Hybrid Yeast Strains Research Articles

Screening using loop-mediated isothermal amplification (LAMP) assay and breeding of a Saccharomyces cerevisiae strain isolated from Muramatsu Park, Japan, for sake brewing.

Sake is a Japanese alcoholic beverage produced by fermenting steamed rice and koji (a culture of Aspergillus oryzae on steamed rice) with sake yeast, a strain of Saccharomyces cerevisiae. Sake yeast strains are important for maintaining product quality and process efficiency. In this study, a S. cerevisiae strain from Muramatsu Park, Gosen City, Niigata Prefecture was isolated using a loop-mediated isothermal amplification (LAMP) assay. The yeast strain was cultured using the mass spore-cell/cell-cell mating method with a sake yeast haploid. The resultant hybrid yeast strain, HG-3-F2, exhibited superior efficiency in alcoholic fermentation compared with the HG-3 strain. Our findings support the applicability of these original and mating strains in sake brewing.

High yield co-production of isobutanol and ethanol from switchgrass: experiments, and process synthesis and analysis

Hybrid yeast strain co-produces isobutanol and ethanol at high yields. Reducing hydrolysis enzyme loading and enhancing xylose conversion greatly impact the economic potential of the biorefinery.

Characterization of Saccharomyces Strains Isolated from “Kéknyelű” Grape Must and Their Potential for Wine Production

Novel wine yeast strains have the potential to satisfy customer demand for new sensorial experiences and to ensure that wine producers have strains that can produce wine as efficiently as possible. In this respect, hybrid yeast strains have recently been the subject of intense research, as they are able to combine the favourable characteristics of both parental strains. In this study, two Saccharomyces “Kéknyelű” grape juice isolates were identified by species-specific PCR and PCR-RFLP methods and investigated with respect to their wine fermentation potential. Physiological characterization of the isolated strains was performed and included assessment of ethanol, sulphur dioxide, temperature and glucose (osmotic stress) tolerance, killer-toxin production, glucose fermentation ability at 16 °C and 24 °C, and laboratory-scale fermentation using sterile “Kéknyelű” must. Volatile components of the final product were studied by gas chromatography (GC) and mass spectrometry (MS). One isolate was identified as a S. cerevisiae × S. kudriavzevii hybrid and the other was S. cerevisiae. Both strains were characterized by high ethanol, sulphur dioxide and glucose tolerance, and the S. cerevisiae strain exhibited the killer phenotype. The hybrid isolate showed good glucose fermentation ability and achieved the lowest residual sugar content in wine. The ester production of the hybrid strain was high compared to the control S. cerevisiae starter strain, and this contributed to the fruity aroma of the wine. Both strains have good oenological characteristics, but only the hybrid yeast has the potential for use in wine fermentation.

Production and characterisation of non-alcoholic beer using special yeast

Non-Saccharomyces yeast strains Saccharomycodes ludwigii, Schizosaccharomyces pombe, Lachancea fermentati and Pichia angusta together with a hybrid yeast strain cross-bred between genetically modified Saccharomyces cerevisiae W303-1A G418R and Saccharomyces eubayanus as well as the parent yeasts of the hybrid were studied for potential use for non-alcoholic beer production. The hybrid yeast, its Saccharomyces cerevisiae W303-1A G418R parent and Saccharomycodes ludwigii were not able to metabolise maltose during Durham tube tests. Schizosaccharomyces pombe, Lachancea fermentati and Pichia angusta metabolised maltose, however, showed limited ethanol production. Parameters, volatile and non-volatile organic compounds of beers produced by the studied yeast were analysed and compared to a beer produced by bottom fermented brewer’s yeast Saccharomyces pastorianus.

Enzyme production and oil palm empty fruit bunch bioconversion to ethanol using a hybrid yeast strain.

Oil palm empty fruit bunch (OPEFB) is a lignocellulosic biomass generated in palm oil mills. It is a sustainable resource for fuels and chemicals. In this study, OPEFB was converted to ethanol by an integrative OPEFB conversion process including dilute alkaline pretreatment, cellulolytic enzyme production, separate OPEFB hydrolysis, and cofermentation using a hybrid xylose-fermenting yeast. OPEFB was pretreated using 1% (w/v) NaOH solution followed by 1% (v/v) H2 O2 . Further, cellulolytic enzymes were produced by submerged fermentation using Trichoderma reesei Rut C30 and used for OPEFB hydrolysis. The filter paper cellulase activity of the crude cellulolytic enzymes was 15.1IU/mL, which was higher than those obtained by reported Trichoderma strains under laboratory conditions. Glucose and xylose yields reached 66.9% and 74.2%, respectively, at 30 filter paper unit (FPU)/g-biomass enzyme dosage and 10% (w/v) biomass loading. The hybrid yeast strain ScF2 was previously constructed through recursive genome shuffling of Pichia stipitis and Saccharomyces cerevisiae and was used in OPEFB hydrolysate fermentation. About 16.9g/L ethanol was produced with an ethanol yield of 0.34g/g sugars, which was 67% of theoretical ethanol yield.

