Content uploaded by Margarita García
Author content
All content in this area was uploaded by Margarita García on Sep 04, 2018
Content may be subject to copyright.
fermentation
Review
Advances in the Study of Candida stellata
Margarita García1, *ID , Braulio Esteve-Zarzoso 2ID , Juan Mariano Cabellos 1and Teresa Arroyo 1
1Department of Food and Agricultural Science, IMIDRA, 28800 Alcaláde Henares, Spain;
juan.cabellos@madrid.org (J.M.C.); teresa.arroyo@madrid.org (T.A.)
2Department of Chemistry and Biotechnology, Rovira i Virgili University, 43007 Tarragona, Spain;
braulio.esteve@urv.cat
*Correspondence: margarita_garcia_garcia@madrid.org
Received: 31 July 2018; Accepted: 1 September 2018; Published: 4 September 2018
Abstract:
Candida stellata is an imperfect yeast of the genus Candida that belongs to the order
Saccharomycetales, while phylum Ascomycota.C. stellata was isolated originally from a must overripe
in Germany but is widespread in natural and artificial habitats. C. stellata is a yeast with a taxonomic
history characterized by numerous changes; it is either a heterogeneous species or easily confused
with other yeast species that colonize the same substrates. The strain DBVPG 3827, frequently used
to investigate the oenological properties of C. stellata, was recently renamed as Starmerella bombicola,
which can be easily confused with C. zemplinina or related species like C. lactis-condensi. Strains of
C. stellata have been used in the processing of foods and feeds for thousands of years. This species,
which is commonly isolated from grape must, has been found to be competitive and persistent
in fermentation in both white and red wine in various wine regions of the world and tolerates a
concentration of at least 9% (v/v) ethanol. Although these yeasts can produce spoilage, several studies
have been conducted to characterize C. stellata for their ability to produce desirable metabolites for
wine flavor, such as acetate esters, or for the presence of enzymatic activities that enhance wine
aroma, such as
β
-glucosidase. This microorganism could also possess many interesting technological
properties that could be applied in food processing. Exo and endoglucosidases and polygalactosidase
of C. stellata are important in the degradation of
β
-glucans produced by Botrytis cinerea. In traditional
balsamic vinegar production, C. stellata shapes the aromatic profile of traditional vinegar, producing
ethanol from fructose and high concentrations of glycerol, succinic acid, ethyl acetate, and acetoin.
Chemical characterization of exocellular polysaccharides produced by non-Saccharomyces yeasts
revealed them to essentially be mannoproteins with high mannose contents, ranging from 73–74%
for Starmerella bombicola. Numerous studies have clearly proven that these macromolecules make
multiple positive contributions to wine quality. Recent studies on C. stellata strains in wines made by
co-fermentation with Saccharomyces cerevisiae have found that the aroma attributes of the individual
strains were apparent when the inoculation protocol permitted the growth and activity of both yeasts.
The exploitation of the diversity of biochemical and sensory properties of non-Saccharomyces yeast
could be of interest for obtaining new products.
Keywords: Candida stellata; ecology; taxonomy; metabolism; processing foods; co-fermentation
1. Characteristics of the Genus Candida
The genus Candida belongs to the order Saccharomycetales of the phylum Ascomycota and is defined
as incerta sedis (of uncertain placement). Candida is phylogenetically heterogeneous and included
314 species and the type species C. vulgaris (syn. C. tropicalis) [1].
Candida are widespread distributed in natural and artificial habitats, being damp and wet with a
high content of organic material, including organic acids and ethanol, a broad range of temperatures,
Fermentation 2018,4, 74; doi:10.3390/fermentation4030074 www.mdpi.com/journal/fermentation
Fermentation 2018,4, 74 2 of 22
and high salt and sugar osmolarity. Some species have been implicated in the conversion of foods and
feeds for thousands of years. Their high biochemical potency makes Candida useful for commercial
and biotechnological processes.
The diversity of the genus is reflected by an amplitude of unique species with respect to colony
texture, microscopic morphology, and fermentation and assimilation profiles. The members of this
genus may ferment a lot of sugars, assimilate the nitrate, and form pellicles and films on the surface
of liquid media. Extracellular starch-like compounds are not produced. Some species assimilate the
inositol and normally the urease is not produced, and gelatin may be liquefied. The reaction with
blue of diazonium blue B is negative. The sugars (xylose, rhamnose, and fucose) are not found in
cell hydrolysates. The dominant ubiquinones are Q9, Q7, Q8, and Q6. Additionally, the inositol
assimilation might be positive or negative; in the case of the inositol-positive response, most strains
develop pseudomycelia [2].
2. Ecological and Physiological Properties of Genus Candida
Candida covers numerous habitats that determine a wide range of physiological properties. Most of
Candida is mesophilic, growing well at temperatures of 25–30
◦
C, with extremes of below 0
◦
C and up
to 50
◦
C. The genus Candida does not have photosynthetic capacity or fix nitrogen and normally cannot
grow anaerobically. Candida yeasts are employed to obtain a wide variety of biotechnologically
interesting compounds like higher alcohols, organic acids, esters, diacetyl, aldehydes, ketones,
acids, long chain dicarboxylic acids, xylitol, and glycerol. Other products are nicotinic acid, biotin,
and D-
β
-hydroxyisobutyric acid. Another property exhibited by some strains of Candida is the ability
to synthesize sophorosides [
3
] when they are growing on substrates like n-alkanes, alkenes, fatty acids,
esters, or triglycerides. Also, the genus Candida is able to liberate extracellular enzymes, such as
pectinases,
β
-glucosidases, proteases, invertases, amylases, and lipases, that are of high commercial
interest [
4
]. Candida dominates in a vast variety of nutrient-rich habitats. These habitats are associated
with plants, rotting vegetation, and insects that feed on plants. Insects (Drosophila, bees and bumblebees,
etc.) act as vectors, and yeasts are an important food source for both the larval and adult stages
of numerous insects [
5
]. Some species of Candida such as C. famata,C. guilliermondii,C. tropicalis,
C. parapsilosis, and others may be isolated from natural and polluted water or sediments. Other species
like C. glabrata and C. parapsilosis are often isolated from seafood; Candida inconspicua and C. parapsilosis
from fish; and C. stellata,C. sake, and C. parapsilosis from oysters. C. krusei and C. valida grow better
on polluted sediments. The presence of the C. krusei complex may be an index of sewage pollution.
C. boidinii is associated with tanning solutions containing sugars, nitrogenous compounds, and mineral
salts (pH 4.0–5.9) [2].
The presence of non-Saccharomyces yeasts in wine fermentation process has been widely
documented [
6
,
7
]. During the early stages of fermentation, a lot of species can grow simultaneously in
the grape must; the species C. stellata has been described in this stage and can survive even with a high
level of ethanol in the medium [
8
,
9
], and it is supposed to play an important role in the contribution of
aroma properties of certain wines [
10
]. In recent years, recent taxonomic studies revealed that C. stellata
can be mistaken for the closely related species C. zemplinina [
11
,
12
]. This confusion around the
taxonomic position of the strains may explain some of the controversial descriptions of the oenological
properties of C. stellata [13].
3. Methods of Isolation and Identification of Genus Candida
In general, the identification and enumeration of microorganisms present in wine involve
enrichment techniques [
14
,
15
]. These methods are considered indirect, because they do not reflect the
number of original cells in the sample, but they are also considered to be progeny, because they are
enriched in a selective growth media for cultivating yeast and bacteria from wine. The characterization
of Candida at the species level is laborious, since they are widely disseminated, highly variable,
change their physiology with varying conditions, and normally are associated with other yeasts,
Fermentation 2018,4, 74 3 of 22
bacteria, and molds. Nonselective media most commonly used for yeast separation, cultivation, and
enumeration are composed of glucose such as carbon source, and these media may be employed
at the beginning. Examples include dextrose agar (pH 6.9), dextrose broth (pH 7.2), Sabouraud
medium, dextrose tryptone agar, rice agar, malt extract medium, or plate count agar. The use
of lactic, tartaric, or citric acid (10%, final pH 3.5) for acidification of the media, as well as the
incorporation of antibiotics (up to 100 mg/L), such as cycloheximide, streptomycin, chloramphenicol,
and gentamycin, enhances their selectivity in order to inhibit the development of acid lactic bacteria
and other yeasts. Biphenyl, propionic acid, and dichloran control overgrowth of filamentous fungi.
The culture temperatures are also an important factor; those between 25
◦
C and 30–32
◦
C should be
chosen. Incubation times are fixed in the range of 3–5 days and must be increased for osmotolerant
and osmophilic yeasts to 5–10 days and 14–28 days, respectively. Many specific commercial media are
available for isolating and enumerating the genus Candida in different food products, including the
brewing industry and wine industry [12].
Although selecting wine yeast strains have been addressed for decades, the unequivocal
characterization has been possible with the knowledge of molecular techniques.
Pramateftaki et al. [16]
applied the PCR amplification and restriction pattern analysis of the ITS1-5.8S-ITS2 regions of the
nuclear ribosomal gene complex for species characterization of isolated yeasts based in the techniques
developed by different authors [17–19].
Most PCR-DGGE studies have been employed to discriminate both yeasts and bacteria in wine.
Cocolin et al. [
20
] were the first to apply PCR-DGGE method in wine fermentation, developing primers
for the D1/D2 domain of the large-subunit rDNA amplification of the yeast species. That work
demonstrated that the population shifts of different wine-related yeasts could be easily followed
using PCR-DGGE [
21
]. This study also confirmed the persistence of Candida sp. throughout wine
fermentation, detecting populations until 104 days later. Supplementary studies on commercial
sweet wine fermentation showed that non-Saccharomyces yeasts could be found in late stages of the
fermentation process by PCR-DGGE and even a long time after could be cultured on specific media [
7
].
This fact was particularly evident for the Candida sp. population, C.zemplinina [
11
]. DGGE signatures
from both RNA and DNA templates directly extracted from wine revealed C. zemplinina signatures
remained throughout the fermentation, even when direct plating manifested clearly a relative low
number of cells. Applying RNA dot blot analysis with C. zemplinina-specific probes shows that the
size of that population could be relatively high (>10
6
cells per mL) at the end of the fermentation,
while only 100–1000 CFU per mL could be detected by plating. These results provided some of the
first evidence of the presence of metabolically active but nonculturable yeasts in wine fermentation.
Endpoint PCR assays have been developed and applied for several wine yeast and bacteria.
López et al. [22]
used a multiplex PCR approach amplifying different segments of the yeast S. cerevisiae
COX1 gene to enumerate different starter strains. Cocolin et al. [
23
] also developed 26S rRNA gene
PCR primers for specific amplification of Hanseniaspora uvarum and C. zemplinina. In that experiment,
the authors founded a persistence of both RNA and DNA signatures for H. uvarum and C. zemplinina in
sulfited wine, even though no growth of either strain was witnessed on plating media. After 20 days of
SO
2
addition and without grow on plates, the detection of H. uvarum and C. zemplinina RNA signatures
in wine provides a useful example of how PCR results must be considered with caution, since both
live and dead cells may be detected.
The more recent QPCR system is being widely applied in wine fermentation. This technique is
used to the exponential amplification of target DNA sequences together with a fluorescent molecule
(SYBR Green dye is commonly used by wine-related species) [
24
]. The application of QPCR to specific
bacteria or non-Saccharomyces yeasts in wine fermentation allows for their enumeration in combination
with high populations of Saccharomyces. Organisms such as Candida sp. can be detected and quantified
in as little as one to two hours, which is a considerable improvement on the five to 10 days necessary
to develop the conventional analysis by plates [25,26].
Fermentation 2018,4, 74 4 of 22
4. Characteristics of Candida stellata
The non-Saccharomyces C. stellata is an Ascomycete, anamorph yeast belonging to the genus Candida,
with a taxonomic history subject to numerous changes; it is either a heterogeneous species or is easily
confused with other yeast species present in the same substrates.
C. stellata, a habitual member of the early yeast strains in both white and red wines in certain wine
regions of the world [
7
,
9
,
27
–
38
], is able to remain active throughout most of the alcoholic fermentation
and much longer than most other non-Saccharomyces yeasts [
29
,
32
,
35
,
39
–
41
]. The habitual presence of
C. stellata in the samples confirmed that this yeast is frequently associated with overripe and botrytized
grape berries and musts proceeding from botrytized grapes [42].
