The Microbial Diversity Analysis Of Realgar Mine And The Isolation Of Arsenic-oxidizing Bacterial For Application

Now with the rapid development of industry, the problem of environmental pollution has become serious increasingly, especially arsenic containing gold mining, because the toxicity of arsenic on human and other organisms, arsenic pollution has been seriously affect our health. Looking for a fast, green method to solve the arsenic pollution is a pressing matter at the moment. In view of the above background, this research mainly focuses on the study of the biological treatment and how to better solve the problem of waste water containing arsenic.Hunan Shimen realgar mine is an old mine with a history of1500, has a long history of mining. Three samples from the pit water of the mine tailings and bottom sludge, the last site of underground for400meters, which were named SY, NY and XY respectively. On three samples by ICP-MS elemental analysis, using denaturing gradient gel electrophoresis (DGGE) and restriction fragment length polymorphism (RFLP) technique, analysis of three samples of community structure and diversity. In order to obtain the oxidation of trivalent arsenic mixed bacteria, the bacteria in the samples were enriched using medium containing arsenic, subculture that bacteria make then stability, and then determine arsenic tolerance and oxidation ability of three kinds of mixed bacteria. At the same time in order to obtain single bacteria oxidation of trivalent arsenic, respectively, using mixed cultures medium containing arsenic enrichment, plate separation, according to the result of the As5+and silver nitrate color reaction, oxidation of single colonies were detected to obtain efficient oxidation strains. Finally by the oxidation of trivalent arsenic mixed bacteria from arsenic containing wastewater treatment of Huaxi Group Chehe concentrator took, to detect the effect of treatment.Through DGGE and RFLP analysis, the NY community diversity is far greater than SY and XY. The typical clones of three samples were sequenced, the sequence obtained by NCBI comparison, discovery and sequencing results higher similarity sequences of strains, mostly from similar environmental conditions. Identification of sequences found, detect α-Proteobacteria,β-Proteobacteria, y-Proteobacteria and many types of bacteria in three samples, and the presence of NY Pseudomonas certain, according to the research results related, probably with oxidation of trivalent arsenic strains. Because there is a higher concentration of sulfur in three samples, so we also detected thiobacillus. XY in the ground, and which related to the sample environment, so many types of Hydrogenophilus appeared.After strain16S rDNA sequence identification of samples screened the oxidation of trivalent arsenic, mainly belong to Pseudomonas, Acinetobacter. Using the obtained pure bacteria were detected in treatment of wastewater containing arsenic, ability of each single bacteria oxidation of trivalent arsenic, can play a good effect. At the same time by cloning protease gene was oxidized trivalent arsenic on objective strain obtained by oxidation, found to have ability of strain, not necessarily with arsenite oxidase gene.Using samples in the above arsenic concentration enrichment medium, the oxidation of trivalent arsenic mixed bacteria obtained, after testing were major for Acinetobacter, Pseudomonas and so on. These three kinds of samples were detected in the culture medium for the tolerance of certain gradient arsenic concentrations, found that three kinds of bacteria in the arsenic concentration of up to0.5g/L under the conditions of growth, although some is slowly, but also can reach108-109. Using the three kinds of bacteria from wastewater containing arsenic treatment of certain concentration, trivalent arsenic in waste water was almost completely oxidized, concentrations of total arsenic in a certain period of time also decreased the number of. The flora with the oxidation of trivalent arsenic capacity of arsenic-containing wastewater, wastewater from Chehe concentrator processing, in the range of10h, the total arsenic in waste water is handled completely.