Saccharomyces Bayanus Research Articles

Chromosome-level subgenome-aware de novo assembly of Saccharomyces bayanus provides insight into genome divergence after hybridization.

Interspecies hybridization is prevalent in various eukaryotic lineages and plays important roles in phenotypic diversification, adaptation, and speciation. To better understand the changes that occurred in the different subgenomes of a hybrid species and how they facilitate adaptation, we completed chromosome-level de novo assemblies of all chromosomes for a recently formed hybrid yeast, Saccharomyces bayanus strain CBS380, using Nanopore MinION long-read sequencing. We characterized the S. bayanus genome and compared it with its parent species, S. uvarum and S. eubayanus, and other S. bayanus genomes to better understand genome evolution after a relatively recent hybridization event. We observed multiple recombination events between the subgenomes in each chromosome, followed by loss of heterozygosity (LOH) in nine chromosome pairs. In addition to maintaining nearly all gene content and synteny from its parental genomes, S. bayanus has acquired many genes from other yeast species, primarily through the introgression of S. cerevisiae, such as those involved in the maltose metabolism. Finally, the patterns of recombination and LOH suggest an allotetraploid origin of S. bayanus The gene acquisition and rapid LOH in the hybrid genome probably facilitated its adaptation to maltose brewing environments and mitigated the maladaptive effect of hybridization. This manuscript describes the first in-depth study using long-read sequencing technology of an S. bayanus hybrid genome which may serve as an excellent reference for future studies of this important yeast and other yeast strains.

Modeling the Change in Amino Acid and Peptide Contents during the Aging of Bottled-Fermented Sparkling Wines by Image Processing Methods

In this study, natural sparkling wine was produced using a mixture (1:1) of Emir and Dimrit grapes harvested (Around the Urgup District of Turkey). The change of free amino acid and peptide contents in sparkling wine depending on the aging time and yeasts (free and immobilized forms of the Saccharomyces bayanus and Saccharomyces oviformis) used in the second fermentation stage were examined by image processing methods. The immobilized yeasts were determined as more than the free ones along the second fermentation. It was also determined that the yeast type does not have a significant effect on both the peptides and free amino acid contents of sparkling wines and these contents were divided into 3 classes from high to low by measuring separately along the aging time. The amino acid contents of sparkling wines reached the highest level between the 335th and 365th days of aging time and also exceeded the amino acid contents of base wine.

Effects of ultrasound and microwave treatments on oenological yeast microbiota: comparison with a flash pasteurisation

SummaryThe control of yeast biota in wine could be a challenge, as different genera could coexist with different effects on wine quality; generally, SO2 plays an important role in this context, while other approaches have been proposed. In this article, two Microwave (MW) and two Ultrasound treatments (US) were tested and compared to a flash pasteurisation on seven yeast strains (Saccharomyces cerevisiae, Saccharomyces bayanus, Brettanomyces spp., Schizosaccharomyces pombe, Hanseniaspora osmophila, Zygosaccharomyces bailii, Pichia membranifaciens); viable count (viability) and yeast growth kinetic (vitality) were assessed. The treatments reduced viable count by 27%, with a higher biocidal effect of US, depending on yeast and treatment conditions; they also impaired yeast growth causing a delay, which is a significant increase of the lag phase, while the effect on the growth rate or the maximum OD attained in the steady state was less significant. In conclusion, the US generally exerted a stronger effect than MW and flash pasteurisation and Schizo. pombe and Z. bailii were the less resistant yeasts. A partial uncoupling was found between vitality and viability for Z. bailii, while in Schizo. pombe the delay in the growth was generally related to the decrease in the cell count immediately after the treatment.

