铜陵新桥矿区土壤中耐Cu微生物的筛选研究

Screening of Cu tolerant microorganism strains in the soil of Xinqiao mining area,Tongling,Anhui province

选择安徽铜陵新桥矿区富Cu的污染土壤,充分利用微生物受自然环境重金属胁迫而产生耐性这一特点,进行土壤中耐Cu微生物的筛选研究。实验过程中分别配制三种不同的培养基,细菌、真菌和放线菌培养基。在水浴恒温振荡器中对土壤中耐受重金属的微生物进行驯化,将得到的对Cu2+耐受性最高的液体培养基作为菌源,在琼脂平板培养基上进行划线分离,并将得到的纯菌株在光学显微镜下进行形态观察,菌种经试管斜面富集培养后保存在4℃冰箱中以便后续使用。研究发现,土样中细菌和真菌对Cu的耐受性低,最高耐受质量浓度分别只达到500mg·L-1和1100mg·L-1。而放线菌表现出Cu高耐受性,分离得到的放线菌耐受Cu的质量浓度最高达到10000mg·L-1,初步鉴定该放线菌株为链霉菌属。该放线菌菌种可能同时对Cu有吸附降解特性,具有成为污染土壤生物治理的高效耐受吸附菌种的潜力巨大。

This paper uses contaminated soil full of Cu of Xinqiao mining area, Tongling, Ahui province. Screening of Cu tolerant microorganism strains in the soil was based on the characteristic of micro-organisms have the tolerance to heavy metal. It was re- suiting from heavy metal stress in the natural environment. The experiment were prepared three different media, bacteria, fungi and actinomycetes culture medium. Soil microorganisms have the tolerance of heavy metals were domesticated in the water bath temperature oscillator. Let the highest Cu2~ tolerance of liquid culture medium as the bacteria source. Then crossed on the agar plate medium for strain separation. The pure strain will be observed in the optical microscope for morphological. Bacteria enriched by slope vitro cultured can be stored in 4 ℃ refrigerator for later use. The study found that soil bacteria and fungi on the Cu tolerance are low, the maximum tolerated concentration only 500 mg＇Lt and 1 100 mg.L-1, respectively. On the otherwise, the actinomycetes showed high Cu tolerance. The strain isolated from it has the tolerance of Cu of up to 10 000 mg.L-1. The preliminary identification of the actinomycetes strain is Streptomyces. The actinomycete strain may also have the adsorbtion and degradation characteristics on the Cu. It has the great potential to become high tolerance and adsorption strains in the process of bioremediation of contaminated soil.