Abstract
A tetrachloroethylene (PCE)-degrading mixed culture was obtained from the drainage sediment of a dry-cleaning factory in where PCE was used. Although the mixed culture was unable to be subcultured with keeping PCE degradation activity, the addition of autoclaved or heated soils at 200°C and 600°C into subculture medium was effective to maintain PCE degradation activity. That effect was observed in all heated soil samples used in this study and zeolite, but lost in acid-treated samples. Therefore, the factor effective to maintain PCE degradation activity was supposed to be metals in the soil samples or “habitat” in soils and zeolite for PCE-degrading bacteria. That mixed culture could dechlorinate PCE to cis-1, 2-DCE via trichloroethylene (TCE), and degrade TCE and carbon tetrachloride, but not trichloroethane, chloroform and dichloromethane. The PCE degradation activity was optimized at about pH7 and 30°C.
