深海热液活动区趋磁细菌生物学特性与生态效应

Deep-sea hydrothermal activity field is one of the extreme marine environments. We have found that these fields contain abundant magnetotactic bacteria (MTB), of which there are two special and dominant members - multicellular magnetotactic prokaryotes (MMPs) and MTB in the Nitrospira Phylum. MMPs affiliated to the sulfate-reducing bacteria, can synthesize Fe3S4 magnetosomes and have Fe, S metabolic pathways. So far known MTB in the Nitrospira Phylum occurred in freshwater environment. Why do they become the dominant of MTB in deep-sea hydrothermal activity fields? And what are the biological characteristics and ecological significance of them? In this project, the magnetotactic bacteria were used as the research object. Through the methods of field investigation, the composition and diversity of the magnetotactic bacteria were study. Meanwhile, the maintenance and biological characteristics of these two kinds of dominant MTB in the sediments will be analyzed. By the technologies of single cell micromanipulation, single cell DNA amplification, whole genome sequencing and annotation, the genomes of dominant MTB will be analyzed. The results will deepen our understanding of metabolic pathway of Fe, S and evolutionary characteristics of magnetosome island. To investigate the interaction and metabolism coupling between MTB and other environmental microbes in the hydrothermal fields, metatranscriptome and metagenome will be used in this project. These data can help us to explore the contribution of MTB in the Fe and S biogeochemical cycles. The characteristics of this project are to study the biological characteristics and ecological effects of two types of dominant MTB in hydrothermal fields. The main purpose of this study is to understand the microbial life process and develop new microbial resources in extreme environment.

深海热液活动区是极端海洋环境之一，我们发现该区域有丰富的趋磁细菌，其中有两类特殊优势类群—多细胞趋磁原核生物和硝化螺菌门趋磁细菌。多细胞趋磁原核生物属于硫酸盐还原菌类，可合成Fe3S4磁小体，有Fe、S代谢途径。已知的硝化螺菌门趋磁细菌都存在淡水环境。它们为何成为热液区的优势趋磁细菌？其生物学特性和生态意义如何？本项目以趋磁细菌为研究对象，通过现场调查，认识趋磁细菌种类组成及多样性特点。针对两类优势类群进行保存培养和细胞学、磁学、材料学特性分析。应用单细胞显微分离-单细胞DNA扩增-测序注释方法，解析优势种基因组，认识其Fe、S代谢途径及磁小体岛的进化特点。开展环境组学分析，探讨热液区趋磁细菌与环境微生物间的互作和代谢耦合关系，了解趋磁细菌在Fe、S循环中的作用贡献。本项目特色是通过对热液区两类优势趋磁细菌的生物学特性和生态作用研究，从新角度认识热液区微生物生命过程，开发新微生物资源。

深海热液活动区是极端海洋环境之一，我们发现该区域有丰富的趋磁细菌，其中有两类特殊优势类群—多细胞趋磁原核生物和硝化螺菌门趋磁细菌。多细胞趋磁原核生物属于硫酸盐还原菌类，可合成Fe3S4磁小体，有Fe、S代谢途径。已知的硝化螺菌门趋磁细菌都存在淡水环境。它们为何成为热液区的优势趋磁细菌？其生物学特性和生态意义如何？本项目以趋磁细菌为研究对象，通过现场调查，认识热液区趋磁细菌的种类组成、群落结构及多样性特点，分析不同热液环境中趋磁细菌的多样性及群落结构的异同。研究热液区化石磁小体的形态、成分等特征，认识热液区趋磁细菌的生物矿化特征。开展环境宏基因组/宏转录组分析，认识热液区微生物的基因功能和代谢特点，探讨趋磁细菌与环境微生物间的互作和代谢耦合关系，了解趋磁性相关基因的类型和丰度分布，探讨趋磁细菌在Fe、S循环中的作用贡献。针对两类特殊的趋磁细菌类群-多细胞趋磁原核生物和海洋硝化螺菌门趋磁细菌进行原位培养和细胞学、磁学、材料学等特性分析，认识两类特殊趋磁细菌的特点。应用单细胞显微分离-单细胞DNA扩增-测序注释方法，获得两类特殊趋磁细菌的基因组，对基因组进行功能注释，认识其Fe、S、N等代谢途径，了解两类趋磁细菌基因组及磁小体岛的进化过程与起源。本项目通过对热液区两类特殊趋磁细菌的生物学特性和生态作用研究，从新角度认识海洋尤其是热液区微生物生命过程，开发新微生物资源。