废弃铅锌矿石和钨矿砂中可培养细菌多样性分析

Diversity Analyses of Culturable Bacteria in Abandoned Lead-zinc Ore and Tungsten Sands

为了了解废弃铅锌矿石和钨矿砂中可培养细菌的多样性,发掘其中的微生物新资源,采用3种培养基(R2A、无磷R2A、无磷R2A+Cd^(2+))分别对其中的可培养细菌进行分离纯化和培养。再通过16S rRNA基因测序获取相关的分类学信息,并进行系统进化分析。从2种材料中共分离到可培养细菌152株。其中,废弃铅锌矿石中的可培养细菌涵盖了5个门、7个分支,分属于Alphaproteobacteria、Betaproteobacteria、Gammaproteobacteria、Deinococcus-Thermus、Actinobacteria、Bacteroidetes和Firmicutes,以Massilia、Methylobacterium、Deinococcus和Sphingomonas为主要类群;而钨矿砂中的可培养细菌涵盖了3个门、4个分支,分属于Alphaproteobacteria、Betaproteobacteria、Actinobacteria和Firmicutes,以Methylobacterium、Massilia、Ralstonia和Microbacterium为主要类群。废弃铅锌矿石中可培养细菌的多样性和新分类单元发现率均大于钨矿砂,且两者的可培养细菌类群组成存在较大差异。此外,向培养基中添加重金属Cd^(2+)降低了可培养细菌的多样性。研究分离到的Cd^(2+)耐受菌株主要属于3个属:Methylobacterium、Herbaspirillum和Ralstonia,其能耐受2 mmol/L Cd^(2+),是金属尾矿中重金属耐受菌的优势种群。研究结果为金属尾矿中微生物新资源的深入发掘提供了依据。

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 R2 A,phosphate free R2 A and phosphate free R2 A ＋ 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 R2 A 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 inmetal tailings. This study provided references for the culturable bacteria community and novel microbial resource exploration.