1
|
Muller G, de Godoy VR, Dário MG, Duval EH, Alves-Jr SL, Bücker A, Rosa CA, Dunn B, Sherlock G, Stambuk BU. Improved Sugarcane-Based Fermentation Processes by an Industrial Fuel-Ethanol Yeast Strain. J Fungi (Basel) 2023; 9:803. [PMID: 37623574 PMCID: PMC10456111 DOI: 10.3390/jof9080803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/26/2023] [Accepted: 07/27/2023] [Indexed: 08/26/2023] Open
Abstract
In Brazil, sucrose-rich broths (cane juice and/or molasses) are used to produce billions of liters of both fuel ethanol and cachaça per year using selected Saccharomyces cerevisiae industrial strains. Considering the important role of feedstock (sugar) prices in the overall process economics, to improve sucrose fermentation the genetic characteristics of a group of eight fuel-ethanol and five cachaça industrial yeasts that tend to dominate the fermentors during the production season were determined by array comparative genomic hybridization. The widespread presence of genes encoding invertase at multiple telomeres has been shown to be a common feature of both baker's and distillers' yeast strains, and is postulated to be an adaptation to sucrose-rich broths. Our results show that only two strains (one fuel-ethanol and one cachaça yeast) have amplification of genes encoding invertase, with high specific activity. The other industrial yeast strains had a single locus (SUC2) in their genome, with different patterns of invertase activity. These results indicate that invertase activity probably does not limit sucrose fermentation during fuel-ethanol and cachaça production by these industrial strains. Using this knowledge, we changed the mode of sucrose metabolism of an industrial strain by avoiding extracellular invertase activity, overexpressing the intracellular invertase, and increasing its transport through the AGT1 permease. This approach allowed the direct consumption of the disaccharide by the cells, without releasing glucose or fructose into the medium, and a 11% higher ethanol production from sucrose by the modified industrial yeast, when compared to its parental strain.
Collapse
Affiliation(s)
- Gabriela Muller
- Department of Biochemistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina 88040-900, Brazil; (G.M.); (V.R.d.G.); (M.G.D.); (E.H.D.); (S.L.A.-J.); (A.B.)
| | - Victor R. de Godoy
- Department of Biochemistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina 88040-900, Brazil; (G.M.); (V.R.d.G.); (M.G.D.); (E.H.D.); (S.L.A.-J.); (A.B.)
| | - Marcelo G. Dário
- Department of Biochemistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina 88040-900, Brazil; (G.M.); (V.R.d.G.); (M.G.D.); (E.H.D.); (S.L.A.-J.); (A.B.)
| | - Eduarda H. Duval
- Department of Biochemistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina 88040-900, Brazil; (G.M.); (V.R.d.G.); (M.G.D.); (E.H.D.); (S.L.A.-J.); (A.B.)
| | - Sergio L. Alves-Jr
- Department of Biochemistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina 88040-900, Brazil; (G.M.); (V.R.d.G.); (M.G.D.); (E.H.D.); (S.L.A.-J.); (A.B.)
| | - Augusto Bücker
- Department of Biochemistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina 88040-900, Brazil; (G.M.); (V.R.d.G.); (M.G.D.); (E.H.D.); (S.L.A.-J.); (A.B.)
| | - Carlos A. Rosa
- Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil;
| | - Barbara Dunn
- Department of Genetics, Stanford University, Stanford, CA 94305, USA; (B.D.); (G.S.)
| | - Gavin Sherlock
- Department of Genetics, Stanford University, Stanford, CA 94305, USA; (B.D.); (G.S.)
| | - Boris U. Stambuk
- Department of Biochemistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina 88040-900, Brazil; (G.M.); (V.R.d.G.); (M.G.D.); (E.H.D.); (S.L.A.-J.); (A.B.)
| |
Collapse
|
2
|
Bergin SA, Allen S, Hession C, Ó Cinnéide E, Ryan A, Byrne KP, Ó Cróinín T, Wolfe KH, Butler G. Identification of European isolates of the lager yeast parent Saccharomyces eubayanus. FEMS Yeast Res 2022; 22:6874782. [PMID: 36473696 PMCID: PMC9726447 DOI: 10.1093/femsyr/foac053] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/19/2022] [Accepted: 11/08/2022] [Indexed: 12/12/2022] Open
Abstract
Lager brewing first occurred in Bavaria in the 15th century, associated with restrictions of brewing to colder months. The lager yeast, Saccharomyces pastorianus, is cold tolerant. It is a hybrid between Saccharomyces cerevisiae and Saccharomyces eubayanus, and has been found only in industrial settings. Natural isolates of S. eubayanus were first discovered in Patagonia 11 years ago. They have since been isolated from China, Tibet, New Zealand, and North America, but not from Europe. Here, we describe the first European strains UCD646 and UCD650, isolated from a wooded area on a university campus in Dublin, Ireland. We generated complete chromosome level assemblies of both genomes using long- and short-read sequencing. The UCD isolates belong to the Holarctic clade. Genome analysis shows that isolates similar to the Irish strains contributed to the S. eubayanus component of S. pastorianus, but isolates from Tibet made a larger contribution.
Collapse
Affiliation(s)
- Sean A Bergin
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Stephen Allen
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Conor Hession
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Eoin Ó Cinnéide
- School of Medicine, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Adam Ryan
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Kevin P Byrne
- School of Medicine, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Tadhg Ó Cróinín
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Kenneth H Wolfe
- School of Medicine, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Geraldine Butler
- Corresponding author: School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland. Tel: +353-1-7166885; E-mail:
| |
Collapse
|
3
|
Maltose-Negative Yeast in Non-Alcoholic and Low-Alcoholic Beer Production. FERMENTATION-BASEL 2022. [DOI: 10.3390/fermentation8060273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although beer is a widely used beverage in many cultures, there is a need for a new drinking alternative in the face of rising issues such as health concerns or weight problems. However, non-alcoholic and low-alcoholic beers (NABLAB) still have some sensory problems that have not been fully remedied today, such as “wort-like”/”potato-like” flavours or a lack of aroma. These defects are due to the lack of alcohol (and the lack of the aldehyde-reducing effect of alcohol fermentation), as well as production techniques. The use of new yeast strains that cannot ferment maltose—the foremost sugar in the wort—is highly promising to produce a more palatable and sustainable NABLAB product because production with these yeast strains can be performed with standard brewery equipment. In the scientific literature, it is clear that interest in the production of NABLAB has increased recently, and experiments have been carried out with maltose-negative yeast strains isolated from many different environments. This study describes maltose-negative yeasts and their aromatic potential for the production of NABLAB by comprehensively examining recent academic studies.
Collapse
|
4
|
Wu Z, Wang J, Niu C, Liu C, Zheng F, Li Q. Transcriptomic and metabolomic analysis reveals genes related to stress tolerance in high gravity brewing. World J Microbiol Biotechnol 2022; 38:59. [DOI: 10.1007/s11274-021-03115-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 07/29/2021] [Indexed: 11/29/2022]
|
5
|
Selection of Saccharomyces eubayanus strains from Patagonia (Argentina) with brewing potential and performance in the craft beer industry. Eur Food Res Technol 2021. [DOI: 10.1007/s00217-021-03897-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
6
|
Timouma S, Balarezo-Cisneros LN, Pinto J, De La Cerda R, Bond U, Schwartz JM, Delneri D. Transcriptional profile of the industrial hybrid Saccharomyces pastorianus reveals temperature-dependent allele expression bias and preferential orthologous protein assemblies. Mol Biol Evol 2021; 38:5437-5452. [PMID: 34550394 PMCID: PMC8662600 DOI: 10.1093/molbev/msab282] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Saccharomyces pastorianus is a natural yeast evolved from different hybridization events between the mesophilic S. cerevisiae and the cold-tolerant S. eubayanus. This complex aneuploid hybrid carries multiple copies of the parental alleles alongside specific hybrid genes and encodes for multiple protein isoforms which impart novel phenotypes, such as the strong ability to ferment at low temperature. These characteristics lead to agonistic competition for substrates and a plethora of biochemical activities, resulting in a unique cellular metabolism. Here, we investigated the transcriptional signature of the different orthologous alleles in S. pastorianus during temperature shifts. We identified temperature-dependent media-independent genes and showed that 35% has their regulation dependent on extracellular leucine uptake, suggesting an interplay between leucine metabolism and temperature response. The analysis of the expression of ortholog parental alleles unveiled that the majority of the genes expresses preferentially one parental allele over the other and that S. eubayanus-like alleles are significantly over-represented among the genes involved in the cold acclimatization. The presence of functionally redundant parental alleles may impact on the nature of protein complexes established in the hybrid, where both parental alleles are competing. Our expression data indicate that the majority of the protein complexes investigated in the hybrid are likely to be either exclusively chimeric or unispecific and that the redundancy is discouraged, a scenario that fits well with the gene balance hypothesis. This study offers the first overview of the transcriptional pattern of S. pastorianus and provides a rationalization for its unique industrial traits at the expression level.
Collapse
Affiliation(s)
- Soukaina Timouma
- Manchester Institute of Biotechnology, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
| | | | - Javier Pinto
- Manchester Institute of Biotechnology, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
| | - Roberto De La Cerda
- Department of Microbiology, School of Genetics and Microbiology, Trinity College Dublin, Dublin, Ireland
| | - Ursula Bond
- Department of Microbiology, School of Genetics and Microbiology, Trinity College Dublin, Dublin, Ireland
| | - Jean-Marc Schwartz
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
| | - Daniela Delneri
- Manchester Institute of Biotechnology, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK.,Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
| |
Collapse
|
7
|
Giannakou K, Visinoni F, Zhang P, Nathoo N, Jones P, Cotterrell M, Vrhovsek U, Delneri D. Biotechnological exploitation of Saccharomyces jurei and its hybrids in craft beer fermentation uncovers new aroma combinations. Food Microbiol 2021; 100:103838. [PMID: 34416971 DOI: 10.1016/j.fm.2021.103838] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 04/16/2021] [Accepted: 05/25/2021] [Indexed: 12/29/2022]
Abstract
Hybridisation is an important evolutionary mechanism to bring about novel phenotypes and may produce new hybrids with advantageous combinations of traits of industrial importance. Within the Saccharomyces genus, Saccharomyces jurei is a newly discovered species and its biotechnological potential has not yet been fully explored. This yeast was found to be able to grow well in unhopped wort and at low temperatures, qualities necessary in good candidates for fermented bevarages. Here, we analysed its fermentation and aroma profile and created novel non-GMO hybrids between S. jurei and S. cerevisiae ale yeasts to develop new starter strains with interesting flavours for the craft brewing and beverage industry in general. Pilot beer fermentations with specific hybrids showed a good fermentation performance, similar to the ale parent strain, while eliminating the hyper-attenuation characteristic and a more complex flavour profile. This study exploits the genetic diversity of yeasts and shows how inter-specific hybridisation and clone selection can be effectively used in brewing to create new products and to eliminate or increase specific traits.
