The differential effect of arginine and canavanine on growth and enzyme formation in Staphylococcus aureus 524 SC

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Abstract
Cultures of S. aureus 524, incubated in a fully synthetic amino acid medium lacking arginine, synthesize some lipid and the mucopeptide component of the bacterial cell wall but no ribonucleic acid (RNA), deoxyribonucleic acid (DNA) and general cell protein. Similarly, such cultures do not form active extracellular hyaluronidase, lytic enzyme and intracellular phosphatase; nor can they be induced to form intracellular [beta]-galactosidase. Addition of 2 [mu]g of arginine/ml to such cultures fully restores the ability of the organisms to synthesize RNA, DNA and phosphatase. Under these conditions, however, no hyaluronidase formation can be detected, the synthesis of lytic enzyme is markedly impaired and the differential rate of [beta]-galactosidase formation is depressed to about half the rate achieved in 100 [mu]g of arginine/ml. As a result of these experiments, the following sequence of decreasing sensitivity to limiting arginine concentrations is suggested: hyaluronidase >lytic enzyme >B-galactosidase >phosphatase, ribonucleic acid and the deoxyribonucleic acid > cell-wall mucopeptide. Cultures incubated in a fully synthetic amino acid medium containing canavanine in the place of arginine increase in turbidity, synthesize cell-wall mucopeptide, ribonucleic acid, deoxyribonucleic acid and general cell protein but do not form active versions of any of the enzymes tested. A possible mechanism of these changes is discussed.