Gaschromatography of constitutive fatty acids in Mycobacterium leprae

A constitutive saturated and monounsaturated fatty acid pattern of Mycobacterium leprae, isolated from the liver of a nine-banded armadillo with experimental leprosy, was analyzed gaschromatographically and compared with that of cultured M. lepraemurium, M. avium, M. bovis, strain BCG and M. smegmatis. In comparing the fatty acid pattern thus obtained and the known structure of mycolic acids in these mycobacteria, an experiential rule that each species of mycobacteria has a relatively high content of normal (straight-chained) saturated fatty acid having two more carbons than those of the alpha-branch in this species' mycolic acids, coincided well for all mycobacteria tested. In particular, M. leprae was found to contain a relatively high content of behenic acid (n-C22:0) and the carbon-number of the alpha-branch in this species' mycolic acids is 20 as we previously reported. These data suggested the possibility of simple detection of M. leprae by gaschromatography, and results sustaining this possibility were obtained.