Collapse
Affiliation(s)
- Konstantina Giannakou
- Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK; Cloudwater Brew Co, 7-8 Piccadilly Trading Estate, Manchester, M1 2NP, UK
| | - Federico Visinoni
- Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - Penghan Zhang
- Foundation Edmund Mach, Via Edmund Mach 1, 38010, San Michele all'Adige, TN, Italy
| | - Nishan Nathoo
- Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - Paul Jones
- Cloudwater Brew Co, 7-8 Piccadilly Trading Estate, Manchester, M1 2NP, UK
| | - Mark Cotterrell
- Cloudwater Brew Co, 7-8 Piccadilly Trading Estate, Manchester, M1 2NP, UK
| | - Urska Vrhovsek
- Foundation Edmund Mach, Via Edmund Mach 1, 38010, San Michele all'Adige, TN, Italy
| | - Daniela Delneri
- Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK.
| |
Collapse
|
8
|
Improving the Utilization of Isomaltose and Panose by Lager Yeast Saccharomyces pastorianus. FERMENTATION 2021. [DOI: 10.3390/fermentation7030107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Approximately 25% of all carbohydrates in industrial worts are poorly, if at all, fermented by brewing yeast. This includes dextrins, β-glucans, arabinose, xylose, disaccharides such as isomaltose, nigerose, kojibiose, and trisaccharides such as panose and isopanose. As the efficient utilization of carbohydrates during the wort’s fermentation impacts the alcohol yield and the organoleptic traits of the product, developing brewing strains with enhanced abilities to ferment subsets of these sugars is highly desirable. In this study, we developed Saccharomyces pastorianus laboratory yeast strains with a superior capacity to grow on isomaltose and panose. First, we designed a plasmid toolbox for the stable integration of genes into lager strains. Next, we used the toolbox to elevate the levels of the α-glucoside transporter Agt1 and the major isomaltase Ima1. This was achieved by integrating synthetic AGT1 and IMA1 genes under the control of strong constitutive promoters into defined genomic sites. As a result, strains carrying both genes showed a superior capacity to grow on panose and isomaltose, indicating that Ima1 and Agt1 act in synergy to consume these sugars. Our study suggests that non-GMO strategies aiming to develop strains with improved isomaltose and panose utilization could include identifying strains that overexpress AGT1 and IMA1.
Collapse
|
9
|
Lin CL, García-Caro RDLC, Zhang P, Carlin S, Gottlieb A, Petersen MA, Vrhovsek U, Bond U. Packing a punch: understanding how flavours are produced in lager fermentations. FEMS Yeast Res 2021; 21:6316108. [PMID: 34227660 PMCID: PMC8310685 DOI: 10.1093/femsyr/foab040] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 07/02/2021] [Indexed: 11/14/2022] Open
Abstract
Beer is one of the most popular beverages in the world and it has an irreplaceable place in culture. Although invented later than ale, lager beers dominate the current market. Many factors relating to the appearance (colour, clarity and foam stability) and sensory characters (flavour, taste and aroma) of beer, and other psychological determinants affect consumers' perception of the product and defines its drinkability. This review takes a wholistic approach to scrutinise flavour generation in the brewing process, focusing particularly on the contribution of the raw ingredients and the yeasts to the final flavour profiles of lager beers. In addition, we examine current developments to improve lager beer flavour profiles for the modern consumers.
Collapse
Affiliation(s)
- Claire Lin Lin
- Brewing 345, Novozymes A/S, Biologiensvej 2, 2800 Kongens, Lyngby, Denmark.,Department of Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg, Denmark
| | | | - Penghan Zhang
- Metabolomic Unit, Food Quality and Nutrition Department, Research and Innovation Centre, Edmund Mach Foundation, Via E.Mach 1, 38010 S.Michele all'Adige, Italy
| | - Silvia Carlin
- Metabolomic Unit, Food Quality and Nutrition Department, Research and Innovation Centre, Edmund Mach Foundation, Via E.Mach 1, 38010 S.Michele all'Adige, Italy
| | - Andrea Gottlieb
- Brewing 345, Novozymes A/S, Biologiensvej 2, 2800 Kongens, Lyngby, Denmark
| | - Mikael Agerlin Petersen
- Department of Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg, Denmark
| | - Urska Vrhovsek
- Metabolomic Unit, Food Quality and Nutrition Department, Research and Innovation Centre, Edmund Mach Foundation, Via E.Mach 1, 38010 S.Michele all'Adige, Italy
| | - Ursula Bond
- School of Genetics and Microbiology, The Moyne Institute, Trinity College Dublin, Dublin 2, Ireland
| |
Collapse
|
10
|
Performance of Wild Non-Conventional Yeasts in Fermentation of Wort Based on Different Malt Extracts to Select Novel Starters for Low-Alcohol Beers. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11020801] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Nowadays, the increasing interest in new market demand for alcoholic beverages has stimulated the research on useful strategies to reduce the ethanol content in beer. In this context, the use of non-Saccharomyces yeasts to produce low-alcohol or alcohol-free beer may provide an innovative approach for the beer market. In our study, four wild non-Saccharomyces yeasts, belonging to Torulaspora delbrueckii, Candida zemplinina and Zygosaccharomyces bailii species, were tested in mixed fermentation with a wild selected Saccharomyces cerevisiae strain as starters for fermentation of different commercial substrates used for production of different beer styles (Pilsner, Weizen and Amber) to evaluate the influence of the fermentative medium on starter behaviour. The results obtained showed the influence of non-Saccharomyces strains on the ethanol content and organoleptic quality of the final beers and a significant wort–starter interaction. In particular, each starter showed a different sugar utilization rate in each substrate, in consequence of uptake efficiency correlated to the strain-specific metabolic pathway and substrate composition. The most suitable mixed starter was P4-CZ3 (S. cerevisiae–C. zemplinina), which is a promising starter for the production of low-alcohol beers with pleasant organoleptic characteristics in all the tested fermentation media.
Collapse
|
11
|
Bourbon-Melo N, Palma M, Rocha MP, Ferreira A, Bronze MR, Elias H, Sá-Correia I. Use of Hanseniaspora guilliermondii and Hanseniaspora opuntiae to enhance the aromatic profile of beer in mixed-culture fermentation with Saccharomyces cerevisiae. Food Microbiol 2020; 95:103678. [PMID: 33397613 DOI: 10.1016/j.fm.2020.103678] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 10/09/2020] [Accepted: 11/09/2020] [Indexed: 12/16/2022]
Abstract
Beer production is predominantly carried out by Saccharomyces species, such as S. cerevisiae and S. pastorianus. However, the introduction of non-Saccharomyces yeasts in the brewing process is now seen as a promising strategy to improve and differentiate the organoleptic profile of beer. In this study, 17 non-Saccharomyces strains of 12 distinct species were isolated and submitted to a preliminary sensory evaluation to determine their potential for beer bioflavouring. Hanseniaspora guilliermondii IST315 and H. opuntiae IST408 aroma profiles presented the highest acceptability and were described as having 'fruity' and 'toffee' notes, respectively. Their presence in mixed-culture fermentations with S. cerevisiae US-05 did not influence attenuation and ethanol concentration of beer but had a significant impact in its volatile composition. Notably, while both strains reduced the total amount of ethyl esters, H. guilliermondii IST315 greatly increased the concentration of acetate esters, especially when sequentially inoculated, leading to an 8.2-fold increase in phenylethyl acetate ('rose', 'honey' aroma) in the final beverage. These findings highlight the importance of non-Saccharomyces yeasts in shaping the aroma profile of beer and suggest a role for Hanseniaspora spp. in improving it.
Collapse
Affiliation(s)
- Nuno Bourbon-Melo
- iBB - Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal; Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal
| | - Margarida Palma
- iBB - Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal; Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal.
| | - Miguel Pinto Rocha
- iBB - Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal; Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal
| | - António Ferreira
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2780-901, Oeiras, Portugal
| | - Maria Rosário Bronze
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2780-901, Oeiras, Portugal; iMED, Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-019, Lisboa, Portugal; ITQB, Instituto de Tecnologia Química e Biológica, Av. da República, 2780-157, Oeiras, Portugal
| | - Hugo Elias
- D'Ourique Flavours - Cerveja Artesanal, Rua dos Cordeiros, S/N, 2640-401, Achada, Mafra, Portugal
| | - Isabel Sá-Correia
- iBB - Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal; Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal
| |
Collapse
|
12
|
Gorter de Vries AR, Pronk JT, Daran JMG. Lager-brewing yeasts in the era of modern genetics. FEMS Yeast Res 2020; 19:5573808. [PMID: 31553794 PMCID: PMC6790113 DOI: 10.1093/femsyr/foz063] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Accepted: 09/23/2019] [Indexed: 12/11/2022] Open
Abstract
The yeast Saccharomyces pastorianus is responsible for the annual worldwide production of almost 200 billion liters of lager-type beer. S. pastorianus is a hybrid of Saccharomyces cerevisiae and Saccharomyces eubayanus that has been studied for well over a century. Scientific interest in S. pastorianus intensified upon the discovery, in 2011, of its S. eubayanus ancestor. Moreover, advances in whole-genome sequencing and genome editing now enable deeper exploration of the complex hybrid and aneuploid genome architectures of S. pastorianus strains. These developments not only provide novel insights into the emergence and domestication of S. pastorianus but also generate new opportunities for its industrial application. This review paper combines historical, technical and socioeconomic perspectives to analyze the evolutionary origin and genetics of S. pastorianus. In addition, it provides an overview of available methods for industrial strain improvement and an outlook on future industrial application of lager-brewing yeasts. Particular attention is given to the ongoing debate on whether current S. pastorianus originates from a single or multiple hybridization events and to the potential role of genome editing in developing industrial brewing yeast strains.
