Mucilaginibacter pedocola sp.nov.的多项分类学鉴定和基因组分析

发布时间：2018-06-04 23:31

本文选题：锌污染 + 多相分类学　；参考：《华中农业大学》2017年硕士论文

【摘要】：为开发具有重金属修复能力的微生物资源,本研究从湖南省临湘市忠坊镇锌污染水稻田中分离了一株具有锌抗性的细菌,命名为TBZ30~T,我们发现该菌株对Zn~(2+)中有较高抗性(MIC=3mM),并且能够去除Zn~(2+),降低Zn~(2+)浓度,可能与该菌产生大量的胞外多糖来吸附Zn~(2+)相关,该特点具有很大的潜在利用价值。通过16S rRNA比对分析,TBZ30~T属于Mucilaginibacter属,且与该属细菌相似度最高为95.8%,基于16S rRNA的系统发育进化树分析,TBZ30~T与Mucilaginibacter gynuensis YC7003T、Mucilaginibacter mallensis MP1X4 T、Mucilaginibacter litoreus BR-18 T三个菌亲缘关系最相近,相似度分别为95.8%、95.4%、95.4%。对该菌进行了进一步的多项分类学分析以及基因组分析,TBZ30~T是一株革兰氏阴性杆状细菌,无鞭毛,无运动性,无孢子产生。该菌严格好氧生长,生长过程中产生粉红色色素,氧化酶和过氧化氢酶阳性,并且在生长后期能够产生大量的胞外多聚物。TBZ30~T含有唯一呼吸醌为MK-7,其主要全细胞脂肪酸是iso-C15:0和summed feature 3,主要的极性脂类型为磷脂酰乙醇胺、未知的磷脂、未知的氨磷脂、未知的氨脂、未知的脂类、未知的糖脂。TBZ30~T的G+C含量是49%mol。通过以上多项分类学鉴定,TBZ30~T属于Mucilaginibacter的一个新种,该种命名为Mucilaginibacter pedocola sp.nov,其模式菌株是TBZ30~T。基因组草图测序以及基因组注释显示,其基因组大小为7,035,113 bp,含有3132个蛋白质编码基因(其中2736个基因在COG分析中预测了相应的功能),50个tRNA编码基因,14个rRNA编码基因以及54个重金属抗性相关的基因,其中与锌抗性相关的基因有21个,与胞外多糖相关的基因有11个,这些基因型特征与TBZ30~T的表型特征相符合,通过分析TBZ30~T的基因组,使得我们对Mucilaginibacter有了进一步的认识,这对Mucilaginibacter属的开发和利用具有深远的意义,同样为锌的微生物修复提供了新的思路。
[Abstract]:In order to develop microbial resources with heavy metal remediation ability, a zinc-resistant bacterium was isolated from Zinc-contaminated paddy field in Zhongfang Town, Linxiang City, Hunan Province. Named TBZ30 (TBZ30), we found that the strain had a high resistance to MIC3mMN, and could remove ZnZZ2 and reduce the concentration of ZnO-2), which may be related to the production of a large amount of extracellular polysaccharides (EPS) to adsorb ZnO-2), which has great potential utilization value. TBZ30T belongs to Mucilaginibacter genus by 16s rRNA comparison, and it has the highest similarity to the genus Mucilaginibacter. The phylogenetic tree analysis of TBZ30T based on 16s rRNA and Mucilaginibacter gynuensis YC7003T Mucilaginibacter mallensis MP1X4TMucaginibacter litoreus BR-18T has the most close relationship, and the similarity is 95.8895. 4%. Further taxonomic analysis and genomic analysis of this strain were carried out. TBZ30T was a gram-negative bacilli with no flagellum, motility and spore production. The bacterium strictly aerobic growth, the growth process produced pink pigments, oxidase and catalase positive, And in the later stage of growth, a large number of extracellular polymers. TBZ30T contained only respiratory quinone MK-7. The main fatty acids in the whole cell were iso-C15: 0 and summed feature 3. The main polar lipid types were phosphatidylethanolamine, unknown phospholipid, unknown aminophosphatidylcholine. The G C content of unknown ammonia lipid, unknown lipids, unknown glycolipid. TBZ30 + T was 49 mol. A new species of Mucilaginibacter, Mucilaginibacter pedocola sp. Nov, was identified by taxonomy. Genome sketch sequencing and genome annotation show, Its genome size is 7035113 BP and contains 3132 protein coding genes (2736 of which predicted corresponding functional genes, 50 tRNA coding genes, 14 rRNA coding genes and 54 heavy metal resistance-related genes in COG analysis. There are 21 genes related to zinc resistance and 11 genes related to exopolysaccharide. These genotypes are consistent with the phenotypic characteristics of TBZ30T. By analyzing the genome of TBZ30T, we have a better understanding of Mucilaginibacter. This is of great significance to the development and utilization of Mucilaginibacter, and also provides a new idea for the microbial remediation of zinc.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X172;Q939

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