Study of growth requirements other than cysteine of naturally occurring Escherichia coli and Klebsiella spp. auxotrophic for cysteine.
Cysteine remains the preferred supplement for cultivation of Cys- auxotrophs in vitro. Methionine, which reduced cysteine requirements, and branched-chain amino acids, which decreased cysteine toxicity, were identified as the components of casein hydrolysate responsible for growth enhancement by this additive. Glutathione and DL-homocysteine can be substituted for cysteine. Accumulation of these compounds in patients with renal impairment may favor selection of Cys- strains in vivo.
McIver
C J
CJ
Department of Microbiology, Prince of Wales Hospital, Randwick, Australia.
Tapsall
J W
JW
D003545:Cysteine / Q000378:metabolism / Q000494:pharmacology*; D004926:Escherichia coli / Q000254:growth & development*; D005978:Glutathione / Q000494:pharmacology; D007709:Klebsiella / Q000254:growth & development*; D008715:Methionine / Q000378:metabolism / Q000494:pharmacology
D008715:Methionine; D005978:Glutathione; D003545:Cysteine