甲烷厌氧氧化—硫酸盐还原体系微生物种群特征与反应途径研究
文献类型：学位论文
| 作者 | 席婧茹 |
| 学位类别 | 硕士 |
| 答辩日期 | 2014-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 李琳 |
| 关键词 | 废气处理 甲烷厌氧氧化 硫酸盐还原 种群演替 氧化途径 off-gas treatment anaerobic methane oxidation sulfate reduction population succession pathway of oxidation |
| 其他题名 | The microbial population of anaerobic methane oxidation coupled with sulfate reductionenrichment from anaerobic sludge |
| 学位专业 | 环境工程 |
| 中文摘要 | 在污水厌氧处理、污泥厌氧消化过程中，释放出大量的含甲烷的恶臭气体。无论是物化法还是生物法，主要考虑去除氨、硫化氢等恶臭物质，但是对甲烷的去除效果甚微。以往研究发现，在海底沉积物中存在甲烷厌氧氧化古菌利用硫酸盐作为电子受体厌氧氧化甲烷的现象。恶臭物质硫化氢的氧化产物为硫酸盐，硫酸盐作为氧化剂，将CH4 氧化为二氧化碳，这样将硫酸盐的还原过程与甲烷厌氧氧化相结合，形成甲烷厌氧氧化协同硫酸盐还原，可以实现CH4 与恶臭物质硫化氢的同步去除。本研究着重于甲烷厌氧氧化-硫酸盐还原体系的微生物种群特征与反应途径的研究。 从污水处理厂厌氧污泥筛选驯化可利用硫化氢的氧化产物硫酸盐作为电子受体的甲烷厌氧氧化菌群，形成稳定的生物体系，建立了甲烷厌氧氧化菌的筛选驯化方法。利用分子生物学方法，构建微生物种群的克隆文库，研究种群的结构和演替特征，采用荧光原位杂交方法分析种群的空间分布。反应体系中甲烷厌氧氧化古菌和硫酸盐还原菌共同存在，甲烷厌氧氧化古菌包括ANME-1 和ANME-2；硫酸盐还原菌包括脱硫肠状菌属和脱硫叶菌属（Ⅰ类），脱硫杆菌科（Ⅱ类），其中脱硫叶菌属可与甲烷厌氧氧化菌ANME-3 共生。反应9 个月后， 细菌优势菌种群多样性增加，优势功能种群包括硫酸盐还原菌和有机物降解菌；古菌优势菌种群结构的多样性降低，甲烷氧化古菌（ANME-1 和ANME-2）逐渐成为优势菌。反应4 个月后，细菌与古菌比例增加至1.99，且古菌在菌群内的分布更趋于均匀。体系内甲烷氧化古菌生长在菌群内部，硫酸盐还原菌环绕在其周围，体系内甲烷氧化古菌的比例增加，超过了硫酸盐还原菌，并且分布更均匀。 底物浓度、硫酸盐与CH4 比例、pH 值及反应时间对甲烷厌氧氧化协同硫酸盐还原反应有影响。当硫酸盐与CH4 摩尔比为2.0-4.6，反应温度30℃，反应时间大于20 天时，甲烷的氧化量可以达到36.1 mg∙g-1(TS)。 利用常规及同位素标记方法，分析甲烷厌氧氧化协同硫酸盐还原生物体系内的反应物、产物、中间产物，研究此生物体系中含碳物质和含硫物质的转移转化规律，结合反应体系甲烷厌氧氧化古菌和硫酸盐还原菌的特征，推测构建的生物体系中甲烷厌氧氧化协同硫酸盐还原可能的转化途径为：CH4 与硫酸盐在甲烷厌氧氧化菌和硫酸盐还原菌的作用下分别经过乙酸、甲硫醇等含碳含硫中间产物，最终生成二氧化碳，硫化氢和硫单质。 |
| 英文摘要 | Odors containing methane may be generated in anaerobic wastewater and sludge digestion treatment processes. Conversional physical-chemical or biological technologies have been applied effectively in the removal of ammonia or hydrogen sulfide, whereas they were inefficient in the treatment of methane in odors.Microorganisms capable of anaerobic oxidation of methane driven by sulfate were found in seafloor sediments. Sulfate, the oxidation product of hydrogen sulfide, can be acted as oxidant in the anaerobic oxidation of methane. Aiming to simultaneous removal of methane and hydrogen sulfide in odors, the present study focuses on the microbial characteristics and pathway of anaerobic methane oxidation coupled with sulfate reduction. Anaerobic sludge from sewage treatment was used to acclimate for the microbial colony which is capable of anaerobic methane oxidation coupled with sulfate. The methods were established successfully for the acclimation and screening the stable biological system. Molecular biological methods, e.g. clone library, fluorescence in situ hybridization and DGGE, were applied in the investigation of microbial structure,distribution characteristics and succession trend. Results showed that methanotroph and sulfate reduction bacteria were co-existed in the reaction system. The species of anaerobic methanotrophic archaea found in the reaction system were anaerobic methanotrophic archaea-1(ANME-1) and anaerobic methanotrophic archaea-2(ANME-2), whereas the species of sulfate reduction bacteria were Desulfotomaculum, Desulfobulbus (typeI) and Desulfobacteraceae (typeII). Desulfobulbus can co-existed with anaerobic methanotrophic archaea-3(ANME-3). Diversity of dominant bacteria increased and that of dominant archaeal decreased with reaction time. The sulfate reduction bacteria and organic-degradating bacteria were abundant in bacterial population, whereas anaerobic methanotrophic archaea (ANME-1 and ANME-2) dominated in archaea population. After 4 months of reaction,the proportion of bacteria and archaea increased to 1.99 with even distribution of archaea. Anaerobic methanotrophic archaea exist inside of microbial population which surrounded by sulfate reduction bacteria. The ratio of anaerobic methanotrophic archaea exceeded that of sulfate reduction bacteria and they distributed more evenly among the population. Anaerobic methane oxidation coupled with sulfate reduction reaction was affected by the concentrations of substrates, the ratio of sulfate and methane, pH and reaction time. When sulfate and methane molar ratio is between 2.0-4.6, temperature is 30℃ and a reaction time of over twenty days, methane oxidation capacity is 36.1 mg·g-1（TS） The reactant, products and intermediates in the system of anaerobic methane oxidation coupled with sulfate reduction were investigated by conventional and isotope-labelling methods to clarify the transformation of carbon-containing substances and sulfur-containing substances. The characteristics of co-existing anaerobic methanotrophic archaea and sulfate reduction bacteria in the same reaction system were also analyzed in order to speculate the possible synergistic mechanism of anaerobic methane oxidation coupled with sulfate reduction. The possible conversion pathway was that methane and sulfate were converted to carbon dioxide, hydrogen sulfide and sulfur via carbon-containing and sulfur-containing intermediates (acetic acid, methyl mercaptan, etc.) by anaerobic methanotrophic archaea and sulfate reduction bacteria, respectively. |
| 公开日期 | 2015-07-08 |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/15698]  |
| 专题 | 生态环境研究中心_水污染控制实验室 |
| 推荐引用方式 GB/T 7714 | 席婧茹. 甲烷厌氧氧化—硫酸盐还原体系微生物种群特征与反应途径研究[D]. 北京. 中国科学院研究生院. 2014. |
入库方式： OAI收割
来源：生态环境研究中心
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