Direct evidence for the oxidation of palmitic acid by host-grown Mycobacterium leprae

Oxidation of palmitic acid by whole-cell suspensions of Mycobacterium leprae free from host tissues was investigated using manometric techniques. After a lag period of about 6-8 h, M. leprae suspensions catalysed an active oxidation of palmitic acid, and the oxidative process (oxygen uptake) was quite sensitive to rotenone, atabrine, amytal, antimycin A and cyanide. The spectrophotometric observations indicated that the M. leprae cytochrome system, under anaerobic conditions, was reduced in the presence of palmitic acid which was completely oxidized by oxygen. These data provide direct evidence that M. leprae cells are capable of oxidizing palmitic acid, and that oxidation is mediated by the electron transport system using oxygen as the terminal electron acceptor.