Archaea predominate among ammonia-oxidizing prokaryotes in soils
Archaea predominate among ammonia-oxidizing prokaryotes in soils
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DOI：
10.1038/nature04983
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发表时间：
2006-08-17
期刊：
影响因子：
64.8
通讯作者：
Schleper, C.
中科院分区：
文献类型：
--
作者：
Leininger, S.;Urich, T.;Schleper, C.
氨氧化是硝化作用的第一步，硝化作用是全球氮循环中的一个关键过程，可通过微生物活动形成硝酸盐(1,2)。土壤中硝酸盐可用性的增加对于植物营养很重要，但它也对淋滤造成的地下水污染产生相当大的影响。在这里，我们发现土壤中的古菌氨氧化剂比众所周知的细菌对应物更丰富。我们调查了三个气候带的 12 个原始和农业土壤中编码关键酶氨单加氧酶 (amoA) 亚基的基因的丰度。 Crenarchaeota（古生菌）的amoA基因拷贝数比细菌amoA基因丰富3,000倍。大量的crearchaeota特异性脂质，包括crearchaeol，与古菌amoA基因拷贝的丰度相关。此外，使用新型不依赖于克隆的焦磷酸测序技术进行的逆转录定量 PCR 研究和互补 DNA 分析证明了古细菌的原位活性，并支持了古细菌相对于细菌氨氧化剂的数量优势。我们的结果表明，crearchaeota 可能是地球上土壤生态系统中最丰富的氨氧化生物。
Ammonia oxidation is the first step in nitrification, a key process in the global nitrogen cycle that results in the formation of nitrate through microbial activity(1,2). The increase in nitrate availability in soils is important for plant nutrition, but it also has considerable impact on groundwater pollution owing to leaching. Here we show that archaeal ammonia oxidizers are more abundant in soils than their well-known bacterial counterparts. We investigated the abundance of the gene encoding a subunit of the key enzyme ammonia monooxygenase (amoA) in 12 pristine and agricultural soils of three climatic zones. amoA gene copies of Crenarchaeota ( Archaea) were up to 3,000-fold more abundant than bacterial amoA genes. High amounts of crenarchaeota-specific lipids, including crenarchaeol, correlated with the abundance of archaeal amoA gene copies. Furthermore, reverse transcription quantitative PCR studies and complementary DNA analysis using novel cloning-independent pyrosequencing technology demonstrated the activity of the archaea in situ and supported the numerical dominance of archaeal over bacterial ammonia oxidizers. Our results indicate that crenarchaeota may be the most abundant ammonia-oxidizing organisms in soil ecosystems on Earth.