the S. cerevisiae during the fermentation differed from that of the non-Saccharomyces yeasts, transcriptional analysis of non-Saccharomyces yeast and S. cerevisiae could be suitable in helping to develop strategies to modulate the transcriptional responses of specific genes that are associated with the aroma compounds released by S. cerevisiae and non-Saccharomyces yeasts. In the case of some non-Saccharomycesyeast species/strains, the diversion of alcoholic fermentation and the formation of a great number of secondary compounds may, in part, account for the low ethanol yield.
... The genus Hanseniaspora was also correlated to the ethyl isobutyrate content. Many studies were conducted in order to a better understanding of the implication of non-Saccharomyces species in the aromatic complexity (Belda et al., 2015;Ciani et al., 2010;Escribano-Viana et al., 2018;Soden et al., 2000;Wei et al., 2019). H. uvarum was also known to affect the chemical and sensory profiles of wines (Hu et al., 2018). ...
... Ainsi, Hanseniaspora est l'unique genre de non-Saccharomyces ayant été corrélé à des arômes (isobutyrate d'éthyle et acétate d'hexyle). De nombreuses études ont été menées afin de mieux comprendre l'implication des espèces non Saccharomyces dans la complexité aromatique (Belda et al., 2015 ;Ciani et al., 2010 ;Escribano-Viana et al., 2018 ;Soden et al., 2000 ;. De plus, la différence au sein des espèces de Saccharomyces entre les différents producteurs laissait supposer un impact probable sur la production de composés volatiles. ...
... De plus, la différence au sein des espèces de Saccharomyces entre les différents producteurs laissait supposer un impact probable sur la production de composés volatiles. Or, seule une corrélation entre S. cerevisiae et l'acétate d'hexyle a pu être mise en évidence alors que le genre Saccharomyces est connu pour contribuer grandement à la complexité aromatique des cidres et des vins (Alves et al., 2015 ;Escribano-Viana et al., 2018 ;Soden et al., 2000 ;Sumby et al., 2010). Par contre, les interactions mises en évidence entre Dekkera/Brettanomyces sp. ...
Le calvados est une eau-de-vie obtenue par distillation du cidre. Le cidre de distillation résulte d’une fermentation naturelle spontanée non maîtrisée, qui permet toutes les interactions possibles entre les différentes communautés microbiennes. En fin de fermentation alcoolique, le glycérol produit peut être dégradé et converti en 3-hydroxypropionaldehyde (3-HPA) par Lactobacillus collinoides via l’enzyme glycérol déshydratase codée par l’opéron pdu. Lors de la distillation, la déshydratation du 3-HPA en acroléine entraîne des désordres organoleptiques connus sous le nom de piqûre acroléique en développant un goût d’amertume dans les calvados. Ces travaux de thèse ont eu pour premier objectif d’apporter une réelle nouveauté dans l’étude de la diversité de dix cidres de distillation normands lors de la fermentation par une approche de métagénomique et d’établir des liens entre la composition microbienne et la qualité aromatique. Cette approche a permis de mettre en évidence plus de 40 genres bactériens et fongiques et des différences significatives ont été constatées au sein de ces populations entre les cidres des différents producteurs au cours du processus de fermentation, suggérant que les pratiques d’élaboration mènent à une typicité du cidre et donc à celle du calvados. L’étude de la composition des communautés microbiennes en lien avec la composition aromatique des cidres de distillation et celle des micro- distillats a été effectuée. Trois groupes de dynamiques et compositions microbiennes, directement liées aux producteurs, émergent conduisant à des compositions aromatiques différentes. L’analyse comparative de huit génomes de souches de Lactobacillus collinoides isolées à partir de cidres de distillation portant sur les métabolismes associés à la fermentation et sur la capacité des souches à métaboliser le glycérol a été effectuée. Deux types d’opéron pdu se profilent et cette variabilité génétique observée entre les souches de L. collinoides suggère des capacités différentes de dégradation du glycérol. Un plan expérimental (D-optimal) faisant varier 6 facteurs (glucose, fructose, azote, éthanol, acide malique, pH) a été élaboré pour étudier le métabolisme du glycérol chez ces souches. Trois profils génétiques et métaboliques ont pu être mis en évidence. Les souches de L. collinoides possédant l’opéron de type I sont toujours capables de dégrader le glycérol, contrairement à celles porteuses de l’opéron de type II. Ces travaux ouvrent des perspectives intéressantes quant à la présence et la physiologie de L. collinoides lors de l’élaboration du cidre et son implication dans la piqûre acroléique.
... Hranilovic, et al. [71] reported that the glycerol content of a Shiraz wine from early harvest grapes (approximately 265 g/L TSS) was much higher than those from the late harvest (approximately 325 g/L TSS), with a M. pulcherrima strain (followed by a S. cerevisiae inoculum), producing early and late harvest wines with 10.51 and 12.59 g/L glycerol, respectively. Juice with high sugar concentration also leads to an excess in acetic acid, which can be explained by yeasts trying to maintain redox balances by using surplus NAD(P) + accumulated during the synthesis of fermentation metabolites [62,[72][73][74]. ...
... Candida stellata is a widely studied yeast due to its positive contributions to wine, including its capacity to produce desirable metabolites such as glycerol [72], and its ability to carry out enzymatic activities that have positive effects on wine sensory attributes. An extensive review of C. stellata was carried out by García et al. [108]. ...
... Soden et al. [72] studied the effect of inoculations with C. stellata and S. cerevisiae on Chardonnay juice. The treatments included sole yeast fermentations of C. stellata and S. cerevisiae, as well as co-inoculation and sequential inoculation conducted at a room temperature of 18 • C. C. stellata in sole fermentation was not able to consume all the sugar, reaching an ethanol concentration of only 5.8% v/v. ...
Non-Saccharomyces and Saccharomyces non-cerevisiae studies have increased in recent years due to an interest in uninoculated fermentations, consumer preferences, wine technology, and the effect of climate change on the chemical composition of grapes, juice, and wine. The use of these yeasts to reduce alcohol levels in wines has garnered the attention of researchers and winemakers alike. This review critically analyses recent studies concerning the impact of non-Saccharomyces and Saccharomyces non-cerevisiae on two important parameters in wine: ethanol and glycerol. The influence they have in sequential, co-fermentations, and solo fermentations on ethanol and glycerol content is examined. This review highlights the need for further studies concerning inoculum rates, aeration techniques (amount and flow rate), and the length of time before Saccharomyces cerevisiae sequential inoculation occurs. Challenges include the application of such sequential inoculations in commercial wineries during harvest time.
... [35]. Une autre étude traite d'inoculations de Saccharomyces cerevisiae conjointement avec la levure Candida stellata pour la fermentation de vin, produisant ainsi des arômes intenses de miel et d'abricot [36]. ...
... 35 3-Phenyllactic acid was reported as being a major component of honey and may have an impact on honey taste. 36 Hydroxyphenyllactic acid (ID 57) has been isolated from the bacteria Klebsiella pneumonia, Escherichia coli, and Staphylococcus aureus. Hydroxyphenyllactic acid is derived from phenyllactic acid and has a reported antioxidant activity. ...
Cette thèse s’intitule « Identification et cartographie des métabolites secondaires de nouvelles souches de levures tropicales ». L’objectif principal est le développement d’une méthodologie de déréplication pour l’exploration des métabolites secondaires extraits de cultures de champignons unicellulaires. La méthode développée fait intervenir la chromatographie liquide à ultra-haute performance couplée à la spectrométrie de masse avec l’outil des réseaux moléculaires en complémentarité de la spectrométrie de masse à ultra-haute résolution. La méthodologie permet d’annoter les métabolites détectés par le procédé analytique, c’est-à-dire formuler des hypothèses sur l’identité et la structure de nombreuses molécules produites par les nouvelles espèces de levures sur lesquelles elle est appliquée. De plus, des cartographies et profils métaboliques sont dressés grâce aux diagrammes et réseaux moléculaires construits. L’application de la méthodologie à de nouvelles souches de levures a permis l’annotation de plusieurs centaines de métabolites, parmi lesquels une large proportion d’alcaloïdes mais aussi des acides aminés, des terpénoïdes et des stérols.
... Investigation on benefits of Candida stellata on aroma profile of dry wines was carried out, revealing an amelioration on the analytical profile of wines after successive inoculation of Candida stellata and Saccharomyces cerevisiae during fermentation (Ciani and Ferraro, 1998), and an intensification of aromas of stone fruits and honey after monoculture fermentation with this Candida sp. (Soden et al., 2000). Bibliography also mentions an increase of glycerol production under the presence of Candida stellata parallel to a very low fermentation rate, while the trend of acetate production is quite controversial (Ciani and Ferraro, 1996;Ciani et al., 2000;Soden et al., 2000). ...
... (Soden et al., 2000). Bibliography also mentions an increase of glycerol production under the presence of Candida stellata parallel to a very low fermentation rate, while the trend of acetate production is quite controversial (Ciani and Ferraro, 1996;Ciani et al., 2000;Soden et al., 2000). ...
Noble rot wine is a specific type of sweet wine that derives from the infection of grape berries by a fungus called Botrytis cinerea. These wines are produced in specific wine regions around the world, with Sauternes region of France and Tokay region of Hungary being the most famous ones. The purpose of the current article is to provide a systematic review on the different stages of botrytized wines production, including a detailed analysis of the technical aspects involved. Specifically, it describes the process and development of berry infection by B. cinerea, and special emphasis is given to the main stages and operations of winemaking, conservation, aging and stabilization. A complex combination of a number of parameters (e.g., very specific environmental conditions) explains the rarity of noble rot occurrence and highlights the uniqueness of botrytized wines. RESUMO Os vinhos botritizados representam uma categoria específica de vinhos doces, sendo obtidos a partir de bagos de uva infectados pelo fungo Botrytis cinerea, através de um processo designado por podridão nobre. Estes vinhos são produzidos em regiões específicas do mundo, sendo Sauternes e Tokay, originários de França e Hungria respectivamente, os exemplos mais conhecidos a nível mundial. No presente trabalho são revistos os principais aspectos relacionados com a produção de vinhos botritizados. É descrito o processo e desenvolvimento da infecção do bago por B. cinerea, e discutidas as principais etapas e operações de vinificação, conservação, envelhecimento e estabilização. A combinação complexa de muitos factores, desde logo a exigência de condições ambientais muito específicas, explica a raridade da ocorrência de podridão nobre e destaca a singularidade deste tipo de vinhos.
... For example, to add a unique flavor, fermentation by S. cerevisiae is usually co-cultured with other microorganisms (Yılmaz and Gökmen 2021;Soden et al. 2008), such as non-Saccharomyces yeast and lactic acid bacteria (Sieuwerts et al. 2018;Jin et al. 2021); meanwhile, and to improve the production efficiency, Acremonium cellulolyticus C-1 was co-cultured with S. cerevisiae for realizing the simultaneous saccharification and fermentation of ethanol by a one-pot method without any pretreatment or addition of cellulase (Park et al. 2012). ...
