中文摘要：

从污染土样中分离出一株多氯联苯（PCBs）降解菌，利用细菌通用引物扩增降解菌的16SrDNA，得到～1500bp的片段。经纯化，测序后在Genbank上进行同源性比较分析及系统发育树构建，初步鉴定该菌株为Pseudomonassp，并用其对PCB77进行降解研究。研究结果表明，该菌株在培养2d后达到对数生长期，当培养温度为30℃、培养基pH值为7．0、微生物接种量为109cfu／mL、PCB77初始浓度为1．0mg／L时，微生物对PCB77的降解率为58．63％。微生物对PCB77降解的最适条件为：培养基pH值为7．0、微生物接种量为2x109cfu／mL、外加蔗糖浓度为2．0g几、PCB77初始浓度为0．5mgm。

英文摘要：

A degrading bacteria strain was isolated from polluted soil by polychlorinated biphenyls （PCBs）. The degrading bacteria strain＇s 16S rDNA was amplified with bacteria universal primer, the amplified product （about 1,500 bp）was purified and sequenced for phylogenetic analyses with Genbank. The bacterium was identified as Pseudomonas sp. which was used to the degradation of PCB77, The results of the study showed that the bacteria reached logarithmic phase on the second day, and the degradation ratio of PCB77 was 58.63% when the temperature was 30 ℃, pH was 7.0, microorganism inoculation amount was 109 cfu/mL and the concentration of PCB77 was 1.0 mg/L. The optimum reaction conditions for PCB77 degradation were pH 7.0 of the solution, external carbon source 2 g/L, microbial inoculation amount 2x109 cfu/mL and the initial concentration of PCB77 0.5 mg/L.