title: Fermentation assays reveal differences in sugar and (off-) flavor metabolism across different Brettanomyces bruxellensis strains.
abstract: Brettanomyces (Dekkera) bruxellensis is an ascomycetous yeast of major importance in the food, beverage and biofuel industry. It has been isolated from various man-made ecological niches that are typically characterized by harsh environmental conditions such as wine, beer, soft drink, etc. Recent comparative genomics studies revealed an immense intraspecific diversity, but it is still unclear whether this genetic diversity also leads to systematic differences in fermentation performance and (off-)flavor production, and to what extent strains have evolved to match their ecological niche. Here, we present an evaluation of the fermentation properties of eight genetically diverse B. bruxellensis strains originating from beer, wine and soft drinks. We show that sugar consumption and aroma production during fermentation are determined by both the yeast strain and composition of the medium. Furthermore, our results indicate a strong niche adaptation of B. bruxellensis, most clearly for wine strains. For example, only strains originally isolated from wine were able to thrive well and produce the typical Brettanomyces-related phenolic off-flavors 4-ethylguaiacol and 4-ethylphenol when inoculated in red wine. Sulfite tolerance was found as a key factor explaining the observed differences in fermentation performance and off-flavor production. Sequence analysis of genes related to phenolic off-flavor production, however, revealed only marginal differences between the isolates tested, especially at the amino acid level. Altogether, our study provides novel insights in the Brettanomyces metabolism of flavor production, and is highly relevant for both the wine and beer industry.
authors.affiliation: Laboratory for Process Microbial Ecology and Bioinspirational Management, Department of Microbial and Molecular Systems (MS), KU Leuven, Campus De Nayer, B-2860 Sint-Katelijne-Waver, Belgium.
authors.forename: Sam
authors.initials: S
authors.lastname: Crauwels
authors.affiliation: Laboratory for Enzyme, Fermentation and Brewing Technology, MS, KU Leuven, Technology Campus Ghent, B-9000 Ghent, Belgium.
authors.forename: Filip
authors.initials: F
authors.lastname: Van Opstaele
authors.affiliation: Laboratory for Enzyme, Fermentation and Brewing Technology, MS, KU Leuven, Technology Campus Ghent, B-9000 Ghent, Belgium.
authors.forename: Barbara
authors.initials: B
authors.lastname: Jaskula-Goiris
authors.affiliation: VIB Lab for Systems Biology and Centre of Microbial and Plant Genetics Lab for Genetics and Genomics, MS, KU Leuven, B-3001 Heverlee, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Steensels
authors.affiliation: Laboratory for Process Microbial Ecology and Bioinspirational Management, Department of Microbial and Molecular Systems (MS), KU Leuven, Campus De Nayer, B-2860 Sint-Katelijne-Waver, Belgium.
authors.forename: Christel
authors.initials: C
authors.lastname: Verreth
authors.affiliation: Laboratory for Process Microbial Ecology and Bioinspirational Management, Department of Microbial and Molecular Systems (MS), KU Leuven, Campus De Nayer, B-2860 Sint-Katelijne-Waver, Belgium.
authors.forename: Lien
authors.initials: L
authors.lastname: Bosmans
authors.affiliation: Laboratory for Process Microbial Ecology and Bioinspirational Management, Department of Microbial and Molecular Systems (MS), KU Leuven, Campus De Nayer, B-2860 Sint-Katelijne-Waver, Belgium.
authors.forename: Caroline
authors.initials: C
authors.lastname: Paulussen
authors.affiliation: VIB Lab for Systems Biology and Centre of Microbial and Plant Genetics Lab for Genetics and Genomics, MS, KU Leuven, B-3001 Heverlee, Belgium.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Herrera-Malaver
authors.affiliation: Department of Plant Systems Biology, VIB and Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium.
authors.forename: Ronnie
authors.initials: R
authors.lastname: de Jonge
authors.affiliation: Laboratory for Enzyme, Fermentation and Brewing Technology, MS, KU Leuven, Technology Campus Ghent, B-9000 Ghent, Belgium.
authors.forename: Jessika
authors.initials: J
authors.lastname: De Clippeleer
authors.affiliation: Department of Plant Biotechnology and Bioinformatics and Department of Information Technology, IMinds, Ghent University, B-9000 Ghent, Belgium.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Marchal
authors.affiliation: Laboratory for Process Microbial Ecology and Bioinspirational Management, Department of Microbial and Molecular Systems (MS), KU Leuven, Campus De Nayer, B-2860 Sint-Katelijne-Waver, Belgium.
authors.forename: Gorik
authors.initials: G
authors.lastname: De Samblanx
authors.affiliation: Laboratory for Process Microbial Ecology and Bioinspirational Management, Department of Microbial and Molecular Systems (MS), KU Leuven, Campus De Nayer, B-2860 Sint-Katelijne-Waver, Belgium.
authors.forename: Kris A
authors.initials: KA
authors.lastname: Willems
authors.affiliation: VIB Lab for Systems Biology and Centre of Microbial and Plant Genetics Lab for Genetics and Genomics, MS, KU Leuven, B-3001 Heverlee, Belgium.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Verstrepen
authors.affiliation: Laboratory for Enzyme, Fermentation and Brewing Technology, MS, KU Leuven, Technology Campus Ghent, B-9000 Ghent, Belgium.
authors.forename: Guido
authors.initials: G
authors.lastname: Aerts
authors.affiliation: Laboratory for Process Microbial Ecology and Bioinspirational Management, Department of Microbial and Molecular Systems (MS), KU Leuven, Campus De Nayer, B-2860 Sint-Katelijne-Waver, Belgium bart.lievens@kuleuven.be.
authors.forename: Bart
authors.initials: B
authors.lastname: Lievens
mesh_terms: D000220:Adaptation, Biological; D055168:Brettanomyces / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D003470:Culture Media / Q000737:chemistry; D005285:Fermentation; D005516:Food Microbiology; D014644:Genetic Variation; D055549:Volatile Organic Compounds / Q000378:metabolism*
chemical_list: D003470:Culture Media; D055549:Volatile Organic Compounds
keywords: (Off-)flavors; ecological niche; phenolic acid decarboxylase; vinylphenol reductase; volatile phenols