China General Microbiological Culture Collection Center, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
China General Microbiological Culture Collection Center, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China; School of Basic Medical Sciences, Guizhou Medical University, Guiyang, 550025 Guizhou, People's Republic of China.
Syst Appl Microbiol. 2021 Jan;44(1):126171. doi: 10.1016/j.syapm.2020.126171. Epub 2020 Nov 28.
Two nitrogen-fixing and heavy oil degrading strains, designated RWY-5-1-1 and ROY-1-1-2, were isolated from an oil production mixture from Yumen Oilfield in China. The 16S rRNA gene sequence showed they belong to Azospirillum and have less than 96.1 % pairwise similarity with each species in this genus. The average nucleotide identity and digital DNA-DNA hybridization values between them and other type strains of Azospirillum species were less than 75.69 % and 22.0 %, respectively, both below the species delineation threshold. Pan-genomic analysis showed that the novel isolate RWY-5-1-1 shared 2145 core gene families with other type strains in Azospirillum, and the number of strain-specific gene families was 1623, almost two times more than the number known from other species. Furthermore, genes related to nitrogenase, hydrocarbon degradation and biosurfactant production were found in the isolates' genomes. Also, this strain was capable of reducing acetylene to ethylene at a rate of 22nmol ethylene h (10 cells) and degrading heavy oil at a rate of 36.2 %. The major fatty acids and polar lipids were summed feature 8 (Cω7c/Cω6c), and phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylcholine. Furthermore, a combination of phenotypic, chemotaxonomic, phylogenetic and genotypic data clearly indicated that strains RWY-5-1-1 and ROY-1-1-2 represent a novel species, for which the name Azospirillum oleiclasticum sp. nov. is proposed. The type strain is RWY-5-1-1 (=CGMCC 1.13426 =KCTC 72259 ). Azospirillum novel strains with the ability of heavy oil degradation associated with the promotion of plant growth has never been reported to date.
两株固氮和降解重油的菌株，RWY-5-1-1 和 ROY-1-1-2，从中国玉门油田的采油混合物中分离得到。16S rRNA 基因序列表明它们属于固氮螺菌，与该属的每个种之间的相似度均小于 96.1%。它们与其他种的模式菌株之间的平均核苷酸同一性和数字 DNA-DNA 杂交值分别小于 75.69%和 22.0%，均低于种的划分阈值。泛基因组分析表明，新型分离株 RWY-5-1-1 与固氮螺菌中的其他模式菌株共享 2145 个核心基因家族，而菌株特异性基因家族的数量为 1623 个，几乎是其他种的两倍。此外，在这些菌株的基因组中发现了与固氮酶、碳氢化合物降解和生物表面活性剂产生相关的基因。此外，该菌株能够将乙炔还原为乙烯，还原速率为 22nmol 乙烯 h（10 个细胞），并以 36.2%的速率降解重油。主要脂肪酸和极性脂类为 summed feature 8（Cω7c/Cω6c），以及磷脂酰乙醇胺、双磷脂酰甘油、磷脂酰甘油和磷脂酰胆碱。此外，表型、化学分类、系统发育和基因型数据的综合分析清楚地表明，菌株 RWY-5-1-1 和 ROY-1-1-2 代表一个新种，建议将其命名为弹性氮单胞菌 oleiclasticum 新种。模式菌株为 RWY-5-1-1（=CGMCC 1.13426=KCTC 72259）。迄今为止，尚未有报道称具有降解重油能力并能促进植物生长的新型固氮菌。
