中文摘要：

从油田地层水中分离到1株嗜热解烃菌（地芽孢杆菌DM-2）,通过研究该菌株在不同条件下降解原油的性能以及在最适条件下降解烃的特性发现：地芽孢杆菌DM-2可在45--70℃p、H 4.0--10.0、0.2%--3.0%的盐离子浓度缺氧条件下降解原油烃类,其降解原油烃的最适温度和pH值分别为60℃和7.0.在此条件下,该菌可乳化液体石蜡作为碳源进行生长;气相色谱和红外光谱进一步分析表明,其能降解原油中的C14--C30的直链烷烃、支链烷烃和芳香烃类,并能降解C16--C36的长链单烷烃,其中对C28的降解量最高,达88.95%.DM-2菌株代谢烷烃的产物之一为脂肪酸,经液相色谱和质谱分析代谢十六烷产生的脂肪酸为乙酸,5 d产量达0.312 g/L,说明其采用次末端氧化途径氧化烷烃,之后进入β-氧化途径代谢.DM-2菌株在高温缺氧的极端环境下对烃的乳化、降解和产酸特性使其在高温石油污水的生物处理和开采重质原油方面具有潜在的应用价值.

英文摘要：

A thermophilic Geobacillus strain DM-2 from a deep-subsurface oil reservoir was investigated on its capability of degrading crude oil under various conditions as well as its characters on degrading hydrocarbons in optimal conditions. The results showed that GeobaciUus strain DM-2 was able to degrade crude oil under anoxic wide-range conditions with pH ranging from 4.0 to 10.0, high temperature in the range of 45- 70℃ and saline concentration ranging from 0.2% to 3.0%. Fuithermore, the optimal temperature and pH value for utilizing hydrocarbons by the strain were 60℃ and 7.0 ,respectively. Under such optimal conditions, the strain utilized liquid paraffine emulsified by itself as its carbon source for growth; further analysis by gas chromatography（GC） and infrared absorption spectroscopy demonstrated that it was able to degrade n-alkanes （C14-C30）, branched-chain alkanes and aromatic hydrocarbons in crude oil and could also utilize long-chain n-alkanes from C16 to C36, among of which the degradation efficiency of C28 was the highest, up to 88.95 %. One metabolite of the strain oxidizing alkanes is fatty acid.While utilizing C16 as carbon source for 5 d, only one fatty acid-acetic acid was detected by HPLC and MS as the product, with the amount of 0. 312 g/L, which indicated that it degraded n-alkanes with pathway of inferior terminal oxidation, and then followed by a/3-oxidation pathway. Due to its characters of efficient emulsification, high-performance degradation of hydrocarbons and fatty-acid production under high temperature and anoxic condition, the strain DM-2 may be potentially applied to oil-waste treatment and microbial enhanced heavy oil recovery in extreme conditions.