Highly efficient production of 2-phenylethanol by wild-type Saccharomyces bayanus strain

2-Phenylethanol (2-PE) is a highly valuable aromatic alcohol utilized in fragrance, cosmetics and food industries. Due to the toxic by-products from chemical synthesis and the low productivity of the extraction method, bioproduction of 2-PE by yeast is considered promising. In this study, a wild-type Saccharomyces bayanus L1 strain producing 2-PE was isolated from soy sauce mash. Transcriptional analysis showed that 2-PE was synthesized via the Ehrlich pathway and Shikimate pathway in S. bayanus L1. By improving the fermentation conditions in shaking flasks, the maximum 2-PE titer reached 4.2 g/L with a productivity of 0.058 g/L/h within 72 h. In fed-batch fermentation, S. bayanus L1 strain produced 6.5 g/L of 2-PE within 60 h, achieving a productivity of 0.108 g/L/h. These findings suggest that S. bayanus L1 strain is an efficient 2-PE producer, paving the way for highly efficient 2-PE production.

Leveduras alternativas como agentes microbianos para vinhos produzidos a partir de uvas não-Vitis vinifera: Uma abordagem sensométrica. Parte 1: BRS Núbia

ABSTRACT Wines are produced from Vitis vinifera or American/hybrid grapes as a result of alcoholic fermentation and this bioprocess is modulated by yeasts of the Saccharomyces or non-Saccharomyces species. This study aimed at characterizing the chemical and sensory acceptance profiles of wines produced from BRS Núbia hybrid grapes with the classic yeast Saccharomyces cerevisiae (SC), and alternative yeasts Saccharomyces bayanus (SB) and Saccharomyces uvarum (SU). The wines produced using the same winemaking protocol were evaluated using the physicochemical parameters of total acidity, volatile acidity, total dry extract, reducing sugars, alcohol content, total phenolic content, color indices and the sensory acceptance method. All the physicochemical parameters evaluated were in accordance with the legislation. The SC wine sample showed greater acceptance of appearance and body due to its high color intensity, reducing sugar and total phenolic content. The SU wine sample was related to the physicochemical parameters of acidity (total and volatile), alcohol content, dry extract and CIELab parameters, showing higher acceptance for aroma, flavor, overall acceptance and purchase intention. The SB wine showed no relationship with any physicochemical property or sensory acceptance attribute. The SU yeast showed potential in producing wines with great acceptance by Brazilian consumers, considered an alternative yeast that can be used for the production of hybrid grape wines.

The influence of different yeast strains and yeast nutrients on the aroma of Krstač and Žižak wines

Krstač and Žižak are autochthonous grape varieties grown in Montenegro. Although international varieties are more popular, the autochthonous varieties are very important, especially for countries developing tourism. The fermentation aromas produced during alcoholic fermentation contribute significantly to wine quality. The effects of yeasts (Saccharomyces cerevisiae and Saccharomyces bayanus) and yeast nutrients (Fermaid E and Fermaid O) on aromatic compounds in wines were investigated. Using GC/FID-MS analysis, aroma compounds in Krstač and Žižak wines were characterized and quantified. Wines produced with the addition of yeast and yeast nutrients had mostly lower total alcohol content than wines obtained by spontaneous fermentation of Krstač and Žižak varieties. The results of this study showed that the concentration of compounds depends on the yeast strains. The yeast S. cerevisiae (ICV) provided a higher content of higher alcohols, while S. bayanus produced a higher concentration of esters and (medium chain) fatty acids. Total ester content ranged from 3.34 to 11.97 mg/l for Krstač wines and 8.51 to 13.68 mg/l for Žižak wines. Among all wines, Krstač and Žižak wines produced with S. bayanus and Fermaid E addition had the highest concentration of total esters. The yeast nutrients Fermaid E and O emphasized different characteristics of the yeasts. They had a statistically significant effect on the content of ethyl and acetate esters. The highest overall scores were obtained for ICVE and BayE Krstač wines (18.1 out of 20 points) and Žižak ICVE wine (18.2 out of 20 points).

Valorisation of chewing gum production waste in bioethanol production: a response surface methodology study

ABSTRACT Interest in fast-moving consumer goods (FMCG) is constantly growing all over the world. Chewing gum, which is in the group of pleasant and entertaining snacks preferred by people of all ages, especially children and young people, is one of the most consumed products in the food sector. Due to its remarkable production and the major components, chewing gum waste has the potential as an alternative sugar source for bioethanol production. To evaluate bioethanol production from chewing gum wastes, the sugar was first extracted, and directly fermented into ethanol under different conditions. Saccharomyces cerevisiae (fresh and dry) and Saccharomyces bayanus were used as the yeast. To determine the optimal fermentation medium, the response surface methodology (RSM) study was employed and the fermentation medium variables were tested such as agar, pepton and glucose (APG medium) concentrations. The APG medium in which the maximum bioethanol yield obtained was determined as 5 g/L agar, 10 g/L peptone and 5 g/L glucose. The highest ethanol yield under optimal APG medium was obtained as 9.1-4 g ethanol/L sugar after 72 h by using Saccharomyces cerevisiae (fresh). The obtained results showed that chewing gum wastes can be utilised a potential source for the bioethanol production.

