焦化废水中酚降解菌及其降解基因的研究

Isolation of Phenol-degrading Bacteria from Coking Wastewater and Their Degradation Gene

酚类化合物是焦化废水的主要污染物,微生物降解在废水处理中起着主要作用.为获得焦化废水活性污泥中主要降解菌,本研究通过富集与平板涂布对某焦化公司的2个活性污泥中的降解菌进行了分离鉴定.通过BOX-PCR和16S rDNA序列分析去除重复菌株后,共获得分属于20个属的28个种的28株细菌,它们主要为变形菌纲β和γ亚群,其中4株菌可能是潜在的新种.间甲酚富集后筛选得到2株高效降解菌株Pseudomonas monteilii GCS-AE-J-1和Pseudomonas plecoglossicida GCS-AN-J-3;前者在48 h内对791 mg/L间甲酚的降解率达到94.6%,而后者对763mg/L间甲酚的降解率也达到了92.2%.通过PCR从菌株GCS-AE-14、GCS-AE-J-1、GCS-AN-J-3和GCS-AN-3得到了苯酚羟化酶基因序列.本研究所获得的降解菌新颖多样,在工业焦化废水的处理中可能起着重要作用,有进一步研究开发的价值.

Phenol and phenolic compounds are main pollutants in wastewater of coking factories.To identify the bacteria responsible for phenol removal in the activated sludge of a coking factory,we isolated bacteria from the sludge directly or after enrichment.From two samples from the aerobic and anaerobic pools,28 strains belonging to 28 species of 20 genera were obtained after identification with BOX-PCR and further 16S rDNA sequence analyses.Most of them belonged to β-and γ-Proteobacteria,four of which are potential novel species of low 16S rDNA sequence similarity to corresponding type strains.From the m-cresol enrichment community,two strains identified and named as Pseudomonas monteilii GCS-AE-J-1 and Pseudomonas plecoglossicida GCS-AN-J-3 were obtained as the efficient degraders;The former can remove 94.6% m-cresol（791 mg/L） in just 48 h;while the latter metabolized 92.2% m-cresol（763 mg/L）.Furthermore,the phenol hydroxylase gene was surveyed by PCR from the phenol-degrading strains,and 4 were positively detected.Summarily,quite diverse bacteria were proved of high capability to degrade phenol and phenolic compounds in this report,which play important role in biotreatment of phenol compounds.