scholarly journals Creation and Characterization of Industrially Applicable de Novo Lager Yeast Hybrids with a Unique Genomic Architecture

2020 ◽  
Author(s):  
Zachari Turgeon ◽  
Thomas Sierocinski ◽  
Cedric A. Brimacombe ◽  
Yiqiong Jin ◽  
Brittany Goldhawke ◽  
...  
Keyword(s):  
De Novo ◽  
Phenotypic Diversity ◽  
Breeding Strategy ◽  
Lager Yeast ◽  
Genomic Architecture ◽  
Group I ◽  
Saccharomyces Pastorianus ◽  
Lager Beer ◽  
Group Ii ◽  
Beer Production

Lager beer is produced by Saccharomyces pastorianus, which is a natural allopolyploid hybrid between Saccharomyces cerevisiae and Saccharomyces eubayanus. Lager strains are classified into two major groups based largely on genomic composition: Group I and Group II. Group I strains are allotriploid, whereas Group II are allotetraploid. A lack of phenotypic diversity in commercial lager strains has led to substantial interest in the reconstitution of de novo allotetraploid lager strains by hybridization of S. cerevisiae and S. eubayanus strains. Such strategies rely on the hybridization of wild S. eubayanus isolates, which carry unacceptable traits for commercial lager beer such as phenolic off-flavours and incomplete utilization of carbohydrates. Using an alternative breeding strategy, we have created de novo lager hybrids containing the domesticated S. eubayanus subgenome from an industrial S. pastorianus strain by hybridizing diploid meiotic segregants of this strain to a variety of S. cerevisiae ale strains. Five de novo hybrids were isolated which had fermentation characteristics similar to those of prototypical commercial lager strains but with unique phenotypic variation due to the contributions of the S. cerevisiae parents. Genomic analysis of these de novo lager hybrids identified novel allotetraploid genomes carrying three copies of the S. cerevisiae genome and one copy of the S. eubayanus genome. Most importantly, these hybrids do not possess the negative traits which result from breeding wild S. eubayanus. The de novo lager strains produced using industrial S. pastorianus in this study are immediately suitable for industrial lager beer production. IMPORTANCE All lager beer is produced using two related lager yeast types: Group I and Group II, which are highly similar resulting in a lack of strain diversity for lager beer production. To date, approaches for generating new lager yeasts have generated strains possessing undesirable brewing characteristics which render them commercially inviable. We have used an alternative approach that circumvents this issue and created new lager strains that are directly suitable for lager beer production. These novel lager strains also possess a unique genomic architecture, which may lead to a better understanding of industrial yeast hybrids. We propose that strains created using our approach be classified as a third group of lager strains (Group III). We anticipate that these novel lager strains will be of great industrial relevance, and that this technique will be applicable to the creation of additional novel lager strains that will help broaden the diversity in commercial lager beer strains.

Heterogeneity of the εγδβ Thalassemias: Characterization of 3 Novel English Deletions.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3609-3609
Author(s):  
Helen Rooks ◽  
Jean Bergounioux ◽  
Laurence Game ◽  
James P. Close ◽  
Steve Best ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Olfactory Receptor ◽  
De Novo ◽  
Globin Gene ◽  
Inherited Disorders ◽  
Chromosome 11P15 ◽  
Globin Gene Cluster ◽  
Group I ◽  
Group Ii

