The genes controlling the biosynthesis of carotenes in Mycobacterium aurum responsible for its yellow pigmentation were previously cloned (FEMS Microbiol Lett 1992, 90:239-244). In this study, the genes Crt I, car alpha, and car Lep, controlling respectively the formation of lycopene from phytoene (phytoene desaturase), alpha-carotene from lycopene, and leprotene from lycopene, were localized.