Collapse
Affiliation(s)
- Arthur R Gorter de Vries
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Jack T Pronk
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Jean-Marc G Daran
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| |
Collapse
|
13
|
Christofoleti-Furlan RM, Portugal CB, Varize CS, Muynarsk ESM, Alcarde AR, Basso LC. Unraveling Brazilian bioethanol yeasts as novel starters for high-gravity brewing. Food Res Int 2020; 135:109282. [PMID: 32527477 DOI: 10.1016/j.foodres.2020.109282] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 04/14/2020] [Accepted: 04/29/2020] [Indexed: 01/21/2023]
Abstract
High-gravity (HG) brewing has broader application to succeed on beer differentiation and production optimization. However, such process imposes a handicap to yeasts, which must be able to deal with stressful conditions in fermentation. In this work, we assessed different physiological traits of 24 Saccharomyces cerevisiae strains isolated from Brazilian bioethanol distilleries for the selection of novel starters for HG brewing. Five yeast strains were selected with ability to overcome different stressors under HG beer fermentation, showing high fermentability rates, resilience to ethanol stress, low production of foam and hydrogen sulfide, as well as similar flocculation rates to brewer's yeasts. After five fermentation recycles, most strains sustained a viability rate higher than 90% and were able to efficiently accumulate trehalose and glycogen, besides presenting no detectable petite mutants at the final stage. In the sensory analysis, the beers obtained from the five selected strains showed greater aromatic complexity, with predominance of 'spicy', 'dried' and 'fresh fruits' descriptors. In conclusion, this study sheds light on the potential of yeast strains from Brazilian bioethanol process to produce distinctive specialty beers, aside from proposing an effective selection methodology based on relevant physiological attributes for HG brewing process.
Collapse
Affiliation(s)
- R M Christofoleti-Furlan
- Dept. Ciências Biológicas, Laboratório de Bioquímica e Tecnologia de Leveduras, Escola Superior de Agricultura "Luiz de Queiroz", University of São Paulo, Avenida Pádua Dias 11, 13418-900 Piracicaba, SP, Brazil.
| | - C B Portugal
- Dept. Agroindústria, Alimentos e Nutrição, Laboratório de Biotecnologia de Alimentos e Bebidas, Escola Superior de Agricultura "Luiz de Queiroz", University of São Paulo, Avenida Pádua Dias 11, 13418-900 Piracicaba, SP, Brazil.
| | - C S Varize
- Dept. Ciências Biológicas, Laboratório de Bioquímica e Tecnologia de Leveduras, Escola Superior de Agricultura "Luiz de Queiroz", University of São Paulo, Avenida Pádua Dias 11, 13418-900 Piracicaba, SP, Brazil.
| | - E S M Muynarsk
- Dept. Ciências Biológicas, Laboratório de Bioquímica e Tecnologia de Leveduras, Escola Superior de Agricultura "Luiz de Queiroz", University of São Paulo, Avenida Pádua Dias 11, 13418-900 Piracicaba, SP, Brazil.
| | - A R Alcarde
- Dept. Agroindústria, Alimentos e Nutrição, Laboratório de Tecnologia e Qualidade de Bebidas, Escola Superior de Agricultura "Luiz de Queiroz", University of São Paulo, Avenida Pádua Dias 11, 13418-900 Piracicaba, SP, Brazil.
| | - L C Basso
- Dept. Ciências Biológicas, Laboratório de Bioquímica e Tecnologia de Leveduras, Escola Superior de Agricultura "Luiz de Queiroz", University of São Paulo, Avenida Pádua Dias 11, 13418-900 Piracicaba, SP, Brazil.
| |
Collapse
|
14
|
Brouwers N, Brickwedde A, Gorter de Vries AR, van den Broek M, Weening SM, van den Eijnden L, Diderich JA, Bai FY, Pronk JT, Daran JMG. Himalayan Saccharomyces eubayanus Genome Sequences Reveal Genetic Markers Explaining Heterotic Maltotriose Consumption by Saccharomyces pastorianus Hybrids. Appl Environ Microbiol 2019; 85:e01516-19. [PMID: 31519660 PMCID: PMC6821976 DOI: 10.1128/aem.01516-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 09/04/2019] [Indexed: 12/27/2022] Open
Abstract
Saccharomyces pastorianus strains are hybrids of Saccharomyces cerevisiae and Saccharomyces eubayanus that have been domesticated for centuries in lager beer brewing environments. As sequences and structures of S. pastorianus genomes are being resolved, molecular mechanisms and evolutionary origins of several industrially relevant phenotypes remain unknown. This study investigates how maltotriose metabolism, a key feature in brewing, may have arisen in early S. eubayanus × S. cerevisiae hybrids. To address this question, we generated a nearly complete genome assembly of Himalayan S. eubayanus strains of the Holarctic subclade. This group of strains has been proposed to be the S. eubayanus subgenome origin of current S. pastorianus strains. The Himalayan S. eubayanus genomes harbored several copies of an S. eubayanusAGT1 (SeAGT1) α-oligoglucoside transporter gene with high sequence identity to genes encountered in S. pastorianus Although Himalayan S. eubayanus strains cannot grow on maltose and maltotriose, their maltose-hydrolase and SeMALT1 and SeAGT1 maltose transporter genes complemented the corresponding null mutants of S. cerevisiae Expression, in Himalayan S. eubayanus of a functional S. cerevisiae maltose metabolism regulator gene (MALx3) enabled growth on oligoglucosides. The hypothesis that the maltotriose-positive phenotype in S. pastorianus is a result of heterosis was experimentally tested by constructing an S. cerevisiae × S. eubayanus laboratory hybrid with a complement of maltose metabolism genes that resembles that of current S. pastorianus strains. The ability of this hybrid to consume maltotriose in brewer's wort demonstrated regulatory cross talk between subgenomes and thereby validated this hypothesis. These results support experimentally the new postulated hypothesis on the evolutionary origin of an essential phenotype of lager brewing strains and valuable knowledge for industrial exploitation of laboratory-made S. pastorianus-like hybrids.IMPORTANCES. pastorianus, an S. cerevisiae × S. eubayanus hybrid, is used for production of lager beer, the most produced alcoholic beverage worldwide. It emerged by spontaneous hybridization and colonized early lager brewing processes. Despite accumulation and analysis of genome sequencing data of S. pastorianus parental genomes, the genetic blueprint of industrially relevant phenotypes remains unresolved. Assimilation of maltotriose, an abundant sugar in wort, has been postulated to be inherited from the S. cerevisiae parent. Here, we demonstrate that although Asian S. eubayanus isolates harbor a functional maltotriose transporter SeAGT1 gene, they are unable to grow on α-oligoglucosides, but expression of S. cerevisiae regulator MAL13 (ScMAL13) was sufficient to restore growth on trisaccharides. We hypothesized that the S. pastorianus maltotriose phenotype results from regulatory interaction between S. cerevisiae maltose transcription activator and the promoter of SeAGT1 We experimentally confirmed the heterotic nature of the phenotype, and thus these results provide experimental evidence of the evolutionary origin of an essential phenotype of lager brewing strains.
Collapse
Affiliation(s)
- Nick Brouwers
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Anja Brickwedde
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | | | - Marcel van den Broek
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Susan M Weening
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | | | - Jasper A Diderich
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Feng-Yan Bai
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Jack T Pronk
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Jean-Marc G Daran
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| |
Collapse
|
15
|
Zhuang S, Smart K, Powell CD. The Relationship Between Wort Sugar Concentration and Yeast Carbon Partitioning During Brewing Fermentations. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2019. [DOI: 10.1080/03610470.2019.1666630] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Shiwen Zhuang
- School of Biosciences, University of Nottingham, Loughborough, UK
| | - Katherine Smart
- School of Biosciences, University of Nottingham, Loughborough, UK
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridgeshire, UK
| | - Chris D. Powell
- School of Biosciences, University of Nottingham, Loughborough, UK
| |
Collapse
|
16
|
Peltier E, Friedrich A, Schacherer J, Marullo P. Quantitative Trait Nucleotides Impacting the Technological Performances of Industrial Saccharomyces cerevisiae Strains. Front Genet 2019; 10:683. [PMID: 31396264 PMCID: PMC6664092 DOI: 10.3389/fgene.2019.00683] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 07/01/2019] [Indexed: 11/13/2022] Open
Abstract
The budding yeast Saccharomyces cerevisiae is certainly the prime industrial microorganism and is related to many biotechnological applications including food fermentations, biofuel production, green chemistry, and drug production. A noteworthy characteristic of this species is the existence of subgroups well adapted to specific processes with some individuals showing optimal technological traits. In the last 20 years, many studies have established a link between quantitative traits and single-nucleotide polymorphisms found in hundreds of genes. These natural variations constitute a pool of QTNs (quantitative trait nucleotides) that modulate yeast traits of economic interest for industry. By selecting a subset of genes functionally validated, a total of 284 QTNs were inventoried. Their distribution across pan and core genome and their frequency within the 1,011 Saccharomyces cerevisiae genomes were analyzed. We found that 150 of the 284 QTNs have a frequency lower than 5%, meaning that these variants would be undetectable by genome-wide association studies (GWAS). This analysis also suggests that most of the functional variants are private to a subpopulation, possibly due to their adaptive role to specific industrial environment. In this review, we provide a literature survey of their phenotypic impact and discuss the opportunities and the limits of their use for industrial strain selection.