Saccharomyces cerevisiae is a widely used strain for ethanol fermentation; meanwhile, efficient utilization of glucose could effectively promote ethanol production. The PFK1 gene is a key gene for intracellular glucose metabolism in S. cerevisiae. Our previous work suggested that although deletion of the PFK1 gene could confer higher oxidative tolerance to S. cerevisiae cells, the PFK1Δ strain was prone to contamination by other microorganisms. High interspecies microbial competition ability is vital for the growth and survival of microorganisms in co-cultures. The result of our previous studies hinted us a reasonable logic that the EMP (i.e., the Embden-Meyerhof-Parnas pathway, the glycolytic pathway) key gene PFK1 could be involved in regulating interspecies competitiveness of S. cerevisiae through the regulation of glucose utilization and ethanol production efficiency. The results suggest that under 2% and 5% glucose, the PFK1Δ strain showed slower growth than the S288c wild-type and TDH1Δ strains in the lag and exponential growth stages, but realized higher growth in the stationary stage. However, relative high supplement of glucose (10%) eliminated this phenomenon, suggesting the importance of glucose in the regulation of PFK1 in yeast cell growth. Furthermore, during the lag growth phase, the PFK1Δ strain displayed a decelerated glucose consumption rate (P < 0.05). The expression levels of the HXT2, HXT5, and HXT6 genes decreased by approximately 0.5-fold (P < 0.05) and the expression level of the ZWF1 exhibited a onefold increase in the PFK1Δ strain compared to that in the S. cerevisiae S288c wild-type strain (P < 0.05).These findings suggested that the PFK1 inhibited the uptake and utilization of intracellular glucose by yeast cells, resulting in a higher amount of residual glucose in the medium for the PFK1Δ strain to utilize for growth during the reverse overshoot stage in the stationary phase. The results presented here also indicated the potential of ethanol as a defensive weapon against S. cerevisiae. The lower ethanol yield in the early stage of the PFK1Δ strain (P < 0.001) and the decreased expression levels of the PDC5 and PDC6 (P < 0.05), which led to slower growth, resulted in the strain being less competitive than the wild-type strain when co-cultured with Escherichia coli. The lower interspecies competitiveness of the PFK1Δ strain further promoted the growth of co-cultured E. coli, which in turn activated the ethanol production efficiency of the PFK1Δ strain to antagonize it from E. coli at the stationary stage. The results presented clarified the regulation of the PFK1 gene on the growth and interspecies microbial competition behavior of S. cerevisiae and would help us to understand the microbial interactions between S. cerevisiae and other microorganisms.
Key points
• PFK1Δ strain could realize reverse growth overshoot at the stationary stage
• PFK1 deletion decreased ethanol yield and interspecific competitiveness
• Proportion of E. coli in co-culture affected ethanol yield capacity of yeast cells
... During fermentation process, the consortium of yeasts is rapidly evolving and shaped by biotic and abiotic factors (Ciani et al., 2004;Jolly et al., 2014;Belda et al., 2016;Sha et al., 2018;Comitini et al., 2021;Dimopoulou et al., 2022). Non-Saccharomyces (NS) yeasts dominate the early stages of fermentation, but the gradual production of ethanol allows the prevalence of the more adaptable species with the most dominant; Saccharomyces cerevisae (Lambrechts and Pretorius, 2000;Soden et al., 2000;Clemente-Jimenez et al., 2005;Sadoudi et al., 2012;Liu et al., 2016;Gobert et al., 2017). Other factors besides ethanol, which create a stressful environment, are high sugar concentration (osmotic stress), low pH (acid stress), decreasing oxygen (hypoxia), presence of numerous microorganisms that compete for nutrients or produce inhibitory compounds and also presence of sulfur dioxide (Mateo et al., 2001;Benito et al., 2015;Roudil et al., 2020;Reiter et al., 2021). ...
The selection of native yeast for alcoholic fermentation in wine focuses on ensuring the success of the process and promoting the quality of the final product. The purpose of this study was firstly to create a large collection of new yeast isolates and categorize them based on their oenological potential. Additionally, the geographical distribution of the most dominant species, Saccharomyces cerevisiae, was further explored. Towards this direction, fourteen spontaneously fermented wines from different regions of Greece were collected for yeast typing. The yeast isolates were subjected in molecular analyses and identification at species level. RAPD (Random Amplified Polymorphic DNA) genomic fingerprinting with the oligo-nucleotide primer M13 was used, combined with Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) technique. All yeast isolates were scrutinized for their sensitivity to killer toxin, production of non-desirable metabolites such as acetic acid and H 2 S, β-glucosidase production and resistance to the antimicrobial agent; SO 2. In parallel, S. cerevisiae isolates were typed at strain level by interdelta-PCR genomic fingerprinting. S. cerevisiae strains were examined for their fermentative capacity in laboratory scale fermentation on pasteurized grape must. Glucose and fructose consumption was monitored daily and at the final point a free sorting task was conducted to categorize the samples according to their organoleptic profile. According to our results, among the 190 isolates, S. cerevisiae was the most dominant species while some less common non-Saccharomyces species such as Trigonopsis californica, Priceomyces carsonii, Zygosaccharomyces bailii, Brettanomyces bruxellensis and Pichia manshurica were identified in minor abundancies. According to phenotypic typing, most isolates were neutral to killer toxin test and exhibited low acetic acid production. Hierarchical Cluster Analysis revealed the presence of four yeast groups based on phenotypic fingerprinting. Strain level typing reported 20 different S. cerevisiae strains from which 65% indicated fermentative capacity and led to dry wines. Sensory evaluation results clearly discriminated the produced wines and consequently, the proposed yeast categorization was confirmed. A novel approach that employs biostatistical tools for a rapid screening and classification of indigenous wine yeasts with oenological potential, allowing a more efficient preliminary selection or rejection of isolates is proposed. CITATION Tzamourani AP, Taliadouros V, Paraskevopoulos I and Dimopoulou M (2023) Developing a novel selection method for alcoholic fermentation starters by exploring wine yeast microbiota from Greece.
... C. stellata presents a strong fructophilic character [56,57], presenting a considerably lower fermentation rate for glucose than for fructose. Gonçalves et al. [58] detected the presence of the Ffz1 transporter as a requirement for fructophily in S. bombicola (the anamorph of C. bombicola and the synonym of Torulaspora bombicola and C. bombicola [59]. ...
The most known and traditional vinegar is the one that is made from wine. For its production, the grape must undergo alcohol fermentation and the posterior oxidation of ethanol to acetic acid. Yeasts and acetic acid bacteria (AAB) carry out the biochemical processes in sequence. The process of wine acetification can be achieved by slow traditional processes (the Orléans or French methods) or by a quick submerged industrial process. High-quality vinegar is usually produced by traditional methods using oak casks, once the wood allows the continuous aeration of the acetic bacteria culture. Sour-sweet vinegar presents a balance of both bitter/sour and sweet flavors. The sourness typically comes from acetic acid, while the sweetness can come from the type of fruit or the amount of sugar present at the end of vinegar production. In general, sour-sweet vinegar has a more complex and nuanced flavor profile compared to regular vinegar, which is often simply sour. One kind of vinegar produced by wine acetification where yeasts and bacteria co-exist and produce savory vinegar is traditional balsamic vinegar (TBV), from Italy. In Spain, fortified sherry wine has also been used for vinegar production. In Portugal, some wine companies have produced port wine vinegar since 2018. These three distinctive vinegar products have in common the sweetness that can be found, well balanced with the acetic acid sourness. In this review, we analyze the sour-sweat wine vinegar process, bearing in mind the possible interactions between yeasts and AAB that occur during vinegar production and considering the symbiotic or competitive features of a diverse microbiota.
... Previous literature has shown that Z. rouxii (Leandro et al., 2014) and Z. bailii (Pina et al., 2004;Sousa-Dias et al., 1996) consume fructose faster than glucose (Emmerich and Radler, 1983). St. bacillaris (Duarte et al., 2012;Magyar and Tóth, 2011;Mills et al., 2002;Tofalo et al., 2012) and St. stellata (García et al., 2018;Magyar and Tóth, 2011;Soden et al., 2000) are also considered to be fructophilic yeasts. ...
The yeast Starmerella (Candida) lactis-condensi is considered a food contaminant microorganism. The aim of our research was to determine why St. lactis-condensi could become the dominant species of Essences, the top sweet wine speciality of Tokaj wine region in Hungary. We investigated the physiological properties of these yeasts based on parameters that may influence their ability to selectively proliferate and persist during maturation in wines with very high sugar content. These include glucose and fructose, alcohol, and sulphur tolerance. Our studies have shown that St. lactis-condensi is a fructophilic yeast that is able to adapt quickly to very high sugar concentrations (up to 500 g/L) in the Essences. The high glucose concentration inhibits its growth, as well as that of the St. bacillaris (Candida zemplinina) strains tested. The type and amount of sugars in the Essences, together with the sulphur and alcohol content, influence the composition of the dominant yeast biota. Analysis of (GTG)5 microsatellite in the nuclear genome and mtDNA-RFLP studies demonstrate that a diverse population of St. lactis-condensi occurs in the Tokaj wine region, in the Essences. This yeast species is characterised by both physiological and genetic biodiversity. GC-MS analysis of Essences colonised exclusively with these yeasts showed no deterioration in quality.
... For example, Englezos and coworkers found that S. bacillaris C.z 03 single inoculation was able to complete the alcohol fermentation of Barbera grapes must (120 g/L glucose, 124 g/L fructose, 4.39 g/L titratable acid, pH 3.20) (Englezos et al. 2015); however, under the same fermentation conditions, it was unable to complete the alcohol fermentation of the same grape variety (Barbera grapes must, 116.4 g/L glucose, 116.8 g/L fructose, 8.20 g/L titratable acid, pH 3.20) in another study (Englezos et al. 2016a). The glycerol content of SE-SB was 1.5 times higher than that of EC1118, which was consistent with the results of Soden et al. (2000). The concentrations of acetic acid in SB (0.25 g/L and 0.14 g/L) were significantly lower than that of EC1118 (0.31 g/L) (Fig. 2, Supplemental Table S2), which may be due to the low activity of the acetaldehyde pathway of S. bacillaris (Englezos et al. 2018c). ...
To broaden knowledge about the oenological characteristics of Starmerella bacillaris, the influence of two Chinese indigenous S. bacillaris strains on the conventional enological parameters and volatile compounds of Cabernet Sauvignon wines were investigated under different inoculation protocols (single inoculation and simultaneous/sequential inoculation with the commercial Saccharomyces cerevisiae EC1118). The results showed that the two S. bacillaris strains could complete alcohol fermentation alone under high sugar concentrations while increasing the content of glycerol and decreasing the content of acetic acid. Compared with wines fermented by EC1118 single inoculation, S. bacillaris single inoculation and S. bacillaris/EC1118 sequential inoculation increased the contents of isobutanol, ethyl isobutanoate, terpenes, and ketones and decreased the contents of isopentanol, phenylethyl alcohol, fatty acids, acetate esters, and total ethyl esters. Furthermore, for S. bacillaris/EC1118 simultaneous inoculation, the concentrations of ethyl esters were increased, contributing to a higher score of “floral” and “fruity” notes in agreement with sensory analysis.
Key points
• S. bacillaris single and simultaneous/sequential inoculation.
• Conventional enological parameters and volatile compounds were investigated.
• S. bacillaris/EC1118 simultaneous fermentation increased ethyl esters.
... Zygosaccharomyces spp. had been suggested because of their ability to produce aroma profile and proteins with killing activities rather than produce acidity, while C. tropicalis could be used to positively affect the taste and flavor of wine and produce new fermentation products (Magyar & Tóth, 2011;Rojo et al., 2014;Soden, Francis, Oakey, & Henschke, 2000). K. apiculata strains had been reported they could increase in esters and relative decrease in alcohols and acids, expanding the flavor diversity with producing enzymes and aroma compounds (Martin, Valera, Medina, Boido, & Carrau, 2018;Matraxia et al., 2021). ...
