THE EFFECT OF PENICILLIN, NOVOBIOCIN, STREPTOMYCIN AND VANCOMYCIN ON MEMBRANE SYNTHESIS BY PROTOPLASTS OF BACILLUS MEGATERIUM

Abstract

Growing protoplasts of B. megaterium KM rapidly incorporated C14-labelled arginine, histidine, tyrosine and glycerol. A method is described of estimating the radioactivity of the membrane fraction of the protoplasts. Each amino-acid was incorporated into the protein of the membrane, and the glycerol into the lipid, without giving rise to other residues. High concentrations of penicillin had no effect on the rates of incorporation. Both novobiocin and streptomycin inhibited the incorporation of amino-acids and (to a much smaller extent) glycerol; vancomycin inhibited the incorporation of amino-acids and glycerol equally. There was no evidence for a selective inhibition, by any of these antibiotics, of incorporation into the membrane fraction compared with the total cell protein and lipid.