Denitrification Activity and Relevant Bacteria Revealed by Nitrite Reductase Gene Fragments in Soil of Temperate Mixed Forest
Denitrification Activity and Relevant Bacteria Revealed by Nitrite Reductase Gene Fragments in Soil of Temperate Mixed Forest
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DOI：
10.1264/jsme2.me08541
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发表时间：
2008-01-01
影响因子：
2.2
通讯作者：
Kato, Kenji
中科院分区：
文献类型：
--
作者：
Katsuyama, Chie;Kondo, Naho;Kato, Kenji
通过N-15示踪实验和克隆测序方法研究了日本中部温带森林排水良好和排水不良土壤中的反硝化活性和细菌群落组成。根据（NN）-N-15-N-15（N-30（2））和（NNO）-N-15-N-15（（N_2O）-N-46）的产生，湿地土壤的反硝化活性远高于旱地土壤。标记的硝酸盐（（NO3-）-N-15）在湿润土壤中立即被还原为N-30（2），而在干燥土壤中仅被还原为（N2 O）-N-46。因此，在集水区下端的湿土壤是一个功能网站的NO3-和N2 O的清除。利用PCR技术扩增、克隆和测序了土壤亚硝酸还原酶基因（nirK和nirS）片段。在湿润土壤中检测到nirK和nirS片段，而在干燥土壤中仅检测到nirK片段。所有nirK和nirS克隆与已知克隆的相似性均小于90%。在湿润土壤中发现了许多nirK和nirS的操作分类单位，在nirK系统发育树上最大的分支内观察到相当大的多样性，其中不包含已知的序列。因此，潮湿的土壤环境可以为反硝化活性的表达提供生境和条件。
Denitrification activity and bacterial community constituents were investigated in both well-drained and poorly drained soils of a temperate forest in central Japan by N-15 tracer experiments and a cloning-sequencing approach. Denitrification activity was much higher in wet soil than in dry soil, based on (NN)-N-15-N-15 (N-30(2)) and (NNO)-N-15-N-15 ((N2O)-N-46) production. Labeled nitrate ((NO3-)-N-15) was immediately reduced to N-30(2) in wet soil, whereas it was only reduced to (N2O)-N-46 in dry soil. Thus, the wet soil at the lower end of the catchment is a functional site for the scavenging for NO3- and N2O. Nitrite reductase gene (nirK and nirS) fragments from these soils were PCR amplified, cloned, and sequenced. Both nirK and nirS fragments were detected in the wet soil, whereas only nirK fragments were detected in the dry soil. All the nirK and nirS clones showed less than 90% similarity to known clones. Numerous operational taxonomic units for nirK and nirS were found in the wet soil, Considerable diversification within the largest clade on the nirK phylogenetic tree, which contained no known sequence, was observed in wet soil. Thus, a wet soil environment can provide both the habitat and conditions for the expression of denitrification activity.