Methylotrophy in Mycobacteria: Dissection of the Methanol Metabolism Pathway in Mycobacterium smegmatis

Abstract

Methylotrophy, the ability to utilize single-carbon (C 1 ) compounds as the sole carbon and energy sources, is only poorly understood in mycobacteria. Both pathogenic and nonpathogenic mycobacteria, including Mycobacterium tuberculosis , are capable of utilizing C 1 compounds to meet their carbon and energy requirements, although the precise pathways are not well studied. Here we present a comprehensive study of methylotrophy in Mycobacterium smegmatis . With several genetic knockouts, we have dissected the entire methanol metabolism pathway in M. smegmatis . We show that while methanol dissimilation in M. smegmatis differs from that in other mycobacterial species, the concluding step of CO 2 fixation is similar to that in M. tuberculosis . It is therefore both interesting and important to examine mycobacterial physiology in the presence of alternative carbon sources.