title: Selection of a Bifidobacterium animalis subsp. lactis strain with a decreased ability to produce acetic acid.
abstract: We have characterized a new strain, Bifidobacterium animalis subsp. lactis CECT 7953, obtained by random UV mutagenesis, which produces less acetic acid than the wild type (CECT 7954) in three different experimental settings: De Man-Rogosa-Sharpe broth without sodium acetate, resting cells, and skim milk. Genome sequencing revealed a single Phe-Ser substitution in the acetate kinase gene product that seems to be responsible for the strain's reduced acid production. Accordingly, acetate kinase specific activity was lower in the low acetate producer. Strain CECT 7953 produced less acetate, less ethanol, and more yoghourt-related volatile compounds in skim milk than the wild type did. Thus, CECT 7953 shows promising potential for the development of dairy products fermented exclusively by a bifidobacterial strain.
authors.affiliation: Instituto de Productos Lácteos de Asturias, Consejo Superior de Investigaciones Científicas, Carretera de Infiesto, Villaviciosa, Asturias, Spain.
authors.forename: Abelardo
authors.initials: A
authors.lastname: Margolles
authors.forename: Borja
authors.initials: B
authors.lastname: Sánchez
mesh_terms: D000084:Acetate Kinase / Q000235:genetics; D019342:Acetic Acid / Q000378:metabolism*; D019943:Amino Acid Substitution; D000818:Animals; D001644:Bifidobacterium / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism* / Q000528:radiation effects; D003470:Culture Media / Q000737:chemistry; D004252:DNA Mutational Analysis; D000431:Ethanol / Q000378:metabolism; D005232:Fatty Acids, Volatile / Q000378:metabolism; D008892:Milk / Q000382:microbiology; D016296:Mutagenesis; D020125:Mutation, Missense; D012641:Selection, Genetic; D014466:Ultraviolet Rays
chemical_list: D003470:Culture Media; D005232:Fatty Acids, Volatile; D000431:Ethanol; D000084:Acetate Kinase; D019342:Acetic Acid