嗜酸氧化亚铁硫杆菌亚铁氧化酶基因分子多态性研究  

Molecular Diversity of the Gene Encoding Fe(II)-oxidizing Enzyme in Acidithiobacillus ferrooxidans

作　　者：杨宇[1] 彭宏[1] 孙斌[1] 王杰伟[1] 胡岳华[1] 

机构地区：[1]中南大学资源加工与生物工程学院,长沙410083

出　　处：《遗传》2005年第5期787-791,共5页Hereditas（Beijing)

基　　金：国家创新研究群体科学基金资助(编号:50321402)资助~~

摘　　要：嗜酸氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,A.f)属于化能自养、革兰氏阴性细菌,好氧嗜酸,以氧化亚铁离子或还原态硫化物(S0&S2-)获得能量生长.在其Fe2+氧化系统中,亚铁氧化酶起重要作用.对不同硫化矿区分离得到的5株A.f进行生长动力学和对亚铁氧化活性的对比研究,结果显示不同菌株之间存在表型差异.提取A.f菌株的基因组DNA,设计引物,对亚铁氧化酶基因进行PCR扩增,同时对扩增产物直接进行测序,并同GenBank的参考序列进行比对分析,发现序列相似性在99%～97%之间,分析编码区域发现在第187～195位可能存在一个高变异区:在第187～189位,菌株YTW编码的氨基酸Thr→Pro ;而在第193～195位,菌株TK是Met→Asn;菌株BY则是Met→Ile.另外在位点第219位,所有菌株都是T→C,但编码的氨基酸未发生变化,属于同义密码子.对于编码区上游序列,比对后没有差异;而对于编码区下游序列,经比对发现存在一些差异位点.Acidithiobacillus ferrooxidans （A. f） is a Gram-negative chemolithotrophic bacterium capable of oxidizing ferrous iron, elemental sulfur and inorganic sulfur compounds. Fe（ Ⅱ）-oxidizing enzyme plays a key role in Fe（ Ⅱ）-oxidizing system. Different A. f strains, which were isolated and purified from various ecological niches, showed obviously phenotypic diversity in growth rate and oxidation of Fe^2＋ . The Fe（Ⅱ）-oxidizing enzyme gene（iro） in five strains was identified by PCR, then sequenced and aligned. The results revealed a putative highly variable region in CDS between the 187th and 195th bp. In strain YTW, positions of 187- 189 corresponded to Thr→Pro; positions of 193- 195 to Met ~Asn in strain TK and to Met→lle in strain BY. However, position of 219 corresponded to T→C in all strains. For upstream of CDS, sequences in all strains were identical to the GenBank sequence （E03451）, but downstream of CDS, the sequences existed some variable sites.

关 键 词：嗜酸氧化亚铁硫杆菌 亚铁氧化酶基因 分子多态性 

分 类 号：Q933[生物学—微生物学]