一株油藏嗜热厌氧杆菌的分离、鉴定及代谢产物特征

Isolation and characterization of Thermoanaerobacter mathranii SC-2 from oil-field water

摘要:

【目的】了解油藏环境中细菌的生理生化特性及代谢产物。【方法】采用Hungate厌氧操作技术从胜利油田罗801区块油层采出水中分离到一株厌氧杆菌SC-2。采用生理生化鉴定结合16S rDNA序列的系统发育学分析确定该菌株的系统发育地位，用气相色谱分析其代谢产物。【结果】菌株SC-2为严格厌氧的革兰氏阴性杆菌，菌体大小为0.38 mm×1.7 mm~3.9 mm，单生、成对或成串生长，产端生芽孢。温度生长范围40℃~75℃（最适温度70℃）；pH范围5.5～9.5（最适pH 6.5）；NaCl浓度范围0%～5%（最适NaCl浓度0%）。能够利用葡萄糖、麦芽糖、甘露糖、木糖等多种碳水化合物，发酵葡萄糖的产物是乙醇、乙酸、丙酸、H2、CO2及少量的乳酸。菌株SC-2的（G+C）mol%含量为30.8%，与Thermoanaerobacter mathranii subsp. mathranii的16S rDNA序列相似性为99.85%。菌株利用葡萄糖产乙酸、乙醇的最佳初始pH为8.0；酵母粉能刺激生长并显著提高发酵葡萄糖的产酸、产醇率；培养基中添加4%（V/V）的乙醇能明显抑制菌体生长。【结论】菌株SC-2是从特殊生境（油层采出水）中分离到的一株嗜热、耐盐的厌氧菌，其发酵葡萄糖产生的代谢产物有利于改善油藏中的微环境。菌株SC-2与T. mathranii subsp. mathranii 11426T的最适pH和最大耐受NaCl浓度有所不同，且二者的（G+C）mol%含量差异较大。

Abstract:

[Objective] We studied physiological, biochemical properties and metabolites of Thermoanaerobacter mathranii SC-2 from oil-field water in Shengli oilfield. [Methods] Strain SC-2 was isolated by Hungate anaerobic technique. Through physiological, biochemical and phylogenetic analysis, the strain was identified. Metabolites were analyzed by gas chromatogram. [Results] The cells were Gram-negative, rod-shaped, spore-forming. Growth was observed in the temperature range from 40 to 75℃(optimum 70℃) and pH range from 5.5 to 9.5 (optimum 6.5). The isolate grew in the presence of 0%~5% NaCl with an optimum without NaCl at pH 7.0 and 65℃. Strain SC-2 used many carbohydrates as carbon sources, including glucose and xylose. Metabolites of glucose were ethanol, acetate, propionate, lactate, CO2 and H2. Based on 16S rDNA studies, strain SC-2 was most close to T. mathranii subsp. mathranii11246T with 99.85% similarity. More ethanol and acetate were produced at initial pH 8.0 than yields at other pH. Yeast extract could significantly increase ethanol and acetate yields. In addition, ethanol (4%) added in the medium obviously inhibited its growth. [Conclusion] Strain SC-2 was extremely thermophilic, halotolerant anaerobe.