Key Lab of Urban Environment and Health, Institute of Urban Environment , Chinese Academy of Sciences , Xiamen 361021 , P. R. China.
Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment , Chinese Academy of Sciences , Xiamen 361021 , P. R. China.
Environ Sci Technol. 2019 May 7;53(9):4841-4849. doi: 10.1021/acs.est.8b05016. Epub 2019 Apr 22.
Anaerobic ammonium oxidation coupled to iron reduction (Feammox) is a recently discovered pathway contributing to nitrogen loss in various ecosystems such as paddy soils and sediments. However, little is known about the microbes driving Feammox in an agricultural ecosystem. Here, we demonstrated the occurrence of Feammox in paddy soils of Southern China using a N isotopic tracing technique, and examined the microbial communities associated with Feammox using RNA based stable isotope probing (RNA-SIP) combined with Illumina sequencing. Feammox was detected in all collected soils with direct N production as the dominant Feammox pathway. It was estimated that approximately 6.91% of the applied nitrogen fertilizers were lost through Feammox in the paddy soils. RNA-SIP results showed that the composition of enriched active microbial communities were dependent on soil properties, especially the soil pH and grain size. Geobacter were enriched in most soils across various properties. The abundance of enriched GOUTA19 were significantly higher in soils with low pH than those in soils with medium pH and high pH, and the relative abundance of active Nitrososphaeraceae and Pseudomonas only increased in soils with medium and high pH during 4-day of incubation. These results suggested Feammox is a ubiquitous and important process for N loss. Geobacter, GOUTA19, Nitrososphaeraceae and Pseudomonas were active during the incubation that favored Feammox and the growth of Feammox microbes, suggesting these microbes were potentially associated with Feammox in natural agricultural soils.
厌氧氨氧化耦合铁还原（Feammox）是一种新发现的途径，有助于各种生态系统（如稻田和沉积物）中的氮损失。然而，对于农业生态系统中驱动 Feammox 的微生物知之甚少。在这里，我们使用氮同位素示踪技术证明了中国南方稻田中存在 Feammox，并通过 RNA 稳定同位素探针（RNA-SIP）结合 Illumina 测序技术研究了与 Feammox 相关的微生物群落。所有采集的土壤中都检测到了 Feammox，直接 N 生产是 Feammox 的主要途径。据估计，大约 6.91%的施氮肥料通过稻田中的 Feammox 损失。RNA-SIP 结果表明，富集的活性微生物群落的组成取决于土壤特性，特别是土壤 pH 值和粒径。在各种性质的土壤中，地杆菌都得到了富集。在 pH 值较低的土壤中，GOUTA19 的丰度明显高于 pH 值中等和较高的土壤，而在 4 天的培养过程中，活性硝化螺旋菌科和假单胞菌的相对丰度仅在中、高 pH 值土壤中增加。这些结果表明，Feammox 是一种普遍存在且重要的氮损失过程。在有利于 Feammox 和 Feammox 微生物生长的培养过程中，地杆菌、GOUTA19、硝化螺旋菌科和假单胞菌都具有活性，表明这些微生物可能与自然农业土壤中的 Feammox 有关。
