稳定性同位素核酸探针技术DNA-SIP 原理与应用

Principle and application of DNA-based stable isotope probing—A review

摘要:

摘要:稳定性同位素核酸探针技术DNA-SIP(Stable isotope probing)，是将复杂环境中微生物物种组成及其生理功能耦合分析的有力工具。微生物的体积在μm 尺度，因此，自然环境中微生物群落在μm 尺度下生理过程的发生、发展，其新陈代谢物质在环境中累积与消减的动力学变化规律，形成了微生物生理生态过程，决定了不同尺度下生态系统物质和能量的良性循环。利用稳定性同位素示踪复杂环境中微生物基因组DNA，实现了单一微生物生理过程研究向微生物群落生理生态研究的转变，能在更高更复杂的整体水平上定向发掘重要微生物资源，推动微生物生理生态学和生物技术开发应用。本文重点探讨了DNA-SIP 的技术原理、主要技术瓶颈及对策，初步展望了DNA-SIP 为基础的环境微生物基因组学发展趋势。

Abstract:

Abstract:Microbial communities are the engines that drive the global biogeochemical cycle of carbon and nitrogen essential for life on Earth． However，microorganisms have evolved as a result of complex interactions with other organisms and environments． Deciphering the metabolism of microorganisms at the community level in nature will be crucial for a better understanding of the mechanisms that lead to the enormous divergence of microbial ecophysiology． Due to the immense number of uncultivated microbial species and the complexity of microbial communities，delineating community metabolism proves a virtually insurmountable hurdle．By tracing the heavy isotope flow of key elements such as carbon and nitrogen，DNA-based stable isotope probing (DNA-SIP) can provide unequivocal evidence for substrate assimilation by microorganisms in complex environments． The essential prerequisite for a successful DNA-SIP is the identification，with confidence，of isotopically enriched 13 C-DNA，of which the amount is generally too low to allow the direct measurement of 13 C atom percent of nucleic acid． The methodological considerations for obtaining unambiguous DNA highly enriched in heavy isotope are presented with emphasis on next-generation sequencing technology and metagenomics．