Box–Behnken design to determine optimal fermentation conditions for apple-fortified mulberry wine using Saccharomyces bayanus

Wine is a fermented product of fruit juice. Mulberry and apple juice can also be used to produce wine. Several factors influence the alcoholic fermentation of the must; therefore, the optimization of the mulberry wine fermentation conditions with the dry yeast strain Saccharomyces bayanus (concentration varied from 0.15 to 0.25 g/L), fermentation conditions as pH value (from 3.5 to 4.5), and total soluble solid (TSS) content (24–28°Brix) were performed in this study. To evaluate the influence of these factors, a Box–Behnken design was used to minimize the number of factor combinations required, which allows the determination of optimal fermentation conditions (pH, TSS content, and dry yeast concentration) to produce wines with high alcohol and bioactive compounds (total anthocyanin (TAC) and polyphenol content (TPC)). Based on the analysis of experimental data, the second-order response surface models were developed to describe the relationship between initial pH value, TSS, and dry yeast concentration on wine quality acquisition (ethanol content and bioactive compounds). The results of the analysis of variance (ANOVA) showed that the model setup by response surface quadratic regression was suitable for predicting the wine quality. It was observed that the quality of the apple-fortified mulberry wine was significantly affected by all variables. The optimal contents of ethanol, total anthocyanin, and total polyphenol were achieved at 12.97% (v/v), 171.85 mg/L, and 87.17 mgGAE/L, respectively, when fermented in juice medium with optimal values of pH, TSS, and yeast concentration of 3.9, 26°Brix, and 0.22 g/L, respectively.

Comparing Mitochondrial Activity, Oxidative Stress Tolerance, and Longevity of Thirteen Ascomycota Yeast Species.

Aging is characterized by a number of hallmarks including loss of mitochondrial homeostasis and decay in stress tolerance, among others. Unicellular eukaryotes have been widely used to study chronological aging. As a general trait, calorie restriction and activation of mitochondrial respiration has been proposed to contribute to an elongated lifespan. Most aging-related studies have been conducted with the Crabtree-positive yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, and with deletion collections deriving from these conventional yeast models. We have performed an unbiased characterization of longevity using thirteen fungi species, including S. cerevisiae and S. pombe, covering a wide range of the Ascomycota clade. We have determined their mitochondrial activity by oxygen consumption, complex IV activity, and mitochondrial redox potential, and the results derived from these three methodologies are highly overlapping. We have phenotypically compared the lifespans of the thirteen species and their capacity to tolerate oxidative stress. Longevity and elevated tolerance to hydrogen peroxide are correlated in some but not all yeasts. Mitochondrial activity per se cannot anticipate the length of the lifespan. We have classified the strains in four groups, with members of group 1 (Kluyveromyces lactis, Saccharomyces bayanus and Lodderomyces elongisporus) displaying high mitochondrial activity, elevated resistance to oxidative stress, and elongated lifespan.

Defining winery processing conditions for the decontamination of must and wine spoilage microbiota by Pulsed Electric Fields (PEF)