Controlled Reduction of Genomic Heterozygosity in an Industrial Yeast Strain Reveals Wide Cryptic Phenotypic Variation.

Abundant genomic heterozygosity can be found in wild strains of the budding yeast Saccharomyces cerevisiae isolated from industrial and clinical environments. The extent to which heterozygosity influences the phenotypes of these isolates is not fully understood. One such case is the PE-2/JAY270 strain, a natural hybrid widely adopted by sugarcane bioethanol distilleries for its ability to thrive under harsh biotic and abiotic stresses during industrial scale fermentation, however, it is not known whether or how the heterozygous configuration of the JAY270 genome contributes to its many desirable traits. In this study, we took a step toward exploring this question by conducting an initial functional characterization of JAY270’s heteroalleles. We manipulated the abundance and distribution of heterozygous alleles through inbreeding and targeted uniparental disomy (UPD). Unique combinations of homozygous alleles in each inbred strain revealed wide phenotypic variation for at least two important industrial traits: Heat stress tolerance and competitive growth. Quantitative trait loci analyses allowed the identification of broad genomic regions where genetic polymorphisms potentially impacted these traits, and there was no overlap between the loci associated with each. In addition, we adapted an approach to induce bidirectional UPD of three targeted pairs of chromosomes (IV, XIV, and XV), while heterozygosity was maintained elsewhere in the genome. In most cases UPD led to detectable phenotypic alterations, often in opposite directions between the two homozygous haplotypes in each UPD pair. Our results showed that both widespread and regional homozygosity could uncover cryptic phenotypic variation supported by the heteroalleles residing in the JAY270 genome. Interestingly, we characterized multiple examples of inbred and UPD strains that displayed heat tolerance or competitive growth phenotypes that were superior to their heterozygous parent. However, we propose that homozygosity for those regions may be associated with a decrease in overall fitness in the complex and dynamic distillery environment, and that may have contributed to slowing down the erosion of heterozygosity from the JAY270 genome. This study also laid a foundation for approaches that can be expanded to the identification of specific alleles of interest for industrial applications in this and other hybrid yeast strains.

Understanding Yeast Impact on 1,1,6-Trimethyl-1,2-dihydronaphthalene Formation in Riesling Wine through a Formation-Pathway-Informed Hydrolytic Assay.

The occurrence in Riesling wine of the potent odorant 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) is dependent upon vineyard and winemaking conditions, and TDN can have a prominent impact on the attributes of a wine after years in a bottle. As such, immediately assessing the impact of vineyard or winery treatments on future TDN formation requires forced creation of the aroma compound under non-wine-like conditions from other precursors. Here, we use a Box-Behnken approach and known TDN end points in commercial wines to optimize the conditions (pH, temperature, and time) of a "total TDN" hydrolytic assay for Riesling wine, which was intended to not interfere with yeast-derived formation pathways. The new assay (75 °C, pH 1.7, and 60 min) was used to determine the role of industry-relevant commercial yeasts as well as novel hybrid yeast strains on total TDN concentrations in young Riesling wines. While significant differences were observed between some yeasts, the impact of defoliation as a viticultural intervention outweighed yeast effects, suggesting that elevated TDN concentrations in wine are likely due to grape growing conditions and cannot be readily reduced or compensated for in the winery.

Improved ethanol productivity and ethanol tolerance through genome shuffling of Saccharomyces cerevisiae and Pichia stipitis.

