Affiliation:
1. Department of Microbiology, University of Umeå, Umeå 6, Sweden
Abstract
In a mutation experiment with a rough, ampicillin-resistant strain, we isolated two smooth mutants which were both sensitive to ampicillin and carried defects in the cell envelope. One of the strains (with the
envA
gene) is hindered in its completion of septa and forms chains of cells. The
envA
gene has been mapped to a position between
leu
and
proB
, at 2 to 4 min. The
envA
gene decreased the resistance mediated by both episomal and chromosomal genes for resistance to several antibiotics. During growth the
envA
mutant was characterized by abnormal ratios between viable count or cell count and optical density. The ratio between viable count and optical density was affected during shift-up and shift-down experiments. When compared to the parent strain, the
envA
mutant was found to be more resistant to ultraviolet irradiation on plates. Prestarvation for tryptophan had a protective effect against irradiation both on the parent strain and the
envA
mutant.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Cited by
152 articles.
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