贵州矿区放线菌多样性及对汞的抗性

为探明贵州喀斯特重金属污染区域土壤放线菌多样性特征以及为其污染修复应用奠定基础,从贵州铜仁地区的25份土壤样品中,采用梯度稀释涂布法,利用3种处理方式、7种培养基分离放线菌;通过形态特征、16SrDNA基因序列分析结合生理生化特征鉴定放线菌;同时筛选重金属汞抗性菌株。结果从土样中共分离出56株典型放线菌菌株,经初步鉴定,分属于链霉菌属、孢囊链霉菌属、高温单孢菌属、线杆菌属、间孢囊菌属、诺卡氏菌属、小单孢菌属;其中链霉菌属放线菌占68%。筛选出了1株对汞有较高抗性(75mg·L~(-1))的放线菌菌株,优良耐受菌株的最大抗性约85 mg·L~(-1),菌株经鉴定为枝链霉菌Streptomyces rameus。共分离出56株,分属于7个属的放线菌菌株;筛选出1株重金属汞高抗菌株,经鉴定为枝链霉菌。

Diversity and Mercury-resistance of Actinomycetes in Tongren,Guizhou

Diversity and mercury-resistance of Actinomycetes in the soil polluted by heavymetals at Tongren karst regeions in Guizhou were studied to gain information for environmental recovery and bioremedies.Twenty-five soil samples were collected from the areas.Microorganisms were screened on 7 different culture media with gradient concentrations of mercury under 3 different treatments to isolate the resistant strains.Subsequently, the isolates were examined for their morphological, physiological and biological characteristics, and subjected to a 16S rDNA phylogenetic an alysis for further identification.As a result, 56 typical Actinomycetes belonging to Streptomyces, Streptosporangium, Thermomonospora, Actinobacillus, Intrasporangium, Nocardia, and Micromonospora were found to be resistant to mercury.Among them,68% were Streptomyces with one particular strain showing a high mercury-resistance to survive under a 75 mg·L-1 up to 85 mg·L-1 mercury stress, which was identified to beStreptomyces rameus.