Isolation, Identification Of The Heterotrophic Acidophilic Bacteria And Its Application In Bioleaching

There are various kinds of acidophilic microbiology which are divided into autotrophic, heterotrophic and amphitrophy by trophic types. The researches of acidophilic heterotrophic bacterium in in ecology were obstructed because of the limited researches in these bacterium. So the taxonomic status of acidophilic heterotrophic bacteriumin in acid mine drainage should be established by further research and their effect on enviroment shoulid be definited on the base of the researches in the physiologic properties of the acidophilic heterotrophic bacterium. Then, the reseach should be done in reciprocity between autotrophic and heterotrophic bacterium in the acid system of bioleaching to make bioleaching develop well.In this report, this strain of heterotrophic acidophilic was isolated from copper mining areas in china(Jiangxi). This strain were studied in phenotypic characteristics, physiological properties and phylogenetic relationships and were maintained in 30% glycerol.. By the reseaches of morphology, this strain of heterotrophic acidopilies was gram negative, rods, motile, no spore. They were mesophiles, optimum growth temperature was 30℃and optimum pH were3.5.They can live in the culture which the concentration of the NaCl is under 3.5%. They can not use ferrous iron and elemental sulfur as the sole energy source, and can use Mannitol, Arabinose, Glutamate, Levulose, Sodium Acetate, Sucrose and Glycerol as energy source. Therefore, the three isolates were acidophilic chemoorganotrophic bacteria.The analysis of 16s rRNA gene and phylogeny relations shows that DX-X shared more than 98% homology with Acidphilium.spp. .The content of C+Gmol% is 64-68%.In order to study the ecological effect of the heterotrophic acidophilic on the bioleaching system, the effects on the growth of Acidithiobacillus ferrooxidans and its bioleaching of Ni should be detected. It appears that the strain of DX-X could promote the growth of the Acidithiobacillus ferrooxidans. The rate of oxidating Fe²⁺ was increased by 17.5% in mixed culture with Acidithiobacillus ferrooxidans, the leaching rate of the Ni was increased by 30% in mixed culture. So, DX-X could improve the leaching activity of the autotrophic bacterium.