大连湾石油污染沉积物中细菌群落结构分析

大连新港"7.16"输油管道爆炸溢油事故发生后,为探究石油污染与细菌群落结构变化之间的关系及在石油生物降解过程中起重要作用的细菌菌群,本研究对大连湾表层沉积物中石油烃含量和细菌宏基因组16SrDNA V3区进行分析。结果表明:溢油初期2010年8月DLW01站位表层沉积物石油烃含量高达1 492mg/kg,符合第三类沉积物质量标准,随着时间推移,2011年4月、2011年7月、2011年12月航次各站位沉积物中石油烃含量基本呈下降趋势,且均符合第一类沉积物质量标准;16S rDNA PCR-DGGE方法分析表明,石油烃含量高的区域优势细菌种类少,反之则较丰富;海洋环境中同一地点的细菌群落能保持一定稳定性;大连湾石油污染沉积物中变形菌门γ-变形菌纲和拟杆菌门一直保持较高的优势度,是在石油生物降解过程中起重要作用的细菌菌群,而厚壁菌门只在石油烃含量低的区域出现;此外,出现的对污染物敏感的嗜冷杆菌可作为石油污染指示生物进行深入研究。

Bacterial communities in Dalian Bay petroleum pollution sediments

In order to explore the connection between petroleum pollution and bacterial community structure change, the important dominant bacteria communities in the process of oil biodegradation, after the "7.16" pipeline explosion and oil spill accident happened in Dalian Xingang, the content of petroleum hydrocarbon and bacterial metagenome were studied in Dalian Bay. Results showed that the petroleum hydrocarbon content in the surface sediment of DLW01 in August 2010 was 1 492 mg/kg, according with the third standard of marine sediment quality. As time went on, the content of petroleum the presented basic downward thrend, and all conformed to the first standard of marine sediment quality in April 2011, July 2011, December 2011. 16S rDNA targeted PCR-DGGE results suggested that the dominant bacteria communities were monotonous in high petroleum hydrocarbons areas, while conversely rich in low oil pollution. Bacterial community in the same place could maintain stability. Phylum Gammaproteobacteria and Bacteroidetes were higher in the oil polluted sediment of Dalian Bay, which played an important role in the process of oil biodegradation. Phylum Firmicutes only detected in the area of low oil pollution. The sensitive pollution indicator Psychrobacter sp. could be used as biological indicator for further research.