Streptomyces thermoautotrophicus does not fix nitrogen.
Streptomyces thermoautotrophicus does not fix nitrogen.
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DOI：
10.1038/srep20086
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发表时间：
2016-02-01
影响因子：
4.6
通讯作者：
Prell J
中科院分区：
文献类型：
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作者：
MacKellar D;Lieber L;Norman JS;Bolger A;Tobin C;Murray JW;Oksaksin M;Chang RL;Ford TJ;Nguyen PQ;Woodward J;Permingeat HR;Joshi NS;Silver PA;Usadel B;Rutherford AW;Friesen ML;Prell J
Streptomyces thermoautotrophicus UBT 1是一种中度嗜热的化能无机自养菌，具有一种对氧不敏感的新型固氮酶。我们培养了UBT 1菌株，并分离出两个表型和遗传性状非常相似的新菌株（H1和P1-2）。这些菌株在无铵培养基上显示出最小的生长，并且在多个独立测定中未能将同位素标记的N2气体掺入生物质中。sdn基因以前被认为是S.热自养芽孢杆菌的基因组序列与本文公开的菌株H1和UBT 1的基因组序列草案中发现的任何基因几乎没有相似性，但与来自许氏水生芽孢杆菌的基因共享>99%的核苷酸同一性，本文也提供了其基因组草案。H. schlegelii同样缺乏固氮酶基因，并且是非固氮生物。我们建议重新分类的物种包含菌株UBT 1，H1，和P1-2作为一个非链霉菌，非重氮营养，兼性chemolithoautotroph，并得出结论，以前提出的耐氧固氮酶的存在是极不可能的。
Streptomyces thermoautotrophicus UBT1 has been described as a moderately thermophilic chemolithoautotroph with a novel nitrogenase enzyme that is oxygen-insensitive. We have cultured the UBT1 strain, and have isolated two new strains (H1 and P1-2) of very similar phenotypic and genetic characters. These strains show minimal growth on ammonium-free media, and fail to incorporate isotopically labeled N2 gas into biomass in multiple independent assays. The sdn genes previously published as the putative nitrogenase of S. thermoautotrophicus have little similarity to anything found in draft genome sequences, published here, for strains H1 and UBT1, but share >99% nucleotide identity with genes from Hydrogenibacillus schlegelii, a draft genome for which is also presented here. H. schlegelii similarly lacks nitrogenase genes and is a non-diazotroph. We propose reclassification of the species containing strains UBT1, H1, and P1-2 as a non-Streptomycete, non-diazotrophic, facultative chemolithoautotroph and conclude that the existence of the previously proposed oxygen-tolerant nitrogenase is extremely unlikely.