Abstract: By using Biolog technique, this paper studied the carbon source utilization characteristics of microbial communities in different layers (0-10 cm, 10-20 cm, and 20-30 cm) of a petroleum-contaminated soil near an oil well having exploited for 36 years in Daqing Oil Field. Petroleum contamination enhanced the metabolic activity of the soil microbial communities obviously. In the three layers of the petroleum-contaminated soil, the metabolic activity of the microbes was higher than that of the control, and there existed significant differences between different layers of the petroleum-contaminated soil. The carbon source metabolic capacity of the microbes in different layers of the petroleum-contaminated soil was in the order of 20-30 cm ＞10-20 cm ＞ 0-10 cm. Petroleum contamination made the kinds of soil carbon source and the metabolic diversity of soil microbes increased, being more obvious in 10-20 cm and 20-30 cm soil layers but less change in 0-10 cm soil layer. In the contaminated soil, the majority of the carbon sources utilized by the microbes in 10-20 cm soil layer were carbohydrates instead of the carboxylic acids in non-contaminated soil, whereas the majority of the carbon substrates utilized in 20-30 cm soil layer were carboxylic acids. All the results suggested that petroleum-contaminated soil had its unique microbial community structure and peculiar microbial carbon source utilization characteristics.

Key words: petroleum contamination, soil microbial community, Biolog, carbon source utilization