不同嗜酸氧化亚铁硫杆菌(DY15,DY26,DC)对黄铜矿的浸出及其基因Afe0022的差异表达  

Bioleaching of chalcopyrite by Acidithiobacillus ferrooxidans DY15,DY26 and DC and difference expressions of gene Afe0022

作　　者：吴学玲[1,2] 袁鹏[1,2] 胡琪[1,2] 侯冬梅[1,2] 苗博[1,2] 邱冠周[1,2] 

机构地区：[1]中南大学资源加工与生物工程学院,长沙410083 [2]中南大学教育部生物冶金重点实验室,长沙410083

出　　处：《中国有色金属学报》2011年第4期932-938,共7页The Chinese Journal of Nonferrous Metals

摘　　要：通过摇瓶浸矿比较研究3株Acidithiobacillus ferrooxidans(At.ferrooxidans)菌DY15、DY26和DC的耐受Cu2+能力的差异以及在不同的初始Cu2+浓度影响下菌对黄铜矿浸出能力的不同。采用Real time RT(Reverse transcriptase)PCR检测这些菌株的阳离子通道蛋白基因Afe0022在不同Cu2+环境下的差异表达,进行相对表达量分析。结果表明:DY15、DY26和DC菌的最高Cu2+抗性分别是0.40、0.22和0.04 mol/L,且在以元素硫为能源的9K培养基中,3株菌DY15,DY26和DC对应的培养体系pH值在7 d内由1.8分别降到0.8、1.2和1.3,说明DY15的硫氧化能力最强;3株菌都具有较好的亚铁氧化能力,在40 h内,DY15、DY26和DC的Fe2+氧化率分别是80%、100%、100%。黄铜矿精矿浸矿实验表明,DY15对黄铜矿精矿的浸出效率最高,DY26的其次,DC的最低,但DY15的单菌浸出效率略低于3株菌的混合浸出效率。对Cu2+抗性越强的菌株,其基因Afe0022表达量越高,这对菌株的Cu2+抗性能力有一定的理论解释作用,在分子层面上为研究At.ferrooxidans菌抗铜机理提供一定的理论依据。The effects of different initial concentrations of Cu2＋ on chalcopyrite concentrate bioleaching and the difference of ability in response to copper ion（Cu2＋） were investigated with three strains of Acidithiobacillus ferrooxidans（At.ferrooxidans） DY15,DY26 and DC.The real time reverse transcriptase（RT） PCR was used to analyze the difference expression of gene Afe0022 cation channel protein in copper ion with different concentrations.The results show that strain DY15,DY26 and DC have the copper ion tolerance level of 0.40,0.22 and 0.04 mol/L,respectively.When the elemental sulfur acts as the energy resource in 9K medium,the oxidation capacity of elemental sulfur of strain DY15 is better than that of elemental sulfur of DY26 and DC,and after 7 d,the pH values of DY15,DY26 and DC decline from 1.8 to 0.8,1.2 and 1.3,respectively.All three strains can oxidize ferrous ions well,and after 40 h,the oxidation capacities of ferrous ions of three strains are 80%（DY15）,100%（DY26）,and 100%（DC）,respectively.In the leaching experiment,strain DY15 has the highest bioleaching efficiency on chalcopyrite concentrate while strain DC has the least bioleaching efficiency in the three strains,but the mixed cultures containing 3 strains exhibit the highest bioleaching efficiency than the pure cultures of DY15.The stronger the capacity of strain resistance to Cu2＋ is,the more the expression of gene Afe0022 is.This result assists interpretation of bacterium resistance to Cu2＋,and provides theoretical basis to study the mechanism of bacterium resistance to Cu2＋ in molecular level.

关 键 词：嗜酸氧化亚铁硫杆菌 黄铜矿精矿浸出 元素硫氧化 Cu2+抗性 差异表达 

分 类 号：Q819[生物学—生物工程]