项目名称: 海洋趋磁大杆菌的特性和进化起源研究
项目编号: No.41206150
项目类型: 青年科学基金项目
立项/批准年度: 2013
项目学科: 海洋科学
项目作者: 张文燕
作者单位: 中国科学院海洋研究所
项目金额: 24万元
中文摘要: 趋磁细菌是一类可以沿着磁力线运动的特殊细菌,在基因调控下能合成具种属特异性的纳米磁性颗粒-磁小体,并借助磁小体的定位作用在磁场下进行趋磁趋氧运动。趋磁细菌属于变形菌门、硝化螺菌门和新门类OP3,广泛分布在海洋、淡水环境中,但地域分析显示海洋与淡水趋磁细菌区分明显。趋磁大杆菌目前仅在淡水中发现,属硝化螺菌门,分类地位特殊,我们青岛潮间带发现了具有双节结构的海洋趋磁大杆菌,在形态等方面与淡水的不同。本项目旨在研究两者分类地位和细胞生物学是否有差异。本研究利用显微操作分离获得纯的海洋趋磁大杆菌,研究其分类地位和系统发育多样性;通过全基因组扩增技术获得基因组序列,分析与磁小体形态、排列方式相关的基因,并通过与已知磁小体岛的比较,研究海洋趋磁大杆菌的进化起源。此外,利用其生态分布特征、分类地位以及基因组中存在的代谢途径,设计培养基,实现海洋趋磁大杆菌的培养,并对其分节结构形成进行细胞生物学研究。
中文关键词: 趋磁细菌;多样性;磁小体岛;基因组;进化
英文摘要: Magnetotactic bacteria (MTB) consist of gram negative bacteria with diverse morphologies, and they can swim along the geomagnetic field lines. MTB can form nano-sized magnetic particle-magnetosome,which is intracellular organelle of prokaryote and display specificity in morphology,chemical composition and arrangements.The formation of magnetosome is under genetically control of Mangnetosome Island. Although magnetotactic bacteria are ubiquitous in water columns and sediments of freshwater or marine habitats, magnetotactic bacteria of freshwater distinguish from that of marine environment according to geographic distribution analysis . Up to now, large rod magnetotactic bacteria-M. bavaricum were only found in freshwater environment, and belongs to Nitrospira. Recently, we found large-rod shaped marine magnetotactic bacteria with special two-part morphology in the intertidal sediments of Qingdao, however, the taxonomic position and cell biology between them are unknown. We will obtain pure sample of marine large rod magnetotactic bacteria by using micromanipulation, and study their taxonomic position and phylogenetic diversity. Then we will obtain their genome sequence by whole genome amplification, and analyse genes related to morphology and alignment of magnetsomes on Magnetosome Island, and study the evolution
英文关键词: magnetotactic bacteria;diversity;magnetosome;genome;evolution