Genome shuffling by recursive protoplast fusion between Saccharomyces cerevisiae and Pichia stipitis also known as Scheffersomyces stipitis resulted in a promising yeast hybrid strain with superior qualities than those of the parental strains in enhancing biofuel production. Our study focused on the substrate utilization, ethanol fermentation, and ethanol tolerance of the hybrids and the parental strains. The parental strain S. cerevisiae is limited to utilize only hexose sugars, and this leads to decrease in the ethanol yield when they are subjected to ethanol production from lignocellulosic biomass which is rich in pentose sugars. To overcome this limitation, we constructed a hybrid yeast strain through genome shuffling which can assimilate all the sugars present in the fermentation medium. After two rounds of recursive protoplast fusion, there was a higher increase in substrate utilization by hybrid SP2-18 compared to parental strain S. cerevisiae. SP2-18 was able to consume 34% of xylose sugar present in the fermentation medium, whereas S. cerevisiae was not able to utilize xylose. Further, the hybrid strain SP2-18 was able to reach an ethanol productivity of 1.03gL-1h-1, ethanol yield 0.447g/g, and ethanol concentration 74.65gL-1 which was relatively higher than that of the parental strain S. cerevisiae. Furthermore, the hybrid SP2-18 was found to be stable in the production of ethanol. The random amplified polymorphic DNA profile of the yeast hybrid SP2-18 shows the polymorphism between the parental strains indicating the migration of specific sugar metabolizing genes from P. stipitis, while the maximum similarity was with the parent S. cerevisiae.

Characterisation of Thiol-releasing and Lower Volatile Acidityforming Intra-genus Hybrid Yeast Strains for Sauvignon blanc Wine

A single Saccharomyces cerevisiae wine yeast strain produces a range of aroma and flavour metabolites (e.g. volatile thiols), as well as unfavourable metabolites (e.g. volatile acidity [VA]) during the alcoholic fermentation of white wine, especially Sauvignon blanc. The former contributes to the organoleptic quality of the final wine. Previous research showed that yeast derived enzymes (proteins) are involved in the release of wine quality enhancing or reducing metabolites during fermentation. Small-scale winemaking trials were initiated to evaluate protein expression and metabolite release of tropical fruit aroma wine producing S. cerevisiae hybrid yeasts. Commercial ‘thiol-releasing’ wine yeasts (TRWY) were included in winemaking trials as references. Improved hybrids were identified which showed enhanced thiol-releasing, specifically 3-mercaptohexanol (3MH), and lower VA formation during the production of Sauvignon blanc wines compared to some commercial TRWY references. It is noteworthy that the hybrid NH 56 produced wines with the second highest 3MH levels after hybrid NH 84, and lowest acetic acid of all strains included in this study. This yeast was also the only strain to have down-regulated proteins linked to amino acid biosynthesis, pentose phosphate pathway, glycolysis and fructose and galactose metabolism during the lag phase. Furthermore, differences in protein expression were reflected in the variation of metabolite release by different strains, thereby confirming that enzymes (proteins) are the final effectors for metabolite release.

Impact of Yeast Breeding for Elevated Glycerol Production on Fermentative Activity and Metabolite Formation in Chardonnay Wine

Glycerol in wine originates mainly as a by-product during fermentation by yeast and is thought to add to the body and smooth mouth-feel. We evaluated the properties of Chardonnay wine produced using various wine yeast strains of Saccharomyces cerevisiae and hybrid strains that were bred to produce elevated glycerol concentrations in laboratory trial experiments. The wine yeast strains (commercial strains or strains from culture collections) produced a mean glycerol and ethanol concentration of 4.38 and 101.2 g/L (12.8% v/v; n=26) respectively, whereas the glycerol and ethanol concentrations in wine made using the hybrid strains was 7.18 g/L and 96.0 g/L (12.2% v/v; n=15). Considerable variability in the glycerol-producing ability of the wine yeast and hybrid strains was apparent. Coupled to the higher glycerol levels formed by the hybrid strains, acetic acid, volatile acidity, acetoin, acetaldehyde and 2,3-butanediol levels were higher than the levels produced by the wine yeast strains. The levels of some of these metabolites were strongly linked to elevated glycerol production. The hybrid strains fermented the Chardonnay grape juice more slowly than the wine yeast strains, but in most instances dryness was achieved. The concentrations of miscellaneous metabolites (alcohols, acids and esters) were in most instances similar in the wine made with the wine yeast strains and hybrid strains, indicating that the breeding of yeast to produce higher glycerol levels has a minor influence on the production of these compounds. In a wine production experiment one hybrid yeast strain producing elevated glycerol levels yielded a Chardonnay wine with a better or equivalent body than wine made with commercial wine yeast strains, although the aroma and general quality were worse. These results suggest that further breeding and selection might yield yeast strains for fermentation that improves the body of wine without impacting on the overall balance of wine.