Abstract The thalassemias are inherited disorders classified genetically into α, β, γ, δβ, δ and εγδβ varieties according to the type of globin(s) that are underproduced. At the molecular level, the εγδβ thalassemias fall into two categories; Group I removes all, or a greater part, of the β globin gene cluster which is embedded in an array of olfactory receptor genes on chromosome 11p15. Group II removes extensive upstream regions leaving the β globin gene itself intact despite which, its expression is silenced due to inactivation of the upstream locus control region (β LCR). Recently, two novel deletions causing εγδβ thalassemia have been reported; a 153 kb deletion removing the entire β globin cluster in a Chilean family (Game, L., et al., Br J Haematol2003, 123:154–9) and an upstream deletion of 112 kb in a Dutch family (Dutch III) (Harteveld, C.L., et al., Br J Haematol2003,122: 855–8). We describe here the characterization of another three novel εγδβ thalassemia deletions, in three English families, named English II, III and IV, to differentiate them from the previously reported English (I) deletion (Curtin, P., et al., J Clin Invest1985, 76: 1554–8). Deletion English II removed 98 kb extending 90 kb upstream of the ε gene to 8 kb upstream of the Gγ gene, and included 4 upstream olfactory receptor (HOR) genes. Deletion English III removed 114 kb extending 60 kb upstream of the ε gene to 9 kb downstream of the β globin gene, thus including the entire β globin gene cluster as well as two upstream HOR genes. English IV is the largest deletion (439 kb) reported so far; starting 326 kb upstream of the ε gene to 70 kb downstream of the β gene and included 13 upstream, and 3 downstream, HOR genes plus the intervening β globin gene cluster. Breakpoints of all the 3 deletions occurred within regions of L1 or Alu repeat elements and contained short regions of direct homology between the flanking sequences, a feature that is likely to have contributed to the illegitimate recombinations. Deletions English II and III appear to be de novo while English IV is not. The proband for the English IV deletion had neonatal hemolytic anemia and required blood transfusions while 3 other family members who were heterozygous for the same deletion, had uneventful post-natal periods. The English III proband also required a blood transfusion soon after birth while the English II proband did not. Although in later life, heterozygotes for εγδβ thalassemia are transfusion-independent, and have a blood picture typical of β thalassemia trait but with normal Hb A2 levels, our data suggest that heterozygotes for εγδβ thalassemias have more severe microcytosis and hypochromia than β thalassemia carriers. To date, a total of 15 deletions causing εγδβ thalassemia have been described - five upstream deletions (Group II) associated with intact β globin genes and ten (Group I) that include the entire β globin gene cluster. These deletions are all unique and illustrate the heterogeneity of the εγδβ thalassemias.

scholarly journals A local gentamicin-collagen sponge reduces cardiovascular implantable electronic device infections and pocket hematoma

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
C Monaco ◽  
L Barone ◽  
G Stifano ◽  
G Magliano ◽  
V Cammalleri ◽  
...  
Keyword(s):  
De Novo ◽  
Electronic Device ◽  
Aminoglycoside Antibiotic ◽  
Infectious Complications ◽  
Collagen Sponge ◽  
Group I ◽  
Group Ii ◽  
Systemic Antibiotics ◽  
Cardiovascular Implantable Electronic Device ◽  
Pocket Hematoma

Abstract Background Implantation or replacement of cardiovascular implantable electronic device (CIED) may be associated with complications such as pocket hematoma and infections. Purpose The aim of this study is to determine whether a lyophilized collagen impact impregnated with the aminoglycoside antibiotic gentamicin, applied according to the size of pocket into the surgical wound during implantation or replacement, reduces major CIED infections and pocket hematoma 12 months after the surgical intervention. Methods We conducted a retrospective study including 1189 patients (mean age 77.45±9.83 y.o.), who underwent implantation or replacement of CIED in our center between June 2007 and November 2018. We compared 475 patients treated with the local gentamicin-collage sponge (group I) with 714 patients who did not receive it (group II). The primary endpoints were the reduction of infectious complications and pocket hematoma through 12 months of follow-up post procedure. Results Complications occurred in 127 of 1189 patients (10.68%): 102 of 1189 patients (8.58%) developed pocket hematoma, 20 of 1189 patients (1.68%) infectious events and 5 of 1189 patients (0.42%) both. Specifically, the rate of complications was lower in group I: pocket hematoma 0.63% vs 13.86% (p<0.001), infections 0.21% vs 2.6% (p=0.02), both 0% vs 0.7% (p=0.17). The study also shows a statistically significant major incidence of infectious complications in subjects undergoing implantation or replacement of ICD, compared to subjects undergoing implantation or replacement of PPM (5.59% vs 1.5%; p<0.05%). Regarding the type of intervention and the incidence of complications within the subgroups, was demonstrated a statistically significant reduction in the incidence of infections in de novo implant-group I subgroup compared to de novo implant-group II subgroup (0.5% vs 3.5%; p<0.05); a statistically significant reduction in the incidence of infectious complications was also observed in replacement-group I subgroup (0%) compared to replacement-group II subgroup (0% vs 1.4%; p<0.05). Similar results were demonstrated for the incidence of pocket hematoma, with a statistically significant reduction in de novo implant-group I subgroup compared to de novo implant-group II subgroup (0.5% vs 14.13%; p<0.05) and in replacement-group I subgroup compared to replacement-group II subgroup (1.4% vs 12.5%; p<0.05). The association between therapy and development of hematoma was not statistically significant. The association between comorbidities and infectious complications in both groups was always statistically significant. Conclusion The local gentamicin-collagen sponge is a medical device which can be used in addition to local hemostasis and prophylactic doses of systemic antibiotics, with the aim of reducing infective complications and pocket hematoma after permanent CIED implantation or replacement. Funding Acknowledgement Type of funding source: None

scholarly journals A Large Set of Newly Created Interspecific Saccharomyces Hybrids Increases Aromatic Diversity in Lager Beers