This study investigated the PEF-resistance of Saccharomyces bayanus, Brettanomyces bruxellensis, Lactobacillus plantarum, and Oenococus oeni in must or wine under continuous PEF processing. Results showed the capacity of PEF to achieve 3.0-log10-cycles (CFU/mL) of inactivation of all the microorganisms under moderate conditions (< 155 kJ/kg). Developed tertiary models accurately predicted the effect of PEF parameters on microbial inactivation, and Monte Carlo simulation considered the variability of factors and the maximum assumable microbial load in the final treated product. Results showed that PEF-treatments at 15 kV/cm and 129 or 153 kJ/kg would ensure the adequate decontamination (< 10 CFU/mL) of spoilage microorganism in must or wine, respectively. Industrial relevancePEF technology has been shown to achieve adequate levels of microbial inactivation (3-log10) in must and wine under industrial applicable processing parameters, making it a suitable alternative to SO2 or sterilizing filtration for microbial control in winemaking. Reductions of 3-log10 CFU/mL of must and wine microbiota were found by continuous flow PEF-processing at 15 to 25 kV/cm and 175 to 148 kJ/kg, parameters applicable at industrial scale at 1 ton/h.

Antioxidant and anti-inflammatory properties of yeasts fermented passion fruit and soursop pulps: A focus on bioactive volatile compounds profile

This work aimed to ferment pasteurized soursop (SF) and passion fruit (PF) pulps inoculated with different yeast strains (Saccharomyces cerevisiae subsp. boulardii CNCM I-745 and Saccharomyces bayanus Safcider AB-1) incubated at 37 °C for 30 h. Throughout fermentation, the concentration of viable cells, soluble solids, and pH were evaluated. In vitro antioxidant and anti-inflammatory activities were determined in the fermented pulps. Additionally, volatile compounds and fatty acids were analyzed by gas chromatography-mass spectrometry. Fermented pulps showed viable cell counts higher than 109 CFU/mL from 12 to 30 h of fermentation, with a significant decrease (p < 0.05) in soluble solids, and constant pH values (3.30 and 4.09 in PF and SF, respectively). PF and SF pulps fermented by S. boulardii, and PF pulp fermented by S. bayanus showed antioxidant activities of 5.142, 5.011, 5.142 and 1.615 mg eq. Trolox/mL by ABTS, respectively. PF pulp fermented by S. bayanus as well as PF and SF pulps fermented by S. boulardii showed antioxidant activities of 0.628, 0.811 and 1.170 mg eq. Trolox/mL by FRAP, respectively. The PF and SF pulps fermented by S. bayanus showed inhibition of protein denaturalization activity (ca. 70% and 85%, respectively), while in SF pulp fermented by S. boulardii the inhibition of heat-induced hemolysis was ca. 90%. Alcohols, esterified carboxylic acids, unsaturated fatty acids (linolenic > linoleic > oleic), and polyphenols were identified in fermented pulps. These findings demonstrate that through controlled yeast fermentation, the potential health-promoting properties of fruit pulps can be improved, generating new fermented functional foods.

Synergetic effect of combining PEF treatments with sublethal doses of SO2 on the inactivation of Saccharomyces bayanus and Brettanomyces bruxellensis in red wine

Certain microorganisms are capable of proliferating in wine despite its low pH and high ethanol content. The yeasts of the Saccharomyces genus responsible for alcoholic fermentation can alter wines with residual sugars; the proliferation of Brettanomyces bruxellensis brings about thoroughly unpleasant sensory changes. The main strategy currently applied in wineries for microbial control is the addition of sulfites (SO2). However, sulfites are being researched due to the symptoms they can cause in allergic individuals. Pulsed electric field (PEF) technology has the capability of inactivating vegetative cells of microorganisms at non-lethal temperatures and could thus prove to be an alternative to SO2. In this study, the resistance of Saccharomyces bayanus and B. bruxellensis suspended in wine to a series of different PEF treatments (10–25 kV/cm; 25–1000 µs; 40–170 kJ/kg) combined with sublethal concentrations of SO2 (10, 25, and 50 ppm) was evaluated. The results showed that even the least intense PEF treatments (10 kV/cm; 115 kJ/kg) inactivated more than 4.0 Log10 cycles in both types of yeasts immediately after treatment. The subsequent incubation of the treated yeasts for 24 h in wine managed to increase inactivation by 3.0 Log10 cycles. The combination of a moderate PEF treatment with sublethal doses of SO2 had a synergistic lethal effect on the two yeasts under study after 24 h of incubation in wine, leading to counts lying below the detection limit (&amp;gt;5.0 Log10 cycles). This synergistic effect was attributed to the existence of a portion of the population that had been sublethally damaged by PEF and in which SO2 could more easily penetrate the cytoplasm. These results demonstrate the capacity of PEF technology for microbial control of spoilage yeasts in wine. PEF could thus represent an alternative with the potential of eliminating or reducing SO2 levels in the winemaking process.

