中等嗜热细菌浸出黄铜矿过程中pH对群落结构的影响

为了优化浸出工艺,研究了pH对浸矿过程主要微生物种群结构的影响。用中度嗜热混合菌槽浸黄铜矿精矿,在不控制pH,控制pH为2．5及控制pH为1．2时,应用PCR-RFLP（限制性酶切片段长度多态性）方法对上述浸出条件下的细菌群落动态变化进行研究。结果表明,浸出体系只有两种微生物,一种为Acidithiobacillus Caldus,一种为Leptospirillum ferriphilum。pH对群落结构有明显影响。不控制pH时,浸出开始阶段At．caldus是优势种群,占群落的96％,随着浸出的进行,L．ferriphilum增多,在浸出后期代替At．caldus成为优势菌种,占69％。控制pH时,L．ferriphilum始终占主导地位,同时发现pH为2．5时At．caldus在群落中的丰度比pH为1．2时高。

Influence of pH on microbial community structure of moderate thermophiles in bioleaching of chalcopyrite

In order to investigate influence of pH on microbial population dynamics in bioleaching system for process optimization,chalcopyrite concentrate was leached by moderately thermophilic mixed microorganism in a stirred tank bioreactor.The method of PCR-RFLP was used to analyze the succession of bacterial community under conditions of uncontrolled pH and pH controlled at 2.5 or 1.2.There were only two species,Acidithiobacillus caldus and Leptospirillum ferriphilum.When pH was not controlled,at the beginning of bioleaching process,At.caldus was the predominant species,accounted for 96% of the whole community.With the process of leaching,L.ferriphilum increased and replaced At.caldus,and accounted for 69% in the later stage of bioleaching; When pH was controlled,L.ferriphilum was always predominant species.It was found that abundance of At.caldus in the whole community at pH 2.5 was more than the situation of pH 1.2.Community diversity of bioleaching system in this experiment was simple.pH had obvious influence on microbial population dynamics.