Among the genus/species linked to Candida stellata, the most notable are Saccharomyces stellatus,
Torulopsis stellata,Cryptococcus stellatus,Cryptococcus bacillaris,Saccharomyces bacillaris,Torulopsis
bacillaris, and Brettanomyces italicus. The cells are spherical to ovoid; they are usually found as single
cells but may be arranged in a star-like configuration of cells; no hyphae or pseudohyphae are
formed. Growing in YPD, colonies are grayish-white to brownish, glossy soft, and smooth. In malt
agar, there are large, round cream, or white colonies. C. stellata does not form spores. A whitish
cheese-like film can appear in liquid medium. This non-Saccharomyces yeast ferments glucose, sucrose,
and raffinose (sometimes it does this slowly). On the other hand, it can assimilate sucrose and raffinose
but not nitrate. C. stellata uses lysine as sole N source. Its growth requires vitamins such as biotin,
pantothenate, inositol, and thiamin. With regard to medium conditions, its growth is variable at 37
◦
C
but is sensitive to heat, while it is able to grow at lower temperatures and higher pH values. Moreover,
it is not sensitive to ethanol and under aerobic conditions; by contrast, it is sensitive to cycloheximide,
sorbate, DMDC, low pH, and acids.
5. Taxonomic Reclassification of Candida stellata
Initially, two types of Candida were isolated from a must elaborated in Germany from overripe
grape berries and raisins with a high sugar concentration (ca. 60%). One type had elongated cells
and was denominated Saccharomyces bacillaris. The other type was nominated Saccharomyces stellatus,
because in liquid media the star-like chains presented cells with spherical shape. Both species were
later included in genus Torulopsis due to the lack of spores’ generation. In another study on taxonomic
research carried out in Italy, a third type of species was isolated from grapes and named as Brettanomyces
italicus. Lastly, these taxa were unified in a single species named C. stellata, and the strain originally
described as S. stellatus was considered as type strain (CBS 157) (Figure 1).
Fermentation 2018, 4, 4 of 22
4. Characteristics of Candida stellata
The non-Saccharomyces C. stellata is an Ascomycete, anamorph yeast belonging to the genus
Candida, with a taxonomic history subject to numerous changes; it is either a heterogeneous species
or is easily confused with other yeast species present in the same substrates.
C. stellata, a habitual member of the early yeast strains in both white and red wines in certain
wine regions of the world [7,9,27–38], is able to remain active throughout most of the alcoholic
fermentation and much longer than most other non-Saccharomyces yeasts [29,32,35,39–41]. The
habitual presence of C. stellata in the samples confirmed that this yeast is frequently associated with
overripe and botrytized grape berries and musts proceeding from botrytized grapes [42].
Among the genus/species linked to Candida stellata, the most notable are Saccharomyces stellatus,
Torulopsis stellata, Cryptococcus stellatus, Cryptococcus bacillaris, Saccharomyces bacillaris, Torulopsis
bacillaris, and Brettanomyces italicus. The cells are spherical to ovoid; they are usually found as single
cells but may be arranged in a star-like configuration of cells; no hyphae or pseudohyphae are
formed. Growing in YPD, colonies are grayish-white to brownish, glossy soft, and smooth. In malt
agar, there are large, round cream, or white colonies. C. stellata does not form spores. A whitish
cheese-like film can appear in liquid medium. This non-Saccharomyces yeast ferments glucose,
sucrose, and raffinose (sometimes it does this slowly). On the other hand, it can assimilate sucrose
and raffinose but not nitrate. C. stellata uses lysine as sole N source. Its growth requires vitamins
such as biotin, pantothenate, inositol, and thiamin. With regard to medium conditions, its growth is
variable at 37° C but is sensitive to heat, while it is able to grow at lower temperatures and higher pH
values. Moreover, it is not sensitive to ethanol and under aerobic conditions; by contrast, it is
sensitive to cycloheximide, sorbate, DMDC, low pH, and acids.
5. Taxonomic Reclassification of Candida stellata
Initially, two types of Candida were isolated from a must elaborated in Germany from overripe
grape berries and raisins with a high sugar concentration (ca. 60%). One type had elongated cells and
was denominated Saccharomyces bacillaris. The other type was nominated Saccharomyces stellatus,
because in liquid media the star-like chains presented cells with spherical shape. Both species were
later included in genus Torulopsis due to the lack of spores’ generation. In another study on
taxonomic research carried out in Italy, a third type of species was isolated from grapes and named
as Brettanomyces italicus. Lastly, these taxa were unified in a single species named C. stellata, and the
strain originally described as S. stellatus was considered as type strain (CBS 157) (Figure 1).
Figure 1. Taxonomic reclassification of Candida stellata [13,43,44].
Figure 1. Taxonomic reclassification of Candida stellata [13,43,44].
Fermentation 2018,4, 74 5 of 22
Traditionally, C. stellata is associated with overripe and botrytized grape berries [
27
,
29
,
34
,
38
]. Candida
is present almost until the final stages of the alcoholic fermentation [
29
,
32
,
39
,
41
], suggesting that C. stellata
might significantly take part in the ecology of fermentation and the wine quality. Nevertheless, the role
of C. stellata in wine attributes seems to be controversial owing to the contradictory enological features
attributed to this yeast by several research groups. Some authors report on the high production of acetic
acid [
45
], glycerol [
10
,
46
], and succinic acid [
47
]; conversely, other works found low acetic acid levels
and low glycerol production [
35
]. These controversial results of Candida show that C. stellata is either
a heterogeneous species or is easily confused with other yeast species of Candida, which are present
in the same substrates. Sipiczki [
11
] found a new osmotolerant and psychrotolerant species studying
four yeast strains isolated from fermenting botrytized grape musts in the Tokaj wine region of Hungary,
corresponding to C. zemplinina. Traditional taxonomic test shows small differences between these isolates
and C. stellata strains CBS 157
T
and DBVPG 3827 (Dipartimento di Biologia Vegetale, Perugia, Italia)
(CBS 843).
The species C. zemplinina was discovered among wine yeasts that showed a taxonomic profile
characteristic of C. stellata [
11
]. Both species grow in similar environments (must with high sugar
concentration) but may form mixed populations in the colonized substrates. Lastly, the strain DBVPG
3827, frequently used to investigate the oenological properties of C. stellata, has been reclassified
as Starmerella bombicola [
43
] (Figure 1). Considering the recent identification of these new species
C. zemplinina and S. bombicola, they may be confused with C. stellata when conventional taxonomic
tests and routine PCR-restriction fragment length polymorphism (RFLP) analysis are used for
identification [
11
,
43
]. In view of these results, Csoma and Sipiczki [
13
] report that the name of
the species C. stellata has been used for group yeasts not conspecific with the type of strain of C. stellata.
Most strains originally identified as C. stellata and examined by the authors turned out to belong to
species that were not known yet at the time of their isolation, such as C. zemplinina,C. lactis-condensi,
C. davenportii, or S. bombicola. Csoma and Spiczki [
13
] studied 41 strains deposited in six culture
collections originally identified as C. stellata (Figure 1). The ITS1-5.8S rRNA-ITS2 sequence region was
studied in all strains by PCR-RFLP. The enzymes MBoI, DraI, and HaeIII were used separately during
the digestion of amplified fragments. Digestion with MboI is known to generate specific patterns for
each of C. stellata,C. zemplinina, and S. bombicola [
12
]. As result of the digestion of the fragments of
amplification, all strains gave three or four patterns. Thirty-nine out of the 41 strains examined showed
combinations of patterns different from those of the type strain of C. stellata; this result highlights the
fact that only two of investigated strains might belong to C. stellata. The digestion of the amplified
region with MboI and DraI distinguished C. stellata from C. zemplinina and the CfoI, HaeIII, and HinfI
restriction patterns separated C. stellata from S. bombicola [
43
]. Later, the D1/D2 domains of the LSU
rRNA gene of all strains studied were amplified and sequenced. The Blast search with the sequences
identified high degrees of similarity (98–100%) with the sequences of the type strains of 11 species.
Based on these sequences, most strains originally isolated from grapes or wine fermentation belonged
to C. zemplinina or S. bombicola (DBVPG strains). At the same time, the results of the taxonomic
physiological test were contrasted with the molecular results and all C. zemplinina strains growing in
the presence of 1% acetic acid, which inhibited the growth of C. stellata. The wine yeasts deposited in
DBVPG as C. stellata strains turned out to be strains of S. bombicola, which were identified species [
48
],
unknown at the time of their deposition.
As a result, it can be concluded that most wine strains preserved in CBS or described in recent
publications as C. stellata proved to belong to C. zemplinina [
13
]. C. stellata was not found among yeasts
newly isolated from noble rotted grapes and botrytized wines either, although overripe grapes and
fermenting grape musts with high sugar concentrations are environmental conditions in which strains
identified as C. stellata were frequently detected [
27
,
28
,
37
,
38
]. C. stellata is far less present in grapes and
natural wine fermentation than hitherto thought. Regarding botrytized wines, the higher appearance
of C. zemplinina is ligated to the capacity to resist higher acetic acid concentrations. It is known that
C. zemplinina can grow in presence of 1% of acetic acid, which is inhibitory to C. stellata. The grapes
Fermentation 2018,4, 74 6 of 22
infected by Botrytis cinerea present a high number of acetic acid bacteria, with can grow in grape must
with production of gluconic and acetic acids [49].
To probe the hypothesis about the broad presence of C. zemplinina, the C. stellata LSU rRNA gene
sequences published by others authors were reviewed [
13
]. The results showed that D1/D2 domain
sequences of the C. stellata strains isolated from French cider by Coton et al. [
50
] and from Spanish
wine by Hierro et al. [
38
] and the corresponding sequence of Candida sp. isolated from Californian
sweet botrytized wine by Mills et al. [
7
] are coincident with those of the type strain of C. zemplinina.
Moreover, C. zemplinina, but not C. stellata, was found in fermented red wine from Portugal grape
variety Castelao. Besides, C. zemplinina was also identified in other Portuguese wine (accession number
AY394855) and in Greek botrytized wines (accession number DQ872872).
The results obtained from electrophoretic karyotypes suppose another means for the differentiation
of these species. Although both species had three chromosomes and showed length polymorphism,
their chromosomes differed in size. C. stellata had a somewhat larger genome, and each chromosome
differed in size from the comparative used strains, CBS 157
T
and CBS 843. C. stellata appears to be prone to
undergo chromosomal rearrangements. In contrast, the C. zemplinina strains did not show chromosomal
polymorphism [13].
C. zemplinina also proved to be much more acidogenic; this aspect may significantly affect the
quality of the wine. C. stellata grew much more slowly at all conditions tested. This observation is in
accordance with earlier reports that described C. stellata as a slow-growing yeast [29].
On the other hand, different studies about the original type Saccharomyces bacillaris described
together with Saccharomyces stellata from overripe grapes and concentrated musts concluded that this
species is not synonymous with C. stellata. Different profiles were observed for the type strain of
C. stellata (CBS 157) for both the isoenzyme and rDNA restriction analysis, and only 91% similarity was
found between the D1/D2 sequence of this strain and S. bacillaris. In view of the results, S. bacillaris
has been recently reinstated as Starmerella bacillaris comb. nov., with C. zemplinina as an obligate
synonym [
44
] (Figure 1). This reorganization is in line with the latest edition of the “International
Code of Nomenclature for Algae, Fungi and Plants” [
51
], which eliminated the rule that was in force
for a long time that anamorphic yeasts with ascomycetous affiliation had to be classified to Candida;
this species was recently moved to the genus Starmerella, leaving the name C. zemplinina as obligate
synonym [
52
]. Following this reclassification of most of the yeasts, S. bacillaris, previously identified as
C. stellata, became Starmerella bacillaris [44].
6. Characteristics of Candida zemplinina sp. nov. Sipiczki
C. zemplinina was discovered studying wine yeasts with a taxonomic profile characteristic of
C. stellata [
11
]. Both species grown in similar environments (overripe grapes and grape must with high
sugar concentration) presumably may form mixed populations in the colonized substrates [13].
C. zemplinina owes its name to the Zemplin mountain range, whose south and south-east facing
slopes form the Tokaj wine region. The type strain is 10-372
T
(=CBS 9494
T
= NCAIM Y016667
T
),
which was isolated from white wine in Zemplin, Hungary [
11
]. Growing on morphologic agar,
the cells are ellipsoid to elongated (2.2–3.0
×
3.0–5.2
µ
m) alone and in pairs after 3 days incubation
at 25
◦
C. Their budding is multilateral. In contrast, after 7 days incubation at 25
◦
C on the same
culture media, colonies are low convex with smooth to finely lobed margins, and their texture is
butyrose. Neither hyphae nor pseudohyphae are generated. Ascospores formation is not seen after
25 days incubation at 25
◦
C on the agar culture media for corn-meal, potato dextrose, or Gorodkowa.
C. zemplinina ferments sugars, glucose, sucrose, and raffinose but does not ferment galactose, maltose,
and lactose. On the other hand, it can assimilate glucose, sucrose, L-sorbose (slowly), raffinose,
and lysine but does not assimilate the following compounds: galactose, D-glucosamine, D-ribose,
D-xylose, L-arabinose, D-arabinose, L-rhamnose, maltose, trehalose, methyl
α
-D-glucoside, cellobiose,
salicin, melibiose, lactose, melezitose, inulin, starch, glycerol, erythritol, ribitol, D-glucitol, D-manitol,
galactitol, inositol, D-glucono-1,5-lactone, succinate, citrate, methanol, ethanol, potassium nitrate,
Fermentation 2018,4, 74 7 of 22
cadaverine, N-acetyl-D-glucosamine, and lysine. Vitamins are essential to its growth. Finally, this yeast
species is able to grow in the presence of 60% (w/v) glucose. Additionally, no growth is observed in
the presence of 10 µg/mL cycloheximide or at 37 ◦C.
