Study On The Distribution Character Of Cultivable Sulfate Reducing Bacteria (SRB) And Pseudomonas In Shihongtan Uranium Deposits And Their Precipation Uranium

With further research on microbial mineralization of uranium, the distribution character of microorganism in different geo-chemistry zone of uranium deposit, and participation in the uranium mineralization seem to have become a focus of geochemistry and microbiology. In this research,we isolated pseudomonas and sulfate reducing bacteria (SRB) from different uranium ore samples with basic microbiological methods,and pure isolates were identified on the basis of series of standard identification method. To investigate the distribution character of sulfate reducing bacteria (SRB) and pseudomonas in Shihongtan sandstone-type uranium deposits by the means of DGGE. At the same time, we conducted simulation research of reductive precipitation U(VI) in the deposit underwater by sulfate reducing bacteria and Pseudomonas, discussed the way of them reducing of U(VI)The results showed that there were six categories of cultivable SRB, and the quantity of them in metallogenic-belt was more than in reducing-belt and this is more than in oxidizing-belt. The main genera of SRB are Desulfotomaculum sp.、Desulfovibrio sp.and Desulfosporosinus sp. by the analysis of DGGE and 16S rDNA. Pseudomonas could be cultured in the distribution of uranium which had seven categories. The amount of Pseudomonas in each belt was no significant difference. The main genera of Pseudomonas is Pseudomonas stutzeri in Shihongtan sandstone-type uranium deposits by the analysis of DGGE and 16S rDNA. The results of reductive reducing experiment indicated that the way of Pseudomonas and SRB reductive reducing of U(VI)was different. Pseudomonas could directly metabolize U(VI) from deposit underwater by biosorption, while SRB was mainly rely on enzymatic metabolism reductive precipitation U(VI). Based on this, we could concluded that sulfate reducing bacteria and pseudomonas were abundant in variety and quantity in Shihongtan sandstone-type uranium deposits, and the distribution character of SRB in accord with geochemical distribution character of uranium.In addition, the distribution of Pseudomonas was no significant biogeochemical zonation feature in various ores.They could precipate U(VI) by enzymatic metabolism reductive precipitation and biosorption respectively,and have great significance for microbial mineralization of uranium.