... Non-Saccharomyces species are generally not capable of completing alcoholic fermentation unaided and therefore co-inoculation or sequential inoculation strategies with S. cerevisiae are needed (Ciani et al., 2006;Jolly et al., 2006;Soden et al., 2000). A key consideration RhoMu, R. mucilaginosa. ...
Way-a-linah, an alcoholic beverage produced from the fermented sap of Eucalyptus gunnii, and tuba, a fermented drink made from the syrup of Cocos nucifera fructifying bud, are two of several fermented beverages produced by Australian Aboriginal and Torres Strait people. Here we describe the characterisation of yeast isolates from samples associated with the fermentation of way-a-linah and tuba. Microbial isolates were obtained from two different geographical locations in Australia - the Central Plateau in Tasmania, and Erub Island in the Torres Strait. While Hanseniaspora species and Lachancea cidri were the most abundant species in Tasmania, Candida species were the most abundant in Erub Island. Isolates were screened for tolerance to stress conditions found during the production of fermented beverages and for enzyme activities relevant to the appearance, aroma and flavour of these beverages. Based on screening results, eight isolates were evaluated for their volatile profile during the fermentation of wort, apple juice and grape juice. Diverse volatile profiles were observed for beers, ciders and wines fermented with different isolates. These findings reveal the potential of these isolates to produce fermented beverages with unique aroma and flavour profiles and highlight the vast microbial diversity associated with fermented beverages produced by Australia's Indigenous peoples.
... Spontaneous fermentations, which are fermentations conducted by mixed cultures of yeasts undergoing sequential dominance, have been recognised for the crucial part indigenous yeasts play in bringing out unique characteristics compared to S. cerevisiae (Comitini et al. 2017). Though exposed to a higher risk of spoilage, wines made in such manner are generally reported to have improved quality through better flavour integration and more complexity (Heard and Fleet 1985, Gil et al. 1996, Lema et al. 1996, Soden et al. 2000, Varela et al. 2009, Izquierdo Canas et al. 2011). Many of the enzymatic mechanisms (both desirable and undesirable) have been elucidated, and this knowledge has been used in the search for potentially useful yeasts [e.g. ...
3‐Isobutyl‐2‐methoxypyrazine (IBMP) is a compound whose aroma is reminiscent of green capsicum and is found in many winegrape cultivars, such as Cabernet Sauvignon and Sauvignon Blanc. A high concentration in grapes can lead to excessive greenness in the resulting wine products, thus reducing quality. This study sought to determine the impact of using non‐Saccharomyces yeast during fermentation on the concentration and perception of IBMP in wines. As a potential postharvest remediation strategy, 11 strains of non‐Saccharomyces were evaluated through fermentation of juices containing IBMP. Wines fermented with Kazachstania servazzii, Metschnikowia pulcherrima, K. aerobia, Hanseniaspora uvarum, Meyerozyma guillermondii and Candida krusei were rated with a higher level of fruitiness and less greenness in sensory analysis, even though no significant difference was observed amongst yeast treatments for IBMP concentration. In mixed fermentation, in which Saccharomyces cerevisiae yeast strain EC1118 was sequentially inoculated, several non‐Saccharomyces yeast strains differentially masked the perception of IBMP. The selective use of non‐Saccharomyces yeast may be a strategy for modulating the excessive perception of greenness in wines derived from grapes containing a high concentration of IBMP.
... This is due to their less efficient fermentative abilities and their respiratory metabolism (Gonzalez, Quirós and Morales 2013;Contreras et al. 2015;Ciani et al. 2016;Röcker et al. 2016;Ivit, Longo and Kemp 2020). Significant differences in alcohol concentrations have been reported between wines fermented with mixed cultures of non-Saccharomyces/S. cerevisiae and S. cerevisiae monocultures (Ferraro, Fatichenti and Ciani 2000;Soden et al. 2000;Comitini et al. 2011;Izquierdo Canas, Palacios Garcia and Garcia Romero 2011;Di Maio et al. 2012;Sadoudi et al. 2012;Benito et al. 2013;Gobbi et al. 2013;Contreras et al. 2014;Ciani et al. 2016;Englezos et al. 2016). ...
Non-Saccharomyces yeasts have been suggested for use in wine production for lowering alcohol content. In this study 23 non-Saccharomyces yeasts were investigated in laboratory-scale trials using previously frozen grape must. Both aerated and standard fermentation conditions were investigated and the fermentations were co-inoculated with a commercial Saccharomyces cerevisiae reference yeast strain. Sugar consumed for percentage alcohol formed was calculated from sugar and alcohol measurements. The non-Saccharomyces yeasts showed greater variability in sugar consumption compared to the S. cerevisiae reference yeast. Two of the yeast strains (Starmerella bacillaris and Wickerhamomyces anomalus) consumed more sugar than the S. cerevisiae reference yeast under the same conditions. These two strains were subsequently used in a small-scale wine production trial following a similar aeration and standard fermentation strategy. The wine production trials using aeration compared to the standard strategy showed shorter fermentation times, increased biomass formation, more sugar utilised for alcohol produced, but reduced wine quality. The same yeasts under standard fermentation conditions also showed increased use of sugar, but neutral or positive effects on wine quality. The S. bacillaris strain showed the most potential for use in wine production for lowering alcohol content.
... Although non-Saccharomyces were once considered spoilage organisms, this belief has now changed and considers that these yeasts are fundamental for spontaneous fermentations, especially in winemaking where they are thought to be integral to determining the authenticity of natural wines by adding mouthfeel and improved flavor integration [2]. In addition, non-Saccharomyces yeasts have been utilized to obtain alcoholic beverage with lower ethanol yields to match the consumer trends of low alcohol drinks [3][4][5][6][7][8][9][10]. ...
Torulaspora delbrueckii is an emerging yeast species in the beverage and food industry that is suitable for alcoholic fermentation and to improve the organoleptic quality of wine, beer, mead, and other beverages. Modern consumer preference toward new flavors and products drives the application of T. delbrueckii to ferment less traditional fruits and vegetables. Thus, it has become increasingly relevant to define those metabolites produced in minute quantities by T. delbrueckii , because they may have an impact when producing these new alcoholic beverages. In this study, we have identified metabolites of T. delbrueckii and have compared them with those of Saccharomyces cerevisiae in a controlled setting with a synthetic, high glucose medium using gas chromatography coupled to flame ionization detector (GC–FID) and stir bar sorptive extraction (SBSE) with GC coupled to mass spectrometry (MS). Results showed that T. delbrueckii produced metabolites with higher changes in odor activity complexes than S. cerevisiae : ethyl propanoate, 1,1-diethoxyethane, ethyl isobutyrate, ethyl butyrate, isoamyl acetate, ethyl heptanoate, nonanal, and decanal. We also report seven metabolites detected for the first time in T. delbrueckii. This datum serves to expand the knowledge of T. delbrueckii performance and shows that application of this yeast species is more suitable to a wide array of beverage producers.
... In this regard, older works, carried out on C. stellata (now reclassified as Starmerella bombicola or Starmerella bacillaris) and related to the enological environment, highlighted the expression of some interesting features. Indeed, C. stellata in cofermentation with S. cerevisiae showed a positive influence on the aroma and composition of Chardonnay wine (Soden, Francis, Oakey, & Henschke, 2000). Other works highlighted specific fermentation behavior such as the wide production of glycerol AU:27 (Ciani & Ferraro, 1996;Ciani Ferraro, 1998) that positively influenced the mouthfeel sensation and flavor of wine (Jolly et al., 2014). ...
The use of selected Saccharomyces cerevisiae starter strains in pure fermentation is widely diffused in winemaking. Indeed, S. cerevisiae is able to suppress the wild microbial community and dominate the process. In the last years, however, there has been a growing interest in the use of non-Saccharomyces yeast in winemaking. Several studies recognized a positive impact on wine complexity of non-Saccharomyces yeasts species in mixed and/or sequential fermentations with S. cerevisiae starter strains. These controlled mixed fermentations led to an increase of important aroma compounds that affect the sensorial profile of wines, particularly in white wines. Indeed, the trend was evaluated in different musts of white grape varieties, such as Chardonnay, Sauvignon blanc, Chenin blanc, Palomino, and Verdicchio. The influence of non-Saccharomyces yeast culture with the yeast interactions in mixed fermentation can lead to the final product influencing both the analytical and aromatic profile. In addition, non-Saccharomyces yeast in mixed fermentation may contribute to control spoilage microorganisms and to reduce the ethanol content. In the present chapter, we describe the biotechnology of non-Saccharomyces yeast in the production of white wines, evaluating the interactions in mixed fermentation and focusing on their influence on the aroma profile and structure of the final product.
... However, the relevant concept should include the sensory complexity when we talk about fermented beverages (Tempère et al., 2018). Increased flavor diversity has been demonstrated by the use of mixed culture inocula by which increased flavor complexity from a sensory point of view could be achieved, for example, in Chardonnay (Soden et al., 2000;Medina et al., 2013) or Sauvignon Blanc wines (Anfang et al., 2009;Knight et al., 2018). More recently, sensory studies of mixed culture fermentations in some other white and red varieties, have been reported (Varela, 2016;Padilla et al., 2017;Hranilovic et al., 2018;Benito et al., 2019;Castrillo et al., 2019;Binati et al., 2020;Del Fresno et al., 2020;Romani et al., 2020;Muñoz-Redondo et al., 2021). ...
In this perspective, we will explain the concept of “friendly” yeasts for developing wine starters that do not suppress desirable native microbial flora at the initial steps of fermentation, as what usually happens with Saccharomyces strains. Some non- Saccharomyces strains might allow the development of yeast consortia with the native terroir microflora of grapes and its region. The positive contribution of non- Saccharomyces yeasts was underestimated for decades. Avoiding them as spoilage strains and off-flavor producers was the main objective in winemaking. It is understandable, as in our experience after more than 30 years of wine yeast selection, it was shown that no more than 10% of the isolated native strains were positive contributors of superior flavors. Some species that systematically gave desirable flavors during these screening processes were Hanseniaspora vineae and Metschnikowia fructicola . In contrast to the latter, H. vineae is an active fermentative species, and this fact helped to build an improved juice ecosystem, avoiding contaminations of aerobic bacteria and yeasts. Furthermore, this species has a complementary secondary metabolism with S. cerevisiae , increasing flavor complexity with benzenoid and phenylpropanoid synthetic pathways practically inexistent in conventional yeast starters. How does H. vineae share the fermentation niche with other yeast strains? It might be due to the friendly conditions it creates, such as ideal low temperatures and low nitrogen demand during fermentation, reduced synthesis of medium-chain fatty acids, and a rich acetylation capacity of aromatic higher alcohols, well-known inhibitors of many yeasts. We will discuss here how inoculation of H. vineae strains can give the winemaker an opportunity to develop ideal conditions for flavor expression of the microbial terroir without the risk of undesirable strains that can result from spontaneous yeast fermentations.
... Y-27208, later identified as Starmerella kuoi (Kurtzman, 2012). S. stellata is a common isolate from grape must and can be used in a co-fermentation with S. cerevisiae for wine production (Soden et al., 2000). S. riodocensis was isolated from pollen-nectar provisions, larvae and faecal pellets of Megachile sp. ...
