Isolation And Characterization Of Arsenic / Antimony Resistant Bacteria In Soil Of Mining Area

With the development of modern industry,the natural environment is suffering from serious damage,heavy metals on the soil and water pollution is particularly serious,China is arsenic and antimony reserves and production rank the forefront of the world,arsenic and antimony mining industry development,Related products are widely used,but the resulting pollution has been very serious,arsenic and antimony are toxic or even carcinogenic effects on the human body,so the pollution of its environment has been urgent.Microorganisms are involved in the geochemical cycle of arsenic and antimony and play an important role in the formation,transformation and repair of arsenic and antimony pollution.In order to enrich the diversity of arsenic and antimony resistant bacteria in order to provide the valuable basic data and experimental materials for later microbiological participation in the mechanism of biochemical cycling of antimony and the bioremediation of antimony resistant bacteria,this paper adopts conventional biological method The antimony-resistant bacteria in the soil samples of Lengshuijiang Antimony Mine in Hunan Province and the arsenic-resistant bacteria in arsenic area of Shimen County,Hunan Province were screened and the related characteristics of heavy metal tolerance were studied.The main contents and related conclusions are as follows:(1)156 antimony-resistant bacteria were isolated from the soil samples of Lengshuijiang Antimony Mine in Hunan Province by means of conventional biological methods such as enrichment,coating separation and purification.Using 16 S rRNA gene sequence analysis,156 strains were identified as eight different genera by PCR amplification and sequence alignment of the screened strains,and the phylogenetic tree was constructed.A total of eight antimony-resistant bacteria were selected: named Bacillus sp L4;Acinetobacter sp L81;Pseudomonas sp L87;Rhodococcus sp L52;Pantoea sp L51;Bacillus sp.Paenibacillus sp L31;Phytophthora curtobacterium sp L70;Fictibacillus sp L19.The results showed that L70 and L87 had the strongest resistance to the two strains,and the tolerance to the two strains was 150 mmol / L.The tolerance of strain L4 was 120 mmol / L;strain L19,L31,L51,L52,L81 were 80 mmol / L.(2)In this experiment,the effects of three kinds of aerobic arsenic-reducing bacteria on the migration and transformation of arsenic in soil were studied by static test.The results showed that the aerobic arsenic reducing bacteria such as IMH could promote arsenic Restore release.The addition of IMH and other strains can change the ORP and pH in the soil solution,and then affect the adsorption and desorption of arsenic in the soil.Compared with the blank control,the addition of IMH and other strains had a certain effect on the release of total arsenic in the soil solution,but it did not contribute much to the release of total iron.(3)An antibiotic-resistant,anaerobic,rod-shaped,non-spore-resistant arsenic bacteria S9 was screened from arsenic-contaminated soil in Xiongmu County,Shimen County,Hunan Province.The strain S9 could be in the range of 4 to 40 °C Growth(the optimum growth temperature of 35oC),the growth of the optimal pH of 7.0.Using 16 S r RNA gene sequence analysis showed that S9 had the highest homology with Ilybacter,and its sequence similarity was 97%.From the phenotypic characteristics,genotype and phylogenetic tree of strain,it was found that strain S9 was Ilybacter A suspected new species.It can be concluded that the strain can efficiently reduce the high concentration of arsenic and determine that the strain can regulate the metabolism of arsenic and sulfur to produce yellow precipitate.The regulation mechanism and product analysis of arsenic sulfur co-metabolism need to be further To explore.In this study,the antimony-resisting bacteria were screened,and their tolerance to antimony was much higher than that of other antimony-resistant bacteria,which enriched the diversity of antimony-resistant bacteria and the mechanism of antimony metabolism in microorganisms The study provided the test material.The results showed that the genus had the same arsenic reduction property and had not been reported before,and the diversity of arsenic-reducing strains was enriched.It was proved that the strain S9 could regulate the activity of arsenic Arsenic and sulfur co-metabolism,so that the water arsenic ions and sulfur ions generated precipitation,and then removed from the water.Screening of strain S9 provides a basis for the study of the mechanism of arsenic and sulfur metabolism and the development of microbial remediation techniques for soil and water pollution.