
Full text loading...
SUMMARY: Mucopeptide synthesis by Pediococcus cerevisiae ATCC 8081 and P. cerevisiae crd (a methicillin-requiring substrain) was measured by incorporation of radioactivity from 14C-labelled-alanine, -glutamate, -lysine and -aspartate into the mucopeptide fraction of organisms incubated in a solution inadequate to support growth. Teichoic acid synthesis was measured by incorporation of [32P]H3PO4 into a hot trichloroacetic acid soluble fraction from isolated walls.
Mucopeptide synthesis by both strains (as measured by incorporation of [1-14C]glutamic acid) was unaffected by chloramphenicol but was sensitive to benzylpenicillin. The incorporation was resistant to methicillin in strain crd (2 mg/ml gave 50 % inhibition) but not in parent organisms (120 μg/ml gave 50 % inhibition).
Strain crd incorporated twenty times less [32P]H3PO4 into teichoic acid than did the parent strain. With either strain, benzylpenicillin (25 μg/ml) and d-cyclo-serine (200 μg/ml) inhibited this synthesis, but methicillin (500 and 1000 μg/ml) did not.
Electron micrographs of strain crd incubated for four hours with methicillin showed large deposits of wall material around septa; these were not seen in parent organisms.
Article metrics loading...
Full text loading...
References
Data & Media loading...