Induction of the cysteine regulon of Salmonella typhimurium in LB medium affects the response of cysB mutants to mecillinam.
Curr Microbiol
; 40(1): 72-7, 2000 Jan.
Article
em En
| MEDLINE
| ID: mdl-10568808
Rapid growth of Salmonella typhimurium LT2 in rich LB-broth caused the induction of the cysteine regulon when the culture reached an optical density at 650 nm of 1.5. Addition of 0.05 mM L-cystine to LB-broth abolished induction, while 0.025 mM L-cystine delayed it for a doubling time (30 min). Induction did not occur when lack of oxygen or a temperature shift to 19 degrees C slowed down growth in LB-broth. Uninduced cultures reached growth yield similar to that of induced cultures after overnight incubation. Growth on solid LB-medium also brought about induction, but to a lower level than in liquid medium. Leaky cysB mutants, which are sensitive to the beta-lactam antibiotic mecillinam, displayed partial induction, whereas mecillinam-resistant cysB and cysE mutants showed no induction. It is suggested that induction develops in these mutants when constitutive transport systems fail to satisfy the high uptake of cysteine demanded by fast-growing cultures. The behavior of cysB mutants agrees with the hypothesis that, under some conditions, mecillinam action would be dependent on expression of the cysteine regulon.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Salmonella typhimurium
/
Proteínas de Bactérias
/
Regulação Bacteriana da Expressão Gênica
/
Regulon
/
Cisteína
/
Andinocilina
Idioma:
En
Revista:
Curr Microbiol
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Estados Unidos