Collapse
Affiliation(s)
- Emilien Peltier
- Department Sciences du vivant et de la sante, Université de Bordeaux, UR Œnologie EA 4577, Bordeaux, France
- Biolaffort, Bordeaux, France
| | - Anne Friedrich
- Department Micro-organismes, Génomes, Environnement, Université de Strasbourg, CNRS, GMGM UMR 7156, Strasbourg, France
| | - Joseph Schacherer
- Department Micro-organismes, Génomes, Environnement, Université de Strasbourg, CNRS, GMGM UMR 7156, Strasbourg, France
| | - Philippe Marullo
- Department Sciences du vivant et de la sante, Université de Bordeaux, UR Œnologie EA 4577, Bordeaux, France
- Biolaffort, Bordeaux, France
| |
Collapse
|
17
|
Brouwers N, Gorter de Vries AR, van den Broek M, Weening SM, Elink Schuurman TD, Kuijpers NGA, Pronk JT, Daran JMG. In vivo recombination of Saccharomyces eubayanus maltose-transporter genes yields a chimeric transporter that enables maltotriose fermentation. PLoS Genet 2019; 15:e1007853. [PMID: 30946741 PMCID: PMC6448828 DOI: 10.1371/journal.pgen.1007853] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 11/26/2018] [Indexed: 11/18/2022] Open
Abstract
Saccharomyces eubayanus is the non-S. cerevisiae parent of the lager-brewing hybrid S. pastorianus. In contrast to most S. cerevisiae and Frohberg-type S. pastorianus strains, S. eubayanus cannot utilize the α-tri-glucoside maltotriose, a major carbohydrate in brewer’s wort. In Saccharomyces yeasts, utilization of maltotriose is encoded by the subtelomeric MAL gene family, and requires transporters for maltotriose uptake. While S. eubayanus strain CBS 12357T harbors four SeMALT genes which enable uptake of the α-di-glucoside maltose, it lacks maltotriose transporter genes. In S. cerevisiae, sequence identity indicates that maltotriose and maltose transporters likely evolved from a shared ancestral gene. To study the evolvability of maltotriose utilization in S. eubayanus CBS 12357T, maltotriose-assimilating mutants obtained after UV mutagenesis were subjected to laboratory evolution in carbon-limited chemostat cultures on maltotriose-enriched wort. An evolved strain showed improved maltose and maltotriose fermentation in 7 L fermenter experiments on industrial wort. Whole-genome sequencing revealed a novel mosaic SeMALT413 gene, resulting from repeated gene introgressions by non-reciprocal translocation of at least three SeMALT genes. The predicted tertiary structure of SeMalT413 was comparable to the original SeMalT transporters, but overexpression of SeMALT413 sufficed to enable growth on maltotriose, indicating gene neofunctionalization had occurred. The mosaic structure of SeMALT413 resembles the structure of S. pastorianus maltotriose-transporter gene SpMTY1, which has high sequences identity to alternatingly S. cerevisiae MALx1, S. paradoxus MALx1 and S. eubayanus SeMALT3. Evolution of the maltotriose transporter landscape in hybrid S. pastorianus lager-brewing strains is therefore likely to have involved mechanisms similar to those observed in the present study. Fermentation of the wort sugar maltotriose is critical for the flavor profile obtained during beer brewing. The recently discovered yeast Saccharomyces eubayanus is gaining popularity as an alternative to S. pastorianus and S. cerevisiae for brewing, however it is unable to utilize maltotriose. Here, a combination of non-GMO mutagenesis and laboratory evolution of the S. eubayanus type strain CBS 12357T was used to enable maltotriose fermentation and improve brewing performance. The improved strain expressed a novel transporter gene, SeMALT413, which was formed by recombination between three different SeMALT maltose-transporter genes. Overexpression of SeMALT413 in CBS 12357T confirmed its neofunctionalization as a maltotriose transporter. As the S. pastorianus maltotriose transporter SpMty1 has a mosaic structure similar to SeMalT413, maltotriose utilization likely involved similar recombination events during the domestication of current lager brewing strains. Based on a posteriori sequence analysis, the emergence of gene functions has been attributed to gene neofunctionalization in a broad range of organisms. The real-time observation of neofunctionalization during laboratory evolution constitutes an important validation of the relevance and importance of this mechanism for Darwinian evolution.
Collapse
Affiliation(s)
- Nick Brouwers
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629HZ Delft, The Netherlands
| | - Arthur R. Gorter de Vries
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629HZ Delft, The Netherlands
| | - Marcel van den Broek
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629HZ Delft, The Netherlands
| | - Susan M. Weening
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629HZ Delft, The Netherlands
| | | | - Niels G. A. Kuijpers
- HEINEKEN Supply Chain B.V., Global Innovation and Research, Zoeterwoude, Netherlands
| | - Jack T. Pronk
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629HZ Delft, The Netherlands
| | - Jean-Marc G. Daran
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629HZ Delft, The Netherlands
- * E-mail:
| |
Collapse
|
18
|
Baker EP, Hittinger CT. Evolution of a novel chimeric maltotriose transporter in Saccharomyces eubayanus from parent proteins unable to perform this function. PLoS Genet 2019; 15:e1007786. [PMID: 30946740 PMCID: PMC6448821 DOI: 10.1371/journal.pgen.1007786] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 10/25/2018] [Indexed: 11/23/2022] Open
Abstract
At the molecular level, the evolution of new traits can be broadly divided between changes in gene expression and changes in protein-coding sequence. For proteins, the evolution of novel functions is generally thought to proceed through sequential point mutations or recombination of whole functional units. In Saccharomyces, the uptake of the sugar maltotriose into the cell is the primary limiting factor in its utilization, but maltotriose transporters are relatively rare, except in brewing strains. No known wild strains of Saccharomyces eubayanus, the cold-tolerant parent of hybrid lager-brewing yeasts (Saccharomyces cerevisiae x S. eubayanus), are able to consume maltotriose, which limits their ability to fully ferment malt extract. In one strain of S. eubayanus, we found a gene closely related to a known maltotriose transporter and were able to confer maltotriose consumption by overexpressing this gene or by passaging the strain on maltose. Even so, most wild strains of S. eubayanus lack native maltotriose transporters. To determine how this rare trait could evolve in naive genetic backgrounds, we performed an adaptive evolution experiment for maltotriose consumption, which yielded a single strain of S. eubayanus able to grow on maltotriose. We mapped the causative locus to a gene encoding a novel chimeric transporter that was formed by an ectopic recombination event between two genes encoding transporters that are unable to import maltotriose. In contrast to classic models of the evolution of novel protein functions, the recombination breakpoints occurred within a single functional domain. Thus, the ability of the new protein to carry maltotriose was likely acquired through epistatic interactions between independently evolved substitutions. By acquiring multiple mutations at once, the transporter rapidly gained a novel function, while bypassing potentially deleterious intermediate steps. This study provides an illuminating example of how recombination between paralogs can establish novel interactions among substitutions to create adaptive functions. Hybrids of the yeasts Saccharomyces cerevisiae and Saccharomyces eubayanus (lager-brewing yeasts) dominate the modern brewing industry. S. cerevisiae, also known as baker’s yeast, is well-known for its role in industry and scientific research. Less well recognized is S. eubayanus, which was only discovered as a pure species in 2011. While most lager-brewing yeasts rapidly and completely utilize the important brewing sugar maltotriose, no strain of S. eubayanus isolated to date is known to do so. Despite being unable to consume maltotriose, we identified one strain of S. eubayanus carrying a gene for a functional maltotriose transporter, although most strains lack this gene. During an adaptive evolution experiment, a strain of S. eubayanus without native maltotriose transporters evolved the ability to grow on maltotriose. Maltotriose consumption in the evolved strain resulted from a chimeric transporter that arose by shuffling genes encoding parent proteins that were unable to transport maltotriose. Traditionally, functional chimeric proteins are thought to evolve by shuffling discrete functional domains or modules, but the breakpoints in the chimera studied here occurred within the single functional module of the protein. These results support the less well-recognized role of shuffling duplicate gene sequences to generate novel proteins with adaptive functions.
Collapse
Affiliation(s)
- EmilyClare P. Baker
- Laboratory of Genetics, Microbiology Doctoral Training Program, Genome Center of Wisconsin, Wisconsin Energy Institute, J. F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Chris Todd Hittinger
- Laboratory of Genetics, Microbiology Doctoral Training Program, Genome Center of Wisconsin, Wisconsin Energy Institute, J. F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail:
| |
Collapse
|
19
|
Gorter de Vries AR, Voskamp MA, van Aalst ACA, Kristensen LH, Jansen L, van den Broek M, Salazar AN, Brouwers N, Abeel T, Pronk JT, Daran JMG. Laboratory Evolution of a Saccharomyces cerevisiae × S. eubayanus Hybrid Under Simulated Lager-Brewing Conditions. Front Genet 2019; 10:242. [PMID: 31001314 PMCID: PMC6455053 DOI: 10.3389/fgene.2019.00242] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 03/04/2019] [Indexed: 11/23/2022] Open
Abstract
Saccharomyces pastorianus lager-brewing yeasts are domesticated hybrids of S. cerevisiae x S. eubayanus that display extensive inter-strain chromosome copy number variation and chromosomal recombinations. It is unclear to what extent such genome rearrangements are intrinsic to the domestication of hybrid brewing yeasts and whether they contribute to their industrial performance. Here, an allodiploid laboratory hybrid of S. cerevisiae and S. eubayanus was evolved for up to 418 generations on wort under simulated lager-brewing conditions in six independent sequential batch bioreactors. Characterization of 55 single-cell isolates from the evolved cultures showed large phenotypic diversity and whole-genome sequencing revealed a large array of mutations. Frequent loss of heterozygosity involved diverse, strain-specific chromosomal translocations, which differed from those observed in domesticated, aneuploid S. pastorianus brewing strains. In contrast to the extensive aneuploidy of domesticated S. pastorianus strains, the evolved isolates only showed limited (segmental) aneuploidy. Specific mutations could be linked to calcium-dependent flocculation, loss of maltotriose utilization and loss of mitochondrial activity, three industrially relevant traits that also occur in domesticated S. pastorianus strains. This study indicates that fast acquisition of extensive aneuploidy is not required for genetic adaptation of S. cerevisiae × S. eubayanus hybrids to brewing environments. In addition, this work demonstrates that, consistent with the diversity of brewing strains for maltotriose utilization, domestication under brewing conditions can result in loss of this industrially relevant trait. These observations have important implications for the design of strategies to improve industrial performance of novel laboratory-made hybrids.