Yeast Hybrids in Winemaking

Summary Aim: There is significant variety in the choice of commercial yeast strains available for wine production. Yeast hybrids represent one class of commercial yeasts. The purpose of this review is to define what yeast hybrids are, to describe how they arise in nature and in the laboratory, and to discuss the features of these yeasts that differentiate them from non-hybrid strains. Key Themes: How does mating occur normally in yeast? What is a hybrid yeast strain? How do hybrid strains form in nature? How are hybrid wine strains constructed in the laboratory? Are natural hybrids of wine yeast found in nature? What are the features of laboratory-generated wine yeast hybrids? What are the impacts of hybrid strains on wine composition? Impact and Significance: Yeast influence wine aroma and flavor profiles in multiple ways1. In addition to the formation of ethanol, yeast can directly produce both positive and negative aroma impact compounds, such as esters, higher alcohols, higher aldehydes, and sulfur-volatile compounds. Some yeast strains can produce factors that enhance mouthfeel, and many can modify varietal aroma through enzymatic and chemical mechanisms. Yeast mannoproteins and polysaccharides may also affect wine stability. Last, yeast end products can alter the wine matrix and therefore the sensory expression of wine characters. Yeast hybrids combine traits of Saccharomyces cerevisiae and other species in this genus, and thereby expand the metabolic repertoire of the strain. These yeasts can create novel characters in wine as well as conduct fermentation under nonstandard conditions.

Hybrid Yeast Strains Can Lead to Better Chocolate

Hybrid Yeast Strains Can Lead to Better Chocolate

The Genome Sequence of the Highly Acetic Acid-Tolerant Zygosaccharomyces bailii-Derived Interspecies Hybrid Strain ISA1307, Isolated From a Sparkling Wine Plant

In this work, it is described the sequencing and annotation of the genome of the yeast strain ISA1307, isolated from a sparkling wine continuous production plant. This strain, formerly considered of the Zygosaccharomyces bailii species, has been used to study Z. bailii physiology, in particular, its extreme tolerance to acetic acid stress at low pH. The analysis of the genome sequence described in this work indicates that strain ISA1307 is an interspecies hybrid between Z. bailii and a closely related species. The genome sequence of ISA1307 is distributed through 154 scaffolds and has a size of around 21.2 Mb, corresponding to 96% of the genome size estimated by flow cytometry. Annotation of ISA1307 genome includes 4385 duplicated genes (∼90% of the total number of predicted genes) and 1155 predicted single-copy genes. The functional categories including a higher number of genes are ‘Metabolism and generation of energy’, ‘Protein folding, modification and targeting’ and ‘Biogenesis of cellular components’. The knowledge of the genome sequence of the ISA1307 strain is expected to contribute to accelerate systems-level understanding of stress resistance mechanisms in Z. bailii and to inspire and guide novel biotechnological applications of this yeast species/strain in fermentation processes, given its high resilience to acidic stress. The availability of the ISA1307 genome sequence also paves the way to a better understanding of the genetic mechanisms underlying the generation and selection of more robust hybrid yeast strains in the stressful environment of wine fermentations.

Production of yeast hybrids for improvement of cider by protoplast electrofusion

This study aimed to construct new yeast hybrid strains for introducing flavor and aroma diversity to ciders. The inactivated protoplasts of Saccharomyces cerevisiae and Candida krusei were electric-induced fused under the optimized electric condition of pulse field density 2200V/cm, pulse time 20μs, pulse number 2 times and pulse interval 1s, and 69 fusants were initially obtained. By performing Durham's fermentation for ten generations, 9 stable hybrid strains were screened. The chemical analysis showed that the alcoholic degree of ciders fermented by R2, R4, R5, R6 and R8 achieved about 12% (v/v), which was statistically the same level as the one fermented by parental strain WF1. The GC–MS results showed different strain generated totally different aroma profiles. R4 produced significant higher concentration of 2-methyl-butanoic acid ethyl ester, 2-methyl-1-propanol, 3-methyl-butanol acetate, 1-butanol, acetic acid hexyl ester, 1-hexanol and 1-octanol. The 9 hybrid yeast strains and parental strains were further compared through fuzzy comprehensive evaluation combining sensory score and aroma components content. The results showed that the hybrid R4 scored highest and displayed desirable properties of both parents.