C. zemplinina cannot be considered a wine-specific yeast. C. zemplinina has been detected in
yeast populations associated with Ghanaian cocoa fermentation and two CBS strains identified as
C. zemplinina originate from soil (CBS 2799) and Drosophila sp. (CBS 4729) [
53
,
54
]. The association of
C. zemplinina with Drosophila confirms that fruit flies can be important vectors of yeasts from winery to
ripening grapes in the vineyard. The related species as C. bombi,C. lactis-condensis, and S. bombicola are
also associated with insects [55,56].
The genome of C. zemplinina is similar in size to the genome of C. stellata and the genomes of
the other related species, C. bombi,C. lactis-condensi, and Starmerella bombicola, but appears to differ
from it in stability. The C. zemplinina chromosomes show less variability than those of C. stellata.
This stability indicates that chromosome rearrangements may not be as important in this species as in
S. cerevisiae [57] for adaptation conditions during wine fermentation.
Kurtzman and Robnett [
58
] observed that strains showing greater than 1% difference in the
D1/D2 domain of the 26S rRNA are usually different species. The D1/D2 domains of the 26S rDNA of
four isolates of C. zemplinina and the control strain C. stellata CBS 157
T
were amplified and sequenced
to confirm the taxonomic separation of C. zemplinina from C. stellata. The amplified fragments of the
C. zemplinina strains had identical nucleotide sequences, which differed from the homologous sequence
of C. stellata 157Tat 39 positions (8.1% sequence difference).
C. zemplinina stand out against C. stellata for being osmotolerant and psychrotolerant and
thus could be better adapted to grow under high sugar concentrations and at low temperatures.
These physiological attributes can be especially favorable for propagating botrytized grape musts,
which normally contain high sugar content and are fermented at low temperatures, as in the case of
Tokaj wines generally below 15 ◦C.
7. Characteristics of Starmerella bombicola
Starmerella bombicola is the type species of genus Starmerella (Rosa and Lachance, 1998) [
48
].
The strain studied, CBS 6009 (type strain), was isolated from honey of bumble bee (Bombus sp.).
S. bombicola is the anamorph of C. bombicola and the synonym of Torulaspora bombicola and
C. bombicola [
59
]. On YM agar after 3 days at 25
◦
C, the cells are ovoidal to elongated,
1–2 ×2–4 µm
,
and occur singly and in pairs. The colonies are small, convex, and white and have an entire margin.
In glucose-yeast extract broth, a ring forms after 1 month. In Dalmau plate culture on corn meal
agar, pseudohyphae and true hyphae are not formed. Positive formation of ascospores after 1 day on
YCBAS (yeast carbon base, Difco, with. 0.01 % ammonium sulphate) agar mixed compatible mating
types fuse in pairs. After 3 days, the conjugated asci contained a single spherical ascospore with a
convoluted wall and a membranous basal ledge. The ascospores are released terminally and tend
to agglutinate. This species presents positive fermentation of glucose and sucrose, and variable to
raffinose. The fermentation of galactose, maltose, lactose, and trehalose is negative. It can grow on agar
media of glucose, ethanol, glycerol, and mannitol, and provides a positive answer to the additional
growth test of glucono-δ-lactone, cadaverine, 50% glucose, amino acid-free, and 30 ◦C CoQ 9.
This yeast had been previously assigned to other species now known to be members of
the Starmerella clade. This species shows the ability to excrete extracellular hydroxyl fatty acid
sophorosides. S. bombicola is associated with bees and flowers, with the bees as the principal
vector. Sophorolipid biosynthesis by S. bombicola may be industrially useful for the production
of biodegradation detergents [60].
To confirm the taxonomic affiliation of species of Candida deposited in DBVPG, their growth under
various conditions was studied. C. zemplinina and C. stellata differed from Candida strains deposited in
DBVPG with regard to temperature profile, osmotolerance, and greater sensitivity to ethanol compared
with these two Candida species. Comparing its electrophoretic karyotype, Candida-type strain differed
Fermentation 2018,4, 74 8 of 22
in the banding pattern; although both had three chromosomal bands, their chromosomes differed in
size, and the genome of C. zemplinina was smaller than the genome of C. stellata. The karyotype of
DBVPG 3827 was indistinguishable from that the karyotype of S. bombicola CBS 6009
T
, which only had
two bands, one of which corresponded in size to one of the Candida chromosomal bands.
Table 1shows the principal aspects that can help to distinguish between Candida stellata,
Candida zemplinina, and Starmerella bombicola to achieve a correct identification of these species.
Table 1.
Main differential characteristics of species Candida stellata (CBS 157), Candida zemplinina,
and Starmerella bombicola.
C. stellata (CBS 157) C. zemplinina S. bombicola
Growth in high sugar concentration + + +
Growth in botrytized grape berries −++ +
Growth in presence of 1% of acetic acid −+v1
Formation of ascospores − − +
Banding pattern (electrophoretic karyotype) 3 3 2
Chromosomal polymorphism yes no no
% D1/D2 sequence in difference with C. stellata
(CBS 157) 8.1 nd 2
MboI and DraI digestion distingue between
the species yes yes
CfoI, HaeIII, and HinfI digestion distingue
between the species yes yes
1v, variable; 2nd, not determined.
8. Characteristics of Starmerella bacillaris (synonym C. zemplinina)
Starmerella bacillaris (synonym Candida zemplinina) [
52
] is a non-Saccharomyces yeast, isolated for the
first time in Napa Valley (Napa, CA, USA) in 2002, under the name EJ1 [
7
]. This yeast is characterized
by ellipsoid to elongate cells upon growth in yeast malt agar. It ferments glucose, sucrose, and raffinose,
but not galactose, maltose, or lactose. It assimilates very few carbon and nitrogen sources, namely,
glucose and L-lysine, and it experiences no growth in the presence of high glucose concentration.
Additionally, it presents high fructophily, average volatile acidity and alcoholic degree production,
and high glycerol production [52].
Starm. bacillaris can be distinguished from the closely related species C. stellata by EST, G6PD,
ACP, LDH, and ADH isoenzymes profiles; restriction profiles of a region of 26S rDNA digested with
endonucleases HinfI, MseI, CfoI, and HaeIII clearly distinguish both species. The nucleotides sequence
of D1/D2 region of 26S rDNA of Starm. bacillaris shows an 8% difference at 39 positions [
52
] thereby
justifying the separation of the two species.
From the point of view of its enological application, this strain was able to ferment exclusively
the fructose from Chardonnay must without affecting the concentration of glucose. Starm. bacillaris
has since been reported to have a potentially important role in the winemaking industry, due to its
extremely fructophilic character and the poor ethanol yield from sugar consumed [61,62].
Starm. bacillaris presents other interesting characteristics, such as growth at high concentrations of
sugars and low temperatures [
11
,
63
] and production of low levels of acetic acid and acetaldehyde and
significant amounts of glycerol from consumed sugars [64].
9. Metabolic Features and By-Products from Candida stellata Activity
Candida spp. are found as food-associated and beverage-associated yeasts. In particular,
C. stellata has been typically isolated during must fermentation process in different wine regions
worldwide, where this yeast species is normally associated with the fermentation of botrytized
wines and other wines produced from overripe grapes in cooked musts and in traditional balsamic
vinegars
[2,3,28,38,65]
. Thus, there are several studies that allow one to better understand the metabolic
Fermentation 2018,4, 74 9 of 22
characteristics of Candida spp. with interesting applications in food and fermented beverages industries,
with special focus on wine elaboration.
9.1. Fructophilic Character
The strong fructophilic character of Candida is one of distinctive features of this yeast
genera. Several studies have described sugar depletion (glucose and fructose) during grape juice
fermentation [
10
,
64
,
66
–
68
]. All C. stellata strains studied in these works showed a significant lower
fermentation rate for glucose than the rate measured for the fructose. In the work with C. stellata CBS
2649 strain [
10
], the extreme fructophilic nature of this strain has been reported, since glucose was not
consumed until the fructose was completely depleted. Similar behavior was observed by
Mills et al. [7]
when studying a Candida sp. isolate (EJ1) in Chardonnay wine elaboration. However, it is still unknown
how preferential consumption of fructose can be beneficial, since vigorous growth on glucose has been
observed when this sugar is the only energy and carbon source available in fructophilic yeasts [
63
,
69
].
As previously observed in Zygosaccharomyces bailii [
70
] and Z. rouxii [
71
], Gonçalves et al. [
72
] have
noted the presence of the transporter Ffz1 as a prerequisite for fructophily in S. bombicola. This Ffz1
is a specific fructose transporter codified by FFZ1 gene [
73
]. The reason for the preferential use of
fructose by C. stellata may be result of a wider remodeling of central carbon metabolism, together with
an adaptation to high-sugar environment [72,74].
9.2. Alternative Carbon Metabolism: Glycerol Production
Glycerol can be used as food additive produced from fats and oils, from chemical synthesis, or by
microbial fermentation [
75
]. Glycerol biosynthesis is an important side-reaction of glycolysis pathway
produced by reduction of dihydroxyacetone phosphate (DHAP) to glycerol-3-phosphate (G3P) and by
dephosphorylation of G3P to glycerol (Figure 2). The first step of this conversion is catalyzed by the
enzyme NAD-dependent glycerol-3-phosphate dehydrogenase (Gpd) and, subsequently, the glycerol
is formed by glycerol-3-phosphatase (Gpp). The enzyme Gpd is encoded as two isoforms by the GPD1
and GPD2 genes [
76
]. Yeast growth under hyperosmotic stress situation leads to the expression of
GPD1 through the so-called HOG (High Osmolarity Glycerol) signaling pathway [
77
–
79
]. On the other
hand, GPD2 is believed to help maintain the cell’s intracellular redox balance.
As mentioned previously, C. stellata species exhibits unusual metabolism of sugar; it is usually
considered a facultatively fermentative yeast characterized by a very low fermentation rate and high
production of secondary metabolites as glycerol, acetaldehyde, acetoin, and succinic acid
[67,80]
.
In regard to glycerol formation, this behavior of C. stellata is probably owing to low alcohol
dehydrogenase activity (4-fold lesser than S. cerevisiae) and high glycerol-3-phosphate dehydrogenase
activity (40-fold higher than S. cerevisiae); thus, this higher Gpd activity causes a strong deviation
towards glycerol production [67] (Figure 2, in red).
Fermentation 2018,4, 74 10 of 22
Fermentation 2018, 4, 10 of 22
Figure 2. Glycerol biosynthesis in yeasts. Glycolysis and the reduction of intermediate DHAP to G3P,
followed by oxidation of NADH to NAD+ leads to glycerol formation (adapted from Scanes et al.
[81]).
In oenology, the glycerol content is appreciated, because it imparts some sensory attributes to
the wine. It is an important alcohol with a slightly sweet taste and viscous nature that contributes to
the smoothness, consistency, and overall body in wine [82,83]. Typically, glycerol concentration is
higher in red than in white wines ranging from 1 to 15 g/L. The threshold taste level of glycerol is
observed to 5.2 g/L in wine, whereas a change of viscosity is only perceived at 25 g/L of glycerol [84].
Also, it is known that its production is raised by the presence of sulfur dioxide, higher incubation
temperature, and high-sugar concentration, but it is significantly influenced by yeast strain and
species [85]. In particular, C. stellata has typically been described as glycerol producer in wine
elaboration [46,68,86,87]. Glycerol concentrations between 9 and 14 g/L have been reported in wines
elaborated with C. stellata, in contrast with lower amounts produced by S. cerevisiae monoculture
[46,64,87]. However, glycerol and ethanol content are inversely related; as consequence, the
tendency of C. stellata to form glycerol seems to be the reason for its low growth and fermentation
rate [67,81]. Other authors found an ethanol yield produced by C. stellata comparable with that of S.
uvarum/bayanus strains, although both produced significantly lower ethanol than S. cerevisiae [64]. By
contrast, Gobbi et al. [88] reported one C. stellata strain with an ethanol yield (9.09 g/100 mL) and
fermentative power (19 g CO2 evolved) without significant differences from S. cerevisiae (9.05 g/100
mL and 19.2 g CO2 evolved, respectively).
9.3. Biotechnological Application of Extracellular Enzymes Secreted by Candida stellata
Enzymes are the bio-catalysts that play an important role in metabolism and biochemical
reactions [89]. Microorganisms are the primary source of enzymes that have a more active and stable
nature than those of plants and animals [90]. Specifically, yeast strains with enzymatic activity could
be a potential source of commercial enzymes and an important factor with which to improve the
food and beverages processing. The Saccharomyces genus is not considered as a good producer of
exogenous enzymes. Instead, several non-Saccharomyces yeast species exhibit natural enzymatic
activities [91]. The enzymes of interest produced by these yeasts include esterases, lipases,
glycosidases, proteases, and cellulases usually related to hydrolysis of structural components [4,92].