2015 ◽  
Vol 81 (23) ◽  
pp. 8202-8214 ◽  
Author(s):  
Stijn Mertens ◽  
Jan Steensels ◽  
Veerle Saels ◽  
Gert De Rouck ◽  
Guido Aerts ◽  
...  
Keyword(s):  
Large Scale ◽  
Alcoholic Beverage ◽  
Pilot Scale ◽  
Temperature Tolerance ◽  
Large Set ◽  
Lager Yeast ◽  
Content Type ◽  
High Attenuation ◽  
Saccharomyces Pastorianus ◽  
Lager Beer

ABSTRACTLager beer is the most consumed alcoholic beverage in the world. Its production process is marked by a fermentation conducted at low (8 to 15°C) temperatures and by the use ofSaccharomyces pastorianus, an interspecific hybrid betweenSaccharomyces cerevisiaeand the cold-tolerantSaccharomyces eubayanus. Recent whole-genome-sequencing efforts revealed that the currently available lager yeasts belong to one of only two archetypes, “Saaz” and “Frohberg.” This limited genetic variation likely reflects that all lager yeasts descend from only two separate interspecific hybridization events, which may also explain the relatively limited aromatic diversity between the available lager beer yeasts compared to, for example, wine and ale beer yeasts. In this study, 31 novel interspecific yeast hybrids were developed, resulting from large-scale robot-assisted selection and breeding between carefully selected strains ofS. cerevisiae(six strains) andS. eubayanus(two strains). Interestingly, many of the resulting hybrids showed a broader temperature tolerance than their parental strains and referenceS. pastorianusyeasts. Moreover, they combined a high fermentation capacity with a desirable aroma profile in laboratory-scale lager beer fermentations, thereby successfully enriching the currently available lager yeast biodiversity. Pilot-scale trials further confirmed the industrial potential of these hybrids and identified one strain, hybrid H29, which combines a fast fermentation, high attenuation, and the production of a complex, desirable fruity aroma.

scholarly journals Lager Yeast Comes of Age

2014 ◽  
Vol 13 (10) ◽  
pp. 1256-1265 ◽  
Author(s):  
Jürgen Wendland
Keyword(s):  
Gene Pool ◽  
Population Genomics ◽  
Strain Improvement ◽  
Network Evolution ◽  
Lager Yeast ◽  
Content Type ◽  
Hybrid Nature ◽  
Saccharomyces Pastorianus ◽  
Lager Beer ◽  
Yeast Genomes

ABSTRACTAlcoholic fermentations have accompanied human civilizations throughout our history. Lager yeasts have a several-century-long tradition of providing fresh beer with clean taste. The yeast strains used for lager beer fermentation have long been recognized as hybrids between twoSaccharomycesspecies. We summarize the initial findings on this hybrid nature, the genomics/transcriptomics of lager yeasts, and established targets of strain improvements. Next-generation sequencing has provided fast access to yeast genomes. Its use in population genomics has uncovered many more hybridization events withinSaccharomycesspecies, so that lager yeast hybrids are no longer the exception from the rule. These findings have led us to propose network evolution withinSaccharomycesspecies. This “web of life” recognizes the ability of closely related species to exchange DNA and thus drain from a combined gene pool rather than be limited to a gene pool restricted by speciation. Within the domesticated lager yeasts, two groups, the Saaz and Frohberg groups, can be distinguished based on fermentation characteristics. Recent evidence suggests that these groups share an evolutionary history. We thus propose to refer to the Saaz group asSaccharomyces carlsbergensisand to the Frohberg group asSaccharomyces pastorianusbased on their distinct genomes. New insight into the hybrid nature of lager yeast will provide novel directions for future strain improvement.

scholarly journals Potential for Lager Beer Production from Saccharomyces cerevisiae Strains Isolated from the Vineyard Environment

