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From the fundamental studies of Louis Pasteur in the XIX century to the current genomic analysis, the essential role of microorganisms in winemaking industry is well recognised. In the last decades, selected Saccharomyces cerevisiae strains with excellent fermentative behaviour have been widely commercialised in form of active dry yeasts. Currently...
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... the sample is diluted until 10 −5 or 10 −6 and aliquots of these suspensions are plated. Wallestein Laboratory (WL) agar solid media allowing to differentiate among yeast species on the basis of different colours of the colonies is usually used for yeast growth (Figure 3). The incubation temperature must be 24-26° C. ...
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... Targeting the success of alcoholic fermentation and the production of high value wines, producers have focused on the selection of indigenous S. cerevisiae strains which have been previously evaluated for their oenological properties to drive AF (Caridi et al., 2002;Le Jeune et al., 2006;Pulcini et al., 2022). Numerous studies focus on the selection of "novel" S. cerevisiae with main concern, their improved technological and organoleptic properties; such as high yields of productivity, stress tolerance, unique aromatic characteristics and positive sensory attributes (Capece et al., 2010(Capece et al., , 2019Suárez-Lepe and Morata, 2012;Basa et al., 2022;Tronchoni et al., 2022). ...
... Numerous studies focus on the selection of "novel" S. cerevisiae with main concern, their improved technological and organoleptic properties; such as high yields of productivity, stress tolerance, unique aromatic characteristics and positive sensory attributes (Capece et al., 2010(Capece et al., , 2019Suárez-Lepe and Morata, 2012;Basa et al., 2022;Tronchoni et al., 2022). Some beneficial oenological traits are alcohol tolerance, lower production of acetic acid and H 2 S, SO 2 tolerance, neutral killer character and resistance to high concentrations of sugars (de Ullivarri et al., 2011;Comitini et al., 2017;Pulcini et al., 2022). Furthermore, some yeasts possess the enzymes of β-glucosidases, whose activity results in releasing aglycones and this procedure directly affects beneficially the produced aroma (Mansfield et al., 2002). ...
... Furthermore, some yeasts possess the enzymes of β-glucosidases, whose activity results in releasing aglycones and this procedure directly affects beneficially the produced aroma (Mansfield et al., 2002). All the abovementioned characteristics are criteria for the selection of starter cultures, resulting in wines with controlled quality and attractive organoleptic profile (Christofi et al., 2022;Pulcini et al., 2022). ...
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.
