Dichloromethane-degrading properties of bacteria isolated from environmental water

Degradation of dichloromethane (DCM) by two environmental isolates, Flevimones sp. strain P3310 and Chryseobacterum sp. strain G31, were studied. The ability of the strains was raised to degrade 3,000 mg/l of DCM by acclimatization, although the original isolates could degrade less than 500 mg/l. The first step in the degradation process was dechlorination, and the liberated chloride ions caused the reduction of pH and the bacterial growth; the addition of phosphate salts, however, restored the growth and the degrading ability of the culture by increasing the buffer capacity. The DCM-degrading activity was also detected in the cell-free extract and the culture-supernatant. These results suggest that the isolates or their products are possible candidates for bioremediation to eliminate DCM pollution.