G. EMTIAZI, F. MALEKZADEH and Z. EMAMI
Abstract
The ability of a Gram-negative (identified as Pseudontonas) bacterium to degrade piperazine when growing in pure culture is reported for the first time. The isolate was able to degrade piperazine and to utilize it as a sole nitrogen and carbon source. This organism was obtained from river water directly on piperazine containing media. Although this isolate grew fast in nutrient broth (mean generation time of ca. 7 hours), it was capable of only slow growth on piperazine (mean generation time of Ca. 27 hours). The isolate produced ammonia from piperazine degradation, but did not grow on morpholine or oxidize it, however immediately oxidized piperidine and pyrrolidine. This isolate was not stable on biodegradation and after one subculture in nutrient broth, 70 per cent of the mutant (which could not biodegrade piperazine) was obtained. The plasmid profile of the mutant and wild type was studied.