陕北石油污染土壤微生物种群变化及影响因素

The influences of petroleum pollution on the microbial population distribution in Northern Shaanxi Province of China

采集陕北地区10个产油区县的石油污染土壤和洁净土壤,利用化学分析法和分子生物学技术对土壤理化性质和细菌群落结构进行测定,采用Pearson相关性分析和冗余分析研究石油污染对土壤理化性质、微生物种群分布和多样性的影响.结果表明,与未受污染土壤相比,石油污染土壤的NO_(3)^(-)-N、总有机碳、全碳、全硫含量和碳氮比增加,pH值减小;土壤细菌群落均匀度明显降低,丰富度无明显变化.不同地区土壤受到石油污染后,一些优势细菌的相对丰度变化明显.变形菌门(Proteobacteria)和绿弯菌门(Chloroflexi)的相对丰度变化与石油烃含量呈显著正相关,Candidatus Saccharibacteria的相对丰度变化与石油烃含量呈极显著负相关.定边、靖边、子长、绥德、吴起、安塞和富县石油污染土壤中假单胞菌属(Pseudomonas)、诺卡氏菌属(Nocardioides)、节杆菌属(Arthrobacter)、不动杆菌属(Acinetobacter)、Alkanindiges、Gaiella和Gp4相对丰度显著增加;定边、靖边、子长和绥德石油污染土壤中Ohtaekwangia、假诺卡氏菌属(Pseudonocardia)、Ramlibacter、Sacchariacteria_genera_incertae_sedis相对丰度显著降低.假单胞菌属(Pseudomonas)、诺卡氏菌属(Nocardioides)、节杆菌属(Arthrobacter)和Alkanindiges为陕北地区石油污染土壤中的主要“嗜油菌”.土壤pH值、含水率、总石油烃和总有机碳等理化性质是影响陕北油田区石油污染土壤微生物种群结构的关键因素.

Oil-contaminated soil and uncontaminated soil from oil well sites in ten oil-producing counties in Northern Shaanxi were collected.Chemical analysis and molecular biology techniques were used to determine the physicochemical properties and bacterial community structure of soil.Methods such as Pearson correlation analysis and redundancy analysis were used to study the impact of oil pollution on physicochemical properties,microbial population distribution and diversity of soil.Results showed that compared with uncontaminated soil,nitrate-nitrogen,total organic carbon,total carbon,total sulfur and carbon-nitrogen ratio of oil-contaminated soil increased,while the pH value decreased.The richness of soil bacterial community did not change significantly,but the evenness decreased significantly.The relative abundance of some dominant bacterial changed obviously after oil contamination in different regions.Changes in relative abundance of Proteobacteria and Chloroflexi were significantly positively correlated with petroleum hydrocarbon content,and changes in relative abundance of Candidatus Saccharibacteria were significantly negatively correlated with petroleum hydrocarbon content.The relative abundance of Pseudomonas,Nocardioides,Arthrobacter,Acinetobacter,Alkanindiges,Gaiella and GP4 increased significantly in Dingbian,Jingbian,Zichang,Suide,Wuqi,Ansai and Fuxian.The relative abundance of Ohtaekwangia,Pseudonocardia,Ramlibacter,and Sacchariacteria_genera_incertae_sedis decreased significantly in Dingbian,Jingbian,Zichang and Suide.Pseudomonas,Nocardioides,Arthrobacter and Alkanindiges were the main oilphilic bacteria in Northern Shaanxi Province.Physicochemical properties such as pH,moisture content,total petroleum hydrocarbon and total organic carbon were the key factors affecting the microbial population structure of oil-contaminated soil in Northern Shaanxi oilfield.