Melomel Production by Saccharomyces bayanus Using Hydrolyzed Jackfruit (Artocarpus heterophyllus) Pulp, Pollen, and Rice (Oryza sativa) Bran Extract as Unconventional Supplements

This work evaluated the effect of hydrolyzed jackfruit pulp, rice (Oryza sativa) bran extract, and pollen concentration as unconventional supplements on mead production by Saccharomyces bayanus. Fermentations were carried out in 500-mL Erlenmeyer flasks containing 250 mL of honey wort (30°Brix). The flasks were supplemented with hydrolyzed jackfruit pulp (10, 20, and 30%), rice bran extract (5, 32.5, and 60 g∙L−1), and pollen (0, 20, and 30 g∙L−1), inoculated with 0.2 g∙L−1 cells and incubated at 30°C for 288 h. Higher cell growth (11.5 g∙L−1 cells) and ethanol production (18.2 %v/v) were observed in the wort supplemented with 32.5 g∙L−1 rice bran extract, 20 g∙L−1 pollen, and 20% hydrolyzed jackfruit pulp. The highest substrate consumption (59%) was verified in the wort containing the highest concentration of hydrolyzed jackfruit pulp (30%). The S. bayanus Premier Blanc yeast had the best ethanol volumetric yield (1.982 g∙(L∙h)−1), product yield coefficient (0.427 g∙g−1), and fermentation efficiency (83.52%) after 48 h of fermentation.

Genetically Isolated Population of &lt;i&gt;Saccharomyces bayanus&lt;/i&gt; in New Zealand and Australia

The genetic relatedness of yeasts in the Saccharomyces bayanus complex has been studied using the methods of molecular and classical genetics. A divergent population of S. bayanus has been found in New Zealand and Australia. The S. bayanus complex includes four genetic populations: S. bayanus var. bayanus, S. bayanus var. uvarum, S. eubayanus and New Zealand population. The strains of the New Zealand population differ significantly in the nucleotide sequences of nuclear (FSY1, HIS3, MET2) and mitochondrial (FUN14, COX2) genes and form semi-sterile hybrids with other populations: viability of ascospores is 6.2–23.3%. There is no complete interspecific postzygotic isolation between S. bayanus var. bayanus, S. bayanus var. uvarum, S. eubayanus, and New Zealand populations: all hybrids showed regular meiotic segregation of control auxotrophic markers. According to the results obtained, four genetic populations belong to the same biological species with genomic divergence at the level of taxonomic varieties.

A Genetically Isolated Population of Saccharomyces bayanus in New Zealand and Australia

A Genetically Isolated Population of Saccharomyces bayanus in New Zealand and Australia

Split batch and coculture fermentation to regulate the organic acids and flavor profile of fruit wine-a case study of Prunus mume Sieb. et Zucc (greengage) wine

The higher acidity in fruits compared with grapes was one of the main obstacles to producing high-quality fruit wines. In the present research, the effect of the split batch fermentation pattern on the metabolites of greengage wines was investigated. This fermentation pattern included whole fruit immersion in the sucrose and coculturing Saccharomyces bayanus Y4 with Torulaspora delbrueckii Y7. These results showed that the contents of total acidity and dominant organic acids were significantly reduced among the batches. Aliphatic compounds were decreased with the batches, while aromatic compounds that contributed to flavor improvement were increased oppositely. The acetate esters, ketones, and terpenes contents were significantly increased in the first batch of coculture. In addition, acidic stress largely affected the kinetics characteristics of greengage wine on a pilot scale. Interestingly, the increment of total acidity was closely associated with the rate of total sugar consumption, which was affected by microbial activities. The acidity content was significantly declined and distinct flavour profiles were formed in split batch and coculture fermentation of greengage wines. It provides a new avenue to enhance the flavor and quality of fruit wines.

