废弃铅锌矿石中重金属耐受菌分离及多相分类研究

Heavy metal pollution has severely threatened to people's health and remediation work is imminent. Heavy metal resistant bacteria played a key role in heavy metal bioremediation, such as heavy metal adsorption or immobilization, reinforcement of phytoremediation, and so on. They have the advantages of low cost effect. Most of the heavy metal resistant bacteria were isolated from heavy metal polluted soil and water or mine tailings so far. Rich mediums amended with different heavy metal were mainly used. Lack of innovation in materials and isolation mediums resulted in limited species of heavy metal resistant bacteria and bioremediation effect, lack of new species. Abandoned lead-zinc ore, characteristic of extreme environment, contained high concentration of different heavy metal, low organic matter and water. Preliminary study had shown that there were variety of heavy metal resistant bacteria and new species or genera in abandoned lead-zinc ore. Selective medium amended with different growth factors will be used to isolate heavy metal resistant bacteria and new species from abandoned lead-zinc ore and polyphasic taxonomy methods will be used for their classification. This study will provide new ideas for heavy metal resistant bacteria isolation from extreme environment and lay an important foundation for the applications in heavy metal bioremediation. This is the first systematic study on the isolation and polyphasic taxonomy of heavy metal resistant bacteria from abandoned lead-zinc ore and will provide important theoretical basis for the bacterial isolation from extreme environmental.

重金属污染严重威胁到了人们的健康，开展修复迫在眉睫。重金属耐受菌在生物吸附、生物固定、以及强化植物富集重金属等方面发挥着极为关键的作用，具有成本低、效果好等优点。目前它们主要自分离土壤和尾矿等材料，培养基多为添加重金属的富营养培养基，这使得已获取的重金属耐受菌种类相对较少，且缺少新资源，对重金属污染的修复效果仍待提高。废弃铅锌矿石具有含大量的重金属(Pb、Cd)，有机质和水分含量少等极端环境特点，前期研究表明其中蕴藏着丰富的重金属耐受菌新资源。本研究以不同类型废弃铅锌矿石为研究对象，利用添加不同促生因子的选择性培养基从中分离重金属耐受菌，致力于获得未培养的新资源，并开展多相分类研究，为极端环境下的重金属耐受菌的分离提供新思路，为重金属污染的生物修复提供更多的物质基础。本项目是首次系统地开展废弃铅锌矿石中重金属耐受菌的分离，研究结果将为极端环境微生物资源的探索研究提供重要的理论依据。

重金属耐受菌在生物吸附、生物固定、以及强化植物富集重金属等方面发挥着极为关键的作用，具有成本低、效果好等优点，是一类重要的微生物资源。但目前已有的重金属耐受菌主要自分离土壤和尾矿等材料，培养基多为添加重金属的富营养培养基，这使得已获取的重金属耐受菌种类相对较少，且缺少新资源。废弃铅锌矿石具有含大量的重金属(Pb、Cd)，有机质和水分含量少等极端环境特点，前期研究表明其中蕴藏着丰富的重金属耐受菌新资源。本项目以不同区域采集的废弃铅锌矿石为研究材料，以贫营养培养基为基础，采用外援添加不同促生因子优化培养基，从废弃铅锌矿石中分离得到了重金属耐受菌282株，涵盖了29个属，7个纲（α-Proteobacteria，β- Proteobacteria，γ- Proteobacteria，Actinobacteria，Deinococci、Bacilli、Sphingobacteria），5个门（Proteobacteria、Actinobacteria、Firmicutes、Bacteroidetes、Deinococcus-Thermus）。重金属耐受菌株以Sphingomonas、Methylobacterium、Massilia、Deinococcus、Arthrobacter属为主。从中发现了疑似新种（属）21株。采用多相分类手段完成了6株疑似新物种的鉴定，将其分别命名为Massilia putida、Deinococcus metalli、Lysobacter mobilis、Acinetobacter guangdongensis、Sphingomonas guangdongensis和Sphingomonas gimensis。这些结果表明废弃铅锌矿石中存在种类丰富的重金属耐受菌新资源。新资源的获取和保藏为其在重金属污染治理中的应用提供了重要的生物材料，同时在分类学上对于认知新物种也具有重要的科学意义。