Sophorolipids are biobased compounds produced by the genera Starmerella and Pseudohyphozyma that gain exponential interest from academic and industrial stakeholders due to their mild and environmental friendly characteristics. Currently, industrially relevant sophorolipid productivities are reached up to 3.7 g∙L-1∙h-1 and sophorolipids are used in the personal care and cleaning industry at small scale. Moreover, applications in crop protection, food, bioflotation and medical fields are being extensively researched. The research and development of sophorolipids is at a crucial stage. Therefore, this work presents an overview of the state-of-the-art on sophorolipid research and their applications, while providing a critical assessment of scientific techniques and standardisation in reporting. In this review, the genuine sophorolipid producing organisms and the natural role of sophorolipids are discussed. Subsequently, an evaluation is made of innovations in production processes and the relevance of in-situ product recovery for process performance is discussed. Furthermore, a critical assessment of application research and its future perspectives are portrayed with a focus on the self-assembly of sophorolipid molecules. Following, genetic engineering strategies that affect the sophorolipid physiochemical properties are summarised. Finally, the impact of sophorolipids on the bioeconomy are uncovered, along with relevant future perspectives.
... Products like beer and wine are produced by fermentation with Saccharomyces cerevisiae due to its superior ability to rapidly convert sugars to ethanol under anaerobic or aerobic conditions (Dashko, Zhou, Compagno, & Piskur, 2014). Foods fermented by S. cerevisiae sometimes require co-cultivation with other microorganisms, such as some non-Saccharomyces yeasts (Soden, Francis, Oakey, & Henschke, 2008;Yılmaz & Gökmen, 2021) or lactic acid bacteria (LAB) (Jin et al., 2021;Sieuwerts, Bron, & Smid, 2018), to obtain a unique taste or flavor. For example, Lactobacillus plantarum, one important LAB strain, has been co-cultured with S. cerevisiae to promote the flavor aspects of some novel and functional foods and beverages (Dysvik et al., 2020;Tufariello et al., 2020;Zhang et al., 2019). ...
Foods prepared by fermentation with Saccharomyces cerevisiae sometimes require co-cultivation with lactic acid bacteria (LAB) or other microorganisms. Co-cultured LAB could compete for nutrients, thereby affecting central metabolism of S. cerevisiae cells; as a result, the oxidative metabolism of yeast might also be influenced. Here, S. cerevisiae ATCC 204508 was co-cultivated with Lactobacillus plantarum ATCC 8014 to evaluate its regulation effects on the oxidative metabolism in yeast cells. Results indicated that co-cultured L. plantarum did not exacerbate membrane lipid peroxidation but reduced intracellular reactive oxygen species (ROS) content of yeast. L. plantarum initiated NADPH oxidase by activation of Ca²⁺ signaling and MAPK pathways, thereby promoting the ROS generation in S. cerevisiae cells. To cope with the increased ROS generation, both enzymatic and non-enzymatic defense systems were activated, accounting for the decreased intracellular ROS level in yeast cells that co-cultured with L. plantarum. At the same time, activated anti-oxidation system also conferred higher oxidative tolerance to yeast cells, which could be considered a desirable characteristic for fermentation using S. cerevisiae. The co-cultivation of L. plantarum also activated energy metabolism and promoted ATP production in yeast. These results will contribute to the understanding of the complex relationship between S. cerevisiae and LAB during fermentation.
... As most non-Saccharomyces yeasts are incapable of completing alcoholic fermentation, S. cerevisiae is usually added, either simultaneously as a coinoculum or sequentially at 24-72 h after non-Saccharomyces yeast inoculation. These inoculation strategies reduce the risk of a stuck fermentation [59,60]. Indeed, in the current study, only the fermentations involving S. cerevisiae were complete. ...
Microbiological strategies are currently being considered as methods for reducing the ethanol content of wine. Fermentations started with a multistarter of three non-Saccharomyces yeasts (Metschnikowia pulcherrima (Mp), Torulaspora delbrueckii (Td) and Zygosaccharomyces bailii (Zb)) at different inoculum concentrations. S. cerevisiae (Sc) was inoculated into fermentations at 0 h (coinoculation), 48 h or 72 h (sequential fermentations). The microbial populations were analyzed by a culture-dependent approach (Wallerstein Laboratory Nutrient (WLN) culture medium) and a culture-independent method (PMA-qPCR). The results showed that among these three non-Saccharomyces yeasts, Td became the dominant non-Saccharomyces yeast in all fermentations, and Mp was the minority yeast. Sc was able to grow in all fermentations where it was involved, being the dominant yeast at the end of fermentation. We obtained a significant ethanol reduction of 0.48 to 0.77% (v/v) in sequential fermentations, with increased concentrations of lactic and acetic acids. The highest reduction was achieved when the inoculum concentration of non-Saccharomyces yeast was 10 times higher (107 cells/mL) than that of S. cerevisiae. However, this reduction was lower than that obtained when these strains were used as single non-Saccharomyces species in the starter, indicating that interactions between them affected their performance. Therefore, more combinations of yeast species should be tested to achieve greater ethanol reductions.
... Noninoculated fermentations involve the sequential action of several non-Saccharomyces yeasts until indigenous S. cerevisiae strains dominate (Jolly et al. 2014). Although carrying a higher risk of spoilage, wines fermented this way can have improved sensory attributes compared to that of inoculated wines, including mouthfeel, aroma and flavour complexity, and integration of flavours (Heard and Fleet 1985, Bisson and Kunkee 1991, Lema et al. 1996, Soden et al. 2000, Varela et al. 2009. ...
Background and Aims
The use of non‐Saccharomyces yeast strains as starter cultures for wine production has become increasingly popular, particularly due to their positive effect on wine composition, colour, aroma and flavour. Here, we characterise the volatile aroma composition and the sensory profile of Shiraz and Cabernet Sauvignon wines produced with novel active dry yeast preparations of Metschnikowia pulcherrima compared to that of reference strains.
Methods and Results
Winemaking treatments included an uninoculated fermentation, two reference Saccharomyces cerevisiae fermentations, and sequential fermentations inoculated with either M. pulcherrima AWRI1149 or M. pulcherrima AWRI3050 and S. cerevisiae. Amplicon‐based internal transcribed spacer phylotyping was used to determine microbial population dynamics during fermentation. Wines were analysed for volatile composition and subjected to sensory analysis. The M. pulcherrima strains survived and dominated in both grape cultivars, and produced distinctive wine volatile profiles depending on the inoculation treatment. These differences in volatiles resulted in significant differences for several sensory attributes.
Conclusions
Wines made with active dry yeast preparations of M. pulcherrima AWRI1149 and M. pulcherrima AWRI3050 were characterised by increased intensity of desirable sensory attributes and by low scores for negative descriptors.
Significance of the Study
This work provides winemakers with additional yeast preparations that can shape sensory profile and wine style.
... Although there are still few commercial preparations of non-Saccharomyces yeasts, they will probably increase in the near future. These include Starmerella bacillaris that produces large amounts of glycerol (Ciani and Ferraro 1996) and also because of its fructophilic character, which favours the end of fermentation (Soden et al. 2000). Other non-Saccharomyces species that can be expected in commercial preparations are the typical apiculate yeasts from the Hanseniaspora genus, such as H. uvarum (Andorrà et al. 2010c), H. vinae (Medina et al. 2013) and H. guilliermondii (Moreira et al. 2008). ...
Alcoholic fermentation and the production of wine has accompanied humanity for more than 10000 years. However, it has been only in the last 50 years when the winemakers have had the tools to manage and control the process. The methodology to analyze and monitor the succession of the microorganisms that participate in the process along with the effective use of antimicrobial compounds (for instance sulfur dioxide), the control of the temperature and, above all, the use of cellar-friendly fermentation starters (mostly as Active Dry Wine Yeast) have provided the appropriate conditions for that control. However, the use of a limited number of commercial presentations of the starters has generated an unwanted uniformity of the wines produced. Furthermore, new tendencies in wine making with limited or no human intervention have considered these tolls as a negative aspect in the wine quality, although most of these concerns are only philosophical, without clear scientific evidence. We present a revision of the present state of the art in these methodologies where our research group has been working for the last 25 years.
... C. albicans was able to produce higher levels of farnesol and farnesene (gardenia/perfume aroma) [21]. C. stellata was found to intensify the apricot, honey and sauerkraut aromas when used alone in monoculture and increase the production of ethyl-acetate in sequential fermentation with S. cerevisiae on Chardonnay wine [77]. In addition, in a recent experiment, C. zemplinina was used in mixed cultures with S. cerevisiae and produce more aliphatic alcohols, certain aldehydes and ketones and esters (hexyl acetate, ethyl hexanoate, ethyl heptanoate, ethyl dodecanoate and ethyl butanoate) providing apple, fruit, herb, sweet or waxy aromas to wine [67]. ...
Aroma profile is one of the main features for the acceptance of wine. Yeasts and bacteria are the responsible organisms to carry out both, alcoholic and malolactic fermentation. Alcoholic fermentation is in turn, responsible for transforming grape juice into wine and providing secondary aromas. Secondary aroma can be influenced by different factors; however, the influence of the microorganisms is one of the main agents affecting final wine aroma profile. Saccharomyces cerevisiae has historically been the most used yeast for winemaking process for its specific characteristics: high fermentative metabolism and kinetics, low acetic acid production, resistance to high levels of sugar, ethanol, sulfur dioxide and also, the production of pleasant aromatic compounds. Nevertheless, in the last years, the use of non-saccharomyces yeasts has been progressively growing according to their capacity to enhance aroma complexity and interact with S. cerevisiae, especially in mixed cultures. Hence, this review article is aimed at associating the main secondary aroma compounds present in wine with the microorganisms involved in the spontaneous and guided fermentations, as well as an approach to the strain variability of species, the genetic modifications that can occur and their relevance to wine aroma construction.
... In comparison, a similar co-inoculation with Macabeo must increased the concentration of ethyl esters, short-chain fatty acids, and higher alcohols [26]. A third study found that despite having a higher concentration of esters, Chardonnay wines scored lower sensory scores when inoculated with C. zemplinina and C. zemplinina/ S. cerevisiae then pure cultures of S. cerevisiae [51]. The study described C. zemplinina as providing a sauerkraut/ethyl acetate aroma, which competed with the fruity aromas and negatively affected the wine. ...
Non-Saccharomyces yeast plays an important role in the initial stages of a wild ferment, as they are found in higher abundance in the vineyard than Saccharomyces cerevisiae. As such, there has been a focus in recent years to isolate these yeast species and characterize their effect on wine fermentation and subsequent aroma. This effect on wine aroma is often species and strain dependent, as the enzymatic profile of each yeast will determine which aroma compounds are formed as secondary metabolites. Semi-fermentative yeast, such as Hanseniaspora spp., Candida spp. and Metschnikowia pulcherrima, are commonly in high abundance in fresh grape must and have diverse enzymatic profiles, however they show a weak tolerance to ethanol, limiting their impact to the initial stages of fermentation. Fully fermentative non-Saccharomyces yeast, characterized by high ethanol tolerance, are often found at low abundance in fresh grape must, similar to Saccharomyces cerevisiae. Their ability to influence the aroma profile of wine remains high, however, due to their presence into the final stages of fermentation. Some fermentative yeasts also have unique oenological properties, such as Lanchancea thermotolerans and Schizosaccharomyces pombe, highlighting the potential of these yeast as inoculants for specific wine styles.
