a 60 kb plasmid in mycobacterium (pip+) involved in degradation of antihelminthic drug (piperazine)

the biodegradation of secondary amines is particularly important due to their propensity for conversion either chemically or microbiologically to n-nitrosamines which are potent carcinogens. in this research, a weak gram-positive organism was isolated from river and identified as mycobacterium. this mycobacterium grows slowly and effectively utilizes piperazine as the sole source of organic, carbon, nitrogen and energy. also, it has one 60-kb plasmid on gel agarose which involves in piperazine degradation however the mutant strain which were obtained by subculturing in nutrient broth (pip-) has lost this plasmid. this might suggest that the ability to degrade piperazine are plasmid encoded.