Comparison of the influence of Saccharomyces pastorianus to Saccharomyces cerevisiae and Saccharomyces bayanus inoculation ratio to oenological characteristics of Sauvignon Blanc wine

The aim of our work was to evaluate the impact of different fermentation schemes by using mixed and pure cultures of S. pastorianus and S. cerevisiae or S. bayanus. For the mixed fermentation schemes, one strain of S. pastorianus has been inoculated under different proportions (99%/1%, 97%/3%, 95%/5%, 90%/10% and 70%/30% w/w) in co-inoculation with two commercial strains of S. cerevisiae and one commercial Saccharomyces bayanus strain. The fermentation kinetics has been controlled by density measurement and classical oenological analyses were performed based on OIV analytical methods. The population dynamics was evaluated by the specific interdelta PCR reaction of the Saccharomyces species in the beginning and in the end of the fermentation process. Volatile compounds of the wine aroma, such as esters, higher alcohols and thiols were analyzed by GC/MS. Sensory assessment by trained panel was carried out for all wines. The wines fermented with S. pastorianus, either in pure or mixed cultures, were characterized by significantly lower acetic acid production and higher malic acid degradation when compared to the wines fermented with S. cerevisiae strains. The presence of S. pastorianus strain enhanced the production of the varietal thiols when compared to the samples fermented with the S. cerevisiae pure cultures. The wines produced by the S. bayanus or cerevisiae monocultures and the ones produced by the co-culture with S. pastorianus at 70%-30% ratio (S. pastorianus to S. bayanus or cerevisiae) were overall better rated from a sensory point of view.

INFLUENCE OF PRE-TREATMENT ON THE MICROBIOLOGICAL AND BIOCHEMICAL PROPERTIES OF WINE PRODUCED FROM OVERRIPE PLANTAIN

Wine is essential in every celebration but it is very expensive in countries where grape is not grown. Agadagidi, an effervescent wine analogue with sweet-sour taste is locally produced from overripe plantain which is abundant in the Tropics. This research produced agadagidi by sulphiting the must with or without inoculating with Saccharomyces cerevisiae strain isolated from spontaneous fermentation. Some of the samples were also pasteurized with a view to producing agadagidi with consistent quality. Microorganisms were enumerated, isolated and identified during storage, sugars, pH, TTA and sensory properties were also assessed using standard methods. The result showed that the range of TVC, LAB, and fungi count were 5.571 – 9.076 log cfu/ml, 2.717- 9.253 log cfu/ml and 4.079 - 9.418 log cfu/ml respectively. Microorganisms isolated were Saccharomyces cerevisiae, Saccharomyces bayanus, Pichia kluyveri, Candida albicans, Bacillus pumilus, Lactobacillus plantarum, Bacillus subtilis and Leuconostoc oenos. The reducing sugar was higher in unpasteurized samples than pasteurized sample at the beginning of storage. Total sugar generally decreased while the TTA increased during storage. The sensory score showed that all unpasteurized samples and pasteurized sample without isolate and sulphite were accepted by the panelists. This study therefore suggests the use of sulphite with or without starter culture in the production of agadagidi with consistent quality.

ДОСЛІДЖЕННЯ УМОВ ОДЕРЖАННЯ АЛКОГОЛЬНИХ НАПОЇВ З ЯБЛУК

The results of research on the fermentation process of apple juice and its concentrate are described. For this, two races of yeast of the types Saccharomyces bayanus (France) were selected and wild yeast was taken for comparison. The influence of temperature (10–30 0C) and duration of fermentation (12–40 days) on alcohol yield, content of total extract and sugar is shown. The quality characteristics of fruit wines characterized by aroma, strength, extract and sugar content has been established. The suitability of ciders for the production of calvados by distillation and aging of the obtained drinks has been studied. The taste and aroma of the obtained drinks were evaluated, namely: the strength, extract content and aroma, which affect the quality of the obtained products, were determined. An organoleptic evaluation of the obtained products and French Calvados was made.

Selection of Saccharomyces bayanus Strains with High Pectinolytic Activity and Phylogenetic Analysis of PGU Genes

Selection of Saccharomyces bayanus Strains with High Pectinolytic Activity and Phylogenetic Analysis of PGU Genes