... The current practice of inhibiting the non-Saccharomyces yeast population which predominates at the beginning of alcoholic fermentation, by inoculation of Saccharomyces starter cultures, need to be reconsidered, due to the fact that research conducted by different authors revealed that some of these yeast strains showed superior oenological characteristics, with positive effects on the aromatic profile of wines. Soden et al. (2000) showed that a positive impact on the sensory characteristics of wine is ensured by the involvement of non-Saccharomyces yeasts in the alcoholic fermentation, due to their potential to secrete extracellular enzymes (βglucosidases, esterases and lipases). Thus, in the last years, the research focused on the study of extracellular enzymes of Saccharomyces and non-Saccharomyces yeasts, finding that the presence or absence of the enzymes influences the wine aromas (Strauss et al., 2001;Buzzini and Martini, 2002;Rodriguez et al., 2004;Ciani et al., 2006;Mendoza et al., 2007;Gaensly et al., 2015;López et al., 2015). ...
This study investigated the oenological potential of indigenous Saccharomyces
and non-Saccharomyces yeasts isolated from different stages of the natural must fermentation process. Screening of extracellular enzymatic activities was performed on agarized media in which the following substrates were added: arbutin, cellobiose, Tween 80, tributyrin, casein and citrus pectin, to highlight the activity of enzymes: ßglucosidase, esterase, lipase, protease and pectinase. Among the 30 Saccharomyces cerevisae strains tested, 37% showed very low β-glucosidase activity, 100% showed esterase activity, 40% lipase activity, 90% protease activity and 53% pectinase activity. The non-Saccharomyces strain tested showed β-glucosidase, esteraseand protease activity. Tolerance to ethanol was assessed in YPD medium with ethanol concentrations of 5, 10 and 15% (v/v) by yeast culture development index. At 15% ethanol, development of all tested strains were inhibited. In the case of SO2 tolerance, decrease in strains development was inversely correlated with the increase in
potassium metabisulphite concentration, up to 200 mg/L. Only four Saccharomyces strains showed specific oenological characteristics and were selected to be tested in mixed and/or sequential cultures to obtain wines with improved sensory features.
... Although there are still a few commercial preparations of non-Saccharomyces yeasts, they will probably increase in the near future. These include Starmerella bacillaris that produces large amounts of glycerol (Ciani and Ferraro, 1996) and also because of its fructophilic character, which favours the end of fermentation (Soden et al., 2000). Other non-Saccharomyces species to be expected in commercial preparations are the typical apiculate yeasts from the Hanseniaspora genus, such as H. uvarum (Andorrà et al., 2010c), H. vinae (Medina et al., 2013) and H. guilliermondii (Moreira et al., 2008). ...
... A few studies have been conducted to analyze the contribution that 'non-Saccharomyces' wine yeast can make to the quality of the wine. These have been shown to contribute to the production of esters and other pleasant volatile compounds (Lema et al., 1996;Romano et al., 1997;Ciani and Maccarelli, 1998;Eglinton et al., 2000;Ferraro et al., 2000;Soden et al., 2000). The non-Saccharomyces strains of the genera Kloeckera and Hanseniaspora have been reported to be having protein protease activity, which has, in turn, profound impact on the protein profile of finished wines (Charoenchai et al., 1997;Dizy and Bisson, 2000). ...
... Non-Saccharomyces yeast species such Lachancea thermotolerans, C. zemplinina, M. pulcherrima, are known to increase glycerol concentration through mixed fermentations with S. cerevisiae Gobbi et al., 2013). Glycerol concentrations of 15.7 g L -1 were achieved in sequential inoculation with Starmerella bombicola, producing values three times higher than those obtained using S. cerevisiae monoculture (Soden et al., 2000). C. cantarelli/S. ...
Biogeography is the study of the distribution of species over space and time and aims to
understand where, why, and at what abundance organisms live. Revealing the diversity and
distribution pattern of populations and communities at multiple spatial scales is thus a central issue in ecology. Recent biogeographic studies based on genetic technologies revealed that microorganisms are not randomly distributed over space and time, showing that their distribution is systematically heterogeneous and structured, revealing specific patterns of microbial distribution. In this context, the study of microbial communities associated with vineyards points to the existence of patterns of microbial distribution across viticultural areas, suggesting a microbiological component of the terroir concept. In the light of this knowledge, the composition of the yeast flora present on grapes, besides representing a long-term known factor of wine quality tends to be presently seen as a potential factor of wine typicality. To assess grape yeast diversity and to understand the ecological and geographical factors shaping the yeast communities and populations composition is of great importance for modern oenology. In this chapter we present
on overview of the research developed in this scope.
... Higher glycerol and lower ethanol levels in Trebbiano Toscano wine (Ferraro et al., 2000) Sim, Seq Increased glycerol levels in Chardonnay (Soden et al., 2000) ( Mehlomakulu et al., 2017), Pichia membranifaciens (Belda et al., 2017a), Tetrapisispora phaffii (originally called Kluyveromyces phaffi; and Ustilago maydis (Santos et al., 2011). Thus, it is proposed to separately propagate and isolate the killer toxin, which could then be added to the fermentations, rather than co-culturing the NSY with S. cerevisiae (Mannazzu et al., 2019). ...
Yeasts play a central role in the ancient process of winemaking. In spontaneous fermentations there is a progressive growth pattern of indigenous Saccharomyces and non-Saccharomyces yeasts, but the final stages are dominated by the alcohol-tolerant Saccharomyces cerevisiae. This unicellular “sugar fungus” is universally known as the wine yeast and is widely preferred for initiating wine fermentations. The primary role of wine yeast is to catalyze the rapid, complete and efficient conversion of grape sugars to ethanol, carbon dioxide and other minor, but important metabolites without the development of off-flavors. After several millennia of winemaking, researchers continue to seek full understanding of the scientific intricacies of the process through which grape juice is turned into wine, and how to perfect this yeast-driven fermentation for targeted consumer markets. Continuous improvement of yeast strains and blends of co-cultures is the corkscrew with which winemakers can open the bottled mystique of wine quality and consumer satisfaction. With every twist and turn, the underpinning biology of “single-species” and “multi-species” fermentations uncork novel ideas of how to improve the quality of wine, while minimizing resource inputs, production costs and environmental impact. Never before has there been so much opportunity to harness modern genomic and other technologies in strain development, and for winemakers to direct vinification to shape their wines according to the ever-evolving preferences of consumers.
... Starmerella bacillaris (synonym Candida zemplinina) contributes to reduce the amount of acetic acid in mixed fermentation with S. cerevisiae [5,[10][11][12]. Moreover, this yeast is usually characterized by high glycerol production [11,[13][14][15][16][17] and low ethanol yield [16,[18][19][20] making it an interesting tool to increase the wine sweetness and modulate the ethanol content. Lachancea thermotolerans strains produce lactic acid during the alcoholic fermentation causing a decrease of wine pH while reducing its volatile acidity [4,[21][22][23][24]. ...
: The production of wines with peculiar analytical and sensorial profiles, together with the microbiological control of the winemaking process, has always been one of the main objectives of the wine industry. In this perspective, the use of oenological starters containing non-Saccharomyces yeasts can represent a valid tool for achieving these objectives. Here we present the results of seven pilot scale fermentations, each of which was inoculated with a different non-Saccharomyces yeast strain and after three days with a commercial Saccharomyces cerevisiae starter. The fermentations were carried out in double on 70 L of Sangiovese grape must, the most widely planted red grape variety in Italy and particularly in Tuscany, where it is utilized for the production of more than 80% of red wines. Fermentations were monitored by assessing both the development of the microbial population and the consumption of sugars at the different sampling times. The impact of the different starters was assessed after stabilization through the evaluation of the standard analytical composition of the resulting wines, also taking into account polysaccharides and volatile compounds. Moreover, quantitative descriptive sensory analyses were carried out. Compared to the control wines obtained by inoculating the S. cerevisiae starter strain, those inoculated with non-Saccharomyces/Saccharomyces mixed starters presented a significant differentiation in the chemical-analytical composition. Moreover, sensory analysis revealed differences among wines mainly for intensity of color, astringency, and dryness mouthfeel perception.
... Cependant, ces levures, intéressantes de part leurs propriétés spécifiques, ont un point commun : des aptitudes fermentaires limitées (Ciani et Maccarelli, 1998;Ciani et Picciotti, 1995;Jolly et al., 2003;Plata et al., 2003;Viana et al., 2008). (Herraiz et al., 1990), Schizosaccharomyces pombe pour dégrader l'acide malique du moût (Snow et Gallander, 1979), Kluyveromyces thermotolerans pour acidifier les vins (Kapsopoulou et al., 2007), Candida stellata pour augmenter la production de glycérol (Ciani et Ferraro, 1998) (2002) Augmentation teneur en glycérol Ciani et Ferraro (1995; Ferraro et al. (2000) Modulation aromatique Soden et al. (2000) Debaryomyces vanriji Augmentation teneur en géraniol Garcia et al. (2002) Hanseniaspora guilliermondii Modulation aromatique Zironi et al. (1993) Hanseniaspora uvarum (Kloeckera apiculata) Modulation aromatique Modulation aromatique Herraiz et al. (1990) Kluyveromyces thermotolerans (Barnett, 1992 ;Yarrow 1984). ...
La caractérisation phénotypique de l’espèce Torulaspora delbrueckii en conditions œnologiques, à partir de l’étude d’un grand nombre de souches, a permis de mettre en évidence une grande variabilité au sein de cette espèce. En effet, les souches de T.delbrueckii présentent des différences au niveau des durées de phase de latence et de fermentation, des capacités biotiques mais aussi des productions d’éthanol (maximum 12% vol.). Cette variabilité se retrouve également pour la production d’acidité volatile, de glycérol et de certains arômes. Ce travail confirme les faibles productions d’acidité volatile et de glycérol de cette espèce et met en évidence une réponse au stress osmotique différente de celle de l’espèce Saccharomyces cerevisiae. Au final, l’espèce T. delbrueckii présente une grande « pureté » de fermentation et produit peu de composés indésirables comme le sulfure d’hydrogène, les phénols volatils, l’acetoïne, l’acétaldéhyde et le diacétyle. La réalisation de co-inoculations T. delbrueckii / S. cerevisiae sur moûts liquoreux, permet une réduction systématique de l’acidité volatile des vins, en comparaison à une fermentation pure de l’espèce S. cerevisiae, quelque soit la souche de T. delbrueckii utilisée. De plus, la souche T. delbrueckii OXT1 1//2 a permis de complexifier la composition aromatique d’un moût sec issu du cépage Sauvignon blanc (esters fermentaires +25%, phényl-2-éthanol +51% et thiols volatils +31%). Enfin, la mise au point d’un fermenteur à double compartiment, avec une séparation physique des levures tout en conservant l’homogénéité du milieu de culture, a permis d’aborder l’étude des interactions entre ces 2 espèces. Des inhibitions de type « cell-cell contact » ont ainsi été mises en évidence.
... stellata (Sipiczki, 2003(Sipiczki, , 2004 (Magyar and Tóth, 2011;Bely, 2013). Certains auteurs ont suggéré que ce faible rendement en éthanol était dû à la surproduction de glycérol et d'acidité volatile (Soden et al., 2000). Néanmoins, d'autres essais ont pû montrer que malgré une faible production de glycérol et d'acidité volatile, le rendement en éthanol observé pour C. zemplinina était toujours inférieur à S. ...