Improvement of multiple stress tolerance in yeast strain by sequential mutagenesis for enhanced bioethanol production

The present work deals with the improvement of multiple stress tolerance in a glucose-xylose co-fermenting hybrid yeast strain RPR39 by sequential mutagenesis using ethyl methane sulfonate, N-methyl-N'-nitro-N-nitrosoguanidine, near and far ultraviolet radiations. The mutants were evaluated for their tolerance to ethanol, temperature and fermentation inhibitors. Among these mutants, mutant RPRT90 exhibited highest tolerance to 10% initial ethanol concentration, 2 g L(-1) furfural and 8 g L(-1) acetic acid. The mutant also showed good growth at high temperature (39-40°C). A study on the combined effect of multiple stresses during fermentation of glucose-xylose mixture (3:1 ratio) was performed using mutant RPRT90. Under the combined effect of thermal (39°C) and inhibitor stress (0.25 g L(-1) vanillin, 0.5 g L(-1) furfural and 4 g L(-1) acetic acid), the mutant produced ethanol with a yield of 0.379 g g(-1), while under combined effect of ethanol (7% v/v) and inhibitor stress the ethanol yield obtained was 0.43 g g(-1). Further, under the synergistic effect of sugar (250 g L(-1)), thermal (39°C), ethanol (7% v/v) and inhibitors stress, the strain produced a maximum of 47.93 g L(-1) ethanol by utilizing 162.42 g L(-1) of glucose-xylose mixture giving an ethanol yield of 0.295 g g(-1) and productivity of 0.57 g L(-1) h(-1). Under same condition the fusant RPR39 produced a maximum of 30.0 g L(-1) ethanol giving a yield and productivity of 0.21 g g(-1) and 0.42 g L(-1) h(-1) respectively. The molecular characterization of mutant showed considerable difference in its genetic profile from hybrid RPR39. Thus, sequential mutagenesis was found to be effective to improve the stress tolerance properties in yeast.

APJ1 and GRE3 Homologs Work in Concert to Allow Growth in Xylose in a Natural Saccharomyces sensu stricto Hybrid Yeast

Creating Saccharomyces yeasts capable of efficient fermentation of pentoses such as xylose remains a key challenge in the production of ethanol from lignocellulosic biomass. Metabolic engineering of industrial Saccharomyces cerevisiae strains has yielded xylose-fermenting strains, but these strains have not yet achieved industrial viability due largely to xylose fermentation being prohibitively slower than that of glucose. Recently, it has been shown that naturally occurring xylose-utilizing Saccharomyces species exist. Uncovering the genetic architecture of such strains will shed further light on xylose metabolism, suggesting additional engineering approaches or possibly even enabling the development of xylose-fermenting yeasts that are not genetically modified. We previously identified a hybrid yeast strain, the genome of which is largely Saccharomyces uvarum, which has the ability to grow on xylose as the sole carbon source. To circumvent the sterility of this hybrid strain, we developed a novel method to genetically characterize its xylose-utilization phenotype, using a tetraploid intermediate, followed by bulk segregant analysis in conjunction with high-throughput sequencing. We found that this strain’s growth in xylose is governed by at least two genetic loci, within which we identified the responsible genes: one locus contains a known xylose-pathway gene, a novel homolog of the aldo-keto reductase gene GRE3, while a second locus contains a homolog of APJ1, which encodes a putative chaperone not previously connected to xylose metabolism. Our work demonstrates that the power of sequencing combined with bulk segregant analysis can also be applied to a nongenetically tractable hybrid strain that contains a complex, polygenic trait, and identifies new avenues for metabolic engineering as well as for construction of nongenetically modified xylose-fermenting strains.

Improved Bioethanol Production Using Fusants of Saccharomyces cerevisiae and Xylose-Fermenting Yeasts

The present research deals with the development of a hybrid yeast strain with the aim of converting pentose and hexose sugar components of lignocellulosic substrate to bioethanol by fermentation. Different fusant strains were obtained by fusing protoplasts of Saccharomyces cerevisiae and xylose-fermenting yeasts such as Pachysolen tannophilus, Candida shehatae and Pichia stipitis. The fusants were sorted by fluorescent-activated cell sorter and further confirmed by molecular characterization. The fusants were evaluated by fermentation of glucose-xylose mixture and the highest ethanol producing fusant was used for further study to ferment hydrolysates produced by acid pretreatment and enzymatic hydrolysis of cotton gin waste. Among the various fusant and parental strains used under present study, RPR39 was found to be stable and most efficient strain giving maximum ethanol concentration (76.8 ± 0.31 g L(-1)), ethanol productivity (1.06 g L(-1) h(-1)) and ethanol yield (0.458 g g(-1)) by fermentation of glucose-xylose mixture under test conditions. The fusant has also shown encouraging result in fermenting hydrolysates of cotton gin waste with ethanol concentration of 7.08 ± 0.142 g L(-1), ethanol yield of 0.44 g g(-1), productivity of 0.45 g L(-1) h(-1) and biomass yield of 0.40 g g(-1).