Collapse
Affiliation(s)
- Arthur R. Gorter de Vries
- Industrial Microbiology, Department of Biotechnology Delft, Delft University of Technology, Delft, Netherlands
| | - Maaike A. Voskamp
- Industrial Microbiology, Department of Biotechnology Delft, Delft University of Technology, Delft, Netherlands
| | - Aafke C. A. van Aalst
- Industrial Microbiology, Department of Biotechnology Delft, Delft University of Technology, Delft, Netherlands
| | - Line H. Kristensen
- Industrial Microbiology, Department of Biotechnology Delft, Delft University of Technology, Delft, Netherlands
| | - Liset Jansen
- Industrial Microbiology, Department of Biotechnology Delft, Delft University of Technology, Delft, Netherlands
| | - Marcel van den Broek
- Industrial Microbiology, Department of Biotechnology Delft, Delft University of Technology, Delft, Netherlands
| | - Alex N. Salazar
- Delft Bioinformatics Lab, Department of Intelligent Systems, Delft University of Technology, Delft, Netherlands
| | - Nick Brouwers
- Industrial Microbiology, Department of Biotechnology Delft, Delft University of Technology, Delft, Netherlands
| | - Thomas Abeel
- Delft Bioinformatics Lab, Department of Intelligent Systems, Delft University of Technology, Delft, Netherlands
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Boston, MA, United States
| | - Jack T. Pronk
- Industrial Microbiology, Department of Biotechnology Delft, Delft University of Technology, Delft, Netherlands
| | - Jean-Marc G. Daran
- Industrial Microbiology, Department of Biotechnology Delft, Delft University of Technology, Delft, Netherlands
| |
Collapse
|
20
|
Brickwedde A, Brouwers N, van den Broek M, Gallego Murillo JS, Fraiture JL, Pronk JT, Daran JMG. Structural, Physiological and Regulatory Analysis of Maltose Transporter Genes in Saccharomyces eubayanus CBS 12357 T. Front Microbiol 2018; 9:1786. [PMID: 30147677 PMCID: PMC6097016 DOI: 10.3389/fmicb.2018.01786] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 07/17/2018] [Indexed: 11/13/2022] Open
Abstract
Saccharomyces pastorianus lager brewing yeasts are domesticated hybrids of Saccharomyces cerevisiae and cold-tolerant Saccharomyces eubayanus. To understand the contribution of both parental genomes to maltose metabolism in brewing wort, this study focuses on maltose transport in the S. eubayanus type strain CBS 12357T/FM1318. To obtain complete sequences of the MAL loci of this strain, a near-complete genome assembly was generated using the Oxford Nanopore Technology MinION sequencing platform. Except for CHRXII, all sixteen chromosomes were assembled as single contigs. Four loci harboring putative maltose transporter genes (SeMALT1-4), located in subtelomeric regions of CHRII, CHRV, CHRXIII, and CHRXVI, were completely resolved. The near-identical loci on CHRV and CHRXVI strongly resembled canonical S. cerevisiae MAL loci, while those on CHRII and CHRXIII showed different structures suggestive of gene loss. Overexpression of SeMALT1-4 in a maltose-transport-deficient S. cerevisiae strain restored growth on maltose, but not on maltotriose, indicating maltose-specific transport functionality of all four transporters. Simultaneous CRISPR-Cas9-assisted deletion of only SeMALT2 and SeMALT4, which shared 99.7% sequence identity, eliminated growth of S. eubayanus CBS 12357T on maltose. Transcriptome analysis of S. eubayanus CBS 12357T established that SeMALT1 and SeMALT3, are poorly expressed in maltose-grown cultures, while SeMALT2 and SeMALT4 were expressed at much higher levels than SeMALT1 and SeMALT3, indicating that only SeMALT2/4 are responsible for maltose consumption in CBS 12357T. These results represent a first genomic and physiological characterization of maltose transport in S. eubayanus CBS 12357T and provides a valuable resource for further industrial exploitation of this yeast.
Collapse
Affiliation(s)
- Anja Brickwedde
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
| | - Nick Brouwers
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
| | | | | | - Julie L Fraiture
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
| | - Jack T Pronk
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
| | - Jean-Marc G Daran
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
| |
Collapse
|
21
|
Capece A, Romaniello R, Pietrafesa A, Siesto G, Pietrafesa R, Zambuto M, Romano P. Use of Saccharomyces cerevisiae var. boulardii in co-fermentations with S. cerevisiae for the production of craft beers with potential healthy value-added. Int J Food Microbiol 2018; 284:22-30. [PMID: 29990636 DOI: 10.1016/j.ijfoodmicro.2018.06.028] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 06/07/2018] [Accepted: 06/29/2018] [Indexed: 01/24/2023]
Abstract
In recent years, the awareness of consumers about the impact of food on health is constantly increasing. A high amount of dietary antioxidant intake can be supplied by beverages widely consumed, such as wine, coffee, beer. Recently, an increase in the consumer interest was observed for beer, in consequence of the high phenolic antioxidants and low ethanol content present in this beverage. Among all beer types, in recent years, consumption of craft beers has gained popularity. Being an unpasteurized and unfiltered, craft beer is potentially a new vehicle for delivering health effects. While health benefits of lactic acid bacteria as probiotics are well known, few data are available on probiotic yeasts in fermented food. Therefore, this study was aimed to analyse the effect of integrating the well-known probiotic yeast strain of S. cerevisiae var. boulardii (S.b) in mixed cultures with S. cerevisiae strains for production of beers with increased healthy benefits. The probiotic strain of S.b was tested in mixed cultures with selected S. cerevisiae strains, during wort fermentation. As the viability during processing operations is one of the criteria for selecting suitable strains of probiotic microorganisms, the survival of probiotic yeast during the fermentation and the presence of highly viable cells at the end of fermentations were evaluated. In almost all the mixed fermentations, at the end of the process the probiotic yeast was predominant on S. cerevisiae strain, and the experimental beers contained a high number of viable cells of S.b strain (ranging between 8 × 106 and 7.0 × 107/mL). The analysis of experimental beers for the content of main volatile compounds showed that the inclusion of S.b strain in mixed starter did not affect negatively beer aroma. Moreover, the inclusion of S.b strain in mixed starters determined an increase in the antioxidant activity and polyphenols content, in comparison to beers from single starter fermentations, indicating the influence of S.b strain on these parameters. Some mixed starter cultures tested in this study resulted a very promising tool to increase the healthy quality of the product, such as the improve the antioxidant activity and polyphenols content of beer.
Collapse
Affiliation(s)
- Angela Capece
- Scuola di Scienze Agrarie, Forestali, Alimentari ed Ambientali, Università degli Studi della Basilicata, Potenza, Italy.
| | - Rossana Romaniello
- Scuola di Scienze Agrarie, Forestali, Alimentari ed Ambientali, Università degli Studi della Basilicata, Potenza, Italy
| | - Angela Pietrafesa
- Scuola di Scienze Agrarie, Forestali, Alimentari ed Ambientali, Università degli Studi della Basilicata, Potenza, Italy
| | - Gabriella Siesto
- Scuola di Scienze Agrarie, Forestali, Alimentari ed Ambientali, Università degli Studi della Basilicata, Potenza, Italy
| | - Rocchina Pietrafesa
- Scuola di Scienze Agrarie, Forestali, Alimentari ed Ambientali, Università degli Studi della Basilicata, Potenza, Italy
| | - Marianna Zambuto
- Scuola di Scienze Agrarie, Forestali, Alimentari ed Ambientali, Università degli Studi della Basilicata, Potenza, Italy
| | - Patrizia Romano
- Scuola di Scienze Agrarie, Forestali, Alimentari ed Ambientali, Università degli Studi della Basilicata, Potenza, Italy
| |
Collapse
|
22
|
Vidgren V, Londesborough J. Overexpressed maltose transporters in laboratory and lager yeasts: Localization and competition with endogenous transporters. Yeast 2018; 35:567-576. [PMID: 29851426 DOI: 10.1002/yea.3322] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 05/01/2018] [Indexed: 11/10/2022] Open
Abstract
Plain and fluorescently tagged versions of Agt1, Mtt1 and Malx1 maltose transporters were overexpressed in two laboratory yeasts and one lager yeast. The plain and tagged versions of each transporter supported similar transport activities, indicating that they are similarly trafficked and have similar catalytic activities. When they were expressed under the control of the strong constitutive PGK1 promoter only minor proportions of the fluorescent transporters were associated with the plasma membrane, the rest being found in intracellular structures. Transport activity of each tagged transporter in each host was roughly proportional to the plasma membrane-associated fluorescence. All three transporters were subject to glucose-triggered inactivation when the medium glucose concentration was abruptly raised. Results also suggest competition between endogenous and overexpressed transporters for access to the plasma membrane.
Collapse
Affiliation(s)
- Virve Vidgren
- VTT Technical Research Centre of Finland Ltd, Espoo, Finland
| | | |
Collapse
|
23
|
Walker GM, Walker RSK. Enhancing Yeast Alcoholic Fermentations. ADVANCES IN APPLIED MICROBIOLOGY 2018; 105:87-129. [PMID: 30342724 DOI: 10.1016/bs.aambs.2018.05.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The production of ethanol by yeast fermentation represents the largest of all global biotechnologies. Consequently, the yeast Saccharomyces cerevisiae is the world's premier industrial microorganism, which is responsible not only for the production of alcoholic beverages, including beer, wine, and distilled spirits, but also for the billions of liters of bioethanol produced annually for use as a renewable transportation fuel. Although humankind has exploited the fermentative activities of yeasts for millennia, many aspects of alcohol fermentation remain poorly understood. This chapter will review some of the key considerations in optimizing industrial alcohol fermentations with a particular emphasis on enhancement opportunities involving cell physiology and strain engineering of the major microbial ethanologen, the yeast S. cerevisiae.
Collapse
Affiliation(s)
- Graeme M Walker
- School of Science, Engineering & Technology, Abertay University, Dundee, Scotland, United Kingdom
| | - Roy S K Walker
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
| |
Collapse
|
24
|
Karabín M, Jelínek L, Kotrba P, Cejnar R, Dostálek P. Enhancing the performance of brewing yeasts. Biotechnol Adv 2017; 36:691-706. [PMID: 29277309 DOI: 10.1016/j.biotechadv.2017.12.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 11/23/2017] [Accepted: 12/20/2017] [Indexed: 12/26/2022]
Abstract
Beer production is one of the oldest known traditional biotechnological processes, but is nowadays facing increasing demands not only for enhanced product quality, but also for improved production economics. Targeted genetic modification of a yeast strain is one way to increase beer quality and to improve the economics of beer production. In this review we will present current knowledge on traditional approaches for improving brewing strains and for rational metabolic engineering. These research efforts will, in the near future, lead to the development of a wider range of industrial strains that should increase the diversity of commercial beers.
