Complete Genome Sequence of Kosakonia radicincitans GXGL-4A, a Nitrogen-Fixing Bacterium with Capability to Degrade TEX
Complete Genome Sequence of Kosakonia radicincitans GXGL-4A, a Nitrogen-Fixing Bacterium with Capability to Degrade TEX
复制标题
Kosakonia radicincitans GXGL-4A（一种具有降解 TEX 能力的固氮细菌）的完整基因组序列
DOI：
10.1007/s00284-020-01942-3
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发表时间：
2020-03-13
影响因子：
2.6
通讯作者：
Feng, Baoyun
中科院分区：
文献类型：
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作者：
Chen, Yunpeng;Huang, Zhibo;Feng, Baoyun
从玉米（Zea mays L.）根中分离得到的一株自由生长固氮菌（Kosakonia radicincitans GXGL-4A）具有降解芳香烃的能力。本研究描述了根茎芽孢杆菌GXGL-4A的主要形态特征、芳香烃降解能力和全基因组。基因组仅由一条5687681 bp的线性染色体组成，G + C含量为53.96%。该菌株具有两种遗传上不同的氮酶系统，一种基于钼（Mo），类似于从广泛的固氮生物中分离出来的氮酶，另一种含有铁（Fe）。采用实时定量反转录PCR （Real-time Quantitative Reverse Transcription PCR, qRT-PCR）检测了富氮（NR）和无氮（NL）培养条件下几种重要固氮（nif）基因转录水平的差异。GXGL-4A细菌细胞在含有1%甲苯、乙苯或二甲苯的LB液体培养基中均能良好生长，对所测芳香烃具有良好的抗性。GC-MS分析结果表明，K. radicincitans GXGL-4A具有良好的降解甲苯、乙苯和二甲苯（TEX）的能力。基因组测序的完成无疑将为该细菌在可持续农业和芳香污染物生物修复中的深入开发和综合利用做出贡献。
Kosakonia radicincitans GXGL-4A, a free-living nitrogen-fixing (NF) bacterial strain isolated from maize (Zea mays L.) roots was found to have ability to degrade aromatic hydrocarbons. In this study, we describe the main morphological characteristics of bacterium, aromatic hydrocarbon-degrading capability, and the complete genome of K. radicincitans GXGL-4A. The genome is consisted of only one 5,687,681 bp linear chromosome with a G + C content of 53.96%. The strain has two genetically distinct nitrogenase systems, one based on molybdenum (Mo) similar to nitrogenase isolated from a wide range of nitrogen-fixing organisms, and the other contains iron (Fe). The differences in transcriptional level of several important nitrogen fixation (nif) genes between LB (nitrogen-rich, NR) and A15 nitrogen-free (nitrogen-limited, NL) culture conditions were detected using Real-time Quantitative Reverse Transcription PCR (qRT-PCR). The bacterial cells of GXGL-4A can grow well in LB liquid medium containing 1% toluene, ethylbenzene or xylene, suggesting a good resistance to the tested aromatic hydrocarbons. The results of GC-MS analysis showed that K. radicincitans GXGL-4A has a good capability to degrade toluene, ethylbenzene, and xylene (TEX). Completion of the genome sequencing will no doubt contribute to the deep exploration and comprehensive utilization of this NF bacterium in sustainable agriculture and bioremediation of aromatic pollutants.