Role of extracellular ribonuclease in growth of Corynebacterium acnes

Abstract

Corynebacterium acnes produces an extracellular nuclease which degrades ribonucleic acid. Growth was stimulated in peptone medium without glucose by the addition of ribonucleic acid and was related to the amount of ribonucleic acid depolymerized. Among other bacteria examined nuclease production was not always associated with the stimulation of growth by ribonucleic acid. Growth of C. acnes in peptone broth was stimulated by xanthine and guanine. Growth was not initiated in a basal nucleic acid free (NAF) medium by the addition of several nucleic acid metabolites nor in the NAF basal medium containing only 0.05% yeast extract. Growth occurred when the NAF–yeast extract base was supplemented with ribonucleic acid or other nucleic acid metabolites. Ribose and ribonucleic acid were equal in growth-supporting ability. Some purine bases in combination with glucose or ribose also supported growth. Other bases such as adenine or cytosine were not stimulatory but their ribotides were. Ribonuclease functioned as a growth stimulating enzyme by its action on ribonucleic acid under certain cultural conditions. Ribose appears to be a major stimulating metabolite made available from nucleic acid breakdown. Other components such as ribotides or nucleic acid bases, particularly purines, will also support growth in media devoid of these compounds or lacking them in sufficient concentration.