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.
出处
《遗传》
CAS
CSCD
北大核心
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~~
关键词
嗜酸氧化亚铁硫杆菌
亚铁氧化酶基因
分子多态性
Acidithiobacillus ferrooxidans, Fe（Ⅱ）-oxidizing enzyme gene
Sequence diversity