Les levures non-Saccharomyces, naturellement présentes dans les moûts, peuvent impacter positivement ou négativement la qualité des vins. Depuis quelques années, l’utilisation de cultures mixtes comme starters, associant une souche de Saccharomyces cerevisiae et une souche d’une autre espèce est proposée aux œnologues. C’est le cas du couple S. cerevisiae/Torulaspora delbrueckii. L’étude des interactions entre la souche T. delbrueckii Zymaflore Alpha et S. cerevisiae Zymaflore X5, de la société Laffort, a été réalisée. Les fermentations alcooliques ont été effectuées dans un réacteur à double compartiment permettant la séparation physique des levures tout en conservant l’homogénéité du milieu de culture. Les résultats ont mis en évidence que la séparation impacte la croissance des deux souches suggérant l’existence d’interactions de type cell-cell contact entre ces deux souches. Si une grande majorité de praticiens utilise désormais les levures sélectionnées, certains ont fait le choix de favoriser les populations autochtones de levures S .cerevisiae et de levures non-Saccharomyces. L’incidence de deux facteurs de l’environnement a été étudié sur un mélange de cinq espèces de non-Saccharomyces (T. delbrueckii, Metschnikowia spp., Candida zemplinina, Hanseniaspora uvarum, Pichia kluyveri) et de deux souches de S. cerevisiae (une à phase de latence courte, une à phase de latence longue) en cultures pures et en mélange. L’inoculation de la souche de S. cerevisiae à phase de latence longue dans un moût saturé en CO2 permet de stimuler les levures non-Saccharomyces d’intérêt (T. delbrueckii/P. kluyveri) tout en inhibant les espèces indésirables (H. uvarum, C. zemplinina).
... Although non-Saccharomyces yeasts have been consistently considered as spoilage organisms that contribute insignificantly towards quality attributes during winemaking, [41,42] some recent studies (including the present one) firmly reaffirm that non-Saccharomyces yeasts also can contribute positively towards the enhancement of wine quality. [35,43] In the present study, the isolates W. anomalus and C. tropicalis proved to be potent candidates for consortia preparations with enhanced survivability for a superior fermentative output, despite low fermentative efficiency ( Table 5). ...
In this study, yeasts inherent in traditional starter materials of four indigenous communities from northeast India were characterized. These included Saccharomyces and non-Saccharomyces types representing several genera and species such as Saccharomyces cerevisiae, Wickerhamomyces anomalus, Candida glabrata and Candida tropicalis. The yeasts were cultured in synthetic minimal media (2% glucose and 2% starch), both individually and in combinations. The propensity of growth of individual isolates in glucose appeared as W. anomalus > C. tropicalis > C. glabrata > S. cerevisiae. In starch, the propensity appeared as C. tropicalis > W. anomalus > C. glabrata > S. cerevisiae. The findings were incongruent when isolates were co-cultured in dual combinations in glucose and starch. In glucose, W. anomalus could not prosper with C. tropicalis, which otherwise was reversed in starch. C. tropicalis dominated all the co-cultures in starch followed by W. anomalus, S. cerevisiae and C. glabrata. In glucose, the order appeared as W. anomalus > C. tropicalis > S. cerevisiae > C. glabrata. S. cerevisiae could not thrive in competition with C. tropicalis and appeared dominant over C. glabrata in both glucose and starch. W. anomalus was dominant over S. cerevisiae and C. glabrata, while C. tropicalis outnumbered C. glabrata in both carbon sources. The fermentation efficiency was highest when S. cerevisiae and C. glabrata were co-cultured together, in both starch and glucose. This study suggests an advantage in co-culturing selective indigenous yeasts as consortia to yield a productive fermentation output that could have commercial benefit but additional strains of each species still needed to be investigated.
... VIP values > 1 (Fig. 6A ) for the bacterial group and fungal group are labeled in red and indicate that the bacterial groups and fungal groups played a key role in the formation of volatile compounds. Actually, the core bacteria genera, i.e., and fermented wines [65][66][67][68][69]. Volatile compounds closely related to the selected microorganisms were identified by the two-way orthogonal partial least squares (O2PLS) method in SIMCA 14.1 software. ...
Vidal grape grown in Ili, Xinjiang Autonomous Region, is one of few grapes used to ferment ice wine in China. Microbial community structure and volatile composition during the spontaneous fermentation of ice wine made from Vidal grapes in Ili were investigated using amplicon sequencing technology and headspace solid-phase microextraction/gas chromatography-mass spectrometer technologies. Among bacterial genera, Sphingobium, Pseudomonas and Sphingomonas gradually decreased, while Lactobacillus and Streptococcus increased during the spontaneous fermentation process. As regards fungi, the relative abundance of Vishniacozymaand Cladosporium reduced, but Hanseniaspora sharply raised. Additionally, correlations between microbes and volatile compounds were constructed based on multivariate data analysis. The results revealed that the functional core microbiota (mainly composed of eight bacterial genera and nine fungal genera) during ice wine fermentation showed considerable correlations with the formation of twenty-four volatile compounds in ice wine made from Vidal grapes. For example, Saccharomyces was positively correlated with ethanol, ethyl acetate and isoamylol; Hanseniaspora and Candidawere negatively correlated with hexanol; and Lactobacillus and Streptococcus were positively correlated with 2,3-butanediol, ethanol, ethyl acetate, isoamylol and isoamyl acetate. This studyprovides a reference for understanding the process of ice wine fermentation and improving the quality of ice wine made from Vidal grapes.
... Indeed, S. bacillaris (formerly C. stellata) is a common member of the first few days of the spontaneous fermentation of grape must remaining active much longer than most other non-Saccharomyces yeasts. Its presence during fermentation is thought to contribute to a more complex and better aroma of wine because of the higher production of specific aroma compounds (Soden et al., 2000) and glycerol (Ciani et al., 2000) and positive interactions with S. cerevisiae in the production and degradation of metabolites (Ciani and Ferraro, 1998). Since its growth rate is significantly lower than that of S. cerevisiae and its cells are sensitive to ethanol, S. bacillaris is usually overgrown by more ethanol-tolerant Saccharomyces strains. ...
The objective of this study was to screen non‐ Saccharomyces yeast suitable for enhancing the aroma of Yinhong plum wine. Five non‐ Saccharomyces yeasts with strong ester‐producing ability, namely, Wa3 ( Wickerhamomyces anomalus ), Hu12 ( Hanseniaspora uvarum ), Pk2A2, PkW2 and PkY2 ( Pichia kluyveri ), were selected from various naturally fermented fruit juices for molecular biological identification, analyses of physiological characteristics and tolerance and determination of their effects on the flavour of Yinhong plum wine. Analysis of brewing characteristics showed that they differed in their abilities of producing acetic acid, hydrogen sulfide, killer activity and tolerance. Among them, Wa3 showed the best tolerance to high concentrations of alcohol, sugar and SO 2 . Compared to the control Saccharomyces cerevisiae FX10, Yinhong plum wine fermented with non‐ Saccharomyces yeast exhibited a decrease in alcohol content, while residual sugar, glycerol content and the types and quantities of volatile compounds all showed an increase. Among the fermented wines, PkY2 generated the highest content of ester compounds in the fermented wine, which was 5.66 times higher than that generated by the control. The compounds produced by PkY2 were closely related to various ethyl and acetate odour‐active compounds (odour‐active value >1), which could impart a rich floral and fruity aroma to Yinhong plum wine. Sensory analysis revealed that both floral and fruity aromas were significantly increased in Yinhong plum wine fermented by non‐ Saccharomyces yeasts, with the highest scores of floral and fruity aromas for PkY2. In conclusion, a Pichia kluyveri strain, PkY2, with excellent brewing characteristics and potential for enhancing the aroma of Yinhong plum wine was identified.
In this chapter, we attempt to bring together in a readable and accessible form the wine volatiles patterns highlighting, in a comprehensive way, their differentiated origins. In this context, it is aimed to describe the volatile compounds i) biosynthesized in the grapes few of them are responsible for the impact aroma of some grape varieties and wines, such us monoterpenes, thiols, and pyrazines, that persist unchanged into wine; ii) the originated during the alcoholic fermentation through fermenting yeasts metabolism, enzymatic reaction and lactic acid bacteria action, and from transformation of grape-specific precursors, namely alcohols, ethyl and alkyl esters, aldehydes, and fatty acids, which contribute substantially to the flavor and to the base wine aroma, and iii) the volatiles formed during the wine storage and/or aging through several chemical reactions, including redox phenomena, Maillard reactions, and Strecker degradation, abiotic transformation of precursor compounds in wine, microbial spoilage, and difusion from oak, from which we can highlight the furanic compounds, lactones and acetals (dioxanes and dioxolanes), among others. The most important and dominant volatile compounds derived from these three main pathways are discussed in some detail.
The relationship between climate change and viticulture has become increasingly apparent in recent years. Rising temperatures have been a critical factor in early grape ripening. This, in turn, has led to wines with imbalanced acidity and, more importantly, higher alcohol content and pH values. Today, consumers demand high-quality and healthy products, and this trend has extended to wine consumption. Consumers prefer wines with reduced alcohol content due to the health risks associated with alcohol consumption. To meet this demand, researchers have developed modified yeast strains that reduce wine alcohol content during fermentation. These strains ferment less sugar or redirect carbon metabolism. However, their use may pose challenges, such as producing undesired secondary metabolites that can affect wine characteristics. Additionally, consumers are still divided on using genetically modified organisms (GMOs) in food and beverages. This review examines the impact of climate change on wine quality and consumer perception, taking into account new technologies used to reduce wine alcohol content or produce low-alcohol-content wines, such as low-cost techniques like bio-dealcoholization performed by non-GMO wine yeast, Saccharomyces, and non-Saccharomyces.
Red grape variety Merlot is vinified and two types of fermentation are applied – conventional winemaking process and other – cold maceration before alcoholic fermentation. Each of the samples is vinified with Non-saccharomyces - Kluyveromycs thermotolerans inoculation done 48 ours before Saccharomyces addition. For each trial the control sample is realized using only Saccharomyses yeasts. The resulting wines are analyzed for some basic compounds and also some specific aromatic compound is determined using GC-MS. High concentration of some ethyl esters are determined in Non-saccharomyces wine and also more neutral polysaccharides.
Key words: red wine, cold maceration, Non-saccharomyces yeast, GC-MS
The use of non-Saccharomyces yeasts in sequential fermentation is a suitable biotechnological process to provide specific oenological characteristics and to increase the complexity of wines. In this work, selected strains of Lachancea thermotolerans and Starmerella bombicola were used in sequential fermentations with Saccharomyces cerevisiae and compared with spontaneous and pure S. cerevisiae fermentation trials in Verdicchio grape juice. Torulaspora delbrueckii together with the other two non-Saccharomyces strains (L. thermotolerans, S. bombicola) in multi-sequential fermentations was also evaluated. Wines, obtained under winery vinification conditions, were evaluated for their analytical and sensorial profile. The results indicated that each fermentation gave peculiar analytical and aromatic features of the final wine. L. thermotolerans trials are characterized by an increase of total acidity, higher alcohols and monoterpenes as well as citric and herbal notes. S. bombicola trials showed a general significantly high concentration of phenylethyl acetate and hexyl acetate and a softness sensation while multi-sequential fermentations showed a balanced profile. Spontaneous fermentation was characterized by the production of acetate esters (ethyl acetate and isoamyl acetate), citrus and herbal notes, and tannicity. The overall results indicate that multi-starter fermentations could be a promising tool tailored to the desired features of different Verdicchio wine styles.
