title: Acid sensitivity of neomycin-resistant mutants of Oenococcus oeni: a relationship between reduction of ATPase activity and lack of malolactic activity.
abstract: Mutants of Oenococcus oeni were isolated as spontaneous neomycin-resistant mutants. Three of these mutants harbored a significantly reduced ATPase activity that represented 50% of that of the wild-type strain. Their growth rates were also impaired at pH 5.3 (46-86% of the wild-type level). However, the profiles of sugar consumption appeared identical to those of the parental strain. At pH 3.2, all the mutant strains failed to grow and a drastic decrease in viability was observed after an acid shock. Surprisingly, all the isolated mutants were devoid of malolactic activity. These results suggest that the ATPase and malolactic activities of O. oeni are linked to each other and play a crucial role in the mechanism of resistance to an acid stress.
authors.affiliation: Laboratoire de Microbiologie UA INRA, ENSBANA, Université de Bourgogne, Dijon, France. tourdot@u-bourgogne.fr
authors.forename: R
authors.initials: R
authors.lastname: Tourdot-Maréchal
authors.forename: L C
authors.initials: LC
authors.lastname: Fortier
authors.forename: J
authors.initials: J
authors.lastname: Guzzo
authors.forename: B
authors.initials: B
authors.lastname: Lee
authors.forename: C
authors.initials: C
authors.lastname: Diviès
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D006095:Gram-Positive Cocci / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism; D018869:Heat-Shock Response; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000378:metabolism*; D007934:Leuconostoc / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D008293:Malates / Q000378:metabolism*; D009355:Neomycin / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D006360:Heat-Shock Proteins; D008293:Malates; D019344:Lactic Acid; C030298:malic acid; D000251:Adenosine Triphosphatases; D009355:Neomycin