Study On Mutation Screening Of Sulfate-Reducing Bacteria And Its Desulfurization Properties

With the development of chemical, monosodium glutamate, pharmaceuticals, alcohol, leather madding, paper and other industries, a lot of the waste water contained high concentrations of sulfate was let into nature enviorment,pollute the environment heavily. However, traditional approach is high cost,inefficiency, and sometimes bring secondary pollution. Sulfate-reducing bacteria used in sulfate wastewater treatment is not only low cost, but also can be used to deal with heavy metal. We first screened sulfate-reducing bacteria from the nature, then we mutated it with UV and ion beam,finally the cultural conditions were optimized, the results are as follows:(1) Sulfate-reducing bacteria strains was isolated from 22 samples,and 40 strains was obtained. Their abilities of reducing sulfate were tested,we got a higher desulfurization efficiency strain, numbered MTG4-B, the biochemical identification result, prove that it belongs to sulfate-reducing bacteria. Identified by 16S rDNA we found that it belongs to Enterobacter.(2) The optimal UV irradiation time was 3 seconds.A large number of strains was obtained under the conditions, through test their efficiency of desulfurization the highest three strains was obtained, numbered 3s-1, 3s-4,3s-9, the desulfurization rate of strain 3s-9 is 22.64%.(3) The stain 3s-9 was chosen as the start srtain of N+ irradiation. It was found that 70x2.6×1013ions/cm2 was the optimal injection dose, and the mutation rate is 35%. After extensive screening, we obtained strain N70-11, the desulfurization rate is 34.57%.(4)After optimization of cultivation conditions,we found that the optimal condtions were:10% inoculum,35℃,pH7.0,initial SO42-concentration 2000mg/L, training time 48 hours. After optimization, the desulfurization rate of stain N70-11 was 39.9%.