To systematically explore the impact of microbial community composition on the quality characteristics of northeast soybean paste, the microbial community structure was determined by high-throughput sequencing technology, and the flavor substance, free amino acid (FAA) and biogenic amine (BA) contents were determined by HS-SPME-GC–MS and HPLC. Furthermore, the correlation between microorganisms and metabolites was investigated. The results indicated that the core bacteria mainly included Tetragenococcus, Bacillus and Lactobacillus; Candida_f__norank, Wickerhamomyces and Aspergillus were the dominant fungi. A total of 139 flavor compounds were detected in all samples, and decamethylcyclopentasiloxane, isoamyl phenylacetate and octamethylcyclotetrasiloxane accounted for the highest proportion. A total of 24 FAAs were detected in the soybean paste. Pantoea, Kroppenstedtia and Kocuria were significantly positively correlated with most FAAs (p < 0.05). Additionally, 5 BAs were detected in the soybean paste, and the contents of BAs in Y4 were highest, which was affected by different microbes. This study provided relevant information for the microbial community composition and metabolites of northeast soybean paste, which was of great significance for understanding the characteristics and safety of soybean paste.
Wine has very rich and complex aromas but is paradoxically obtained from grape juice that has very little odor itself. This aromatic transformation is mainly due to the action of yeasts during the alcoholic fermentation. First, yeasts produce secondary metabolites that give to wines its basic “winy” characteristic. Second, some enzymatic activities may transform nonodorous compounds of certain grape varieties into varietal aromas, giving the specific characteristics of “cépage.” Depending on the yeast strain, the concentration of aromatic molecules is determined, modifying the organoleptic perception of wine. The enzymatic activities of yeast metabolism and their genetic control have been widely studied, allowing genetic selection approaches as well as molecular engineering for selecting more specialized commercial starters.
Chongqing radish paocai (paocai) is produced by fermentation of fresh vegetables. It gained attention for its non-negligible contribution in Sichuan cuisine and potential health benefits. This study explored microbial structures in six home-made paocai using high through-put sequencing. Key microbial communities were identified based on significant correlations with quality-related physiochemical attributes. Results suggest bacterial diversity level significantly decreased during fermentation, while fungal diversity level were inconsistent across different alpha-diversity indexes. Firmicutes and Proteobacteria were the predominant bacterial phylum in all samples. Lactic acid bacteria, namely Lactobacillus and L. plantarum were the predominant bacteria at genus and species levels. Fungi had overall weak correlations with physiochemical attributes, several bacterial species significantly correlated with physiochemical attributes, including Lactobacillus plantarum, Lactobacillus acetotolerans, and Weissella cibaria. Overall, this study identified key microbial communities and discussed their functional roles that could contribute to consistent production of high-quality Chongqing radish paocai.
In recent years, there had been growing demand for distinctive high quality beer. Fermentation management has a fundamental role in beer quality and the levels of aroma compounds. Use of non-conventional yeast has been proposed to enhance beer flavor. In this study, the bioflavor of traditional sorghum beer from Côte d’Ivoire was investigated. The flavor profile of two beers fermented with wild yeasts and with pure culture of Saccharomyces cerevisiae respectively were studied. The main flavor components of the beer fermented by pure culture of Saccharomyces cerevisiae were different from those of the beer fermented with wild yeasts. The total level of esters and higher alcohols were (173.51 and 128.85 mg/L) respectively in the beer fermented with wild yeasts. These levels were significantly higher than those in the beer fermented with pure culture of Saccharomyces cerevisiae which were 13.08 and 78.26 mg/L for higher alcohols and esters respectively. On the other hand, the beer fermented with pure culture of Saccharomyces cerevisiae had an acid content higher than beer fermented with wild yeasts, i.e. 9.3 mg/L and 7.53 mg/L respectively.
Quorum sensing (QS) in yeast is a population density dependant phenomenon defined as the complex process of cell to cell communication, where the participating organisms detect, analyse and respond to the small diffusible quorum sensing molecules (QSMs), resulting in activation or repression of certain genes leading to changes in morphogenic transition, biofilm development or expression of virulence characters. Yeasts are eukaryotic micro-organisms which are widely used for preparation of fermented foods and beverages worldwide. For the purpose of this investigation, yeast from traditional fermentative cakes exhibiting appreciable ethanol tolerance and IAA synthesizing ability were chosen that included Saccharomyces cerevisiae, Wickerhamomyces anomalous, Candida glabrata and Candida tropicalis. The isolates were assessed for their ability to express QSMs and responds to them. In order to determine their dominance, isolates were subjected to glucose and starch medium both individually and in combinations. Finally, the probable role of QSMs in ethanol fermentation process was examined. Results displayed the ability of the isolates to synthesize the QS molecule tyrosol. Isolate C tropicalis exhibited filamentous growth in response to tyrosol retrieved from other isolates. The dominance of isolates during resource competition appeared as W anomalous > C tropicalis > C glabrata > S cerevisiae in glucose medium and C tropicalis > W anomalous > C glabrata > S cerevisiae in starch medium in mono-culture conditions. In co-culture conditions, W anomalous could not sustain with C tropicalis in glucose which otherwise was reverse in starch. C tropicalis dominated all the co-cultures in starch followed by W anomalous, S cerevisiae and C glabrata. In glucose, the order was somewhat different. The fermentation efficiency was highest when Saccharomyces cerevisiae and Candida glabrata were co-cultured together in both starch and glucose. Under the influence of tyrosol, isolates C tropicalis, S cerevisiae and C glabrata were observed to exhibit higher ethanol tolerance compared to their normal threshold limits. Additionally, significant increase in growth was observed in C tropicalis and W anomalus isolates in starch and in C tropicalis and S cerevisiae in glucose medium. Enhancement in fermentative capacity of isolate S cerevisiae in starch medium under the influence of tyrosol was noted. The study concludes that tyrosol exerts enhancing effect in cell growth during fermentation and thereby augments the outcome of the process.
Depuis 2006, mes travaux ont été centrés sur l’étude de la diversité génétique et phénotypique des levures du raisin et du vin, qu’il s’agisse d’espèces bénéfiques utilisées comme auxiliaires technologiques (Saccharomyces sp., non-Saccharomyces d’intérêt oenologique) ou qu’il s’agisse d’espèces d’altération (Brettanomyces bruxellensis). Nous avons développé des approches multi-échelles, combinant des outils classiques (microbiologie traditionnelle, génétique des populations), des approches spécifiques de l’oenologie (suivi des cinétiques fermentaires, analyse sensorielle), et des analyses –omic à haut-débit couplées à des outils bio-informatiques. Ces différents projets ont été financés sur fonds publiques (ANR, région, Bordeaux INP, etc.) ou privés (industriels de l’oenologie, interprofession, etc.), et ont nécessité l’engagement de nombreux collègues, collaborateurs et étudiants – nationaux ou internationaux. Sur le plan fondamental, nos travaux ont permis d’améliorer nos connaissances des levures d’oenologie à travers la publication de >40 articles scientifiques dans des revues avec comité de lecture. Quelques applications finalisées ont également vu le jour (sélection de souches de levure pour l’oenologie, développement de marqueurs moléculaires, etc.). Nous avons également contribué au transfert de connaissance vers la profession sous la forme d’articles ou de communications techniques.
Les projets que j’aimerai développer à l’avenir se déclinent en trois grands thèmes :
1- mieux comprendre l’adaptation des espèces et sous-populations de levure à des environnements variés, anthropisés ou non ;
2- améliorer nos connaissances des mécanismes d’interactions entre espèces microbiennes, notamment dans l’environnement vitivinicole ;
3- approfondir l’étude de certains phénotypes d’intérêt oenologique.
Comme pour nos travaux passés, les projets futurs comporteront lorsque cela est possible un volet fondamental et appliqué afin de mieux maitriser la qualité et l’identité des vins d’aujourd’hui et demain.
Ice wine is a sweet dessert wine made from pressing grapes naturally frozen on the vines. The structure and metabolic characteristics of native microbial community dominated by organics and nutrients transformation in fermenting process of ice wine on the grape skin are likely to change due to climate events. Our objective was to evaluate the influence of harvest time on structure and metabolic characteristics of bacterial and fungal communities on Vidal ice grape surface. Vidal grape samples were picked between October and December in 2018; Harvest 1 (VG1): 14 October; Harvest 2 (VG2): 16 November; Harvest 3 (VG3): 18 December. Vishniacozyma, Alternaria, Cladosporium, Stenotrophomonas, unidentified_Cyanobacteria and Sphingomonas existed in all harvest dates and were the main genera widespread in most grape samples from the three harvest periods. Saprotrophic fungi and bacteria involved in metabolism were also dominant. For fungi, wood saprotrophs and unidentified saprotrophs were detected comprising Phoma, Didymella, Filobasidium and Clavaria. Delayed harvest of ice grapes has a distinct advantage for pathogen reduction compared with that of normally harvested grapes. Among bacteria, the most frequently occurring types in the metabolism category were energy metabolism, carbohydrate metabolism and lipid metabolism. In short, the harvest period can positively regulate the function of Vidal ice grape epidermal microorganisms.
The international competitiveness of the wine sector and consumer demands for the unique wine styles pose challenges in improving the fermentation process. The basis of proper alcoholic fermentation is knowledge about how individual yeast strains interact with the aroma, taste and color of wine, what results in possibility to select species used as starter cultures. To use the value of non-Saccharomyces yeast strains in wine production and to minimize the possibility of wine deterioration, it is necessary to precisely recognize the yeast cultures present on the fruit of the vine and in grape must, as well as their metabolic properties. The aim of the study was to determine the oenological properties of yeasts isolated from spontaneously fermented grape musts obtained from cool climate grapes. For this purpose, Zweigelt grape must was fermented with yeast monocultures. Alcohol, extract, sugars, glycerol, total acidity and free amine nitrogen were analyzed in the obtained wines. Poor fermentation properties of yeast strains results in obtaining wines with relatively large amounts of residual sugars and low alcohol. A decrease in overall acidity was noted in sets with the participation of M. pulcherrima MG971264, while in other tests the opposite trend was observed. Although some microorganisms have the ability to assimilate organic acids found in wine, they are not able to carry out fermentation or they do it inefficiently. Solution to this problem may, therefore, be use of mixed cultures of noble and non-Saccharomyces yeast, what effectively reduce the concentration of organic acids, while not adversely affecting the organoleptic characteristics of the drink.
Fermentation is one of the most ancient forms of energy metabolism. Wine may involve two forms of alcoholic (yeast and grape cell) and several types of organic acid fermentation in its production. The chapter first begins with a basic outline of winemaking followed by an exploration of prefermentation practices: grape sorting, crushing, destemming, maceration, dejuicing, and pressing as well as clarification and adjustment techniques (sugar and acid contents, enzyme addition, decoloration, blending, sulfiting). Principal alcoholic fermentation is under the control of yeast action, notably but not exclusively by Saccharomyces cerevisiae. Its discussion includes the various types of fermentors that may be employed; the biochemical aspects of yeast fermentation; yeast taxonomy, ecology, inoculation, genetics, and breeding; the influences of grape constituents, additives, pesticide residues, and the physical environment; and slow and stuck fermentation. This is followed by a discussion of malolactic fermentation including the involvement of lactic acid bacteria and their ecology; sensory consequences; chemical, physical, and biologic influences; inoculation; and inhibition.
