AEROBIC DEGRADATION PROPERTIES AND BACTERIAL DIVERSITY OF TOLUENE DEGRADED BY DIFFERENT ACCLIMATED BACTERIA

摘要

To explore differences in degradation properties of toluene by different acclimated bacteria and determine the factors affecting toluene degradation efficiency, bacteria acclimated by benzene, toluene, ethylbenzene, xylene (BTEX) and BTEX mixture were used to degrade toluene under aerobic conditions. Then degradation properties were explored and bacterial diversity was investigated by poly-merase chain reaction-denaturing gradient gel electro-phoresis (PCR-DGGE). Bacterial genomic DNA was extracted after cultured by Luria Bertani (LB) medium. 16S rRNA fragments were amplified with universal primers (F357-GC and R518) and analyzed by DGGE. Experimental results demonstrated that five kinds of acclimated bacteria had good effect on degrading toluene, in 54 h, all degradation ratios reached 80% or more. Ethylbenzene acclimated bacteria had the best degradation efficiency, followed by toluene acclimated bacteria. Dominant bacteria and stable community structure were two significant factors to maintain high efficiency of toluene degradation. Longer lag phase would result in lower degradation efficiency. Results and findings gained from this study will be helpful in improving degradation ability of toluene-degrading bacteria.