Isolation of a Pseudomonas Strain Resistant to Organic Solvents and Capable of Degrading Coplanar Polychlorinated Biphenyls

抄録

Biological treatment of waste polychlorinated biphenyls (PCBs) mixed with organic solvents (OSs) requires bacteria that have both OS tolerance and PCB-degrading capacity. Therefore, we tried to find such bacteria strongly capable of both tolerating OS and degrading PCBs. We screened eleven bacteria capable of degrading more than 70% (w/v) of KC-300 containing 10ppm PCB from 200 samples of soil and sea water taken from the mouth of Sagami river and elsewhere. We selected six of the 11 strains that could degrade more than 50% (w/v) of KC-500 (10 ppm). The six strains were subjected to experiments using high concentrations of PCBs (HC-PCBs) and OS tolerance tests. Of these six, a strain that could degrade HC-PCBs was selected, and identified by physiological, biological and electron microscopic examinations as Pseudomonas putida. The isolate was then named SN-4992. SN-4992 degraded more than 60% of PCBs at 100 ppm (KC-400) over 15 d, and 86.8 % of very toxic coplanar PCBs (c-PCBs) in KC-400 (100 ppm).