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1628
Author(s):  
Massimo Iorizzo ◽  
Francesco Letizia ◽  
Gianluca Albanese ◽  
Francesca Coppola ◽  
Angelita Gambuti ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Pilot Scale ◽  
Brewing Industry ◽  
Saccharomyces Pastorianus ◽  
Lager Beer ◽  
Efficient Fermentation ◽  
Saccharomyces Eubayanus ◽  
Beer Production ◽  
New Strategies

Saccharomyces pastorianus, genetic hybrids of Saccharomyces cerevisiae and the Saccharomyces eubayanus, is one of the most widely used lager yeasts in the brewing industry. In recent years, new strategies have been adopted and new lines of research have been outlined to create and expand the pool of lager brewing starters. The vineyard microbiome has received significant attention in the past few years due to many opportunities in terms of biotechnological applications in the winemaking processes. However, the characterization of S. cerevisiae strains isolated from winery environments as an approach to selecting starters for beer production has not been fully investigated, and little is currently available. Four wild cryotolerant S. cerevisiae strains isolated from vineyard environments were evaluated as potential starters for lager beer production at laboratory scale using a model beer wort (MBW). In all tests, the industrial lager brewing S. pastorianus Weihenstephan 34/70 was used as a reference strain. The results obtained, although preliminary, showed some good properties of these strains, such as antioxidant activity, flocculation capacity, efficient fermentation at 15 °C and low diacetyl production. Further studies will be carried out using these S. cerevisiae strains as starters for lager beer production on a pilot scale in order to verify the chemical and sensory characteristics of the beers produced.

Improving the molecular risk classification for younger (<60 years) de novo cytogenetically normal acute myeloid leukemia (CN AML) patients (pts)

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 7002-7002
Author(s):  
G. Marcucci ◽  
K. Maharry ◽  
S. P. Whitman ◽  
P. Paschka ◽  
C. D. Baldus ◽  
...  
Keyword(s):  
High Risk ◽  
De Novo ◽  
Information Criterion ◽  
Risk Groups ◽  
Risk Classification ◽  
Low Risk ◽  
Treatment Protocols ◽  
Group I ◽  
Group Ii ◽  
Wt1 Mutation

7002 Background: CN AML pts are currently stratified into Low-risk [FLT3-ITD negative (neg)/NPM1 mutated (mut)] and High-risk [FLT3-ITD positive (pos) or NPM1 wild type (wt)] groups (FLT3-ITD/NPM1-only classification). We recently showed that low ERG expression and CEBPAmut identify pts with better outcome within, respectively, the Low- and High-risk groups, and that WT1mut confers poor outcome regardless of FLT3-ITD/NPM1 status. Here, we assess if adding CEBPA and WT1 mutation and ERG expression testing improves the currently used CN AML molecular risk classification. Methods: FLT3, NPM1, CEBPA and WT1 mutations and ERG and BAALC expression were tested at diagnosis in 143 CN AML adults enrolled on CALGB treatment protocols 9621 and 19808. Pts were divided into two molecular risk groups: i) CALGB Group I that included Low-risk pts with low ERG & High-risk pts with CEBPAmut and ii) CALGB Group II that included WT1mut pts & Low-risk pts with high ERG & High- risk pts with CEBPAwt. Results: CALGB Group I (n=56) v Group II (n=87) had more complete remissions (CRs) (P=.005; 96% v 79%), and longer disease-free (DFS; P<.0001; 5 year (y) 69% v 21%) and overall (OS; P<.0001; 5 y 70% v 31%) survival [median follow-up for pts alive 6 y]. In multivariable (MV) analyses, Group I predicted higher rate of CR (P=.02), and longer DFS (P<.0001) and OS (P=.0002), after correcting for other variables (Table). In contrast, for the same cohort of pts grouped by the FLT3-ITD/NPM1-only classification, CRs were 94% v 82% and 5 y DFS 59% v 32% and OS 67% v 36% in the Low- v High-risk groups. Based on the Akaike Information Criterion, MV models for DFS and OS using the CALGB risk Groups were better than those using the FLT3-ITD/NPM1-only risk groups. Conclusions: Prognostic classification of younger de novo CN AML pts is improved by adding CEBPA and WT1 mutation and ERG expression testing. While mutational analyses are ready for use in clinical trials, quantification of ERG expression is yet to be standardized. [Table: see text] No significant financial relationships to disclose.