L'étude par chromatographie en phase gazeuse des produits volatils formés par 50 souches de levures d'espèces diverses, isolées de la région NAOUSSA (Grèce) a montré que les levures les plus alcoogènes forment le plus de substances, en particulier d'esters, favorables à la qualité du vin.
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Investigation, by gas chromatography, on volatile products formed by 50 various yeast strains isolated in NAOUSSA vineyard (Greece) shows that the most alcohogene strains synthesize these substances, and particularly esters, in a greatest extent, this is favourable to the quality of the wine.
A PCR-based method has been developed that permits both intraspecies differentiation and species identification of yeast isolates. Oligonucleotide primers that are complementary to intron splice sites were used to produce PCR fingerprints that display polymorphisms between different species of indigenous wine yeasts. Although polymorphisms existed between isolates of the same species, the banding patterns shared several amplification products that allowed species identification. Importantly, the method was able to distinguish between species of the closely related Saccharomyces sensu stricto yeasts. In two cases where isolates could not be positively identified there was discrepancy between the phenetic and phylogenetic species concept. The method has applications in yeast ecological studies, enabling the rapid grouping of isolates with related genomes and the investigation of population dynamics of strains of the same species.
The growth of yeasts that occur naturally in grape juice was quantitatively examined during the fermentation of four wines that had been inoculated with Saccharomyces cerevisiae. Although S. cerevisiae dominated the wine fermentations, there was significant growth of the natural species Kloeckera apiculata, Candida stellata, Candida colliculosa, Candida pulcherrima, and Hansenula anomala.
Screening tests carried out for 10 strains of Candida stellata confirmed high levels of glycerol production, although a low fermentation rate and reduced ethanol content were observed. To overcome the poor competition with Saccharomyces cerevisiae, fermentation tests with immobilized C. stellata cells, alone or in combination with S. cerevisiae, have been carried out. The immobilization of C. stellata cells consistently reduced the fermentation length when compared with that obtained with free cells, immobilized cells exhibiting about a 30-and a 2-fold improvement in fermentation rate compared with rates for C. stellata and S. cerevisiae free cells, respectively. Moreover, immobilized C. stellata cells produced a twofold increase in ethanol content and a strong reduction in acetaldehyde and acetoin production in comparison with levels for free cells. The evaluation of different combinations of C. stellata immobilized cells and S. cerevisiae showed interesting results with regard to analytical profiles for practical application in wine making. In fact, analytical profiles of combinations showed, apart from a high glycerol content, a reduction in the amounts of acetic acid and higher alcohols and a consistent increase in succinic acid content in comparison with values for the S. cerevisiae control strain. Sequential fermentation first with immobilized C. stellata cells and then after 3 days with an added inoculum of S. cerevisiae free cells was the best combination, producing 15.10 g of glycerol per liter, i.e., 136% more than the S. cerevisiae control strain produced. Fermentation with immobilized C. stellata cells could be an interesting process by which to enhance glycerol content in wine.
Riesling musts, with or without sulfur dioxide added, were fermented either with or without the addition of yeast. Uninoculated fermentations took much longer to finish than inoculated musts. There were no significant differences in growth of non-Saccharomyces yeasts in uninoculated musts with less than 50 mg l(-1) SO2 added. The starter culture was completely dominant over indigenous Saccharomyces cerevisiae and strongly inhibitory to non-Saccharomyces. Alcohol and acetaldehyde were greater in the inoculated treatments; titratable acidity and acetic acid were greater in the uninoculated fermentations. There were no statistically significant differences among any treatments in final pH, ammonia content, or colour (A(420)). Uninoculated fermentations had higher sensory scores (P > 0.95) for 'spicy', 'apple', 'melon', 'pear', and 'H2S', while inoculated wines had higher scores (P > 0.95) for 'paper', 'oxidized', and 'sweaty'. Sulfite treatment produced an assortment of significant sensory differences in the finished uninoculated wines, but in inoculated wines the additions of SO2 to the must had no significant effect on indigenous yeast populations or on flavour.
One of the most commonly found wild yeasts in musts of the Niagara region of Ontario, Canada, is highly fermentative and is resistant to control with SO2. Previous attempts to classify the organism have been inconclusive. An extensive re-examination of the assimilation data and the use of clamped hexagonal electric field electrophoresis to derive a karyotype indicated that the strains are metabolic and morphological variants of Candida stellata.
Wine yeasts were isolated from spontaneous alcoholic fermentations performed with white and red grape musts from vintages 1991 and 1992. Yeast cells were analysed by physiological tests and gel electrophoretic karyotyping. It was shown that there is a succession of different strains in the yeast population during the time course of the fermentation process. Furthermore, the composition of the yeast strain population differs from grape must to grape must and from year to year, and may therefore be considered vineyard (terrain)- and vintage-dependent.
The aroma properties of hydrolysed glycosidic precursors from Semillon, Sauvignon Blanc and Chardonnay grape juices were investigated in a neutral wine medium using sensory descriptive analysis. The glycosidic fractions were hydrolysed by acid catalysis in the presence or absence of ethanol, by glycosidase enzyme action, or by a sequence of glycosidase and acid treatments. Wines made from the Chardonnay and Semillon juices were also assessed. Sensory difference tests showed that samples from each variety for each treatment were distinct, except the hydrolysates prepared enzymically from Semillon and Chardonnay. The aroma of each acid hydrolysate was distinguishable from the neutral wine by enhanced intensity of the attributes honey, tea, lime and floral. Enzyme treatment of the glycosides from Sauvignon Blanc gave a hydrolysate with aroma properties similar to those of the corresponding acid hydrolysate, but with less intense tea, oak and honey attributes. The treatment consisting of enzyme followed by acid hydrolysis produced an artefact, apparently due to degradation of the added enzyme. Aroma attributes that characterise Chardonnay and Semillon wines were also aromas perceived in the hydrolysed precursor samples, indicating that grape precursors on hydrolysis contribute to and enhance these key aromas in the wines.
Riesling musts, with or without sulfur dioxide added, were fermented either with or without the addition of yeast. Uninoculated fermentations took much longer to finish than inoculated musts. There were no significant differences in growth of non-Saccharomyces yeasts in uninoculated musts with less than 50 mg l−1 SO2 added. The starter culture was completely dominant over indigenous Saccharomyces cerevisiae and strongly inhibitory to non-Saccharomyces. Alcohol and acetaldehyde were greater in the inoculated treatments ; titratable acidity and acetic acid were greater in the uninoculated fermentations. There were no statistically significant differences among any treatments in final pH, ammonia content, or colour (A420). Uninoculated fermentations had higher sensory scores (P > 0·95) for ‘spicy’, ‘apple’, ‘melon’, ‘pear’, and ‘H2S’, while inoculated wines had higher scores (P > 0·95) for ‘paper’, ‘oxidized’, and ‘sweaty’. Sulfite treatment produced an assortment of significant sensory differences in the finished uninoculated wines, but in inoculated wines the additions of SO2 to the must had no significant effect on indigenous yeast populations or on flavour.
A total of 78 strains of non-Saccharomyces yeasts were isolated: 30 strains of Kloeckera apiculata, 20 of Candida stellata, 8 of Candida valida and 20 of Zygosaccharomyces fermentati. The diversity of yeast species and strains was monitored by determining the formation of secondary products of fermentation, such as acetaldehyde, ethyl acetate and higher alcohols. Within each species, the strains were distinguishable in phenotypes through the production of different amounts of by-products. In particular, a great variability was found in C. stellata, where six different phenotypes were identified by means of the production of acetaldehyde, ethyl acetate, isobutanol and isoamyl alcohol. At different stages of the spontaneous fermentation different phenotypes of the non-Saccharomyces yeasts were represented, characterized by consistent differences in some by-products involved in the wine bouquet, such as acetaldehyde.
Several yeast cultures belonging to five non-Saccharomyces species associated with wine-making were evaluated for their oenological properties. Results showed that Candida stellata and Torulaspora delbrueckii could positively affect the taste and flavour of alcoholic beverages. Apiculate yeasts exhibited large amounts of negative byproducts, particularly ethyl acetate. Nevertheless, Kloeckera apiculata showed a significantly negative correlation between either acetic acid and ethyl acetate formation and ethanol production. Selected non-Saccharomyces yeast cultures could be applied profitably in wine-making for optimization of wine bouquet using new fermentation technologies.
Volatile substances of wines obtained by fermentation of musts from 'Monastrell' grapes (Alicante, Spain) was studied for yeast isolated from such musts. The results of the statistical treatment performed show the importance of yeasts of low fermentative power, particularly Kloeckera apiculata, in the production of volatile substances. Saccharomyces cerevisiae var. chevalieri was found to be the most important yeast of high fermentative power.
The spectacular increase in world population has led to a major effort, on a national and international basis, for the increased production of foods. Microorganisms determine—to a great extent—the characteristic flavor of the final product. Recent advances in flavor analysis have opened new fields for the characterization of various beer types, although no definite correlations have so far been laid down. Although substantial advances have been made in producing nutritionally valuable food ingredients of low cost, such as protein from microbial sources and fishmeal concentrate, the acceptance of these foods in the needy developing countries where undernourishment is frequently encountered is far from satisfactory. One of the major disadvantages of these unconventional foods is their poor taste. This chapter refers only to the processes in which microbial activity is taking place in situ during manufacturing. Many workers have pointed out that after all the nutritional requirements of foods have been met with, the incorporation of suitable flavoring material into these “synthetic foods” have become imperative. There have been spectacular advances in the characterization of flavor. Gas–liquid chromatography and mass spectroscopy have opened new fields in the analysis of flavor and flavoring materials.
A total of 78 strains of non-Saccharomyces yeasts were isolated: 30 strains of Kloeckera apiculata, 20 of Candida stellata, 8 of Candida valida and 20 of Zygosaccharomyces fermentati. The diversity of yeast species and strains was monitored by determining the formation of secondary products of fermentation, such as acetaldehyde, ethyl acetate and higher alcohols. Within each species, the strains were distinguishable in phenotypes through the production of different amounts of by-products. In particular, a great variability was found in C. stellata, where six different phenotypes were identified by means of the production of acetaldehyde, ethyl acetate, isobutanol and isoamyl alcohol. At different stages of the spontaneous fermentation different phenotypes of the non-Saccharomyces yeasts were represented, characterized by consistent differences in some by-products involved in the wine bouquet, such as acetaldehyde.
The levels of yeasts and lactic acid bacteria that naturally developed during the vinification of two red and two white Bordeaux wines were quantitatively examined. Yeasts of the genera Rhodotorula, Pichia, Candida, and Metschnikowia occurred at low levels in freshly extracted grape musts but died off as soon as fermentation commenced. Kloeckera apiculata (Hanseniaspora uvarum), Torulopsis stellata, and Saccharomyces cerevisiae, the dominant yeasts in musts, proliferated to conduct alcoholic fermentation. K. apiculata and eventually T. stellata died off as fermentation progressed, leaving S. cerevisiae as the dominant yeast until the termination of fermentation by the addition of sulfur dioxide. At least two different strains of S. cerevisiae were involved in the fermentation of one of the red wines. Low levels of lactic acid bacteria (Pediococcus cerevisiae, Leuconostoc mesenteroides, and Lactobacillus spp.) were present in grape musts but died off during alcoholic fermentation. The malolactic fermentation developed in both red wines soon after alcoholic fermentation and correlated with the vigorous growth of at least three different strains of Leuconostoc oenos.
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