【作者】 吴月红；

【导师】 吴敏；

【作者基本信息】 浙江大学 ， 微生物学， 2009， 博士

【摘要】 嗜盐微生物是栖息于各种盐域环境中的微生物的总称。根据它们对培养基中盐的需求差异分为嗜盐微生物和耐盐微生物。其广泛分布于盐湖、盐碱湖、晒盐场、盐岩和海洋等富盐环境,种类繁多,其耐盐性状与其适应环境的丰富酶系和活性产物相关。针对其开展资源挖掘与利用工作,不仅在生命起源探索、生物适应环境机制研究等多个方面具有重要的理论意义,而且在工农业生产、医药食品和污染环境治理等多个领域具有一定的研究价值。本研究在课题组已采集大量高盐环境样品、开展嗜盐菌培养工作、建立相关技术手段的基础上,采用多种条件重点分离培养新疆阿牙克库木湖、东海长江口和深海结核区3种环境下微生物,开展可培养微生物的分子鉴定与生态学研究,建立并完善菌株库和数据库。通过分子生物学手段构建东海长江口河口系统细菌16S rDNA及相关功能基因硝酸盐还原基因nap A和亚硝酸盐基因nir S分子文库,开展系统发育学研究,分析了366个克隆子,共测得256个序列。细菌的微生物种群数量丰富,主要群落分布于γ-变形杆菌纲,α-变形杆菌纲、酸杆菌门、δ-变形杆菌纲和拟杆菌门等类群也有较多的分布,较为清晰的反映了东海长江口河口系统细菌群落结构特点及可能参与的地球化学循环过程。按多相分类学原则,应用传统分类学、化学分类学和分子系统学手段相结合的方法,对来自我国西部内陆盐湖盐山、东部沿海近海和太平洋深远海具有代表性的8株细菌进行系统的分类学研究。研究结果表明8株细菌分别代表了6个嗜盐细菌新种(Halomonas caseinilytica、Halomonas salifodinae、Marinobacterpelagius、Pseudidiomarina maritima、Pseudidiomarina donghaiensis、Vibriohangzhouensis)、1个耐盐细菌新种(Microbacterium profundi)和1个耐盐细菌新属(Croceicoccus gen.nov,Croceicoccus marinus),研究丰富了物种资源库,属首次报道。更多还原

【Abstract】 Halophilic microorganisms are microbes inhabited in diverse saline environments. According to their adaptation to salt supplemented in media, these microbes are divided into halophilic and halotolerant groups. The halophilic microorganisms can grow up to the high salt concentrations, such as salt lakes, soda lakes, solar salterns, hypersaline soils, marine environments, etc, and they often have strong impact on the ecosystems in which the thrive. The property of microbial adaptation to high salt environments is mainly relation with enzymes and other bio-active substance. Much interest in halophilic adaptation has been supported by the search for life on the planets and the applications in biotechnology. So it is very significant not only in theory but also in practice to study halophiles.My research is based on our lab’s work such as samples collection from high saline, microorganisms cultivation and related molecular technology. Ayakekumu Lake located in Xinjiang region, the estuary of the Yangtze River of the East China sea and the China nodule province in East Pacific ocean which were collected from three environment ecosystems were investigated. Cultivation-independent approaches based on rRNA cloning and sequencing were applied to survey microbial diversity in natural ecosystems. The identification and biodiversity of culturable microorganisms were performed by using the molecular technique subsequently. Based on the analysis of 16S rDNA gene sequence analysis and phenotype characteristics, the database of halophiles was established and enriched.In this study using molecular biology methods, construct 16S rDNA, nap A, nir S biomarker genes clone libraries at the estuary of the Yangtze River of the East China sea. Total 366 clones were analysis and 256 clones were sequenced and phylogenetic analysed. Bacteria biodiversity was very rich, mainly composed byγ-Proteobacteria,α-Proteobacteria, Acidobacteria,δ- Proteobacteria and Bacteroidetes. It indicate microbial community structure and their possible geochemical process.In accordance with the principle of polyphasic taxonomy, a systematic study had been conducted on the taxonomy of eight isolates. Six novel moderate halophilic bacteria species (Halomonas caseinilytica, Halomonas salifodinae, Marinobacter Pelagius, Pseudidiomarina maritima, Pseudidiomarina donghaiensis, Vibrio hangzhouensis ) as well as one halotorlerant halophilic bacteria species (Microbacterium profundi) and one halotorlerant halophilic bacteria genus (Croceicoccus gen. nov, Croceicoccus marinus) were proposed. This is the first study on the eight halophilic microbial species which was isolated from multiregions in China.更多还原