The diversity and physiological characteristics of microbes involved in hydrogen metabolism from deep-sea hydrothermal vent fields

由微生物介导的发酵产氢由于具有众多的优点，在制氢方面可能具有更大的生产潜力。深海热液系统具有特殊生态环境,与陆地和海洋中的其他生物群落有着根本的区别。本研究针对深海热液环境开展氢代谢菌的研究工作,以期获得特殊生境中的氢代谢微生物资源和氢酶资源。 利用西南印度洋，南大西洋，东太平洋等不同来源的深海热液环境样品，进行了氢代谢菌的分离培养工作。共获得7个高温发酵产氢富集培养物。细菌16SrRNA基因序列分析表明，富集培养物中的主要类群是Calroanaerobacter，Clostridium,Caminicella,Desulfotomaculum和Caulobacter，其中Caloranae...Hydrogen production performed by microbiology has many advantages, which considered as the most promising method for H2 production. The deep-sea hydrothermal vents exhibit unique physicochemical characteristics and host diverse ecosystems, which different from terrestrial and other ocean environments. However, less study has been focused on microbes and their role involving in hydrogen turnover in...学位：理学博士院系专业：能源研究院_能源化学学号：3242010015380

The Communities of Ammonia-oxidizing Organisms in Pearl River Estuary Sediments

[目的]对珠江口海岸带沉积物中的氨氧化细菌和古菌的组成进行分析,并进行定量研究。[方法]用构建克隆文库和Q-PCr定量的方法对珠江口沉积物中氨氧化细菌和古菌AMOA基因的含量和多样性特征进行研究。[结果]在2个沉积物表层,氨氧化古菌的含量是细菌的9和22倍,揭示氨氧化古菌在珠江口的氨氧化过程中起主导作用;系统发育分析表明大多数古菌和细菌的AMOA基因序列与不可培养的源于河口区和污染区域的环境克隆子序列有较高的同源性;细菌AMOA序列可分成5个类群(CluSTEr A、b、C、d和E),均属于nITrOSOMOnAS类群,其中CluSTEr A是主要类群(72.1%);古菌AMOA序列分析表明来自于表层的序列有52.2%属于“水/沉积物“簇,47.8%属于“土壤/沉积物“簇,而沉积物底层厌氧区,检测到的古菌AMOA基因93.3%属于“土壤/沉积物“簇,6.7%属于“水/沉积物“簇,且AMOA基因数量略高于表层。[结论]该研究有助于了解珠江口区域氮的循环过程,为氮的富营养化处理提供重要的理论依据。[Objective] This study aimed to investigate the abundance and composition of ammonia-oxidizing organism in Pearl River Estuary sediment.[Method] Based on amoA genes,we detected the abundance and composition of ammonia-oxidizing organism in Pearl River Estuary sediment by using quantitative real-time polymerase chain reaction(Q-PCR),cloning and sequencing approaches.[Result] The results of Q-PCR presented that ammonia-oxidizing archaea were more abundant than ammonia-oxidizing bacteria in the top of sediment cores,with AOA to AOB ratios 8.96(site Q5) and 3.69(site Q7).It suggested that ammonia-oxidizing archaea maybe play more important roles than ammonia-oxidizing bacteria in the process of ammonia oxidation in the Pearl River Estuary sediment.In the top sediment layer of Q7,bacterial amoA-like gene sequences were dominated by Nitrosomonas-like sequence types,which could be classified into five groups(clusters A,B,C,D,and E).Interestingly,archeal amoA-like gene was successfully amplified while bacterial amoA-like gene failed to be detected.These archeal amoA-like genes fell into two groups "water column/sediment" cluster and "soil/sediment" cluster.Most of the sequences(93.3%) in the bottom sediment layer of Q7 fell into "soil/sediment" cluster.[Conclusion] This study helps to realize the cycle of nitrogen in Pearl River Estuary region,and thus to provide theoretical support for the treatment of nitrogen eutrophication.国家973前期项目(2006CB708200);国家自然科学重点基金项目(40532011