The assimilation of amino acids by bacteria. 21. The effect of nucleic acids on the development of certain enzymic activities in disrupted staphylococcal cells

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Abstract
Development of certain enzymic activities, "glucozymase", catalase and beta-galactosidase, in disrupted cell preparations of Staphylococcus aureus is described. Preparations B, C and D correspond to progressive stages in removal of nucleic acid from the disrupted cells. Preparations at stage B develop "glucozymase" and catalase activities when incubated with a complete mixture of amino acids, and beta-galactosidase if galactose is added to the incubation medium. Nucleic acids have little or no effect on enzyme development at this stage. At stage C , preparations develop little enzymic avticity unless nucleic acid or its derivatives are added: catalase development is strongly stimulated by ribonucleic acid (RNA) but not by a mixture of purines and pyrimidines (PP); beta-galactosidase development is stimulated by PP but not by RNA whether derived from glucose- or galactose-grown cells. Desoxyribonucleic acid (DNA) has little or no effect at this stage. Preparations at stage D, highly depleted of nucleic acid, respond less markedly to RNA or PP than stage C preparations, but DNA is now stimulatory both for catalase and beta-galactosidase development. "Glucozymase" development is stimulated by RNA, DMA or PP. Development of all 3 enzyme activities is abolished by chloramphenicol at a concentration of 10-30 [mu]g/ml. Penicillin and bacitracin at a concentration oi 30 [mu]g/ml strongly inhibit formation of beta-galactosidase but are without action on catalase development. Incubation of disrupted cells with C14-uracil under conditions suitable for enzyme development results in incorporation of radioactivity into the nucleic acid fraction; this incorporation is markedly increased by the presence of galactose in the medium. The increase due to galactose is abolished 75% by penicillin in concentrations inhibiting beta-galactosidase formation.