Improved inhibitor tolerance in xylose-fermenting yeast Spathaspora passalidarum by mutagenesis and protoplast fusion

The xylose-fermenting yeast Spathaspora passalidarum showed excellent fermentation performance utilizing glucose and xylose under anaerobic conditions. But this yeast is highly sensitive to the inhibitors such as furfural present in the pretreated lignocellulosic biomass. In order to improve the inhibitor tolerance of this yeast, a combination of UV mutagenesis and protoplast fusion was used to construct strains with improved performance. Firstly, UV-induced mutants were screened and selected for improved tolerance towards furfural. The most promised mutant, S. passalidarum M7, produced 50% more final ethanol than the wild-type strain in a synthetic xylose medium containing 2 g/l furfural. However, this mutant was unable to grow in a medium containing 75% liquid fraction of pretreated wheat straw (WSLQ), in which furfural and many other inhibitors were present. Hybrid yeast strains, obtained from fusion of the protoplasts of S. passalidarum M7 and a robust yeast, Saccharomyces cerevisiae ATCC 96581, were able to grow in 75% WSLQ and produce around 0.4 g ethanol/g consumed xylose. Among the selected hybrid strains, the hybrid FS22 showed the best fermentation capacity in 75% WSLQ. Phenotypic and partial molecular analysis indicated that S. passalidarum M7 was the dominant parental contributor to the hybrid. In summary, the hybrids are characterized by desired phenotypes derived from both parents, namely the ability to ferment xylose from S. passalidarum and an increased tolerance to inhibitors from S. cerevisiae ATCC 96581.

ReCombine: A Suite of Programs for Detection and Analysis of Meiotic Recombination in Whole-Genome Datasets

In meiosis, the exchange of DNA between chromosomes by homologous recombination is a critical step that ensures proper chromosome segregation and increases genetic diversity. Products of recombination include reciprocal exchanges, known as crossovers, and non-reciprocal gene conversions or non-crossovers. The mechanisms underlying meiotic recombination remain elusive, largely because of the difficulty of analyzing large numbers of recombination events by traditional genetic methods. These traditional methods are increasingly being superseded by high-throughput techniques capable of surveying meiotic recombination on a genome-wide basis. Next-generation sequencing or microarray hybridization is used to genotype thousands of polymorphic markers in the progeny of hybrid yeast strains. New computational tools are needed to perform this genotyping and to find and analyze recombination events. We have developed a suite of programs, ReCombine, for using short sequence reads from next-generation sequencing experiments to genotype yeast meiotic progeny. Upon genotyping, the program CrossOver, a component of ReCombine, then detects recombination products and classifies them into categories based on the features found at each location and their distribution among the various chromatids. CrossOver is also capable of analyzing segregation data from microarray experiments or other sources. This package of programs is designed to allow even researchers without computational expertise to use high-throughput, whole-genome methods to study the molecular mechanisms of meiotic recombination.

Newly generated interspecific wine yeast hybrids introduce flavour and aroma diversity to wines

Increasingly, winemakers are looking for ways to introduce aroma and flavour diversity to their wines as a means of improving style and increasing product differentiation. While currently available commercial yeast strains produce consistently sound fermentations, there are indications that sensory complexity and improved palate structure are obtained when other species of yeast are active during fermentation. In this study, we explore a strategy to increase the impact of non-Saccharomyces cerevisiae inputs without the risks associated with spontaneous fermentations, through generating interspecific hybrids between a S. cerevisiae wine strain and a second species. For our experiments, we used rare mating to produce hybrids between S. cerevisiae and other closely related yeast of the Saccharomyces sensu stricto complex. These hybrid yeast strains display desirable properties of both parents and produce wines with concentrations of aromatic fermentation products that are different to what is found in wine made using the commercial wine yeast parent. Our results demonstrate, for the first time, that the introduction of genetic material from a non-S. cerevisiae parent into a wine yeast background can impact favourably on the wine flavour and aroma profile of a commercial S. cerevisiae wine yeast.