Bertagnolli Anthony D, McCalmont Dylan, Meinhardt Kelley A, Fransen Steven C, Strand Stuart, Brown Sally, Stahl David A
Department of Civil and Environmental Engineering and School of Environmental and Forest Sciences, University of Washington Seattle, Seattle, WA, USA.
Department of Crop and Soil Sciences, Washington State University, Prosser, WA, USA.
Environ Microbiol. 2016 Jun;18(6):1918-29. doi: 10.1111/1462-2920.13114. Epub 2016 Jan 21.
Application of nitrogen fertilizer has altered terrestrial ecosystems. Ammonia is nitrified by ammonia and nitrite-oxidizing microorganisms, converting ammonia to highly mobile nitrate, contributing to the loss of nitrogen, soil nutrients and production of detrimental nitrogen oxides. Mitigating these costs is of critical importance to a growing bioenergy industry. To resolve the impact of management on nitrifying populations, amplicon sequencing of markers associated with ammonia and nitrite-oxidizing taxa (ammonia monooxygenase-amoA, nitrite oxidoreductase-nxrB, respectively) was conducted from long-term managed and nearby native soils in Eastern Washington, USA. Native nitrifier population structure was altered profoundly by management. The native ammonia-oxidizing archaeal community (comprised primarily by Nitrososphaera sister subclusters 1.1 and 2) was displaced by populations of Nitrosopumilus, Nitrosotalea and different assemblages of Nitrososphaera (subcluster 1.1, and unassociated lineages of Nitrososphaera). A displacement of ammonia-oxidizing bacterial taxa was associated with management, with native groups of Nitrosospira (cluster 2 related, cluster 3A.2) displaced by Nitrosospira clusters 8B and 3A.1. A shift in nitrite-oxidizing bacteria (NOB) was correlated with management, but distribution patterns could not be linked exclusively to management. Dominant nxrB sequences displayed only distant relationships to other NOB isolates and environmental clones.
氮肥的施用改变了陆地生态系统。氨被氨氧化和亚硝酸盐氧化微生物硝化，将氨转化为流动性很强的硝酸盐，导致氮素流失、土壤养分损失以及有害氮氧化物的产生。减轻这些代价对于不断发展的生物能源产业至关重要。为了确定管理措施对硝化菌群的影响，对美国华盛顿州东部长期管理的土壤和附近原生土壤中与氨氧化和亚硝酸盐氧化类群相关的标记物（分别为氨单加氧酶-amoA、亚硝酸盐氧化还原酶-nxrB）进行了扩增子测序。管理措施深刻改变了原生硝化菌群的结构。原生氨氧化古菌群落（主要由亚硝化球菌姐妹亚群1.1和2组成）被亚硝化侏儒菌、亚硝化塔菌以及不同组合的亚硝化球菌（亚群1.1以及亚硝化球菌的非关联谱系）所取代。氨氧化细菌类群的替代与管理措施有关，原生的亚硝化螺菌属（与簇2相关，簇3A.2）被亚硝化螺菌属的簇8B和3A.1所取代。亚硝酸盐氧化细菌（NOB）的变化与管理措施相关，但分布模式不能完全归因于管理措施。主要的nxrB序列与其他NOB分离株和环境克隆仅显示出远缘关系。
