Molecular characterization of a microbial consortium involved in methane oxidation coupled to denitrification under micro-aerobic conditions.
Molecular characterization of a microbial consortium involved in methane oxidation coupled to denitrification under micro-aerobic conditions.
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DOI：
10.1111/1751-7915.12097
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发表时间：
2014-01
影响因子：
5.7
通讯作者：
Chen Y
中科院分区：
文献类型：
--
作者：
Liu J;Sun F;Wang L;Ju X;Wu W;Chen Y
甲烷可以作为生物反硝化的替代碳源，因为它无毒、广泛可用且相对便宜。一个参与甲烷氧化-反硝化（MOD）的微生物联合体在微好氧条件下富集了亚硝酸盐和硝酸盐作为电子受体。分析16S rRNA基因结合甲烷养菌的pmoA系统发育和反硝化菌的nirK系统发育，揭示优势菌群和功能微生物。实时定量聚合酶链反应结果显示，富集菌群中有大量的甲烷氧化菌和反硝化菌。16S rRNA基因克隆文库显示，甲基球菌科和甲基亲和科是MOD生态系统的优势种群。对pmoA基因克隆文库的系统发育分析表明，所有甲烷化养菌均属于甲基球菌科，是一种通过单磷酸核酮糖途径氧化甲烷的I型甲烷化养菌。甲基化反硝化菌利用甲烷化菌释放的有机中间体甲醛、柠檬酸盐和醋酸盐，在好氧反硝化中起着至关重要的作用。本研究首次证实了微好氧反硝化作用，并对参与MOD的一些微生物组合成员进行了系统发育和功能定位。
Methane can be used as an alternative carbon source in biological denitrification because it is nontoxic, widely available and relatively inexpensive. A microbial consortium involved in methane oxidation coupled to denitrification (MOD) was enriched with nitrite and nitrate as electron acceptors under micro-aerobic conditions. The 16S rRNA gene combined with pmoA phylogeny of methanotrophs and nirK phylogeny of denitrifiers were analysed to reveal the dominant microbial populations and functional microorganisms. Real-time quantitative polymerase chain reaction results showed high numbers of methanotrophs and denitrifiers in the enriched consortium. The 16S rRNA gene clone library revealed that Methylococcaceae and Methylophilaceae were the dominant populations in the MOD ecosystem. Phylogenetic analyses of pmoA gene clone libraries indicated that all methanotrophs belonged to Methylococcaceae, a type I methanotroph employing the ribulose monophosphate pathway for methane oxidation. Methylotrophic denitrifiers of the Methylophilaceae that can utilize organic intermediates (i.e. formaldehyde, citrate and acetate) released from the methanotrophs played a vital role in aerobic denitrification. This study is the first report to confirm micro-aerobic denitrification and to make phylogenetic and functional assignments for some members of the microbial assemblages involved in MOD.