Ammonia-oxidizing bacteria and archaea grow under contrasting soil nitrogen conditions
Ammonia-oxidizing bacteria and archaea grow under contrasting soil nitrogen conditions
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DOI：
10.1111/j.1574-6941.2010.00861.x
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发表时间：
2010-06-01
影响因子：
4.2
通讯作者：
He, Ji-Zheng
中科院分区：
文献类型：
--
作者：
Di, Hong J.;Cameron, Keith C.;He, Ji-Zheng
硝化作用是土壤氮素循环的关键过程，具有重要的环境意义。氨氧化古菌（AOA）的发现对传统的氨氧化细菌（AOB）在硝化作用中占主导地位的假设提出了质疑。研究了3种草地土壤在动物尿基质和硝化抑制剂[双氰胺（DCD）]处理下两个不同土层中AOB和AOA的生长和硝化速率。我们发现，AOB更丰富的表土比在底土，而AOA更丰富的底土之一。AOB在高剂量的尿底物中生长，而AOA仅在无尿氮底物的对照中生长。DCD对AOB的生长和amoA基因转录活性有明显的抑制作用。硝化速率在表层土壤中比在底土中高得多，并且与AOB丰度显著相关，但与AOA丰度无关。这些结果表明，AOB和AOA喜欢不同的土壤氮条件下生长：AOB在高氨（NH3）基质和AOA在低NH3基质条件下。
Nitrification is a key process of the nitrogen (N) cycle in soil with major environmental implications. The recent discovery of ammonia-oxidizing archaea (AOA) questions the traditional assumption of the dominant role of ammonia-oxidizing bacteria (AOB) in nitrification. We investigated AOB and AOA growth and nitrification rate in two different layers of three grassland soils treated with animal urine substrate and a nitrification inhibitor [dicyandiamide (DCD)]. We show that AOB were more abundant in the topsoils than in the subsoils, whereas AOA were more abundant in one of the subsoils. AOB grew substantially when supplied with a high dose of urine substrate, whereas AOA only grew in the Controls without the urine-N substrate. AOB growth and the amoA gene transcription activity were significantly inhibited by DCD. Nitrification rates were much higher in the topsoils than in the subsoils and were significantly related to AOB abundance, but not to AOA abundance. These results suggest that AOB and AOA prefer different soil N conditions to grow: AOB under high ammonia (NH3) substrate and AOA under low NH3 substrate conditions.