十红滩铀矿床中可培养产氢、烃气细菌类群分布与铀成矿相关性探讨

发布时间：2018-09-07 14:08

【摘要】：砂岩型铀矿是为核工业研究提供铀元素的重要矿产资源之一,研究砂岩型铀矿中本源微生物群落关系有利于了解微生物对铀矿化的影响。研究表明,铀矿床中存在的大量生物烃气在铀矿床继续沉积过程中起一定重要作用。目前关于铀矿床本源产烃气菌类群与现代铀矿床沉积作用相关性的研究甚少,而产氢菌可为产烃气菌提供生长条件,因此有必要对铀矿床本源产氢、烃气菌类群分布进行研究。本文首次确定了新疆十红滩砂岩型铀矿床中存在产氢、烃气菌并调查了其菌群的多样性,为微生物铀沉积作用提供一定依据,也为铀矿开采可持续发展并对因铀矿的开发导致的铀污染进行生物修复提供一定参考。本文应用MPN法对十红滩铀矿床中产氢菌进行计数,结果表明不同地化分带均分布有产氢菌。通过深层富集培养、分离纯化手段对铀矿床中可培养产氢菌类群进行研究,共分离得到12株产氢菌,主要归属于肠杆菌科Enterobacteriaceae及梭菌属Clostridium sp.。PCR-DGGE研究表明产氢菌菌属种类主要归属于肠杆菌科Enterobacteriaceae及梭菌属Clostridium sp.,假单胞菌属Pseudomonas sp.及芽孢菌属Bacillus sp.,产氢菌种群丰度在不同矿带呈氧化带过渡带还原带。通过厌氧培养结合产甲烷菌MCRA基因及细菌16S rRNA基因V3区PCR-DGGE对产烃气菌类群进行研究,结果表明,产甲烷菌菌群种类主要归属于甲烷螺菌属Methanospirllum sp.,甲烷嗜甲基菌属Methanomethylovorans sp.,甲烷八叠球菌属Methanosarcina sp.及甲烷囊菌属Methanoculleus sp.。采用荧光检测产甲烷菌菌体形态与DGGE结果一致,其种群在铀矿床不同地化分带的丰度分布呈氧化带过渡带还原带。产甲烷菌富集培养物伴生细菌种类主要归属于肠杆菌科Enterobacteriaceae,梭菌属Clostridium sp.,泛菌属Pantoea sp.,微杆菌属Exiguobacterium sp.,纤维单胞菌属Cellulomonas sp.和四球菌属Tessaracoccus sp.。主成分分析(PCA)表明产氢菌类群结构在不同地化分带无明显差异而产甲烷菌类群结构在不同地化分带有差异；典型对应分析(CCA)表明,产氢菌数量类群及产烃菌类群分布与环境因子有机碳、硫含量等相关。十红滩砂岩型铀矿床中存在具有活性的产氢、烃气菌,其种类分布呈现一定地球化学分带性。产氢、烃气菌的生态多样性从微生物学角度揭示了生物气对铀还原沉积的作用,对微生物铀成矿作用研究具有重要意义。
[Abstract]:Sandstone-type uranium deposits are one of the important mineral resources for the study of uranium elements in nuclear industry. It is helpful to understand the effect of microbes on uranium mineralization by studying the relationship of native microbial communities in sandstone-type uranium deposits. The study shows that the existence of a large amount of biogenic hydrocarbon gas in uranium deposits plays an important role in the continuous deposition of uranium deposits. At present, there is little research on the correlation between the original hydrocarbon producing gas bacteria group of uranium deposit and the sedimentary process of modern uranium deposit, and the hydrogen producing bacteria can provide the growth conditions for the hydrocarbon producing gas bacteria. Therefore, it is necessary to study the distribution of the origin hydrogen production and hydrocarbon gas bacteria group of the uranium deposit. In this paper, the existence of hydrogen and hydrocarbon gas bacteria in Shihongtan sandstone-type uranium deposit in Xinjiang is determined for the first time, and the diversity of its flora is investigated, which provides a basis for microbial uranium deposition. It also provides a certain reference for the sustainable development of uranium mining and bioremediation of uranium pollution caused by uranium exploitation. In this paper, the hydrogen producing bacteria in Shihongtan uranium deposit are counted by MPN method. The results show that hydrogen producing bacteria are distributed in different geochemical zonation. A total of 12 strains of hydrogen-producing bacteria were isolated from uranium deposits by means of deep enrichment culture, separation and purification. Studies on Enterobacteriaceae and Clostridium sp..PCR-DGGE showed that the species of hydrogen producing bacteria mainly belong to Enterobacteriaceae of Enterobacteriaceae and Pseudomonas sp. of Clostridium sp.,. And the abundance of hydrogen producing bacteria of Bacillus sp., in different ore zones is in the transition zone of oxidizing zone and reducing zone. The hydrocarbon-producing bacteria group was studied by anaerobic culture combined with methanogenic bacteria MCRA gene and 16s rRNA gene V3 PCR-DGGE. The species of methanogenic bacteria mainly belong to the genus Methanospirllum sp., methanophilic bacteria Methanomethylovorans sp., methanemophilus genus Methanosarcina sp.. And methanocystis Methanoculleus sp.. The morphology of methanogenic bacteria detected by fluorescence was consistent with that of DGGE. The abundance distribution of methanogenic bacteria in different geochemical zonation zones of uranium deposits was in the transition zone of oxidizing zone and reducing zone. The bacteria associated with the enrichment culture of methanogenic bacteria mainly belong to the Enterobacteriaceae, family of Enterobacteriaceae, Clostridium sp., pantobacillus, Pantoea sp., microbacillus, Exiguobacterium sp., fibrinomonas, Cellulomonas sp.. And tetracoccus Tessaracoccus sp.. Principal component analysis (PCA) showed that there was no significant difference in the structure of hydrogen producing bacteria group in different geochemical zoning, while methanogenic bacteria group structure was different in different geochemistry, and typical correspondence analysis (CCA) showed that, The distribution of hydrocarbon-producing bacteria and hydrocarbon-producing bacteria was related to the organic carbon and sulfur content of environmental factors. In Shihongtan sandstone-type uranium deposit, there are active hydrocarbon-producing and hydrocarbon gas-producing bacteria, and their species distribution shows a certain geochemical zonation. The ecological diversity of hydrocarbon-producing and hydrocarbon-gas bacteria reveals the effect of biogas on uranium reduction and deposition from the microbiological point of view, which is of great significance to the study of microbial uranium mineralization.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P619.14

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