Collapse
Affiliation(s)
- Marcel Karabín
- Department of Biotechnology, University of Chemistry and Technology, Prague, Technická 5, 16628 Prague 6, Czech Republic
| | - Lukáš Jelínek
- Department of Biotechnology, University of Chemistry and Technology, Prague, Technická 5, 16628 Prague 6, Czech Republic
| | - Pavel Kotrba
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Technická 5, 16628 Prague 6, Czech Republic
| | - Rudolf Cejnar
- Department of Biotechnology, University of Chemistry and Technology, Prague, Technická 5, 16628 Prague 6, Czech Republic
| | - Pavel Dostálek
- Department of Biotechnology, University of Chemistry and Technology, Prague, Technická 5, 16628 Prague 6, Czech Republic.
| |
Collapse
|
25
|
Krogerus K, Arvas M, De Chiara M, Magalhães F, Mattinen L, Oja M, Vidgren V, Yue JX, Liti G, Gibson B. Ploidy influences the functional attributes of de novo lager yeast hybrids. Appl Microbiol Biotechnol 2016; 100:7203-22. [PMID: 27183995 PMCID: PMC4947488 DOI: 10.1007/s00253-016-7588-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 04/03/2016] [Accepted: 04/24/2016] [Indexed: 12/25/2022]
Abstract
The genomes of hybrid organisms, such as lager yeast (Saccharomyces cerevisiae × Saccharomyces eubayanus), contain orthologous genes, the functionality and effect of which may differ depending on their origin and copy number. How the parental subgenomes in lager yeast contribute to important phenotypic traits such as fermentation performance, aroma production, and stress tolerance remains poorly understood. Here, three de novo lager yeast hybrids with different ploidy levels (allodiploid, allotriploid, and allotetraploid) were generated through hybridization techniques without genetic modification. The hybrids were characterized in fermentations of both high gravity wort (15 °P) and very high gravity wort (25 °P), which were monitored for aroma compound and sugar concentrations. The hybrid strains with higher DNA content performed better during fermentation and produced higher concentrations of flavor-active esters in both worts. The hybrid strains also outperformed both the parent strains. Genome sequencing revealed that several genes related to the formation of flavor-active esters (ATF1, ATF2¸ EHT1, EEB1, and BAT1) were present in higher copy numbers in the higher ploidy hybrid strains. A direct relationship between gene copy number and transcript level was also observed. The measured ester concentrations and transcript levels also suggest that the functionality of the S. cerevisiae- and S. eubayanus-derived gene products differs. The results contribute to our understanding of the complex molecular mechanisms that determine phenotypes in lager yeast hybrids and are expected to facilitate targeted strain development through interspecific hybridization.
Collapse
Affiliation(s)
- Kristoffer Krogerus
- VTT Technical Research Centre of Finland, Tietotie 2, P.O. Box 1000, FI-02044, Espoo, Finland.
- Department of Biotechnology and Chemical Technology, Aalto University, School of Chemical Technology, Kemistintie 1, Aalto, P.O. Box 16100, FI-00076, Espoo, Finland.
| | - Mikko Arvas
- VTT Technical Research Centre of Finland, Tietotie 2, P.O. Box 1000, FI-02044, Espoo, Finland
| | - Matteo De Chiara
- Institute for Research on Cancer and Ageing of Nice (IRCAN), CNRS UMR 7284, INSERM U1081, University of Nice Sophia Antipolis, 06107, Nice, France
| | - Frederico Magalhães
- VTT Technical Research Centre of Finland, Tietotie 2, P.O. Box 1000, FI-02044, Espoo, Finland
- Department of Biotechnology and Chemical Technology, Aalto University, School of Chemical Technology, Kemistintie 1, Aalto, P.O. Box 16100, FI-00076, Espoo, Finland
| | - Laura Mattinen
- ValiRx Finland Oy, Kiviharjuntie 8, FI-90220, Oulu, Finland
| | - Merja Oja
- VTT Technical Research Centre of Finland, Tietotie 2, P.O. Box 1000, FI-02044, Espoo, Finland
| | - Virve Vidgren
- VTT Technical Research Centre of Finland, Tietotie 2, P.O. Box 1000, FI-02044, Espoo, Finland
| | - Jia-Xing Yue
- Institute for Research on Cancer and Ageing of Nice (IRCAN), CNRS UMR 7284, INSERM U1081, University of Nice Sophia Antipolis, 06107, Nice, France
| | - Gianni Liti
- Institute for Research on Cancer and Ageing of Nice (IRCAN), CNRS UMR 7284, INSERM U1081, University of Nice Sophia Antipolis, 06107, Nice, France
| | - Brian Gibson
- VTT Technical Research Centre of Finland, Tietotie 2, P.O. Box 1000, FI-02044, Espoo, Finland
| |
Collapse
|
26
|
Magalhães F, Vidgren V, Ruohonen L, Gibson B. Maltose and maltotriose utilisation by group I strains of the hybrid lager yeast Saccharomyces pastorianus. FEMS Yeast Res 2016; 16:fow053. [PMID: 27364826 PMCID: PMC5815069 DOI: 10.1093/femsyr/fow053] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 02/12/2016] [Accepted: 06/26/2016] [Indexed: 11/13/2022] Open
Abstract
Brewer's wort is a challenging environment for yeast as it contains predominantly α-glucoside sugars. There exist two subgroups of the lager yeast Saccharomyces pastorianus which differ in sugar utilisation. We performed wort fermentations and compared representative strains from both groups with respect to their ability to transport and ferment maltose and maltotriose. Additionally, we mapped the transporters MALx1, AGT1, MPHx and MTT1 by Southern blotting. Contrary to previous observations, group I comprises a diverse set of strains, with varying ability to transport and ferment maltotriose. Of the eight group I strains, three efficiently utilised maltotriose, a property enabled by the presence of transmembrane transporters SeAGT1 and MTT1 A58, a variant of the group I type strain (CBS1513) performed particularly well, taking up maltotriose at a higher rate than maltose and retaining significant transport activity at temperatures as low as 0°C. Analysis of transporter distribution in this strain revealed an increased copy number of the MTT1 gene, which encodes the only permease known with higher affinity for maltotriose than maltose and low temperature dependence for transport. We propose that much of the variation in lager yeast fermentation behaviour is determined by the presence or absence of specific transmembrane transporters.
Collapse
Affiliation(s)
- Frederico Magalhães
- VTT Technical Research Centre of Finland Ltd, Tietotie 2, PO Box 1000, FI-02044 VTT, Espoo, Finland Department of Biotechnology and Chemical Technology, Aalto University, School of Chemical Technology, Kemistintie 1, PO Box 16100, FI-00076 Aalto, Espoo, Finland
| | - Virve Vidgren
- VTT Technical Research Centre of Finland Ltd, Tietotie 2, PO Box 1000, FI-02044 VTT, Espoo, Finland
| | - Laura Ruohonen
- VTT Technical Research Centre of Finland Ltd, Tietotie 2, PO Box 1000, FI-02044 VTT, Espoo, Finland
| | - Brian Gibson
- VTT Technical Research Centre of Finland Ltd, Tietotie 2, PO Box 1000, FI-02044 VTT, Espoo, Finland
| |
Collapse
|
27
|
Oomuro M, Kato T, Zhou Y, Watanabe D, Motoyama Y, Yamagishi H, Akao T, Aizawa M. Defective quiescence entry promotes the fermentation performance of bottom-fermenting brewer's yeast. J Biosci Bioeng 2016; 122:577-582. [PMID: 27212268 DOI: 10.1016/j.jbiosc.2016.04.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 04/04/2016] [Accepted: 04/25/2016] [Indexed: 10/21/2022]
Abstract
One of the key processes in making beer is fermentation. In the fermentation process, brewer's yeast plays an essential role in both the production of ethanol and the flavor profile of beer. Therefore, the mechanism of ethanol fermentation by of brewer's yeast is attracting much attention. The high ethanol productivity of sake yeast has provided a good basis from which to investigate the factors that regulate the fermentation rates of brewer's yeast. Recent studies found that the elevated fermentation rate of sake Saccharomyces cerevisiae species is closely related to a defective transition from vegetative growth to the quiescent (G0) state. In the present study, to clarify the relationship between the fermentation rate of brewer's yeast and entry into G0, we constructed two types of mutant of the bottom-fermenting brewer's yeast Saccharomyces pastorianus Weihenstephan 34/70: a RIM15 gene disruptant that was defective in entry into G0; and a CLN3ΔPEST mutant, in which the G1 cyclin Cln3p accumulated at high levels. Both strains exhibited higher fermentation rates under high-maltose medium or high-gravity wort conditions (20° Plato) as compared with the wild-type strain. Furthermore, G1 arrest and/or G0 entry were defective in both the RIM15 disruptant and the CLN3ΔPEST mutant as compared with the wild-type strain. Taken together, these results indicate that regulation of the G0/G1 transition might govern the fermentation rate of bottom-fermenting brewer's yeast in high-gravity wort.