Specifically, Candida spp. have been described as extracellular enzymes producer. The
enzymatic capacities of this non-Saccharomyces genus have been widely researched in oenology, as
Figure 2.
Glycerol biosynthesis in yeasts. Glycolysis and the reduction of intermediate DHAP to G3P,
followed by oxidation of NADH to NAD
+
leads to glycerol formation (adapted from Scanes et al. [
81
]).
In oenology, the glycerol content is appreciated, because it imparts some sensory attributes to
the wine. It is an important alcohol with a slightly sweet taste and viscous nature that contributes
to the smoothness, consistency, and overall body in wine [
82
,
83
]. Typically, glycerol concentration is
higher in red than in white wines ranging from 1 to 15 g/L. The threshold taste level of glycerol
is observed to 5.2 g/L in wine, whereas a change of viscosity is only perceived at 25 g/L of
glycerol [
84
]. Also, it is known that its production is raised by the presence of sulfur dioxide,
higher incubation temperature, and high-sugar concentration, but it is significantly influenced
by yeast strain and species [
85
]. In particular, C. stellata has typically been described as glycerol
producer in wine elaboration [
46
,
68
,
86
,
87
]. Glycerol concentrations between 9 and 14 g/L have been
reported in wines elaborated with C. stellata, in contrast with lower amounts produced by S. cerevisiae
monoculture [
46
,
64
,
87
]. However, glycerol and ethanol content are inversely related; as consequence,
the tendency of C. stellata to form glycerol seems to be the reason for its low growth and fermentation
rate [
67
,
81
]. Other authors found an ethanol yield produced by C. stellata comparable with that of
S. uvarum/bayanus strains, although both produced significantly lower ethanol than S. cerevisiae [
64
].
By contrast, Gobbi et al. [
88
] reported one C. stellata strain with an ethanol yield (9.09 g/100 mL) and
fermentative power (19 g CO
2
evolved) without significant differences from S. cerevisiae (9.05 g/100 mL
and 19.2 g CO2evolved, respectively).
9.3. Biotechnological Application of Extracellular Enzymes Secreted by Candida stellata
Enzymes are the bio-catalysts that play an important role in metabolism and biochemical
reactions [
89
]. Microorganisms are the primary source of enzymes that have a more active and
stable nature than those of plants and animals [
90
]. Specifically, yeast strains with enzymatic activity
could be a potential source of commercial enzymes and an important factor with which to improve
the food and beverages processing. The Saccharomyces genus is not considered as a good producer
of exogenous enzymes. Instead, several non-Saccharomyces yeast species exhibit natural enzymatic
activities [
91
]. The enzymes of interest produced by these yeasts include esterases, lipases, glycosidases,
proteases, and cellulases usually related to hydrolysis of structural components [4,92].
Fermentation 2018,4, 74 11 of 22
Specifically, Candida spp. have been described as extracellular enzymes producer. The enzymatic
capacities of this non-Saccharomyces genus have been widely researched in oenology, as they can
improve the process of winemaking and enhance wine quality [
93
,
94
]. However, it is well known that
the secretion of enzymes with technological interest is not characteristic of a particular genus or species
but depends specifically on yeast strain analyzed [
33
,
92
]. In the following paragraphs, a brief overview
will be given of enzymes used in oenology with a special focus on those produced by C. stellata.
9.3.1. Pectinases
Pectic substances are the major component of the plant cell wall and comprise a network in which
cellulose microfibrils are linked [
95
]. The high viscosity of pectin prevents juice extraction, clarification,
and filtration when it is dissolved after berry crushing. Furthermore, pectin impedes the phenolic and
aroma compounds’ diffusion into the must during wine fermentation [
94
]. Thus, pectinases such as
polygalacturonase, pectin lyase, pectin methyl esterase, and polygalactosidase have the capacity to
reduce the molecular size of pectin polymers by cleaving neutral side chain residues, facilitating the
pressing and filtration processes of wines and ciders [
96
,
97
]. In addition to their use in winemaking,
these enzymes are also utilized in oil extraction [
98
], coffee and cocoa curing [
99
], the extraction and
clarification of fruit juices, and the retting of textile fibers [100].
Several authors have reported the production of polygalacturonase and pectin methyl esterase by
Candida in wine [
4
,
101
,
102
]. In a study realized by Cordero-Bueso et al. [
103
], C. stellata CLI 920 strain,
which was isolated during spontaneous fermentation in Malvar (Vitis vinifera cv. L.) must, produced
the highest quantity of pectinases (polygalacturonases) in comparison with other non-Saccharomyces.
This pectinase activity of C. stellata CLI 920 could be correlated with the higher galacturonic acid
content observed into the oligosaccharides fraction of the wine produced with this strain alone [
104
].
Also, polygalactosidases enzymes produced by C. stellata together with exo and endoglucosidases are
important in the degradation of the β-glucans by Botrytis cinerea [2].
9.3.2. Proteases
Protein haze supposes the most common physical instability in white wine and fruit juices.
Proteases activity hydrolyzes the proteins into smaller stable molecules promoting clarification and
stabilization of beverages and helping to prevent stuck and sluggish fermentations due to low level
of assimilable nitrogen in the must [
101
,
105
]. Yeast producers of proteases can be a good substitute
with which to bentonite for removal undesirable wine proteins [
106
]. In the study of Strauss et al. [
4
],
38% of C. stellata yeast strains presented protease activity. Also, other works have recorded protease
activity in several strains of Candida species [101,107].
9.3.3. Cellulases and Hemicellulases
Hemicelluloses are a group of polysaccharides strongly bound to cellulose in plant cell walls.
In winemaking, cellulases (glucanases) and hemicellulases (xylanases) enzymes have an impact
on organoleptic properties of wine by promoting extraction of pigments and volatile compounds
from grape skins, thus improving the filtration and clarification processes and reducing the time of
maceration [
4
,
108
]. Only a few yeast strains have been known as major producers of these enzymes,
but Candida species have been reported as able to produce cellulases and hemicellulases [
4
,
102
,
109
,
110
].
9.3.4. Glycosidases
The organoleptic characteristics of beverages (taste and aroma) can be enhanced by
glycosidases that hydrolyse odourless and non-volatile glycosidic precursors of the fruits [
111
].
Glycosidase activities comprise
β
-D-glucosidase,
β
-D-xylosidase,
β
-D-apiosidase,
α
-L-rhamnosidase,
and
α
-L-arabinofuranosidase. The bound aroma complex includes glucosides and diglycosides,
and compounds such as terpenols, terpene diols, benzene derivatives, aliphatic alcohols, phenols, and C-13
norisoprenoids; additionally, the enzymatic hydrolysis of these sugar-conjugated precursors released
Fermentation 2018,4, 74 12 of 22
very aromatic volatile monoterpenes (aglycons) through two-step reaction [
112
]. Numerous works have
been based on glycosidase activities in yeasts of an oenological origin; in particular, some of them have
observed
β
-glucosidase activity in C. stellata strains possibly related to the fruity and floral aroma found in
the wines elaborated with these strains [4,87,103,113,114]. Hock et al. [115] had already documented the
terpenes production (
β
-myrcene, limonene, linalool,
α
-terpineol, and farnesol) of C. stellata. Another study
using one C. stellata strain isolated from Denomination of Origin (D.O.) “Vinos de Madrid” showed the
highest concentration of
β
-phenylethyl alcohol (roses) in wine compared to other Saccharomyces and
non-Saccharomyces strains analyzed [
87
]; the flowery and fruity aroma of pure culture with this C. stellata
strain could be related to
β
-glucosidase activity previously documented by Cordero-Bueso et al. [
103
].
Similar results were obtained by other authors [
105
,
116
]; they concluded that the use of C. stellata, alone or
combined with S. cerevisiae, enhanced the final quality and complexity of wines.
9.3.5. Invertases
Invertase enzyme, also known as
β
-D-fructofuranosidase, is commonly used in industries with
numerous applications as production of lactic acid [
117
], fermentation of sugarcane to ethanol [
118
],
and production of fructose syrup. Furthermore, it is employed in pharmaceutical industry,
child nutrition, and fortified wines [
119
]. These enzymes hydrolyse the glycosidic linkage from
sucrose in its respective monomers, glucose and fructose, to form “inverted sugar syrup” with
special characteristics: 40% sweeter than sucrose, stable at high temperatures, more soluble than
sucrose and higher point of boiling and lower of freezing [
119
]. Yeast production of these enzymes is
typically studied in S. cerevisiae [
120
]. Recently, Gargel et al. [
121
] have observed that one C. stellata
strain (N5) isolated from Brazilian grapes is a potential invertase producer. They propose this new
invertase as a promising catalytic agent for use in biotechnological processes in the food industry and
alcoholic fermentations.
9.4. Production of Sophorolipids Biosurfactants by Candida
The worldwide production of surfactants is about 10 million tons per year, divided between
domestic and laundry detergents and different industrial applications. Currently, the surfactants
are usually petroleum-derived, although the aim is to produce these compounds from renewable
substances. Sophorolipids (SLs), which are composed of sophorose (a dimeric sugar) linked to a
long-chain hydroxy fatty acid, are good candidates as surfactant product from renewable sources.
These molecules are produced in high concentrations by phylogenetically diverse group of yeasts [
122
],
and their biosynthesis is clearly influenced by aeration, initial glucose concentration, and pH
values [
123
,
124
]. SLs present two different forms: a closed lactone and an open acidic form. Each form
has different properties: Lactonic SLs have antimicrobial activity and are better in surface tension
reduction, while acidic SLs have better foaming attributes [122].
The yeast S. bombicola has been widely studied as a major producer of SLs together with Candida
apicola within Starmerella clade [
122
]. The highest C. bombicola (ATCC 22214) SL yield of 400 g/L was
obtained when corn oil and honey served as the carbon sources [
125
]; also, Cavalero and Cooper [
126
]
showed that the same strain synthetized SLs with antibacterial activity mainly against Gram-positive
bacteria. In a study with 19 species of Starmerella yeast clade [
123
], C. stellata NRRL Y-1446 strain from
Rovello bianco grape variety was one of 19 species with a significant production of SLs with 11.9 g/L
predominantly as di-O-acetyl free-acid form, plus lesser amounts of mono-O-acetyl and non-acetyl
SLs. Parekh et al. [
124
] obtained similar SLs concentration (18.2 g/L) using S. bombicola NRRL
Y-17069 and determining the optimal fermentation method to generate these surfactant compounds.
Recently, a novel lactone esterase enzyme from S. bombicola, which catalyzes the intramolecular
lactonization of acidic SLs in an aqueous environment, is being investigated to become an ecological
tool in industry applications [127].
Fermentation 2018,4, 74 13 of 22
10. Co-Fermentations between Candida stellata and Saccharomyces cerevisiae: A Way against
Standardized Wines
The use of co-fermentation strategies between non-Saccharomyces and S. cerevisiae yeast species in a
controlled manner can be a useful tool for wine production. Several aspects support this consideration,
such as
1.
Effect on some analytical compounds as increased glycerol concentration, enhanced total acidity,
and reduced acetic acid concentration of wine.
2. Enhancement of desirable aromatic compounds (esters, volatile thiols).
3. Reduction of final ethanol content of the wine.
4. Improvement of complexity and overall quality of wine.
5. Larger release of polysaccharides (mannoproteins).
In the last few years, the use of C. stellata yeast in multi-starter fermentations with S. cerevisiae
has been widely investigated for its ability to increase the glycerol content in wines and their special
fructophilic character [
66
], its capacity to contribute to greater aroma complexity of the wine [
128
],
and its capacity to minimize the risk of fermentation problems [
68
]. Ciani and Ferraro [
66
] carried out
mixed and sequential fermentations with C. stellata and S. cerevisiae; the final wines were rich in glycerol
and succinic acid, and with less alcohol and acetic acid in comparison with the mono-inoculated
S. cerevisiae control. Milanovic et al. [
68
] concluded that S. bombicola influenced the alcohol production
ability of S. cerevisiae under mixed inoculation, since pyruvate decarboxylase (Pdc1) activity in mixed
fermentation was lower than pure culture of S. cerevisiae, while alcohol dehydrogenase (Adh1) activity
showed opposite behavior.
The wines made through C. stellata/S. cerevisiae co-fermentations usually present higher aroma
complexity and overall quality. In a study using Malvar white grape [
87
], an autochthonous grape
variety from Madrid (Spain), different inoculation strategies were applied with C. stellata CLI 920
(Cs) and S. cerevisiae CLI 889 (Sc). Mixed and sequential were significantly different with regard to
their volatile composition and the control of S. cerevisiae. These wines were characterized by increased
esters concentration and
β
-phenylethyl alcohol (Figure 3). After sensory analysis, the sequential
inoculation was well appreciated by tasters for its pleasant fruity (green apple, grapefruit) and floral
aroma and its freshness and full-bodied on the palate. These results were corroborated by pilot scale
fermentations [26].
