Fatty acid synthesizing enzyme activity of cultured Mycobacterium lepraemurium

In comparing the specific activity of enzymes pertaining to the biosynthesis of fatty acids in crude extracts of cultivated M. lepraemurium and M. smegmatis, it was found that: 1. The activity of acetyl CoA carboxylase of the former organism was undetectable and that of de novo fatty acid synthetase was too weak to measure exactly, under the condition used, whereas both activities of the latter organism were comparable to those already reported by other authors. 2. The activity of acetyl CoA dependent acyl CoA elongation system of M. lepraemurium was relatively high and close to that of M. smegmatis. 3. The activities of acetyl CoA synthetase and acyl CoA synthetase of M. lepraemurium were moderately lower than those of M. smegmatis. The relation between this peculiar fatty acid synthesizing enzyme system of M. lepraemurium and its extremely sluggish growth is discussed.