关键词: 废弃铅锌矿石, 钨矿砂, R2A, 可培养细菌, 16S rRNA基因

Abstract: To investigate the diversity of culturable bacteria in abandoned lead-zinc ore and tungsten sands and explore novel microorganism, three media were used to isolate bacteria from the two materials, including R2A, phosphate free R2A and phosphate free R2A + Cd2+. Then the 16S rRNA gene sequences of the isolates were PCR amplified and sequenced, and then phylogenetic analysis was carried out. A total of 152 isolates were obtained from the abandoned lead-zinc ore and tungsten sands. The culturable bacteria isolated from abandoned lead-zinc ore were affiliated to 5 phyla and 7 branches, including Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Deinococcus-Thermus, Actinobacteria, Bacteroidetes, Firmicutes, with Massilia, Methylobacterium, Deinococcus, Sphingomonas as the dominant group, while those from tungsten sands were distributed into 3 phyla and 4 branches, including Alphaproteobacteria, Betaproteobacteria, Actinobacteria, Firmicutes, with Methylobacterium, Massilia, Ralstonia, Microbacterium as the dominant group. It showed that the diversity and novel taxon discovery rate of culturable bacteria in abandoned lead-zinc ore were greater than those in tungsten sands. The two materials showed huge differences in bacterial composition. Adding cadimum into the phosphate free R2A medium dramatically reduced the diversity of culturable bacteria, and only 3 genera were obtained from the medium with cadmium, including Methylobacterium, Herbaspirillum and Ralstonia. These strains could tolerate 2 mmol/L Cd2+ and they were the dominant group in metal tailings. This study provided references for the culturable bacteria community and novel microbial resource exploration.

Key words: abandoned lead-zinc ore, tungsten sands, R2A, culturable bacteria, 16S rRNA gene