Reduction of membrane-bound ATPase activity in a Lactobacillus helveticus strain with slower growth at low pH

• Published in: FEMS microbiology letters 1996-05, Vol.138 (2/3), p.179-184
• Main Authors: Yamamoto, N, Masujima, Y, Takano, T
• Format: Article
• Language: English
• Subjects: acid sensitivity; acidification; acidity; Acid‐sensitive variant; Adenosine; Adenosine triphosphatase; adenosinetriphosphatase; Alanine; amino acids; Bacteriology; Biological and medical sciences; enzyme activity; fermented milk; Fundamental and applied biological sciences. Psychology; growth; Lactobacilli; Lactobacillus helveticus; Leucine; Membrane vesicles; Membranes; Membrane‐bound ATPase; Metabolism. Enzymes; Microbiology; Milk; Neomycin; Neomycin resistance; nutrient uptake; pH effects; post-acidification; proton motive force; Quinacrine; storage quality; Triphosphatase; Tyrosine; Vesicles
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.1996.tb08153.x

One acid-sensitive variant of Lactobacillus helveticus, designated L. helveticus CPN4, was isolated from L. helveticus CP790 using neomycin resistance as a selective marker. In a milk medium, the variant strain showed similar growth to the parent strain until the pH reached 4.5, afterwards growth was slower than the parent strain. The variant strain had lower activity of membrane bound adenosine triphosphatase (ATPase, EC 3.6.1.3) over several batch growth ranges from pH 3.5 to 7.5. Membrane vesicles of the variant strain showed lower uptake of quinacrine than vesicles of the parent strain. The variant strain had lower uptake ability for tyrosine, leucine and alanine.