嗜酸硫杆菌属物种的比较基因组学分析

Comparative genome analysis of Acidithiobacillus strains

[目的]对喜温嗜酸硫杆菌和氧化亚铁嗜酸硫杆菌菌株的基因组数据进行比较分析和数据挖掘。[方法]采用Blast程序、MUMmer软件以及Artemis比对软件对4株嗜酸硫杆菌的基因组序列和蛋白质组序列进行同源比对分析以及可视化呈现,并通过RT-PCR对缺失基因进行验证。[结果]与喜温嗜酸硫杆菌相比,氧化亚铁嗜酸硫杆菌不含有鞭毛编码基因,并且含有较少的转座元件(26和41个);喜温嗜酸硫杆菌主要采用SOX系统(clusterⅠ和clusterⅡ)进行无机硫化合物的氧化;除硝酸盐还原外,氧化亚铁嗜酸硫杆菌还可以通过固氮酶(AFE1522-1515和Lferr_1240-1233)固定氮气获得氮源。此外,插入序列造成硫氧化还原酶基因的缺失以及7个功能基因失活等现象表明冶金微生物基因组存在不稳定性。[结论]比较基因组学为更好地挖掘嗜酸硫杆菌属物种的基因组数据信息、揭示其基因组结构特征以及冶金性状等差异提供了重要支持。

[ Objective] Comparative genomic methods were utilized to analyze and date -mining the genome features of AcidithiobaciUus caldus and Acidithiobacillus ferrooxidans. [ Methods ] Genome and whole proteome sequences of four Acidithiobacillus strains were alignment and visualized by using the Blast program, MUMmer software and Artemis Comparison Tool. The deletion of sulfur oxygenase reductase （SOR） gene was validated by the RT - PCR experiments. [ Results ] There are large differences between At. caldus and At.ferrooxidans. No flagella coding - genes and least transposable elements （26 and 41 ） were identified in the At.ferrooxidans geuomes. Sulfur oxidation systems （SOX, cluster I and cluster II ） were used to RISCs （Reduced inorganic sulfur compounds） oxidation metabolism in At. caldus. Nitrogen can be fixed by At.ferrooxidans （AFE1522 - 1515 and Lferr_1240 - 1233 ） to provide necessary nitrogen source except nitrate reduction and assimilation. In addition, the deletion of SOR gene and inactivation of seven functional genes caused by the insert sequences suggested the instability of bioleaching microbial genome. [ Conclusion ] Comparative genomics provides a powerful method for genome date mining of Acidithiobacillus, which will help to reveal the differences of genome structure and genetic differences of metabolism properties.