Fermentation 2018, 4, 13 of 22
10. Co-Fermentations between Candida stellata and Saccharomyces cerevisiae: A Way against
Standardized Wines
The use of co-fermentation strategies between non-Saccharomyces and S. cerevisiae yeast species
in a controlled manner can be a useful tool for wine production. Several aspects support this
consideration, such as
1. Effect on some analytical compounds as increased glycerol concentration, enhanced total
acidity, and reduced acetic acid concentration of wine.
2. Enhancement of desirable aromatic compounds (esters, volatile thiols).
3. Reduction of final ethanol content of the wine.
4. Improvement of complexity and overall quality of wine.
5. Larger release of polysaccharides (mannoproteins).
In the last few years, the use of C. stellata yeast in multi-starter fermentations with S. cerevisiae
has been widely investigated for its ability to increase the glycerol content in wines and their special
fructophilic character [66], its capacity to contribute to greater aroma complexity of the wine [128],
and its capacity to minimize the risk of fermentation problems [68]. Ciani and Ferraro [66] carried
out mixed and sequential fermentations with C. stellata and S. cerevisiae; the final wines were rich in
glycerol and succinic acid, and with less alcohol and acetic acid in comparison with the
mono-inoculated S. cerevisiae control. Milanovic et al. [68] concluded that S. bombicola influenced the
alcohol production ability of S. cerevisiae under mixed inoculation, since pyruvate decarboxylase
(Pdc1) activity in mixed fermentation was lower than pure culture of S. cerevisiae, while alcohol
dehydrogenase (Adh1) activity showed opposite behavior.
The wines made through C. stellata/S. cerevisiae co-fermentations usually present higher aroma
complexity and overall quality. In a study using Malvar white grape [87], an autochthonous grape
variety from Madrid (Spain), different inoculation strategies were applied with C. stellata CLI 920
(Cs) and S. cerevisiae CLI 889 (Sc). Mixed and sequential were significantly different with regard to
their volatile composition and the control of S. cerevisiae. These wines were characterized by
increased esters concentration and β-phenylethyl alcohol (Figure 3). After sensory analysis, the
sequential inoculation was well appreciated by tasters for its pleasant fruity (green apple, grapefruit)
and floral aroma and its freshness and full-bodied on the palate. These results were corroborated by
pilot scale fermentations [26].
0.00 5.00 10.00 15.00 20.00 25.00
β-Phenylethyl alcohol
Ethyl but yrate
Ethyl isovalerate
Ethyl hexanoate
Ethyl octanoate
Isoamyl acetate
p-Sc p-Cs m-Cs/Sc s-Cs/Sc
Figure 3. Relevant volatile compounds (mg/L) of pure (p), mixed (m), and sequential (s)
fermentations made with C. stellata CLI 920 (Cs) and S. cerevisiae CLI 889 (Sc) native strains (adapted
from García et al. [87]).
Figure 3.
Relevant volatile compounds (mg/L) of pure (p), mixed (m), and sequential (s) fermentations
made with C. stellata CLI 920 (Cs) and S. cerevisiae CLI 889 (Sc) native strains (adapted from
García et al. [87]).
Fermentation 2018,4, 74 14 of 22
In agreement with above, Soden et al. [
10
] described the aroma of banana, flowers, and lime in wines
conducted by sequential inoculation in comparison with the control of S. cerevisiae. Other works have also
shown the fruity and flowery aroma in cocultures between C. stellata and S. cerevisiae, which is the result
of greater concentration of desirable aromatic compounds including some higher alcohols;
β
-phenylethyl
alcohol and ethyl esters correlated well with its medium-chain fatty acids [26,64,105,116,129].
In recent years, multiples studies have focused on polysaccharides content in wines, giving special
attention to the mannoproteins. These molecules are one of the major polysaccharide groups in wines
from yeast cell walls [
130
], and they are secreted into wine during alcoholic fermentation and yeast
autolysis during ageing on lees [131]. Mannoproteins composition consists mainly of mannose (80 to
90%) and small amounts of glucose, associated with 10–20% of protein. Numerous investigations
have clearly confirmed that these macromolecules are related to technological and sensorial properties
in wines, such as prevention of protein haze in white wines [
132
], protection against crystallization
of tartrate salts [
133
], interaction with aroma compounds [
134
], improvement of foam stability and
flocculation in sparkling wines [
135
], reduction of astringency and increased body and mouthfeel [
136
],
and increase of the growth of malolactic bacteria [
137
]. Moreover, it has been noted that the utilization
of Saccharomyces/non-Saccharomyces co-fermentations results in increased release of polysaccharides
into the wine, since the high capacity of non-Saccharomyces wine yeasts to release polysaccharides
(including mannoproteins) has been verified [
104
,
138
–
140
]. Giovani et al. [
139
] characterized the
monosaccharide composition of mannoproteins produced by S. bombicola 3827; they noted that
the polysaccharides produced by S. bombicola were essentially mannoproteins with 73–74% of
mannose residues.
In the previously mentioned study [
87
] (Figure 3), the polysaccharides’ content and structure
were studied in Malvar wines elaborated with C. stellata CLI 920 and S. cerevisiae CLI 889. The greater
content of arabinose, galactose, and mannose in the total colloids means that mannoproteins from
yeast cell walls and Polysaccharides Rich in Arabinose and Galactose (PRAGs) were the main
macromolecules in Malvar wines regardless of the inoculation strategy used (Figure 4a). The high
content of galactose observed, especially in C. stellata pure culture (p-Cs), could also be explained by
the presence of this monosaccharide-like galactomannan in yeast cell walls, as in Schizosaccharomyces
pombe. However, a phylogenetic study with 33 species of Candida carried out by Suzuki et al. [
141
]
determined that the cell wall of C. stellata lacked galactose.
Fermentation 2018, 4, 14 of 22
In agreement with above, Soden et al. [10] described the aroma of banana, flowers, and lime in
wines conducted by sequential inoculation in comparison with the control of S. cerevisiae. Other
works have also shown the fruity and flowery aroma in cocultures between C. stellata and S.
cerevisiae, which is the result of greater concentration of desirable aromatic compounds including
some higher alcohols; β-phenylethyl alcohol and ethyl esters correlated well with its medium-chain
fatty acids [26,64,105,116,129].
In recent years, multiples studies have focused on polysaccharides content in wines, giving
special attention to the mannoproteins. These molecules are one of the major polysaccharide groups
in wines from yeast cell walls [130], and they are secreted into wine during alcoholic fermentation
and yeast autolysis during ageing on lees [131]. Mannoproteins composition consists mainly of
mannose (80 to 90%) and small amounts of glucose, associated with 10‒20% of protein. Numerous
investigations have clearly confirmed that these macromolecules are related to technological and
sensorial properties in wines, such as prevention of protein haze in white wines [132], protection
against crystallization of tartrate salts [133], interaction with aroma compounds [134], improvement
of foam stability and flocculation in sparkling wines [135], reduction of astringency and increased
body and mouthfeel [136], and increase of the growth of malolactic bacteria [137]. Moreover, it has
been noted that the utilization of Saccharomyces/non-Saccharomyces co-fermentations results in
increased release of polysaccharides into the wine, since the high capacity of non-Saccharomyces wine
yeasts to release polysaccharides (including mannoproteins) has been verified [104,138–140].
Giovani et al. [139] characterized the monosaccharide composition of mannoproteins produced by S.
bombicola 3827; they noted that the polysaccharides produced by S. bombicola were essentially
mannoproteins with 73‒74% of mannose residues.
In the previously mentioned study [87] (Figure 3), the polysaccharides’ content and structure
were studied in Malvar wines elaborated with C. stellata CLI 920 and S. cerevisiae CLI 889. The greater
content of arabinose, galactose, and mannose in the total colloids means that mannoproteins from
yeast cell walls and Polysaccharides Rich in Arabinose and Galactose (PRAGs) were the main
macromolecules in Malvar wines regardless of the inoculation strategy used (Figure 4a). The high
content of galactose observed, especially in C. stellata pure culture (p-Cs), could also be explained by
the presence of this monosaccharide-like galactomannan in yeast cell walls, as in Schizosaccharomyces
pombe. However, a phylogenetic study with 33 species of Candida carried out by Suzuki et al. [141]
determined that the cell wall of C. stellata lacked galactose.
0%
20%
40%
60%
80%
100%
p-Sc p-Cs m-Cs/Sc s-Cs/Sc
Rhamnose Arabinose Galactose Glucose Manno se
0%
20%
40%
60%
80%
100%
p-Sc p-Cs m-Cs/Sc s-Cs/Sc
2346 Mannose 346 Mannose 246 Mannose 3 4 Mannose
(a) (b)
Figure 4. Study of polysaccharides content and structure in Malvar wines elaborated under different
inoculation strategies with C. stellata and S. cerevisiae native strains *: (a) Glycosyl residue
composition of polysaccharides from Malvar white wines and (b) Glycosil-linkage composition of
mannose residue isolated from Malvar white wines. * Abbreviations associated with type of
fermentation and yeast strains are explained in Figure 3.
Mannose residues are larger in C. stellata/S. cerevisiae sequential fermentation (s-Cs/Sc) than
control (Figure 4a); s-Cs/Sc could be the best combination for mannoproteins release into the wine
using these yeast strains. Other studies also showed that mixed inoculations with C. zemplinina/S.
Figure 4.
Study of polysaccharides content and structure in Malvar wines elaborated under different
inoculation strategies with C. stellata and S. cerevisiae native strains *: (
a
) Glycosyl residue composition
of polysaccharides from Malvar white wines and (
b
) Glycosil-linkage composition of mannose residue
isolated from Malvar white wines. * Abbreviations associated with type of fermentation and yeast
strains are explained in Figure 3.
Mannose residues are larger in C. stellata/S. cerevisiae sequential fermentation (s-Cs/Sc) than control
(Figure 4a); s-Cs/Sc could be the best combination for mannoproteins release into the wine using
Fermentation 2018,4, 74 15 of 22
these yeast strains. Other studies also showed that mixed inoculations with
C. zemplinina/S. cerevisiae
supposed an increase of polysaccharides mainly mannoproteins in the final wines [
142
,
143
]. Regarding the
structure of mannose residues from mannoproteins (Figure 4b), these results are consistent with the
Candida mannoproteins structure described by Ballou [
144
]. The structure of mannoproteins consists of a
6-linked backbone, substituted on the 2-position with 2- and 3- linked mannose. This 3-linked mannose
(2,4,6-tri-O-mannose) proportion is substantially lower in p-Cs than in the control, which agrees with the
results previously reported [
144
]. The high proportion of 3,4,6-tri-O-methyl mannose (2-linked mannose)
in p-Cs can be observed in comparison with the control (p-Sc); therefore, the C. stellata mannoproteins
released into the wine present a greater branched structure than those released by the control (Figure 4b).
Also, sequential fermentation contained mannoproteins structurally similar to those in the monoculture
with C. stellata. This could be explained by the important contribution of C. stellata strain to wine
composition before the inoculation of S. cerevisiae strain.
11. Conclusions
At present, a preliminary genetic study needs to be used before the application of Candida stellata
in food and beverage processing. This research should help to distinguish it from other closely related
species within Starmerella clade.
Author Contributions:
M.G.: revision of articles, writing, and editing; B.E.-Z.: revision and critical reading;
J.M.C.: revision and critical reading; and T.A.: revision of articles, writing, and editing.
Funding: This research received no external funding.
Conflicts of Interest: The authors declare no conflict of interest.
References
1.
Lachance, M.A.; Boekhout, T.; Scorzetti, G.; Fell, J.W.; Kurtzman, C.P. Candida Berkhout (1923). In The Yeasts;
Kurtzman, C.P., Fell, J.W., Boekhout, T., Eds.; Elsevier, B.V.: Amsterdam, The Netherlands, 2011; pp. 987–1278.
ISBN 9780444521491.
2.
Hommel, R.K. Candida: Introduction. In Encyclopedia of Food Microbiology: Second Edition; Batt, C.A.,
Tortorello, M.L., Eds.; Elsevier: London, UK, 2014; pp. 367–373. ISBN 9780123847331.
3.
Van Bogaert, I.N.A.; Zhang, J.; Soetaert, W. Microbial synthesis of sophorolipids. Process Biochem.
2011
,46,
821–833. [CrossRef]
4.
Strauss, M.L.A.; Jolly, N.P.; Lambrechts, M.G.; van Rensburg, P. Screening for the production of extracellular
hydrolytic enzymes by non-Saccharomyces wine yeasts. J. Appl. Microbiol.
2001
,91, 182–190. [CrossRef]
[PubMed]
5.
Günther, C.S.; Goddard, M.R. Do yeasts and Drosophila interact just by chance? Fungal Ecol.