Phenotypic diversity and capsaicinoid content of chilli pepper landraces (Capsicum spp.) from the Yucatan Peninsula

2021 ◽  
pp. 1-8
Author(s):  
C. C. Castillo-Aguilar ◽  
L. C. López Castilla ◽  
N. Pacheco ◽  
J. C. Cuevas-Bernardino ◽  
R. Garruña ◽  
...  
Keyword(s):  
Phenotypic Diversity ◽  
Yucatan Peninsula ◽  
Plant Genetic Resources ◽  
Conservation Status ◽  
Morphological Characteristics ◽  
Chilli Pepper ◽  
Southern Mexico ◽  
Yucatán Peninsula ◽  
Group I ◽  
Group Ii

Abstract Mexico has a wealth of plant genetic resources, including Capsicum species. In southern Mexico, specifically in the western part of the Yucatan Peninsula, Maya farmers have preserved a great diversity of chilli pepper landraces of C. annuum, C. frutescens and C. chinense. However, the morphological diversity, capsaicinoid content, conservation status and potential use of these species have not been studied. To fill this gap and generate information to support the conservation and use of these species, we characterized the phenotypic diversity and capsaicinoid content for nine chilli pepper landraces from the western Yucatan Peninsula by assessing 15 quantitative and 39 qualitative traits for 10 plants of each landrace. For quantitative variables, two groups of chilli pepper landraces were obtained by principal component analysis and cluster analysis. Group I was formed by Rosita, Bobo, Dulce, Xcat'ik1, Xcat'ik2 and Verde landraces; Group II included the Maax, Bolita and Pico Paloma landraces. For qualitative variables, three groups of chilli pepper landraces were obtained; Group I included Dulce, Bobo, Xcat'ik1, Xcat'ik2 and Verde landraces, Group II only included the Rosita landrace, and Group III included Maax, Bolita and Pico Paloma landraces. Ultra-performance liquid chromatography–photodiode array (UPLC-PDA) quantification of capsaicinoids indicated higher values in landraces Rosita (14,062.3 μg/g D.W), Bolita (5928.1 μg/g D.W), Maax (3438.4 μg/g D.W) and Pico Paloma (3138.9 μg/g D.W). The Yucatan chilli pepper landraces provide valuable diverse germplasm for morphological characteristics and capsaicinoid content that can be used in breeding and conservation programmes.

scholarly journals Aneuploidy influences the gene expression profiles in Saccharomyces pastorianus group I and II strains during fermentation.

2021 ◽  
Author(s):  
Roberto de la Cerda ◽  
Karsten Hookamp ◽  
Fiona Roche ◽  
Georgia Thompson ◽  
Soukaina Timouma ◽  
...  
Keyword(s):  
Gene Expression ◽  
Copy Number ◽  
Gene Dosage ◽  
Expression Patterns ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Gene Expression Patterns ◽  
Group I ◽  
Saccharomyces Pastorianus ◽  
Group Ii

The lager yeasts, Saccharomyces pastorianus, are hybrids of Saccharomyces cerevisiae and Saccharomyces eubayanus and are divided into two broad groups, Group I and II. The two groups evolved from at least one common hybridisation event but have subsequently diverged with Group I strains losing many S. cerevisiae chromosomes while the Group II strains retain both sub-genomes. The complex genomes, containing orthologous alleles from the parental chromosomes, pose interesting questions regarding gene regulation and its impact on the fermentation properties of the strains. Superimposed on the presence of orthologous alleles are complexities of gene dosage due to the aneuploid nature of the genomes. We examined the contribution of the S. cerevisiae and S. eubayanus alleles to the gene expression patterns of Group I and II strains during fermentation. We show that the relative expression of S. cerevisiae and S. eubayanus orthologues is positively correlated with gene copy number. Despite the reduced S. cerevisiae content in the Group I strain, S. cerevisiae orthologues contribute to biochemical pathways upregulated during fermentation which may explain the retention of specific chromosomes in the strain. Conversely, S. eubayanus genes are significantly overrepresented in the upregulated gene pool in the Group II strain. Comparison of the transcription profiles of Group I and II strains during fermentation identified both common and unique gene expression patterns, with gene copy number being a dominant contributory factor. Thus, the aneuploid genomes create complex patterns of gene expression during fermentation with gene dosage playing a crucial role both within and between strains.

scholarly journals Hybridization of Saccharomyces cerevisiae Sourdough Strains with Cryotolerant Saccharomyces bayanus NBRC1948 as a Strategy to Increase Diversity of Strains Available for Lager Beer Fermentation

