珠穆朗玛峰自然保护区土壤放线菌的生态分布及拮抗性研究

Study on Ecological Distribution and Antimicrobial Activity of Actinomycete from Soil in the Mt. Everest National Nature Preserve

[目的]探究珠穆朗玛峰自然保护区土壤放线菌的生态分布及抑菌活性,为放线菌新药物先导化合物筛选提供资源。[方法]采用稀释平板法及琼脂块法对珠穆朗玛峰自然保护区土壤放线菌进行分离及拮抗性测定。[结果]珠穆朗玛峰自然保护区植被类型不同,放线菌的数量分布均有明显差异。农田土放线菌数量最多,人工林与原始森林土壤放线菌数量最少。在同一剖面内表层放线菌数量最高,随着土层加深,有机质含量减少,放线菌数量亦相应降低。该区放线菌种类较复杂,共分离到10个属,其中链霉菌属占绝对优势。链霉菌属分离到11个类群,以白孢类群、灰褐类群和粉红孢类群为主。供试菌株抗病原真菌强于细菌,抗革兰氏阳性细菌强于抗革兰氏阴性细菌。[结论]珠穆朗玛峰自然保护区土壤蕴含着种类和拮抗活性丰富的放线菌,可进一步用于生物农药的开发利用。

[Objective]In order to explore the ecological distribution and antibacterial activity of soil actinomycete in Everest Nature Reserve,which could also provide microbial resources to screen new drug lead compounds.[Methods] Soil actinomyces of Everest Nature Reserve were isolated and antagonistic determination by dilution method of slab and Agar-agar method.[Results]The number of actinomycetes distribution was significantly different in different vegetation types in Everest Nature Reserve.Farmland soil contained a greater number of actinomyces,the soil of plantations and the original forest soil contained the least amount.In the same soil profile,the number of the actinomyces on the layer of litter was the greatest,the deeper the soil,the less the organic matter and the fewer the number of actinomyces.The soil actinomycetes flora were complex and 10 genera were found.Streptomyces occupied an absolutely dominant position,and could be classified into 11 groups,Albacores,Griseofuscus and Roseosporus were dominant groups.Determination of antagonistic actinomycetes illustrated that the tested strains had stronger antimicrobal activity against fungi than bacteria,had stronger antimicrobal activity against Gram positive bacteria than Gram-negative bacteria in Everest Natural Reserver.[Conclusion]Everest Nature Reserve implied rich and strong antagonistic activity of actinomycetes.The strains showed high antimicrobial activities,and could be further researched for exploiting new compounds of pharmaceutical.