Open AccessEfflux of choline and glycine betaine from osmoregulating cells of Escherichia coli
Author(s) -
Lamark Trond,
Styrvold Olaf B.,
Strøm Arne R.
Publication year - 1992
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.1574-6968.1992.tb05408.x
Subject(s) - betaine , efflux , escherichia coli , glycine , choline , chemistry , microbiology and biotechnology , biochemistry , biology , amino acid , gene
We present evidence that glycine betaine (betaine) which was synthesized from choline was excreted and reaccumulated in osmoregulating cells of Escherichia coli . Choline which was accumulated in bet mutants defective in betaine synthesis was shown to be excreted in response to betaine uptake. Our data suggest that E. coli has efflux systems for betaine and choline which are independent of the uptake systems for these metabolites. The ProU system of E. coli , but not that of Salmonella typhimurium , can mediate low‐affinity choline uptake.