State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road, No. 18, Haidian District, Beijing 100085, China.
Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Jimei Road, No. 1799, Jimei District, Xiamen 361021, China.
Environ Sci Technol. 2021 Mar 2;55(5):3430-3441. doi: 10.1021/acs.est.0c08022. Epub 2021 Feb 18.
Electrotrophs play an important role in biogeochemical cycles, but the effects of long-term fertilization on electrotrophic communities in paddy soils remain unclear. Here, we explored the responses of electrotrophic communities in paddy soil-based microcosms to different long-term fertilization practices using microbial electrosynthesis systems (MESs), high-throughput quantitative PCR, and 16s rRNA gene-based Illumina sequencing techniques. Compared to the case in the unfertilized soil (CK), applications of only manure (M); only chemical nitrogen, phosphorous, and potassium fertilizers (NPK); and M plus NPK (MNPK) clearly changed the electrotrophic bacterial community structure. The genus of the Actinobacteria phylum was the dominant electrotroph in the CK, M, and MNPK soils. The latter two soils also favored of Deinococcus-Thermus or and of Proteobacteria. Furthermore, of Proteobacteria and of Firmicutes were major electrotrophs in the NPK soil. These electrotrophs consumed biocathodic currents coupled with nitrate reduction and recovered 18-38% of electrons via dissimilatory nitrate reduction to ammonium (DNRA). The increased abundances of the gene for DNRA induced by electrical potential further supported that the electrotrophs enhanced DNRA for all soils. These expand our knowledge about the diversity of electrotrophs and their roles in N cycle in paddy soils and highlight the importance of fertilization in shaping electrotrophic communities.
电营养体在生物地球化学循环中起着重要作用，但长期施肥对稻田电营养体群落的影响尚不清楚。在这里，我们使用微生物电化学合成系统（MESs）、高通量定量 PCR 和基于 16s rRNA 基因的 Illumina 测序技术，探索了长期施肥对稻田土壤微宇宙中电营养体群落的响应。与未施肥土壤（CK）相比，仅施用有机肥（M）、仅施用化学氮、磷、钾肥（NPK）以及 M 加 NPK（MNPK）明显改变了电营养细菌群落结构。厚壁菌门的属是 CK、M 和 MNPK 土壤中的主要电营养体。后两种土壤还有利于放线菌或变形菌的和 ，以及厚壁菌或Firmicutes 的 。此外，在 NPK 土壤中，Proteobacteria 的 和 Firmicutes 的 是主要的电营养体。这些电营养体通过硝酸盐还原消耗生物阴极电流，并通过异化硝酸盐还原为铵（DNRA）回收 18-38%的电子。电势能诱导的 DNRA 基因丰度增加进一步支持了电营养体增强了所有土壤的 DNRA。这些扩展了我们对电营养体多样性及其在稻田氮循环中作用的认识，并强调了施肥在塑造电营养体群落中的重要性。
