title: Metabolic strategies of beer spoilage lactic acid bacteria in beer.
abstract: Beer contains only limited amounts of readily fermentable carbohydrates and amino acids. Beer spoilage lactic acid bacteria (LAB) have to come up with metabolic strategies in order to deal with selective nutrient content, high energy demand of hop tolerance mechanisms and a low pH. The metabolism of 26 LAB strains of 6 species and varying spoilage potentialwas investigated in order to define and compare their metabolic capabilities using multivariate statistics and outline possible metabolic strategies. Metabolic capabilities of beer spoilage LAB regarding carbohydrate and amino acids did not correlate with spoilage potential, but with fermentation type (heterofermentative/homofermentative) and species. A shift to mixed acid fermentation by homofermentative (hof) Pediococcus claussenii and Lactobacillus backii was observed as a specific feature of their growth in beer. For heterofermentative (hef) LAB a mostly versatile carbohydrate metabolism could be demonstrated, supplementing the known relevance of organic acids for their growth in beer. For hef LAB a distinct amino acid metabolism, resulting in biogenic amine production, was observed, presumably contributing to energy supply and pH homeostasis.
authors.affiliation: Technische Universität München, Lehrstuhl für Technische Mikrobiologie, 85354 Freising, Germany.
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Geissler
authors.affiliation: Technische Universität München, Lehrstuhl für Technische Mikrobiologie, 85354 Freising, Germany. Electronic address: juergen.behr@wzw.tum.de.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Behr
authors.affiliation: Technische Universität München, Lehrstuhl für Technische Mikrobiologie, 85354 Freising, Germany.
authors.forename: Kristina
authors.initials: K
authors.lastname: von Kamp
authors.affiliation: Technische Universität München, Lehrstuhl für Technische Mikrobiologie, 85354 Freising, Germany.
authors.forename: Rudi F
authors.initials: RF
authors.lastname: Vogel
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001515:Beer / Q000382:microbiology*; D050260:Carbohydrate Metabolism / Q000502:physiology*; D005285:Fermentation / Q000502:physiology*; D005516:Food Microbiology; D019344:Lactic Acid / Q000378:metabolism; D007778:Lactobacillus / Q000254:growth & development / Q000378:metabolism*; D010376:Pediococcus / Q000254:growth & development / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D019344:Lactic Acid
keywords: Beer spoilage; Biogenic amines; Disaccharide metabolism; Lactic acid bacteria metabolism; Mixed acid fermentation