PMID: 6404516Jan 17, 1983Paper

Beta-lactamase synthesis and excretion in a non-leaky wild strain and a leaky mutant of Escherichia coli K-12

Comptes rendus des séances de l'Académie des sciences. Série III, Sciences de la vie
N Fognini-Lefebvre, R Portalier

Abstract

After transformation of Escherichia coli strains with plasmid pBR 322 and growth in rich L medium, the total amount of beta-lactamase produced, strongly decreased when the temperature was raised from 30 to 42 degrees C, but increased after addition of ampicillin or tetracycline to the medium. beta-lactamase was synthesized and exported into the periplasmic space of wild-type strain, but was not significantly released into the extracellular medium, after growth at low temperature. We have identified an E. coli mutant which excreted up to 90% of total amount of beta-lactamase activity, any temperature. This mutant has been used as an indicator strain, for the development of an in situ test allowing the detection of beta-lactamase excretion.

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