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[目的]了解油藏微生物Thermoanaerobacter sp DF3的生理生化特性,优化木糖产乙醇培养方案。[方法]利用厌氧分离技术从大港油田油层采出液中分离到一株产乙醇厌氧杆菌DF3采用生理生化鉴定与16SrDNA序列的系统发育学分析其系统发育地位,用气相色谱分析其代谢产物。[结果]菌株DF3是一株严格厌氧的嗜热细菌,呈直杆状,G-,菌体大小为0.42μm×(1.60～5.20)μm,单生成对或成串生,产顶端芽孢;生长温度为45～78℃(最适65℃),能利用葡萄糖、木糖、果糖、核糖、甘露糖、阿拉伯糖、蔗糖、半乳糖、乳糖、纤维二糖、松三糖、棉子糖、淀粉等作为底物;其16SrRNA与T.pseudoethanolicus相似性为99.7%发酵葡萄糖与木糖的主要产物为乙醇,培养方案优化后其代谢木糖产乙醇终浓度为2.0g/L。[结论]通过试验证明菌株DF3是目前已知菌株中产乙醇活性较强的菌株之一,在65℃时代谢木糖能产生2.0g/L的乙醇目前代谢木糖高产乙醇的菌株均由国外分离获得,菌株DF3的分离获得为我国研究木质纤维素产乙醇提供了优良的出发菌株。
[Objective] The research aimed to understand the physiological and biochemical characteristics of Thermoanaerobacter sp DF3 and optimize the cultivation plan of xylose ethanol. [Method] Anaerobic ethanologenic strain DF3 was isolated from oil production fluid in Dagang Oilfield by anaerobic separation technology. Phylogenetic analysis of physiological and biochemical characteristics and 16S rDNA sequence of DF3 was used to analyze its phylogenetic position. The metabolites of its metabolites . [Result] Strain DF3 was a strictly anaerobic thermophilic bacterium, which was in the shape of a straight rod with a diameter of 0.42μm × (1.60 ~ 5.20) μm. The growth temperature is 45 to 78 ° C (optimum temperature is 65 ° C) and glucose, xylose, fructose, ribose, mannose, arabinose, sucrose, galactose, lactose, cellobiose, melezitose, raffinose, Starch, etc. as the substrate. The similarity of 16S rRNA and T. pseudoethanolicus was 99.7%. The main product of fermentation glucose and xylose was ethanol. After optimization of culture protocol, the final concentration of xylose-producing ethanol was 2.0 g / L. [Conclusion] The strain DF3 was proved to be one of the strains with strong ethanol production activity at present. At 65 ℃, metabolizing xylose could produce 2.0g / L ethanol. At present, strains producing high-yielding ethanol from xylose were separated from abroad Obtained, the isolation of strain DF3 obtained for our study of lignocellulosic ethanol production provided an excellent starting strain.