2018
. [CrossRef]
6.
Pretorius, I.S.; van der Westhuizen, T.J.; Augustyn, O.P.H. Yeast biodiversity in vineyards and wineries and
its importance to the South African wine industry. S. Afr. J. Enol. Vitic. 1999,20, 61–75. [CrossRef]
7.
Mills, D.A.; Johannsen, E.A.; Cocolin, L. Yeast diversity and persistence in botrytis-affected wine
fermentations. Appl. Environ. Microbiol. 2002,68, 4884–4893. [CrossRef] [PubMed]
8.
Mora, J.; Mulet, A. Effects of some treatments of grape juice on the population and growth of yeast species
during fermentation. Am. J. Enol. Vitic. 1991,42, 133–136.
9.
Antunovics, Z.; Csoma, H.; Sipiczki, M. Molecular and genetic analysis of the yeast flora of botrytized Tokaj
wines. Bull. O.I.V. 2003,76, 380–397.
10.
Soden, A.; Francis, I.L.; Oakey, H.; Henschke, P.A. Effects of co-fermentation with Candida stellata and
Saccharomyces cerevisiae on the aroma and composition of Chardonnay wine. Aust. J. Grape Wine Res.
2000
,6,
21–30. [CrossRef]
11.
Sipiczki, M. Candida zemplinina sp. nov., an osmotolerant and psychrotolerant yeast that ferments sweet
botrytized wines. Int. J. Syst. Evol. Microbiol. 2003,53, 2079–2083. [CrossRef] [PubMed]
12.
Sipiczki, M. Species identification and comparative molecular and physiological analysis of Candida
zemplinina and Candida stellata.J. Basic Microbiol. 2004,44, 471–479. [CrossRef] [PubMed]
Fermentation 2018,4, 74 16 of 22
13.
Csoma, H.; Sipiczki, M. Taxonomic reclassification of Candida stellata strains reveals frequent occurrence of
Candida zemplinina in wine fermentation. FEMS Yeast Res. 2008,8, 328–336. [CrossRef] [PubMed]
14.
Boulton, R.B.; Singleton, V.L.; Bisson, L.F.; Kunkee, R.E. Principles and Practices of Winemaking;
Chapman & Hall
:
New York, NY, USA, 1996.
15. Fuselsang, K.C. Wine Microbiology; Chapman & Hall: New York, NY, USA, 1997.
16.
Pramateftaki, P.V.; Lanaridis, P.; Typas, M.A. Molecular identification of wine yeasts at species or strain
level: A case study with strains from two vine-growing areas of Greece. J. Appl. Microbiol.
2000
,89, 236–248.
[CrossRef] [PubMed]
17.
Valente, P.; Gouveia, F.C.; De Lemos, G.A.; Pimentel, D.; Van Elsas, J.D.; Mendonça-Hagler, L.C.; Hagler, A.N.
PCR amplification of the rDNA internal transcribed spacer region for differentiation of Saccharomyces cultures.
FEMS Microbiol. Lett. 1996,137, 253–256. [CrossRef] [PubMed]
18.
Guillamón, M.; Sabat, J.; Barrio, E.; Cano, J.; Querol, A. Rapid identification of wine yeast species based on
RFLP analysis of the ribosomal internal transcribed spacer (ITS) region. Arch. Microbiol.
1998
,169, 387–392.
[CrossRef] [PubMed]
19.
Esteve-Zarzoso, B.; Belloch, C.; Uruburu, F.; Querol, A. Identification of yeasts by RFLP analysis of the 5.8S
rRNA gene and the two ribosomal internal transcribed spacers. Int. J. Syst. Bacteriol.
1999
,49, 329–337.
[CrossRef] [PubMed]
20.
Cocolin, L.; Bisson, L.F.; Mills, D.A. Direct profiling of the yeast dynamics in wine fermentations.
FEMS Microbiol. Lett. 2000,189, 81–87. [CrossRef] [PubMed]
21.
Cocolin, L.; Heisey, A.; Mills, D.A. Direct identification of the indigenous yeasts in commercial wine
fermentations. Am. J. Enol. Vitic. 2001,52, 49–53.
22.
López, V.; Fernández-Espinar, M.T.; Barrio, E.; Ramón, D.; Querol, A. A new PCR-based method for
monitoring inoculated wine fermentations. Int. J. Food Microbiol. 2003,81, 63–71. [CrossRef]
23.
Cocolin, L.; Mills, D.A. Wine yeast inhibition by sulfur dioxide: A comparison of culture-dependent and
independent methods. Am. J. Enol. Vitic. 2003,54, 125–130.
24.
Vitzthum, F.; Bernhagen, J. SYBR Green I: An ultrasensitive fluorescent dye for double-stranded DNA
quantification in solution and other applications. Recent Res. Devel. Anal. Biochem. 2002,2, 65–93.
25.
Phister, T.G.; Mills, D. A Real-time PCR assay for detection and enumeration of Dekkera bruxellensis in wine.
Appl. Environ. Microbiol. 2003,69, 7430–7434. [CrossRef] [PubMed]
26.
García, M.; Esteve-Zarzoso, B.; Crespo, J.; Cabellos, J.M.; Arroyo, T. Yeast monitoring of wine mixed or
sequential fermentations made by native strains from D.O. “Vinos de Madrid” using real-time quantitative
PCR. Front. Microbiol. 2017,8. [CrossRef] [PubMed]
27.
Minarik, E.; Hanikova, A. Die hefeflora konzentrierer traubenermoste und deren einfluss auf die stabilitat
der weine. Wein-Wissen 1982,3, 187–192.
28.
Rosini, G.; Federici, F.; Martini, A. Yeast flora of grape berries during ripening. Microb. Ecol.
1982
,8, 83–89.
[CrossRef] [PubMed]
29.
Fleet, G.H. Evolution of yeasts and lactic acid bacteria during fermentation and storage of Bordeaux wines.
Appl. Environ. Microbiol. 1984,48, 1034–1038. [PubMed]
30.
Pardo, I.; Garcia, M.I.; Zuniga, M.; Uruburu, F. Dynamics of microbial populations during fermentation of
wine from the Utiel-Requena region of Spain. Appl. Environ. Microbiol. 1989,50, 539–541.
31.
Holloway, P.; van Twest, R.A.; Subden, R.E.; Lachance, M.A. A strain of Candida stellata of special interest to
oenologists. Food Res. Int. 1992,25, 147–149. [CrossRef]
32.
Constanti, M.; Poblet, M.; Arola, L.; Mas, A.; Guillamón, J.M. Analysis of yeast populations during alcoholic
fermentation in a newly established winery. Am. J. Enol. Vitic. 1997,48, 339–344.
33.
Fernández, M.T.; Úbeda, J.F.; Briones, A.I. Comparative study of non-Saccharomyces microflora of musts in
fermentation, by physiological and molecular methods. FEMS Microbiol. Lett.
1999
,173, 223–229. [CrossRef]
34.
Torija, M.J.; Rozès, N.; Poblet, M.; Guillamón, J.M.; Mas, A. Yeast population dynamics in spontaneous
fermentations: Comparison between two different wine-producing areas over a period of three years.
Antonie Van Leeuwenhoek 2001,79, 345–352. [CrossRef] [PubMed]
35.
Clemente-Jiménez, J.M.; Mingorance-Cazorla, L.; Martínez-Rodríguez, S.; Las Heras-Vázquez, F.J.;
Rodríguez-Vico, F. Molecular characterization and oenological properties of wine yeasts isolated during
spontaneous fermentation of six varieties of grape must. Food Microbiol. 2004,21, 149–155. [CrossRef]
Fermentation 2018,4, 74 17 of 22
36.
Combina, M.; Elía, A.; Mercado, L.; Catania, C.; Ganga, A.; Martínez, C. Dynamics of indigenous yeast
populations during spontaneous fermentation of wines from Mendoza, Argentina. Int. J. Food Microbiol.
2005,99, 237–243. [CrossRef] [PubMed]
37.
Divol, B.; Lonvaud-Funel, A. Evidence for viable but nonculturable yeasts in botrytis-affected wine.
J. Appl. Microbiol. 2005,99, 85–93. [CrossRef] [PubMed]
38.
Hierro, N.; González, Á.; Mas, A.; Guillamón, J.M. Diversity and evolution of non-Saccharomyces yeast
populations during wine fermentation: Effect of grape ripeness and cold maceration. FEMS Yeast Res.
2006
,
6, 102–111. [CrossRef] [PubMed]
39.
Mora, J.; Barbas, J.I.; Mulet, A. Growth of yeast species during the fermentation of musts inoculated with
Kluyveromyces thermotolerans and Saccharomyces cerevisiae.Am. J. Enol. Vitic. 1990,41, 156–159.
40.
Povhe Jemec, K.; Raspor, P. Initial Saccharomyces cerevisiae concentration in single or composite cultures
dictates bioprocess kinetics. Food Microbiol. 2005,22, 293–300. [CrossRef]
41.
Xufre, A.; Albergaria, H.; Inácio, J.; Spencer-Martins, I.; Gírio, F. Application of fluorescence in situ
hybridisation (FISH) to the analysis of yeast population dynamics in winery and laboratory grape must
fermentations. Int. J. Food Microbiol. 2006,108, 376–384. [CrossRef] [PubMed]
42.
Jackson, R.S. Wine Science-Principles, Practice, Perception, 2nd ed.; Academic Press: San Diego, CA, USA, 2000.
43.
Šipiczki, M.; Ciani, M.; Csoma, H. Taxonomic reclassification of Candida stellata DBVPG 3827.
Folia Microbiol. (Praha) 2005,50, 494–498. [CrossRef] [PubMed]
44.
Englezos, V.; Giacosa, S.; Rantsiou, K.; Rolle, L.; Cocolin, L. Starmerella bacillaris in winemaking: Opportunities
and risks. Curr. Opin. Food Sci. 2017,17, 30–35. [CrossRef]
45.
Soles, R.M.; Ough, C.S.; Kunkee, R.E. Ester concentration differences in wine fermented by various species
and strains of yeasts. Am. J. Enol. Vitic. 1982,33, 94–98.
46.
Ciani, M.; Ferraro, L. Enhanced glycerol content in wines made with immobilized Candida stellata cells.
Appl. Environ. Microbiol. 1996,62, 128–132. [PubMed]
47.
Ciani, M.; Maccarelli, F. Oenological properties of non-Saccharomyces yeasts associated with wine-making.
World J. Microbiol. Biotechnol. 1998,14, 199–203. [CrossRef]
48.
Rosa, C.A.; Lachance, M.A. The yeast genus Starmerella gen. nov. and Starmerella bombicola sp. nov.,
the teleomorph of Candida bombicola (Spencer, Gorin & Tullock) Meyer & Yarrow. Int. J. Syst. Bacteriol.
1998
,
48, 1413–1417. [CrossRef] [PubMed]
49.
Barbe, J.C.; De Revel, G.; Joyeux, A.; Bertrand, A.; Lonvaud-Funel, A. Role of botrytized grape
micro-organisms in SO2binding phenomena. J. Appl. Microbiol. 2001,90, 34–42. [CrossRef] [PubMed]
50.
Coton, E.; Coton, M.; Levert, D.; Casaregola, S.; Sohier, D. Yeast ecology in French cider and black olive
natural fermentations. Int. J. Food Microbiol. 2006,108, 130–135. [CrossRef] [PubMed]
51.
McNeill, J.; Barrie, F.; Buck, W.; Demoulin, V.; Greuter, W.; Hawkworth, D.L.; Herendeen, P.; Knapp, S.;
Marhold, K.; Prado, J.; et al. International Code of Nomenclature for Algae, Fungi and Plants; Regnum Vegetabile:
Melbourne, Australia, 2012.
52.
Duarte, F.L.; Pimentel, N.H.; Teixeira, A.; Fonseca, A. Saccharomyces bacillaris is not a synonym of Candida
stellata: Reinstatement as Starmerella bacillaris comb. nov. Antonie van Leeuwenhoek
2012
,102, 653–658.
[CrossRef] [PubMed]
53.
Nielsen, D.S.; Hønholt, S.; Tano-Debrah, K.; Jespersen, L. Yeast populations associated with Ghanaian cocoa
fermentations analysed using denaturing gradient gel electrophoresis (DGGE). Yeast
2005
,22, 271–284.
[CrossRef] [PubMed]
54.
Nielsen, D.S.; Teniola, O.D.; Ban-Koffi, L.; Owusu, M.; Andersson, T.S.; Holzapfel, W.H. The microbiology of
Ghanaian cocoa fermentations analysed using culture-dependent and culture-independent methods. Int. J.
Food Microbiol. 2007,114, 168–186. [CrossRef] [PubMed]
55.
Lachance, M.A.; Starmer, W.T.; Rosa, C.A.; Bowles, J.M.; Barker, J.S.F.; Janzen, D.H. Biogeography of the
yeasts of ephemeral flowers and their insects. FEMS Yeast Res. 2001,1, 1–8. [CrossRef] [PubMed]
56.
