盐碱土壤多环芳烃降解菌群筛选及其降解特性

Screening and Biodegradation Characteristics of Polycyclic Aromatic Hydrocarbons-Degrading Consortium From Saline-Alkali Soil

为了强化多环芳烃(PAHs)污染盐碱土壤原位微生物修复的应用,并提供高效的菌种资源,从天津大港油田盐碱化的油污土壤中富集分离出1组高效降解菲、芘的耐盐碱菌群,分离获得可培养优势细菌5株、真菌3株,考察了该菌群对菲、芘的降解效果,并进行了其对菲、芘降解特性分析。结果表明,该菌群在菲、芘质量浓度分别为25、50和75mg/L的液体无机盐培养基中培养15d,菲、芘的降解率分别达到75.3%和53.6%、56.6%和52.0%、25.2%和13.6%;该菌群对菲、芘降解具有较广泛的盐质量分数和pH值范围,在菲、芘初始质量浓度各为50mg/L,最适盐质量分数0～2%,最适pH值8.6条件下,添加质量分数0.4%葡萄糖培养15d后,菲、芘的降解率显著提高,达到92.1%和65.8%。细菌16SrDNA和真菌18SrDNA测序结果表明,该菌群由叶杆菌属(Phyllobacterium)、假单胞菌属(Pseudomonas)、盐单胞属(Halomonas)、泛菌属(Pantoea)和青霉属(Penicillium)、双曲孢属(Sigmoidea)、胶孢炭疽属(Colletotrichum)组成。

The salt and alkaline endurable microbial consortium of degrading phenanthrene and pyrene effectively was developed from oil-contaminated saline-alkali soil of Tianjin Dagang oil field to intensify the application of situ bioremediation of polycyclic aromatic hydrocarbons in saline-alkaline soil and to provide highly effective microorganisms resources.Five cultivable dominate bacterium strains and three fungi strains through separation were obtained,and their degradation characteristics for phenanthrene and pyrene were analyzed.The degradation rates of phenanthrene and pyrene with 25,50 and 75 mg/L initial concentration by the microbial consortium in liquid mineral medium after 15 d cultivation were 75.3% and 53.6%,56.6% and 52.0%,25.2% and 13.6% respectively,meanwhile,when the initial concentration of phenanthrene and pyrene was 50 mg/L,respectively,the most suitable salt mass fraction was 0-2%,under the most suitable pH value 8.6,phenanthrene and pyrene degradation rates increased significantly after 15 d when adding 0.4%（mass fraction） glucose,reaching 92.1% and 65.8%,respectively.According to the analysis of 16S rDNA and 18S rDNA sequence,the microbial consortium consisted of 5 bacteria and 3 fungi including Phyllobacterium,Pseudomonas,Halomonas,Pantoea,Penicillium,Sigmoidea,Colletotrichum.