| The acid mine drainage water, sediment and tailing samples were collected from Shizishan sulfide mine, Tongling, Anhui province. Using four selective media YE, Fe, FeT, FeS, prokaryotic microorganisms and eukaryotic microorganisms were separated. After purification,17 strains of prokaryotic microorganisms and 50 strains of eukaryotic microorganisms (yeast 35, mold 15) were obtained. The 16S rDNA, ITS1/ITS4 and D1/D2 sequences were amplified from total genomic DNA of these isolates, then sequenced and homologous features of the sequences was analyzed. The isolated 17 strains of prokaryotic microorganisms belong to ten genera, namely Streptomyces sp., Comamonas sp., Acidithiobacillus sp., Aacidophillus sp., Ralstonia sp., Terrabacter sp., Escherichia sp., Herbaspirillum sp., Dyella sp. and Acidolella sp.. Some strains of them have function with iron oxidation, iron reduction and sulfur oxidation.35 strains of yeast belong to four genera, Rhodotorula sp., Rhodosporidium sp., Candida sp. and Cryptococcus sp., respectively. Some strains of them have acid resistance.15 strains of mold belong to five genera, Penicillium sp., Eurotiales sp., Trichoderma sp., Beauveria sp. and Penidiella sp., respectively. Some strains of them have the function with adsorption of metal ions and biomineralization. The biomass of prokaryotic microorganisms isolated from acid mine drainage water, sediment and tailing samples was higher than that of eukaryotic microorganisms. The microbial biomass from tailings samples was less than that from the acid mine drainage water and sediments. According to the function of microorganisms, they were classified into several function groups, mainly including acidophilic iron-oxidazing bacteria, acidophilic sulfur-oxidazing bacteria, moderately acidophilic iron-oxidazing bacteria, heterotrophic acidophiles and iron reducing bacteria. These microbial function groups cooperate and collaborate mutually to maintain the stability of entire acid mine ecosystem and dynamic balance of elements.A detailed study on the biological characteristics and identification of a fungal strain of TY6-2 was carried out. The characteristics of TY6-2 in PDA culture medium are as follows: fast growth, loose colonies, colony is initially white, then gradually turns emerald green with spores. The characteristics of TY6-2 in FeT culture media are as follows:colonies were dispersed, cell surface with yellow shell. TY6-2 has different levels of growth in the range of pH 1-10 and the optimum growth pH is 7. TY6-2 has different levels of growth in the range of 0-50℃ and the optimum growth temperature is 30℃. TY6-2 can grow in the range of less than 6% of the salinity and the optimum growth salinity is 0%. TY6-2 is aerobic and can not grow under anaerobic conditions. By molecular biological identification, the homology of ITS sequence of TY6-2 with Penicillium oxalicum is as high as 99% and TY6-2 was classified as Penicillium oxalicum.Through the research on functional characteristics of TY6-2, it was found that TY6-2 has the ability to adsorpt iron ions in near neutral environments and the adsorption rate is as high as 70%, obviously higher than that of the other isolated mold. The biomineralizing ability of TY6-2 live cells is higher than that of dead bacteria with sterilization treatment. A large number of mineral particles which morphology is more regular attached to live cell surfaces. The hypha of dead cell was rupture, hollow, organic matter disappearance and no regular mineral particles forming. When TY6-2 interacted with culture fluid for long-term, precipitation particls were formed. The mineral precipitation mainly composed of Fe2O3, which has important value for the recovery of iron from acid mine water, sediment and tailings. |
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