Loureiro, V.; Malfeito-Ferreira, M. Spoilage yeasts in the wine industry. Int. J. Food Microbiol.
2003
,86, 23–50.
[CrossRef]
57.
Puig, S.; Querol, A.; Barrio, E.; Pérez-Ortín, J.E. Mitotic recombination and genetic changes in Saccharomyces
cerevisiae during wine fermentation. Appl. Environ. Microbiol. 2000,66, 8–13. [CrossRef]
Fermentation 2018,4, 74 18 of 22
58.
Kurtzman, C.P.; Robnett, C.J. Identification and phylogeny of ascomycetous yeasts from analysis of nuclear
large subunit (26S) ribosomal DNA partial sequences. Antonie Van Leeuwenhoek
1998
,73, 331–371. [CrossRef]
[PubMed]
59.
Yarrow, D.; Meyer, S.A. Proposal for amendment of the diagnosis of the genus Candida Berkhout nom. cons.
Int. J. Syst. Bacteriol. 1978,28, 611–615. [CrossRef]
60.
de Koster, C.G.; Heerma, W.; Pepermans, H.A.M.; Groenewegen, A.; Peters, H.; Haverkamp, J. Tandem mass
spectrometry and nuclear magnetic resonance spectroscopy studies of Candida bombicola sophorolipid and
product formed on hydrolysis by cutinase. Anal. Biochem. 1995,230, 135–148. [CrossRef] [PubMed]
61.
Pfliegler, W.P.; Horváth, E.; Kállai, Z.; Sipiczki, M. Diversity of Candida zemplinina isolates inferred from
RAPD, micro/minisatellite and physiological analysis. Microbiol. Res.
2014
,169, 402–410. [CrossRef]
[PubMed]
62.
Englezos, V.; Rantsiou, K.; Torchio, F.; Rolle, L.; Gerbi, V.; Cocolin, L. Exploitation of the non-Saccharomyces
yeast Starmerella bacillaris (synonym Candida zemplinina) in wine fermentation: Physiological and molecular
characterizations. Int. J. Food Microbiol. 2015,199, 33–40. [CrossRef] [PubMed]
63.
Tofalo, R.; Schirone, M.; Torriani, S.; Rantsiou, K.; Cocolin, L.; Perpetuini, G.; Suzzi, G. Diversity of Candida
zemplinina strains from grapes and Italian wines. Food Microbiol. 2012,29, 18–26. [CrossRef] [PubMed]
64.
Magyar, I.; Tóth, T. Comparative evaluation of some oenological properties in wine strains of Candida stellata,
Candida zemplinina,Saccharomyces uvarum and Saccharomyces cerevisiae.Food Microbiol.
2011
,28, 94–100.
[CrossRef] [PubMed]
65.
Solieri, L.; Landi, S.; De Vero, L.; Giudici, P. Molecular assessment of indigenous yeast population from
traditional balsamic vinegar. J. Appl. Microbiol. 2006,101, 63–71. [CrossRef] [PubMed]
66.
Ciani, M.; Ferraro, L. Combined use of immobilized Candida stellata cells and Saccharomyces cerevisiae to
improve the quality of wines. J. Appl. Microbiol. 1998,85, 247–254. [CrossRef] [PubMed]
67.
Ciani, M.; Ferraro, L.; Fatichenti, F. Influence of glycerol production on the aerobic and anaerobic growth of
the wine yeast Candida stellata.Enzyme Microb. Technol. 2000,27, 698–703. [CrossRef]
68.
Milanovic, V.; Ciani, M.; Oro, L.; Comitini, F. Starmerella bombicola influences the metabolism of Saccharomyces
cerevisiae at pyruvate decarboxylase and alcohol dehydrogenase level during mixed wine fermentation.
Microb. Cell Fact. 2012,3, 11–18. [CrossRef] [PubMed]
69.
Alves-Araújo, C.; Pacheco, A.; Almeida, M.J.; Spencer-Martins, I.; Leão, C.; Sousa, M.J. Sugar utilization
patterns and respiro-fermentative metabolism in the baker’s yeast Torulaspora delbrueckii.Microbiology
2007
,
153, 898–904. [CrossRef] [PubMed]
70.
Pina, C.; Gonçalves, P.; Prista, C.; Loureiro-Dias, M.C. Ffz1, a new transporter specific for fructose from
Zygosaccharomyces bailii.Microbiology 2004,150, 2429–2433. [CrossRef] [PubMed]
71.
Leandro, M.J.; Cabral, S.; Prista, C.; Loureiro-Dias, M.C.; Sychrová, H. The high-capacity specific fructose
facilitator ZrFfz1 is essential for the fructophilic behavior of Zygosaccharomyces rouxii CBS 732T. Eukaryot. Cell
2014,13, 1371–1379. [CrossRef] [PubMed]
72.
Gonçalves, C.; Wisecaver, J.H.; Kominek, J.; Salema-Oom, M.; Leandro, M.J.; Shen, X.-X.; Opulente, D.;
Zhou, X.; Peris, D.; Kurtzman, C.P.; et al. Evidence for loss and adaptive reacquisition of alcoholic
fermentation in an early-derived fructophilic yeast lineage. Elife 2018,7, e33034. [CrossRef] [PubMed]
73.
Gonçalves, C.; Coelho, M.A.; Salema-Oom, M.; Gonçalves, P. Stepwise functional evolution in a fungal sugar
transporter family. Mol. Biol. Evol. 2016,33, 352–366. [CrossRef] [PubMed]
74.
Flores, C.L.; Rodriguez, C.; Petit, T.; Gancedo, C. Carbohydrate and energy-yielding metabolism in
non-conventional yeasts. FEMS Microbiol. Rev. 2000,24, 507–529. [CrossRef]
75.
Mortensen, A.; Aguilar, F.; Crebelli, R.; Di Domenico, A.; Dusemund, B.; Frutos, M.J.; Galtier, P.; Gott, D.;
Gundert-Remy, U.; Leblanc, J.; et al. Re-evaluation of glycerol (E 422) as a food additive. EFSA J.
2017
,15.
[CrossRef]
76.
Eriksson, P.; Andre, L.; Ansell, R.; Blomberg, A.; Alder, L. Cloning and characterization of GPD2,
a second gene encoding sn-glycerol 3-phosphate dehydrogenase (NAD
+
) in Saccharomyces cerevisiae, and its
comparison with GPD1. Mol. Microbiol. 1995,17, 95–107. [CrossRef] [PubMed]
77.
Hohmann, S. Osmotic stress signalling and osmoadaptation in yeasts. Microbiol. Mol. Biol. Rev.
2002
,66,
300–372. [CrossRef] [PubMed]
Fermentation 2018,4, 74 19 of 22
78.
Dihazi, H.; Kessler, R.; Eschrich, K. High osmolarity glycerol (HOG) pathway-induced phosphorylation and
activation of 6-phosphofructo-2-kinase are essential for glycerol accumulation and yeast cell proliferation
under hyperosmotic stress. J. Biol. Chem. 2004,279, 23961–23968. [CrossRef] [PubMed]
79.
Rodríguez-Peña, J.M.; García, R.; Nombela, C.; Arroyo, J. The high-osmolarity glycerol (HOG) and cell wall
integrity (CWI) signalling pathways interplay: A yeast dialogue between MAPK routes. Yeast
2010
,27,
495–502. [CrossRef] [PubMed]
80.
Ciani, M. Wine vinegar production using base wines made with different yeast species. J. Sci. Food Agric.
1998,78, 290–294. [CrossRef]
81.
Scanes, K.T.; Hohmann, S.; Prior, B.A. Glycerol production by the yeast Saccharomyces cerevisiae and its
relevance to wine: A review. S. Afr. J. Enol. Vitic. 1998,19, 17–24. [CrossRef]
82.
Prior, B.A.; Toh, T.H.; Jolly, N.; Baccari, C.; Mortimer, R.K. Impact of yeast breeding for elevated glycerol
production on fermentative activity and metabolite formation in Chardonnay wine. S. Afr. J. Enol. Vitic.
2000,21, 92–99. [CrossRef]
83.
Pretorius, I.S. Tailoring wine yeast for the new millennium: Novel approaches to the ancient art of
winemaking. Yeast 2000,16, 675–729. [CrossRef]
84.
Noble, A.C.; Bursick, G.F. The contribution of glycerol to perceived viscosity and sweetness in white wine.
Am. J. Enol. Vitic. 1984,35, 110–112.
85.
Fleet, G.H. Wine. In Food Microbiology: Fundamentals and Frontiers; Doyle, M.P., Beuchat, L.R., Eds.; ASM Press:
Washington, DC, USA, 2007; pp. 863–890.
86.
Ferraro, L.; Fatichenti, F.; Ciani, M. Pilot scale vinification process using immobilized Candida stellata cells
and Saccharomyces cerevisiae.Process Biochem. 2000,35, 1125–1129. [CrossRef]
87.
García, M.; Arroyo, T.; Crespo, J.; Cabellos, J.M.; Esteve-Zarzoso, B. Use of native non-Saccharomyces strain:
A. new strategy in D.O. “Vinos de Madrid” (Spain) wines elaboration. Eur. J. Food Sci. Technol.
2017
,5, 1–31.
88.
Gobbi, M.; De Vero, L.; Solieri, L.; Comitini, F.; Oro, L.; Giudici, P.; Ciani, M. Fermentative aptitude of
non-Saccharomyces wine yeast for reduction in the ethanol content in wine. Eur. Food Res. Technol.
2014
,239,
41–48. [CrossRef]
89.
Nigam, P.S. Microbial enzymes with special characteristics for biotechnological applications. Biomolecules
2013,3, 597–611. [CrossRef] [PubMed]
90.
Anbu, P.; Gopinath, S.C.B.; Chaulagain, B.P.; Lakshmipriya, T. Microbial enzymes and their applications in
industries and medicine 2016. Biomed. Res. Int. 2017. [CrossRef] [PubMed]
91.
Pando Bedriñana, R.; Lastra Queipo, A.; Suárez Valles, B. Screening of enzymatic activities in
non-Saccharomyces cider yeasts. J. Food Biochem. 2012,36, 683–689. [CrossRef]
92.
Maturano, Y.P.; Rodríguez, L.A.; Toro, M.E.; Nally, M.C.; Vallejo, M.; Castellanos de Figueroa, L.I.;
Combina, M.; Vazquez, F. Multi-enzyme production by pure and mixed cultures of Saccharomyces and
non-Saccharomyces yeasts during wine fermentation. Int. J. Food Microbiol.
2012
,155, 43–50. [CrossRef]
[PubMed]
93.
Esteve-Zarzoso, B.; Manzanares, P.; Ramón, D.; Querol, A. The role of non-Saccharomyces yeasts in industrial
winemaking. Int. Microbiol. 1998,1, 143–148. [CrossRef] [PubMed]
94.
Claus, H.; Mojsov, K. Enzymes for wine fermentation: Current and perspective applications. Fermentation
2018,4, 52. [CrossRef]
95.
Carpita, N.C.; Gibeaut, D.M. Structural models of primary cell walls in flowering plants: Consistency of
molecular structure with the physical properties of the walls during growth. Plant J.
1993
,3, 1–30. [CrossRef]
[PubMed]
96.
Canal-Llaubères, R.-M. Enzymes in winemaking. In Wine Microbiology and Biotechnology; Fleet, G.H., Ed.;
Harwood Academic Publishers: Chur, Switzerland, 1993; pp. 477–506.
97.
Hadfield, K.A.; Bennett, A.B. Polygalacturonases: Many genes in search of a function. Plant Physiol.
1998
,
117, 337–343. [CrossRef] [PubMed]
98.
Grassin, C.; Fauquembergue, P. Application of pectinases in beverages. In Pectin and pectinases; Visser, J.,
Voragen, A.G.J., Eds.; Elsevier: Amsterdam, The Netherlands, 1996; pp. 453–462.
99.
Boccas, F.; Roussos, S.; Gutiérrez, M.; Serrano, L.; Viniegra, G.G. Production of pectinase from coffee pulp in
solid-state fermentation system-selection of wild fungal isolate of high potency by a simple 3-step screening
technique. J. Food Sci. Technol. 1994,31, 22–26.
Fermentation 2018,4, 74 20 of 22
100.
Evans, J.D.; Akin, D.E.; Foulk, J.A. Flax-retting by polygalacturonase-containing enzyme mixtures and effects
on fiber properties. J. Biotechnol. 2002,97, 223–231. [CrossRef]
101.
Fernández, M.; Úbeda, J.F.; Briones, A.I. Typing of non-Saccharomyces yeasts with enzymatic activities of
interest in wine-making. Int. J. Food Microbiol. 2000,59, 29–36. [CrossRef]
102.
Merín, M.G.; Martín, M.C.; Rantsiou, K.; Cocolin, L.; De Ambrosini, V.I.M. Characterization of pectinase
activity for enology from yeasts occurring in Argentine Bonarda grape. Braz. J. Microbiol.
