State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430010, China.
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430010, China; Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430010, China.
Sci Total Environ. 2021 Jun 10;772:145472. doi: 10.1016/j.scitotenv.2021.145472. Epub 2021 Jan 30.
Nitrite-oxidizing bacteria (NOB) catalyze the second step of nitrification by oxidizing nitrite to nitrate, which is a key process in the biogeochemical nitrogen cycling. However, little is known about the co-occurrence patterns and assembly processes of NOB communities in agricultural soils with different salinities. Here, we explored the effects of salinity on Nitrobacter and Nitrospira community using high-throughput sequencing and multivariate statistical analyses. Our results showed that high salinity significantly inhibited the nitrite oxidation rates and decreased the abundance of Nitrobacter and Nitrospira. Extreme salty conditions significantly altered the diversity and composition of Nitrospira community but had little effect on Nitrobacter community. Nitrobacter network in high salinity soils was more closely connected while the connectivity of Nitrospira network became weak. Nitrobacter and Nitrospira community exhibited distinct assembly processes at different salinity levels. Stochastic processes were dominant in the Nitrobacter community assembly in both low and high salinity soils. Interestingly, the assembly of Nitrospira community was governed by stochastic and deterministic processes in low and high salinity soils, respectively. To our knowledge, our study provides the first description of the co-occurrence patterns and assembly processes of NOB communities in agricultural soils with different salinities. These results can help us understand the NOB ecological roles and improve the nitrite oxidation activity in a high salinity environment.
亚硝酸盐氧化菌（NOB）通过将亚硝酸盐氧化为硝酸盐来催化硝化作用的第二步，这是生物地球化学氮循环中的关键过程。然而，对于不同盐度的农业土壤中 NOB 群落的共存模式和组装过程知之甚少。在这里，我们使用高通量测序和多变量统计分析来研究盐度对 Nitrobacter 和 Nitrospira 群落的影响。我们的结果表明，高盐度显著抑制了亚硝酸盐氧化速率，并降低了 Nitrobacter 和 Nitrospira 的丰度。极端盐度条件显著改变了 Nitrospira 群落的多样性和组成，但对 Nitrobacter 群落影响不大。高盐度土壤中的 Nitrobacter 网络连接更紧密，而 Nitrospira 网络的连接性变弱。在不同盐度水平下，Nitrobacter 和 Nitrospira 群落表现出不同的组装过程。在低盐度和高盐度土壤中，随机过程都在 Nitrobacter 群落组装中占主导地位。有趣的是，在低盐度和高盐度土壤中，Nitrospira 群落的组装分别受随机和确定性过程的控制。据我们所知，本研究首次描述了不同盐度农业土壤中 NOB 群落的共存模式和组装过程。这些结果可以帮助我们了解 NOB 的生态作用，并提高高盐环境中亚硝酸盐氧化活性。
