苏北海岸带盐沼卤代甲烷降解菌的时空分布及其生态环境意义

Among the trace gases that destroy the ozonosphere, methyl halides have the most serious extent of detriment. Recently the mechanism of methyl halides producing has been kown and the coastal salt marsh as the important source of methyl halides has been discovered. Our reasearch found out that salt marsh is not only the source of methyl halides, but may be the sink of methyl halides with the spatio-temporal changes. This project aims at the designated research region of salt marsh at northern Jiangsu, reaveals the distribution characteristics and diversity of methyl halides ultilizing bacteria in coastal salt marsh at the cultruable level and the unculturable level and the ecological and environmental effects on the pattern of methyl halides distribution. At the cultruable level, the bacteria enrichment culture and isolation methods will be established to isolate the methyl halides ultilizing bacteria. At the uncultruable level, functional gene probes, DNA-SIP and 16S rRNA gene nucleotide homology analysis will be used to reveal spatio-temporal distribution characteristics of community structure and function of methyl halides ultilizing bacteria. The different levels of research results are integrated to deepen the understanding of the process of methyl halides circulation closely related with the global climate change, realize the microbiological mechanism of methyl halides source and sink of coastal salt marsh, provide theoretical reference of the accurate evaluation of methyl halides flux control mechanism.

在破坏臭氧层的痕量气体中，卤代甲烷的总体危害程度最为严重。近年来对卤代甲烷产生机制的认识有了长足的进展，发现了海岸带盐沼是卤代甲烷重要的源。在我们的研究中发现，盐沼不仅是卤代甲烷的源，而且随着不同时空分布格局变化，很可能也可以作为卤代甲烷的汇。本项目针对苏北海岸带盐沼这一特定研究区域，在可培养和不可培养微生物两个不同层次阐明盐沼卤代甲烷降解菌分布特征、多样性及其对卤代甲烷分布格局的生态环境作用。在可培养水平上，建立卤代甲烷降解菌的富集培养和分离方法，分离获得卤代甲烷降解菌；在不可培养水平上，利用功能基因探针、DNA-SIP技术以及16S rRNA基因同源性分析等查明盐沼卤代甲烷降解菌群落结构和功能的时空分布特征。整合不同层次的研究结果，为加深与全球变化气候密切相关的卤代甲烷物质循环过程的认识，深入了解海岸带盐沼作为卤代甲烷源/汇功能的微生物学机制，准确评价卤代甲烷通量控制机制提供理论参考。