3种硫化矿生物浸出细菌种群演替差异性研究

Differences of Strain Succession among Chalcopyrite,Pyrite and Pentlandite Bioleaching

对黄铜矿、黄铁矿、镍黄铁矿生物浸出过程,浸矿用细菌种群演替差异性进行了研究。初始条件相同,原始菌种中Leptospirillum ferriphilum,Acidithiobacillus caldus占比接近1∶1。研究发现:黄铁矿生物浸出过程中Leptospirillum ferriphilum为优势菌;黄铜矿生物浸出过程中Leptospirillum ferriphilum由优势菌转为劣势菌;镍黄铁矿生物浸出过程中Leptospirillum ferriphilum为劣势菌,但随浸出时间的延长,其在群落组成中的占比有所增加。差异性产生原因分析表明:3种矿物生物浸出过程,浸出液p H并未对细菌种群演替差异产生影响。能源物质硫的供应除对黄铁矿生物浸出过程浸矿用细菌种群演替规律有一定影响外,并未对黄铜矿、镍黄铁矿浸矿用细菌种群演替差异产生影响;3种矿物浸矿用细菌种群演替差异产生的根本原因在于3种矿物生物浸出机制不同,导致了能源物质Fe2+供应差异。

The differences of strains succession among chalcopyrite,pyrite and pentlandite bioleaching were studied under the same starting conditions. The proportion of Leptospirillum ferriphilum and Acidithiobacillus caldus in the original strains was near to 1 ∶ 1. A phylogenetic analysis based on 16 Sr RNA sequences showed that Leptospirillum ferriphilum was the dominant bacteria in pyrite bioleaching process. In chalcopyrite bioleaching process,Leptospirillum ferriphilum turned from dominant bacteria to inferior organisms. Different from chalcopyrite and pyrite bioleaching process,Leptospirillum ferriphilum was the inferior organisms in pentlandite bioleaching process and its proportion rose with time. The reason accounting for the differences of strains succession between these minerals was not the p H of leaching liquid,but the Fe2 ＋supply difference caused by different leaching mechanisms. Furthermore,the supply of sulfur might have some influences on the strains succession of pyrite,but had no effect on those of chalcopyrite and pentlandite.