2020 ◽  
Author(s):  
Martina Catallo ◽  
Fabrizio Iattici ◽  
Cinzia Randazzo ◽  
Cinzia Caggia ◽  
Kristoffer Krogerus ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
De Novo ◽  
Yeast Culture ◽  
Culture Collections ◽  
Lager Yeast ◽  
Ethyl Hexanoate ◽  
Brewing Yeast ◽  
Saccharomyces Bayanus ◽  
Lager Beer ◽  
Saccharomyces Eubayanus

The search for novel brewing strains from non-brewing environments represents an emerging trend to increase genetic and phenotypic diversities in brewing yeast culture collections. Another valuable tool is hybridization, where beneficial traits of individual strains are combined in a single organism. This has been used successfully to create de novo hybrids from parental brewing strains by mimicking natural Saccharomyces cerevisiae ale x Saccharomyces eubayanus lager yeast hybrids. Here, we integrated both these approaches to create synthetic hybrids for lager fermentation using parental strains from niches other than beer. Using a phenotype-centered strategy, S. cerevisiae sourdough strains and the S. eubayanus x Saccharomyces uvarum strain NBRC1948 (also referred to as Saccharomyces bayanus) were chosen for their brewing aptitudes. We demonstrated that, in contrast to S. cerevisiae x S. uvarum crosses, hybridization yield was positively affected by time of exposure to starvation, but not by staggered mating. In laboratory-scale fermentation trials at 20&deg;C, one triple S. cerevisiae x S. eubayanus x S. uvarum hybrid showed a heterotic phenotype compared with the parents. In 2L wort fermentation trials at 12&deg;C, this hybrid inherited the ability to consume efficiently maltotriose from NBRC1948 and, like the sourdough S. cerevisiae parent, produced appreciable levels of the positive aroma compounds 3-methylbutyl acetate (banana/pear), ethyl acetate (general fruit aroma) and ethyl hexanoate (green apple, aniseed, and cherry aroma). Based on these evidences, the phenotype-centered approach appears promising for design of de novo lager beer hybrids and may help to diversify aroma profiles in lager beers.

scholarly journals Hybridization of Saccharomyces cerevisiae Sourdough Strains with Cryotolerant Saccharomyces bayanus NBRC1948 as a Strategy to Increase Diversity of Strains Available for Lager Beer Fermentation

2021 ◽  
Vol 9 (3) ◽  
pp. 514
Author(s):  
Martina Catallo ◽  
Fabrizio Iattici ◽  
Cinzia L. Randazzo ◽  
Cinzia Caggia ◽  
Kristoffer Krogerus ◽  
...  
Keyword(s):  
De Novo ◽  
Yeast Culture ◽  
Culture Collections ◽  
Lager Yeast ◽  
Ethyl Hexanoate ◽  
Brewing Yeast ◽  
Single Organism ◽  
Saccharomyces Bayanus ◽  
Lager Beer ◽  
Beneficial Traits

The search for novel brewing strains from non-brewing environments represents an emerging trend to increase genetic and phenotypic diversities in brewing yeast culture collections. Another valuable tool is hybridization, where beneficial traits of individual strains are combined in a single organism. This has been used successfully to create de novo hybrids from parental brewing strains by mimicking natural Saccharomycescerevisiae ale × Saccharomyceseubayanus lager yeast hybrids. Here, we integrated both these approaches to create synthetic hybrids for lager fermentation using parental strains from niches other than beer. Using a phenotype-centered strategy, S. cerevisiae sourdough strains and the S. eubayanus × Saccharomyces uvarum strain NBRC1948 (also referred to as Saccharomyces bayanus) were chosen for their brewing aptitudes. We demonstrated that, in contrast to S. cerevisiae × S. uvarum crosses, hybridization yield was positively affected by time of exposure to starvation, but not by staggered mating. In laboratory-scale fermentation trials at 20 °C, one triple S. cerevisiae × S. eubayanus × S. uvarum hybrid showed a heterotic phenotype compared with the parents. In 2 L wort fermentation trials at 12 °C, this hybrid inherited the ability to consume efficiently maltotriose from NBRC1948 and, like the sourdough S. cerevisiae parent, produced appreciable levels of the positive aroma compounds 3-methylbutyl acetate (banana/pear), ethyl acetate (general fruit aroma) and ethyl hexanoate (green apple, aniseed, and cherry aroma). Based on these evidences, the phenotype-centered approach appears promising for designing de novo lager beer hybrids and may help to diversify aroma profiles in lager beer.

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