Open AccessReduction of membrane‐bound ATPase activity in a Lactobacillus helveticus strain with slower growth at low pH
Author(s) -
Yamamoto Naoyuki,
Masujima Yoshiko,
Takano Toshiaki
Publication year - 1996
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1996.tb08153.x
Subject(s) - lactobacillus helveticus , strain (injury) , atpase , biochemistry , efflux , chemistry , neomycin , leucine , growth medium , biology , bacteria , lactobacillus , enzyme , amino acid , fermentation , anatomy , antibiotics , genetics
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.