【作者】 吕国；

【导师】 于炳松； 董海良；

【作者基本信息】 中国地质大学（北京） ， 矿物学、岩石学、矿床学， 2011， 博士

【摘要】 在中国大陆科学钻探项目(CCSD)研究中,从地下深880米的钻孔深处,采集的泥浆样品中分离出了一个嗜碱性厌氧菌新种。在形态上,该细菌新种表现出轻微的弧形杆菌形态。在生理上对该细菌进行了定性,通过在10-48℃这一温度范围内进行观察,发现其最适生长温度为38℃,通过对0-7.5% NaCl盐度范围和0-6% KCl盐度范围分别进行观察,并对6.4-12.4 pH值范围进行测量,发现其最适pH值为9.4。严格意义上的厌氧细菌能够利用多种有机物作为营养物质,如蛋白胨、肉汁、乳酸盐、纤维二糖、葡萄糖、核糖和延胡索酸盐等。该菌基因组G+ C含量为35.4 mol%。基于16S rRNA序列的系统发生分析,结果表明分离到的细菌新种属于厚壁菌门,即G+ C含量较低的革兰氏阳性菌。对16S rRNA进行的系统发育分析,表明该细菌属于Clostridiaceae科,G+ C含量低,与Anaerobranca gottschalkii和Anaerobranca californiensis的核苷酸同源性分别达到94%和93%。分离出来的细菌代表了一个嗜碱性新种。根据其生理和分子特性,建议将该细菌命名为Alkaliphilus Aanaerobic- sp. nov。高度厌氧生存环境,以及该细菌与CCSD钻孔中的其他分离物的比较,也在本文中进行了讨论。更多还原

【Abstract】 A novel iron-reducing alkaliphilic anaerobic species was isolated from an 880-m-depth drilling mud sample of a subsurface borehole of CCSD (Chinese Continental Scientific Drilling Program). The bacterium displayed a slightly curved rod morphologically, and was physiologically characterized with an optimal temperature of 38℃, the salinity of (NaCl), (KCl), respectively, and an optimal pH 9.4. The strictly anaerobic bacterium was able to utilize various carbon substrates such as peptone, nutrient broth, lactate, cellobiose, glucose, ribose, fumarate and so on. The G+ C content of genomic DNA was 35.4 mol%. Phylogenetic analysis based on the 16S rRNA sequence indicated that the isolate is a member of Firmicutes within the low G+C Gram-positive bacteria. Phylogenetic analysis of the 16S rRNA indicated the bacterium was a low G+C Gram-positive microorganism in the Clostridiaceae, and had 94% and 93% nucleotide identity with Anaerobranca gottschalkii and Anaerobranca californiensis, respectively. The isolate represented a novel metal-reducing, alkaliphilic species and the name Alkaliphilus Aanaerobium sp. nov. is proposed based on its physiological and molecular properties. The highly anaerobic habitat and the comparison with other isolates from the CCSD boreholes are discussed. The interactions between the iron-reducing and iron-bearing minerals are also tested in the paper.更多还原