National Key R&D Program of China, Natural Science Foundation of China, China Postdoctoral Science Foundation
甲烷氧化微生物和氨氧化微生物均是既可以氧化甲烷（CH4）又可以氧化氨（NH3），氨氧化是硝化作用的限速步骤，也是好氧土壤氧化亚氮（N2O）排放的主要生物路径。选取内蒙古草原围封禁牧土壤为研究对象，利用稳定同位素核酸探针技术（DNA-SIP）探讨不同氮水平下土壤活性甲烷氧化微生物与硝化微生物及其相互作用机制。结果发现低氮添加促进甲烷氧化活性，而高氮添加抑制甲烷氧化活性；低氮和高氮添加均显著增强硝化活性。基于DNA-SIP的高通量测序结果发现Methylobacter MOB和Nitrosospira AOB/Nitrospira NOB分别是该土壤的主要活性甲烷氧化和硝化微生物。网络结构分析发现Methylobacter MOB和Nitrosospira AOB/Nitrospira NOB存在显著负相关关系，进一步证明活性甲烷氧化和硝化微生物之间存在竞争性相互作用。以上结果表明，氮素水平影响草原土壤甲烷氧化和硝化微生物的相互作用，研究结果为采取措施调控草原土壤CH4的汇和N2O的源功能以及减缓气候变暖的进程提供理论基础。
[Objective] Ammonia oxidation is the limited step of nitrification and it is the main microbial pathway of N2O emissions in aerobic soils. Grassland soils are sinks for CH4and sources of N2O. However, the mechanisms of the interactions between methane and ammonia oxidation under various N levels in grassland soils remain elusive.[Method] A microcosm experiment was implemented using Inner Mongolia grassland soils based on DNA-Stable-Isotope-Probing (DNA-SIP), and the methane and ammonia oxidation under various N levels was studied.[Result] The results showed that methane-oxidizing activity was stimulated by low N while it was suppressed by high N application. Contrarily, the nitrification activity was stimulated by both low and high N addition. The Methylobacter lineage of methane-oxidizing bacteria(MOB) were the active players in methane oxidation, while nitrifying communities dominated by Nitrosospira lineage of AOB and Nitrospira-like nitrite-oxidizing bacteria (NOB) were the active players in nitrification. Also, the network analysis unraveled significant negative relationships between active Methylobacter MOB and Nitrosospira AOB/Nitrospira NOB, which suggested competitive interactions between active nitrifiers and methanotrophs in grassland soils.[Conclusion] The interactions between active methanotrophs and nitrifiers can be affected by N levels. Our results provide theoretical support for regulating CH4 sinks and N2O sources of grassland soils and for greenhouse gas mitigation.
潘红,李勇,孟春梅,郑燕,刘杏梅,诸葛玉平,贾仲君,邸洪杰,徐建明.氮素水平对土壤甲烷氧化和硝化微生物相互作用的影响[J].土壤学报,2022,59(2):557-567. DOI:10.11766/trxb202101050577 PAN Hong, LI Yong, MENG Chunmei, ZHENG Yan, LIU Xingmei, ZHUGE Yuping, JIA Zhongjun, DI Hongjie, XU Jianming. Effects of Nitrogen Levels on Interactions between Active Nitrifiers and Methanotrophs[J]. Acta Pedologica Sinica,2022,59(2):557-567.复制