Collapse
Affiliation(s)
- Mayu Oomuro
- Department of Brewing Microbiology, Asahi Breweries Ltd., 1-1-21 Midori, Moriya, Ibaraki 302-0106, Japan.
| | - Taku Kato
- Department of Brewing Microbiology, Asahi Breweries Ltd., 1-1-21 Midori, Moriya, Ibaraki 302-0106, Japan
| | - Yan Zhou
- National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-0046, Japan
| | - Daisuke Watanabe
- National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-0046, Japan
| | - Yasuo Motoyama
- Department of Brewing Microbiology, Asahi Breweries Ltd., 1-1-21 Midori, Moriya, Ibaraki 302-0106, Japan
| | - Hiromi Yamagishi
- Quality Control Center, Asahi Breweries Ltd., 1-1-21 Midori, Moriya, Ibaraki 302-0106, Japan
| | - Takeshi Akao
- National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-0046, Japan
| | - Masayuki Aizawa
- Department of Brewing Microbiology, Asahi Breweries Ltd., 1-1-21 Midori, Moriya, Ibaraki 302-0106, Japan
| |
Collapse
|
28
|
Petruzzi L, Rosaria Corbo M, Sinigaglia M, Bevilacqua A. Brewer’s yeast in controlled and uncontrolled fermentations, with a focus on novel, nonconventional, and superior strains. FOOD REVIEWS INTERNATIONAL 2015. [DOI: 10.1080/87559129.2015.1075211] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
|
29
|
New lager yeast strains generated by interspecific hybridization. J Ind Microbiol Biotechnol 2015; 42:769-78. [PMID: 25682107 PMCID: PMC4412690 DOI: 10.1007/s10295-015-1597-6] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 01/30/2015] [Indexed: 12/24/2022]
Abstract
The interspecific hybrid Saccharomyces pastorianus is the most commonly used yeast in brewery fermentations worldwide. Here, we generated de novo lager yeast hybrids by mating a domesticated and strongly flocculent Saccharomyces cerevisiae ale strain with the Saccharomyces eubayanus type strain. The hybrids were characterized with respect to the parent strains in a wort fermentation performed at temperatures typical for lager brewing (12 °C). The resulting beers were analysed for sugar and aroma compounds, while the yeasts were tested for their flocculation ability and α-glucoside transport capability. These hybrids inherited beneficial properties from both parent strains (cryotolerance, maltotriose utilization and strong flocculation) and showed apparent hybrid vigour, fermenting faster and producing beer with higher alcohol content (5.6 vs 4.5 % ABV) than the parents. Results suggest that interspecific hybridization is suitable for production of novel non-GM lager yeast strains with unique properties and will help in elucidating the evolutionary history of industrial lager yeast.
Collapse
|
30
|
Ganatsios V, Koutinas AA, Bekatorou A, Kanellaki M, Nigam P. Promotion of maltose fermentation at extremely low temperatures using a cryotolerant Saccharomyces cerevisiae strain immobilized on porous cellulosic material. Enzyme Microb Technol 2014; 66:56-9. [DOI: 10.1016/j.enzmictec.2014.08.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 07/21/2014] [Accepted: 08/18/2014] [Indexed: 11/26/2022]
|
31
|
Abstract
Alcoholic 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 two Saccharomyces species. 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 within Saccharomyces species, so that lager yeast hybrids are no longer the exception from the rule. These findings have led us to propose network evolution within Saccharomyces species. 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 as Saccharomyces carlsbergensis and to the Frohberg group as Saccharomyces pastorianus based on their distinct genomes. New insight into the hybrid nature of lager yeast will provide novel directions for future strain improvement.
Collapse
|
32
|
Gibson B, Krogerus K, Ekberg J, Monroux A, Mattinen L, Rautio J, Vidgren V. Variation in α-acetolactate production within the hybrid lager yeast group Saccharomyces pastorianus and affirmation of the central role of the ILV6 gene. Yeast 2014; 32:301-16. [PMID: 24965182 DOI: 10.1002/yea.3026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 06/13/2014] [Accepted: 06/16/2014] [Indexed: 12/28/2022] Open
Abstract
A screen of 14 S. pastorianus lager-brewing strains showed as much as a nine-fold difference in wort total diacetyl concentration at equivalent stages of fermentation of 15°Plato brewer's wort. Two strains (A153 and W34), with relatively low and high diacetyl production, respectively, but which did not otherwise differ in fermentation performance, growth or flavour production, were selected for further investigation. Transcriptional analysis of key genes involved in valine biosynthesis showed differences between the two strains that were consistent with the differences in wort diacetyl concentration. In particular, the ILV6 gene, encoding a regulatory subunit of acetohydroxy acid synthase, showed early transcription (only 6 h after inoculation) and up to five-fold greater expression in W34 compared to A153. This earlier transcription was observed for both orthologues of ILV6 in the S. pastorianus hybrid (S. cerevisiae × S. eubayanus), although the S. cerevisiae form of ILV6 in W34 also showed a consistently higher transcript level throughout fermentation relative to the same gene in A153. Overexpression of either form of ILV6 (by placing it under the control of the PGK1 promoter) resulted in an identical two-fold increase in wort total diacetyl concentration relative to a control. The results confirm the role of the Ilv6 subunit in controlling α-acetolactate/diacetyl concentration and indicate no functional divergence between the two forms of Ilv6. The greater contribution of the S. cerevisiae ILV6 to acetolactate production in natural brewing yeast hybrids appears rather to be due to higher levels of transcription relative to the S. eubayanus form.
Collapse
Affiliation(s)
- Brian Gibson
- VTT Technical Research Centre of Finland, Espoo, Finland
| | | | | | | | | | | | | |
Collapse
|
33
|
Vidgren V, Viljanen K, Mattinen L, Rautio J, Londesborough J. Three Agt1 transporters from brewer's yeasts exhibit different temperature dependencies for maltose transport over the range of brewery temperatures (0-20 °C). FEMS Yeast Res 2014; 14:601-13. [DOI: 10.1111/1567-1364.12147] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Virve Vidgren
- VTT Technical Research Centre of Finland; VTT Finland
| | | | | | | | | |
Collapse
|
34
|
Blanco CA, Caballero I, Barrios R, Rojas A. Innovations in the brewing industry: light beer. Int J Food Sci Nutr 2014; 65:655-60. [PMID: 24601667 DOI: 10.3109/09637486.2014.893285] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The demand for light beers has led brewers to innovate by developing light beer. However, these products are not widely accepted in Europe compared to North America and Australasia because of their lack of fullness in the taste and low bitterness compared with conventional beer. The lower levels of some important compounds, present in light beer, can explain these features since they are responsible for the characteristics of the beer. These include alcohol soluble proteins, oligosaccharides, glycerol, polyphenols, iso-α-acids, fusel alcohols and trihydroxy fatty acids. Light beer is produced by several methods, the most commonly used is the addition of glucoamylase to the wort before or during fermentation. This enzyme metabolizes residual carbohydrates (mainly dextrins) transforming them into fermentable sugars and reducing the caloric and alcohol content in this type of beer. Recently pilot studies have been carried out with genetically engineered yeast strains in which amylolytic genes are introduced into the yeast genome in order to metabolize carbohydrate residues. When introducing amylolytic genes, a better fermentability occurs although the fullness of flavor still becomes reduced.
Collapse
Affiliation(s)
- Carlos A Blanco
- Dpto. Ingeniería Agrícola y Forestal (Área de Tecnología de los Alimentos), E.T.S. Ingenierías Agrarias, Universidad de Valladolid , Palencia , Spain
| | | | | | | |
Collapse
|
35
|
Stewart GG, Hill AE, Russell I. 125thAnniversary Review: Developments in brewing and distilling yeast strains. JOURNAL OF THE INSTITUTE OF BREWING 2013. [DOI: 10.1002/jib.104] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Graham G. Stewart
- 13 Heol Nant Castan, Rhiwbina Cardiff CF14 6RP UK
- ICBD; Heriot-Watt University; Riccarton Edinburgh EH14 4AS UK
| | - Annie E. Hill
- ICBD; Heriot-Watt University; Riccarton Edinburgh EH14 4AS UK
| | - Inge Russell
- ICBD; Heriot-Watt University; Riccarton Edinburgh EH14 4AS UK
- Alltech Inc.; Nicholasville KY 40356 USA
| |
Collapse
|
36
|
Gibson BR, Storgårds E, Krogerus K, Vidgren V. Comparative physiology and fermentation performance of Saaz and Frohberg lager yeast strains and the parental species Saccharomyces eubayanus. Yeast 2013; 30:255-66. [PMID: 23695993 DOI: 10.1002/yea.2960] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 05/03/2013] [Accepted: 05/07/2013] [Indexed: 01/30/2023] Open
Abstract
Two distinct genetic groups (Saaz and Frohberg) exist within the hybrid Saccharomyces pastorianus (S. cerevisiae × S. eubayanus) taxon. However, physiological/technological differences that exist between the two groups are not known. Fermentative capability of the parental S. eubayanus has likewise never been studied. Here, 58 lager strains were screened to determine which hybrid group they belonged to, and selected strains were characterized to determine salient characteristics. In 15 °P all-malt wort fermentations at 22 °C, Frohberg strains showed greater growth and superior fermentation (80% apparent attenuation, 6.5% alcohol by volume in 3-4 days) compared to all other strains and maintained highest viability values (>93%). Fermentation with S. eubayanus was poor at the same temperature (33% apparent attenuation, 2.7% alcohol by volume at 6 days and viability reduced to 75%). Saaz strains and S. eubayanus were the least sensitive to cold (10 °C), though this did not translate to greater fermentation performance. Fermentation with S. eubayanus was poor at 10 °C but equal to or greater than that of the Saaz strains. Performance of Saaz yeast/S. eubayanus was limited by an inability to use wort maltotriose. [(14)C]-Maltotriose transport assays also showed negligible activity in these strains (≤0.5 µmol min(-1) g(-1) dry yeast). Beers from Saaz fermentations were characterized by two- to sixfold lower production of the flavour compounds methyl butanol, ethyl acetate and 3-methylbutyl acetate compared to Frohberg strains. Higher alcohol and ester production by S. eubayanus was similar to that of Frohberg strains.
