环境微生物不依赖于培养的基因组学研究及应用

微生物在生物圈中分布广泛，并且在地球物质循环中占有重要地位，但是约99﹪的微生物目前还不能通过传统的培养方法得到纯培养物（即未培养微生物），给这些未培养微生物的研究带来很大的困难。随着分子生物学的快速发展及其在微生物研究中的广泛运用，促进了以环境中未培养微生物为研究对象的新兴学科--环境基因组学的产生和发展。在不进行相关微生物培养分离的情况下，通过从环境样品中直接提取获得所有微小生物的全部遗传物质，并构建环境基因组文库；进一步利用功能基因组学研究策略，从文库中寻找编码产生新的有生物活性产物的基因；通过对系统发育相关锚定位点基因序列分析，从而确定特定生态环境体系中未培养微生物的种类结构组成及进化地位，并最终重建该体系中微生物群体的基本物质循环模式。此外，环境基因组学也可以在对未培养微生物生理生化特性深入了解的基础上，建立发展合适的培养体系，最终获得某些特定微生物的纯培养物。本文对环境基因组的构建及相关分析研究策略的进展进行了综述；同时介绍了其在微生物分类及生态学研究的应用。

Metagenomics: cultutre-independent genomic analysis of environmental microbial communities and its application

The biosphere is dominated by microorganisms which play an important role in the substance cycle of the earth, yet about 99 % of these microorganisms have not been or can not be cultured by traditional methods, thus impeding the detailed study on them. With the development of molecular biology and its application in microbiology, a new research field, namely environmental genomics, has been developed. Without prior isolation and cultivation of relative microorganisms from environmental directly extracted and an environmental genomic library is constructed. The samples, all the genetic materials are library strategies for functional genomics, either to screen active metabolites and their is further analyzed with similar coding genes, or to analyze sequences of relative phylogenic anchors to establish the organization, evolution of relative microorganisms and their respective roles in substance cycle in a specific ecosystem. On the other hand, with more information about the physiological and biochemical characteristics of uncultured microorganisms revealed by environmental genomics, appropriate culturing conditions might be developed and pure cultures of relative uncultured microorganisms could be finally obtained. The strategies for the construction and analysis of environmental libraries and recent progress in this field are reviewed. The application of environmental genomics in microbial ecology is also introduced.