2015
,46, 815–823.
[CrossRef] [PubMed]
103.
Cordero-Bueso, G.; Esteve-Zarzoso, B.; Cabellos, J.M.; Gil-Díaz, M.; Arroyo, T. Biotechnological potential of
non-Saccharomyces yeasts isolated during spontaneous fermentations of Malvar (Vitis vinifera cv. L.). Eur. Food
Res. Technol. 2013,236, 193–207. [CrossRef]
104.
García, M.; Apolinar-Valiente, R.; Williams, P.; Esteve-Zarzoso, B.; Arroyo, T.; Crespo, J.; Doco, T.
Polysaccharides and oligosaccharides produced on Malvar wines elaborated with Torulaspora delbrueckii CLI
918 and Saccharomyces cerevisiae CLI 889 native yeasts from D.O. “Vinos de Madrid”. J. Agric. Food Chem.
2017,65, 6656–6664. [CrossRef]
105.
Andorrà, I.; Berradre, M.; Rozès, N.; Mas, A.; Guillamón, J.M.; Esteve-Zarzoso, B. Effect of pure and mixed
cultures of the main wine yeast species on grape must fermentations. Eur. Food Res. Technol.
2010
,231,
215–224. [CrossRef]
106.
Theron, L.W.; Divol, B. Microbial aspartic proteases: Current and potential applications in industry.
Appl. Microbiol. Biotechnol. 2014,98, 8853–8868. [CrossRef] [PubMed]
107. Dizy, M.; Bisson, L.F. Proteolytic activity of yeast strains during grape juice fermentation. Am. J. Enol. Vitic.
2000,51, 155–167.
108.
Romero-Cascales, I.; Fernández-Fernández, J.I.; Ros-García, J.M.; López-Roca, J.M.; Gómez-Plaza, E.
Characterisation of the main enzymatic activities present in six commercial macerating enzymes and
their effects on extracting colour during winemaking of Monastrell grapes. Int. J. Food Sci. Technol.
2008
,43,
1295–1305. [CrossRef]
109.
Capozzi, V.; Garofalo, C.; Chiriatti, M.A.; Grieco, F.; Spano, G. Microbial terroir and food innovation: The case
of yeast biodiversity in wine. Microbiol. Res. 2015,181, 75–83. [CrossRef] [PubMed]
110.
Thongekkaew, J.; Kongsanthia, J. Screening and identification of cellulase producing yeast from Rongkho
Forest, Ubon Ratchathani University. Bioeng. Biosci. 2016,4, 29–33. [CrossRef]
111.
Williams, P.J.; Cynkar, W.; Francis, I.L.; Gray, J.D.; Iland, P.G.; Coombe, B.G. Quantification of glycosides in
grapes, juices, and wines through a determination of glycosyl glucose. J. Agric. Food Chem.
1995
,43, 121–128.
[CrossRef]
112.
Winterhalter, P.; Skouroumounis, G.K. Glycoconjugated aroma compounds: Occurrence, role and
biotechnological transformation. Adv. Biochem. Eng. Biotechnol. 1997,55, 73–105. [PubMed]
113.
Rosi, I.; Vinella, M.; Domizio, P. Characterization of
β
-glucosidase activity in yeasts of oenological origin.
J. Appl. Bacteriol. 1994,77, 519–527. [CrossRef] [PubMed]
114.
Cordero Otero, R.R.; Ubeda Iranzo, J.F.; Briones-Perez, A.I.; Potgieter, N.; Villena, M.A.; Pretorius, I.S.;
van Rensburg, P. Characterization of the
β
-glucosidase activity produced by enological strains of
non-Saccharomyces yeasts. Food Microbiol. Saf. 2003,68, 2564–2569. [CrossRef]
115.
Hock, R.; Benda, I.; Schreier, P. Formation of terpenes by yeasts during alcoholic fermentation. Zeitschrift für
Leb. Und-forsch. 1984,179, 450–452. [CrossRef]
116.
Jolly, N.P.; Augustyn, O.H.P.; Pretorius, I.S. The effect of non-Saccharomyces yeasts on fermentation and wine
quality. S. Afr. J. Enol. Vitic. 2003,24, 55–62. [CrossRef]
117.
Acosta, N.; Beldarraín, A.; Rodríguez, L.; Alonso, Y. Characterization of recombinant invertase expressed in
methylotrophic yeasts. Biotechnol. Appl. Biochem. 2000,32, 179–187. [CrossRef] [PubMed]
118.
Lee, W.; Huang, C. Modeling of ethanol fermentation using Zymomonas mobilis ATCC 10988 grown on the
media containing glucose and fructose. Biochem. Eng. J. 2000,4, 217–227. [CrossRef]
119.
Uma, C.; Gomathi, D.; Ravikumar, G.; Kalaiselvi, M.; Palaniswamy, M. Production and properties of
invertase from a Cladosporium cladosporioides in SmF using pomegranate peel waste as substrate. Asian Pac. J.
Trop. Biomed. 2012, S605–S611. [CrossRef]
120.
Pataro, C.; Guerra, J.B.; Gomes, F.C.O.; Neves, M.J.; Pimentel, P.F.; Rosa, C.A. Trehalose accumulation,
invertase activity and physiological characteristics of yeasts isolates from 24 h fermentative cycles during
the production of artisanal Brazilian cachaça. Braz. J. Microbiol. 2002,33, 202–208. [CrossRef]
Fermentation 2018,4, 74 21 of 22
121.
Gargel, C.A.; Baffi, M.A.; Gomes, E.; Da-Silva, R. Invertase from a Candida stellata strain isolated from grape:
Production and physico-chemical characterization. J. Microbiol. Biotechnol. Food Sci.
2014
,4, 24–28. [CrossRef]
122.
Van Bogaert, I.N.A.; Saerens, K.; De Muynck, C.; Develter, D.; Soetaert, W.; Vandamme, E.J. Microbial
production and application of sophorolipids. Appl. Microbiol. Biotechnol.
2007
,76, 23–34. [CrossRef]
[PubMed]
123.
Kurtzman, C.P.; Price, N.P.J.; Ray, K.J.; Kuo, T.M. Production of sophorolipid biosurfactants by multiple
species of the Starmerella (Candida)bombicola yeast clade. FEMS Microbiol. Lett.
2010
,311, 140–146. [CrossRef]
[PubMed]
124.
Parekh, V.J.; Pandit, A.B. Optimization of fermentative production of sophorolipid biosurfactant by
Starmerella bombicola NRRL Y-17069 using response surface methodology. Int. J. Pharm. Biol. Sci.
2011
,
1, 103–116.
125.
Pekin, G.; Vardar-Sukan, F.; Kosaric, N. Production of sophorolipids from Candida bombicola ATCC 22214
using Turkish corn oil and honey. Eng. Life Sci. 2005,5, 357–362. [CrossRef]
126.
Cavalero, D.A.; Cooper, D.G. The effect of medium composition on the structure and physical state of
sophorolipids produced by Candida bombicola ATCC 22214. J. Biotechnol. 2003,103, 31–41. [CrossRef]
127.
De Waele, S.; Vandenberghe, I.; Laukens, B.; Planckaert, S.; Verweire, S.; Van Bogaert, I.N.A.; Soetaert, W.;
Devreese, B.; Ciesielska, K. Optimized expression of the Starmerella bombicola lactone esterase in
Pichia pastoris through temperature adaptation, codon-optimization and co-expression with HAC1.
Protein Expr. Purif. 2018,143, 62–70. [CrossRef] [PubMed]
128.
Andorrà, I.; Berradre, M.; Mas, A.; Esteve-Zarzoso, B.; Guillamón, J.M. Effect of mixed culture fermentations
on yeast populations and aroma profile. LWT-Food Sci. Technol. 2012,49, 8–13. [CrossRef]
129.
Sadoudi, M.; Tourdot-Maréchal, R.; Rousseaux, S.; Steyer, D.; Gallardo-Chacón, J.J.; Ballester, J.; Vichi, S.;
Guérin-Schneider, R.; Caixach, J.; Alexandre, H. Yeast-yeast interactions revealed by aromatic profile analysis
of Sauvignon Blanc wine fermented by single or co-culture of non-Saccharomyces and Saccharomyces yeasts.
Food Microbiol. 2012,32, 243–253. [CrossRef] [PubMed]
130.
Aguilar-Uscanga, B.; François, J.M. A study of the yeast cell wall composition and structure in response to
growth conditions and mode of cultivation. Lett. Appl. Microbiol. 2003,37, 268–274. [CrossRef] [PubMed]
131.
Doco, T.; Quellec, N.; Moutounet, M.; Pellerin, P. Polysaccharide patterns during the ageing of Carignan noir
red wines. Am. J. Enol. Vitic. 1999,50, 25–32.
132.
Dufrechou, M.; Doco, T.; Poncet-Legrand, C.; Sauvage, F.X.; Vernhet, A. Protein/Polysaccharide interactions
and their impact on haze formation in white wines. J. Agric. Food Chem.
2015
,63, 10042–10053. [CrossRef]
[PubMed]
133.
Marchal, R.; Jeandet, P. Use of enological additives for colloid and tartrate salt stabilization in white wines and for
improvement of sparkling wine foaming properties. In Wine Chemistry and Biochemistry; Moreno-Arribas, M.V.,
Polo, M.C., Eds.; Springer: New York, NY, USA, 2009; pp. 127–158. ISBN 9780387741161.
134.
Chalier, P.; Angot, B.; Delteil, D.; Doco, T.; Gunata, Z. Interactions between aroma compounds and whole
mannoprotein isolated from Saccharomyces cerevisiae strains. Food Chem. 2007,100, 22–30. [CrossRef]
135.
Pérez-Magariño, S.; Martínez-Lapuente, L.; Bueno-Herrera, M.; Ortega-Heras, M.; Guadalupe, Z.;
Ayestarán, B. Use of commercial dry yeast products rich in mannoproteins for white and rosésparkling wine
elaboration. J. Agric. Food Chem. 2015,63, 5670–5681. [CrossRef] [PubMed]
136.
Vidal, S.; Francis, L.; Williams, P.; Kwiatkowski, M.; Gawel, R.; Cheynier, V.; Waters, E. The mouth-feel properties
of polysaccharides and anthocyanins in a wine like medium. Food Chem. 2004,85, 519–525. [CrossRef]
137.
Guilloux-Benatier, M.; Guerreau, J.; Feuillat, M. Influence of initial colloid content on yeast macromolecule
production and on the metabolism of wine microorganisms. Am. J. Enol. Vitic. 1995,46, 486–492.
138.
Domizio, P.; Romani, C.; Comitini, F.; Gobbi, M.; Lencioni, L.; Mannazu, I.; Ciani, M. Potential spoilage
non-Saccharomyces yeasts in mixed cultures with Saccharomyces cerevisiae. Ann. Microbiol.
2011
,61, 137–144.
[CrossRef]
139.
Giovani, G.; Rosi, I.; Bertuccioli, M. Quantification and characterization of cell wall polysaccharides released
by non-Saccharomyces yeast strains during alcoholic fermentation. Int. J. Food Microbiol.
2012
,160, 113–118.
[CrossRef] [PubMed]
Fermentation 2018,4, 74 22 of 22
140.
González-Royo, E.; Pascual, O.; Kontoudakis, N.; Esteruelas, M.; Esteve-Zarzoso, B.; Mas, A.; Canals, J.M.;
Zamora, F. Oenological consequences of sequential inoculation with non-Saccharomyces yeasts (Torulaspora
delbrueckii or Metschnikowia pulcherrima) and Saccharomyces cerevisiae in base wine for sparkling wine
production. Eur. Food Res. Technol. 2015,240, 999–1012. [CrossRef]
141.
Suzuki, M.; Suh, S.O.; Sugita, T.; Nakase, T.A. phylogenetic study on galactose-containing Candida species
based on 18S ribosomal DNA sequences. J. Gen. Appl. Microbiol. 1999,45, 229–238. [CrossRef] [PubMed]
142.
Cominiti, F.; Gobbi, M.; Domizio, P.; Romani, C.; Lencioni, L.; Mannazzu, I.; Ciani, M. Selected non-Saccharomyces
wine yeasts in controlled multistarter fermentations with Saccharomyces cerevisiae.Food Microbiol.
2011
,28, 873–882.
[CrossRef] [PubMed]
143.
Domizio, P.; Liu, Y.; Bisson, L.F.; Barile, D. Use of non-Saccharomyces wine yeasts as novel sources of
mannoproteins in wine. Food Microbiol. 2014,43, 5–15. [CrossRef] [PubMed]
144.
Ballou, C. Structure and biosynthesis of the mannan component of the yeast cell envelope.
Adv. Microb. Physiol.
1976,14, 93–158. [CrossRef] [PubMed]
©
2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access
article distributed under the terms and conditions of the Creative Commons Attribution
(CC BY) license (http://creativecommons.org/licenses/by/4.0/).