Collapse
Affiliation(s)
- Brian R Gibson
- VTT Technical Research Centre of Finland, FI-02044 VTT, Finland.
| | | | | | | |
Collapse
|
37
|
Gibson BR, Londesborough J, Rautio J, Mattinen L, Vidgren V. Transcription ofα-glucoside transport and metabolism genes in the hybrid brewing yeastSaccharomyces pastorianuswith respect to gene provenance and fermentation temperature. JOURNAL OF THE INSTITUTE OF BREWING 2013. [DOI: 10.1002/jib.66] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- B. R. Gibson
- VTT, Technical Research Centre of Finland; Tietotie 2, PO Box 1000; FI-02044 VTT; Espoo; Finland
| | - J. Londesborough
- VTT, Technical Research Centre of Finland; Tietotie 2, PO Box 1000; FI-02044 VTT; Espoo; Finland
| | - J. Rautio
- Plexpress Oy; Viikinkaari 6; 00790; Helsinki; Finland
| | - L. Mattinen
- Plexpress Oy; Viikinkaari 6; 00790; Helsinki; Finland
| | - V. Vidgren
- VTT, Technical Research Centre of Finland; Tietotie 2, PO Box 1000; FI-02044 VTT; Espoo; Finland
| |
Collapse
|
38
|
Influence of valine and other amino acids on total diacetyl and 2,3-pentanedione levels during fermentation of brewer's wort. Appl Microbiol Biotechnol 2013; 97:6919-30. [PMID: 23677441 PMCID: PMC3708283 DOI: 10.1007/s00253-013-4955-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 04/22/2013] [Accepted: 04/24/2013] [Indexed: 11/18/2022]
Abstract
Undesirable butter-tasting vicinal diketones are produced as by-products of valine and isoleucine biosynthesis during wort fermentation. One promising method of decreasing diacetyl production is through control of wort valine content since valine is involved in feedback inhibition of enzymes controlling the formation of diacetyl precursors. Here, the influence of valine supplementation, wort amino acid profile and free amino nitrogen content on diacetyl formation during wort fermentation with the lager yeast Saccharomyces pastorianus was investigated. Valine supplementation (100 to 300 mg L−1) resulted in decreased maximum diacetyl concentrations (up to 37 % lower) and diacetyl concentrations at the end of fermentation (up to 33 % lower) in all trials. Composition of the amino acid spectrum of the wort also had an impact on diacetyl and 2,3-pentanedione production during fermentation. No direct correlation between the wort amino acid concentrations and diacetyl production was found, but rather a negative correlation between the uptake rate of valine (and also other branched-chain amino acids) and diacetyl production. Fermentation performance and yeast growth were unaffected by supplementations. Amino acid addition had a minor effect on higher alcohol and ester composition, suggesting that high levels of supplementation could affect the flavour profile of the beer. Modifying amino acid profile of wort, especially with respect to valine and the other branched-chain amino acids, may be an effective way of decreasing the amount of diacetyl formed during fermentation.
Collapse
|
39
|
Wang XX, Ji XP, Li JX, Keyhani NO, Feng MG, Ying SH. A putative α-glucoside transporter gene BbAGT1 contributes to carbohydrate utilization, growth, conidiation and virulence of filamentous entomopathogenic fungus Beauveria bassiana. Res Microbiol 2013; 164:480-9. [PMID: 23499939 DOI: 10.1016/j.resmic.2013.02.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 02/20/2013] [Indexed: 11/17/2022]
Abstract
Carbohydrate transporters are critical players mediating nutrient uptake during saprophytic and pathogenic growth for most filamentous fungi. For entomopathogenic fungi, such as Beauveria bassiana, assimilation of α-glucosides, in particular, trehalose, the major carbohydrate constituent of the insect haemolymph, has been hypothesized to represent an important ability for infectious growth within the insect hemocoel. In this study, a B. bassiana α-glucoside transporter homolog was identified and genetically characterized via generation of a targeted gene disruption mutant. Trehalose utilization was compromised in the mutant strain. In addition, inactivation of the α-glucoside transporter resulted in decreased conidial germination, growth, and yield on various carbohydrates (α-glucosides, monosaccharides and polyols) as compared to the wild-type strain. Insect bioassays revealed decreased mean lethal mortality time using both topical and intrahemocoel injection assays, although final mortality levels were comparable in both the mutant and wild type. Gene expression profiles showed altered expression of other putative transporters in the knockout mutant as compared to the wild type. These results highlighted complex sugar utilization and responsiveness in B. bassiana and the potential role for trehalose assimilation during fungal pathogenesis of insects.
Collapse
Affiliation(s)
- Xiu-Xiu Wang
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China.
| | | | | | | | | | | |
Collapse
|
40
|
Ekberg J, Rautio J, Mattinen L, Vidgren V, Londesborough J, Gibson BR. Adaptive evolution of the lager brewing yeastSaccharomyces pastorianusfor improved growth under hyperosmotic conditions and its influence on fermentation performance. FEMS Yeast Res 2013; 13:335-49. [DOI: 10.1111/1567-1364.12038] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 02/08/2013] [Accepted: 02/08/2013] [Indexed: 11/26/2022] Open
Affiliation(s)
| | | | | | - Virve Vidgren
- VTT Technical Research Centre of Finland; Espoo; Finland
| | | | | |
Collapse
|
41
|
Cousseau FEM, Alves SL, Trichez D, Stambuk BU. Characterization of maltotriose transporters from the Saccharomyces eubayanus subgenome of the hybrid Saccharomyces pastorianus lager brewing yeast strain Weihenstephan 34/70. Lett Appl Microbiol 2012; 56:21-9. [PMID: 23061413 DOI: 10.1111/lam.12011] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 09/03/2012] [Accepted: 09/30/2012] [Indexed: 11/29/2022]
Abstract
The genome from the Saccharomyces pastorianus industrial lager brewing strain Weihenstephan 34/70, a natural Saccharomyces cerevisiae/Saccharomyces eubayanus hybrid, indicated the presence of two different maltotriose transporter genes: a new gene in the S. eubayanus subgenome with 81% of homology to the AGT1 permease from S. cerevisiae, and an amplification of the S. eubayanus MTY1 maltotriose permease previously identified in S. pastorianus yeasts. To characterize these S. eubayanus transporter genes, we used a S. cerevisiae strain deleted in the AGT1 permease and introduced the desired permease gene(s) into this locus through homologous recombination. Our results indicate that both the MTY1 and AGT1 genes from the S. eubayanus subgenome encode functional maltotriose transporters that allow fermentation of this sugar by yeast cells, despite their apparent differences in the kinetics of maltotriose-H(+) symport activity. The presence of two maltotriose transporters in the S. eubayanus subgenome not only highlights the importance of sugar transport for efficient maltotriose utilization by industrial yeasts, but these new genes can be used in breeding and/or selection programs aimed at increasing yeast fitness for the efficient fermentation of brewer's wort.
Collapse
Affiliation(s)
- F E M Cousseau
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | | | | | | |
Collapse
|
42
|
Characterization of the Saccharomyces bayanus-type AGT1 transporter of lager yeast. JOURNAL OF THE INSTITUTE OF BREWING 2012. [DOI: 10.1002/jib.22] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
43
|
Gao C, Wang Z, Liang Q, Qi Q. Global transcription engineering of brewer’s yeast enhances the fermentation performance under high-gravity conditions. Appl Microbiol Biotechnol 2010; 87:1821-7. [DOI: 10.1007/s00253-010-2648-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 04/22/2010] [Accepted: 04/24/2010] [Indexed: 10/19/2022]
|
44
|
Vidgren V, Multanen JP, Ruohonen L, Londesborough J. The temperature dependence of maltose transport in ale and lager strains of brewer's yeast. FEMS Yeast Res 2010; 10:402-11. [PMID: 20402791 PMCID: PMC2878602 DOI: 10.1111/j.1567-1364.2010.00627.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Lager beers are traditionally made at lower temperatures (6–14 °C) than ales (15–25 °C). At low temperatures, lager strains (Saccharomyces pastorianus) ferment faster than ale strains (Saccharomyces cerevisiae). Two lager and two ale strains had similar maltose transport activities at 20 °C, but at 0 °C the lager strains had fivefold greater activity. AGT1, MTT1 and MALx1 are major maltose transporter genes. In nine tested lager strains, the AGT1 genes contained premature stop codons. None of five tested ale strains had this defect. All tested lager strains, but no ale strain, contained MTT1 genes. When functional AGT1 from an ale strain was expressed in a lager strain, the resultant maltose transport activity had the high temperature dependence characteristic of ale yeasts. Lager yeast MTT1 and MALx1 genes were expressed in a maltose-negative laboratory strain of S. cerevisiae. The resultant Mtt1 transport activity had low temperature dependence and the Malx1 activity had high temperature dependence. Faster fermentation at low temperature by lager strains than ale strains may result from their different maltose transporters. The loss of Agt1 transporters during the evolution of lager strains may have provided plasma membrane space for the Mtt1 transporters that perform better at a low temperature.
Collapse
Affiliation(s)
- Virve Vidgren
- VTT Technical Research Centre of Finland, Espoo, Finland
| | | | | | | |
Collapse
|
45
|
Saerens SMG, Duong CT, Nevoigt E. Genetic improvement of brewer’s yeast: current state, perspectives and limits. Appl Microbiol Biotechnol 2010; 86:1195-212. [DOI: 10.1007/s00253-010-2486-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Revised: 01/29/2010] [Accepted: 01/29/2010] [Indexed: 10/19/2022]
|
46
|
Selection from industrial lager yeast strains of variants with improved fermentation performance in very-high-gravity worts. Appl Environ Microbiol 2010; 76:1563-73. [PMID: 20081007 DOI: 10.1128/aem.03153-09] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
There are economic and other advantages if the fermentable sugar concentration in industrial brewery fermentations can be increased from that of currently used high-gravity (ca. 14 to 17 degrees P [degrees Plato]) worts into the very-high-gravity (VHG; 18 to 25 degrees P) range. Many industrial strains of brewer's yeast perform poorly in VHG worts, exhibiting decreased growth, slow and incomplete fermentations, and low viability of the yeast cropped for recycling into subsequent fermentations. A new and efficient method for selecting variant cells with improved performance in VHG worts is described. In this new method, mutagenized industrial yeast was put through a VHG wort fermentation and then incubated anaerobically in the resulting beer while maintaining the alpha-glucoside concentration at about 10 to 20 g.liter(-1) by slowly feeding the yeast maltose or maltotriose until most of the cells had died. When survival rates fell to 1 to 10 cells per 10(6) original cells, a high proportion (up to 30%) of survivors fermented VHG worts 10 to 30% faster and more completely (residual sugars lower by 2 to 8 g.liter(-1)) than the parent strains, but the sedimentation behavior and profiles of yeast-derived flavor compounds of the survivors were similar to those of the parent strains.
Collapse
|
47
|
Current awareness on yeast. Yeast 2009. [DOI: 10.1002/yea.1624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|