Degradation of morpholine, piperidine, and pyrrolidine by mycobacteria: evidences for the involvement of a cytochrome P450

Nine bacterial strains that grew on morpholine and pyrrolidine as sole carb on, nitrogen, and energy sources were isolated from three different environ ments with no known morpholine contamination. One of these strains could al so degrade piperidine. These bacteria were identified as Mycobacterium stra ins. A phylogenetic analysis based on the partial 16S rDNA sequences indica ted that the isolated strains clustered within the fast growing group of my cobacteria. When the above-mentioned cyclic amines were used as growth subs trates, the synthesis of a soluble cytochrome P450 was induced in all these bacteria. Other laboratory strains, Mycobacterium fortuitum and Mycobacter ium smegmatis mc(2)155, were tested for their abilities to degrade morpholi ne. Neither of them degraded morpholine but could use pyrrolidine and piper idine. The growth of M. fortuitum and M. smegmatis mc2155 on these compound s involved a soluble cytochrome P450, suggesting that mycobacterial strains are naturally able to use pyrrolidine and have developed a similar enzymat ic pathway to metabolize this amine.