Production and Excretion of Polyamines To Tolerate High Ammonia, a Case Study on Soil Ammonia-Oxidizing Archaeon "Candidatus Nitrosocosmicus agrestis".
Production and Excretion of Polyamines To Tolerate High Ammonia, a Case Study on Soil Ammonia-Oxidizing Archaeon "Candidatus Nitrosocosmicus agrestis".
复制标题
耐高氨态下多胺的产生和排泄--以土壤氨氧化古细菌“Candidatus Nitroocosmicus agrestis”为例
DOI：
10.1128/msystems.01003-20
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发表时间：
2021-02-16
期刊：
影响因子：
6.4
通讯作者：
Luo J
中科院分区：
文献类型：
--
作者：
Liu L;Liu M;Jiang Y;Lin W;Luo J
耐氨性是氨氧化细菌（AOB）的普遍特征;相反，已知的氨氧化古菌（AOA）一直被认为是氨敏感的，直到“亚硝化菌”的鉴定。然而，其耐氨性的机制还未见报道。在这项研究中，从农业土壤中获得的AOA物种“Agroscosmicus agrestis”被确定能够耐受高浓度的NH3（> 1，500 μM）。在从宏基因组数据恢复的该菌株的基因组中，鉴定了用于多糖代谢、尿素水解、精氨酸合成和多胺合成途径的全套基因。其中，编码胞质碳酸酐酶（CA）和潜在的多胺转运蛋白（药物/代谢物输出蛋白[DME]）的基因被发现是“Ca.亚硝虫”当“钙。在高氨水平下生长，参与CO2/HCO 3 −转化、谷氨酸/谷氨酰胺合成、精氨酸合成、多胺合成和多胺排泄的基因显著上调，多胺（包括腐胺和亚精胺）的产量显著增加。基于基因组分析、基因表达定量和多胺测定，我们认为多胺的产生和分泌可能是“Ca. Nitrosocosmicus agrestis，甚至是Ca。亚硝虫”AOA的氨耐受性通常远低于AOB，这使得AOB而不是AOA成为农业土壤中的主要氨氧化剂，从而导致全球N2 O排放。近年来，一些AOA物种的属“Ca。亚硝小蜂也具有很高的耐氨性。然而，氨耐受机制的报道是非常罕见的，不确定的AOB和AOA物种。在这项研究中，一个耐氨AOA菌株的物种“钙。本文报道了一种名为“Nitrososcosmicusagrestis”的亚硝小蜂，并探讨了其耐氨性的可能机制。本研究将有助于进一步了解AOA在农业土壤或其他环境中的生态作用。
Ammonia tolerance is a universal characteristic among the ammonia-oxidizing bacteria (AOB); in contrast, the known species of ammonia-oxidizing archaea (AOA) have been regarded as ammonia sensitive, until the identification of the genus “Candidatus Nitrosocosmicus.” However, the mechanism of its ammonia tolerance has not been reported. In this study, the AOA species “Candidatus Nitrosocosmicus agrestis,” obtained from agricultural soil, was determined to be able to tolerate high concentrations of NH3 (>1,500 μM). In the genome of this strain, which was recovered from metagenomic data, a full set of genes for the pathways of polysaccharide metabolism, urea hydrolysis, arginine synthesis, and polyamine synthesis was identified. Among them, the genes encoding cytoplasmic carbonic anhydrase (CA) and a potential polyamine transporter (drug/metabolite exporter [DME]) were found to be unique to the genus “Ca. Nitrosocosmicus.” When “Ca. Nitrosocosmicus agrestis” was grown with high levels of ammonia, the genes that participate in CO2/HCO3− conversion, glutamate/glutamine syntheses, arginine synthesis, polyamine synthesis, and polyamine excretion were significantly upregulated, and the polyamines, including putrescine and spermidine, had significant levels of production. Based on genome analysis, gene expression quantification, and polyamine determination, we propose that the production and excretion of polyamines is probably one of the reasons for the ammonia tolerance of “Ca. Nitrosocosmicus agrestis,” and even of the genus “Ca. Nitrosocosmicus.” IMPORTANCE Ammonia tolerance of AOA is usually much lower than that of the AOB, which makes the AOB rather than AOA a predominant ammonia oxidizer in agricultural soils, contributing to global N2O emission. Recently, some AOA species from the genus “Ca. Nitrosocosmicus” were also found to have high ammonia tolerance. However, the reported mechanism for the ammonia tolerance is very rare and indeterminate for AOB and for AOA species. In this study, an ammonia-tolerant AOA strain of the species “Ca. Nitrosocosmicus agrestis” was identified and its potential mechanisms for ammonia tolerance were explored. This study will be of benefit for determining more of the ecological role of AOA in agricultural soils or other environments.