基于功能基因的微生物碳循环分子生态学研究进展

Advances in molecular ecology on microbial functional genes of carbon cycle

碳循环是生态系统中重要的生物地球化学元素循环之一。微生物参与碳固定、甲烷代谢、碳降解等多个重要的碳循环过程,深入了解微生物群落在碳循环过程中的功能和作用,有助于获悉微生物对全球气候变化的响应、适应和反馈机制,这也是微生物生态学研究的关键问题之一。传统的研究多集中于微生物分离培养技术,无法覆盖绝大部分未培养微生物,并且无法深入解析碳循环过程中微生物群落的结构和功能,宏基因组学技术的出现克服了这些缺陷,成为研究微生物群落结构和功能的有效手段。本文对目前宏基因组学的主要技术——定量PCR、DNA分子指纹图谱、基因芯片、克隆文库和高通量测序等技术进行了简要介绍,着重介绍了参与碳固定、甲烷生成和氧化、碳降解等主要碳循环过程的关键功能基因的研究现状,最后对碳循环过程中微生物宏基因组学研究的未来发展进行了总结与展望。

Carbon cycle is among the most important biogeochemical cycles in ecosystems, and microorganisms play critical roles in lots of its primary processes, such as carbon fixation, methane metabolism and carbon degradation. With the deep insight into functions of microbes in carbon cycle, we could better understand how they response and regulate the global climate change, which is a hot spot in the studies of microbial ecology. Previous studies focused on microbial isolations and cultivations, however, only little of the microorganisms in nature are cultivable while a majority of microorganisms are uncultured. With rapid development of the metagenomics technology, in-situ and comprehensive investigation of microbial functions and structures became feasible. In this article, we briefly introduced several widely-applied metagenomics technology such as quantitative PCR, DNA fingerprinting, microarray, clone library and high-throughput sequencing. Furthermore, we reviewed the advanced studies by using metagenomic methods to investigate the key functional genes involving in carbon cycle, including carbon fixation, methanogenesis, methane oxidation and carbon degradation. Finally, we prospected the future studies of the microbial metagenornics in carbon cycle.