The Study Of Isolation And Identification And Diversity Of Guizhou Karst Soil Actinomyces

Guizhou,the East Asia Karst area center,is one of the world's three largest concentration areas in Karst.Microorganisms,the most active part of the soil,are the main promoters of energy flow and material circulation in the ecosystem.Actinomycetes are mainly found in soil,and actinomycetes can produce a large number of biologically active secondary metabolites,Therefore,it is very important value to the study the actinomycetes in soil.The data of actinomycetes in Guizhou karst soil is still very limited,urgent need for in-depth study.This study used different separation methods to isolate and identify actinomycetes from 8 area,including Guizhou Wanfenglin National Geological Park,Caohai National Nature Reserve,Shuanghe Cave National Geological Park.The diversity of actinomycetes was also studied,and then the antibacterial activity of the isolated strains was test.The results are as follows:1.Four different pretreatmen ways were introduced to deal with 106 soil samples,in which,the microwave drying method was the best.Finally,76 strains of actinomycetes were obtained.2.Nine kinds of different culture mediums were carried out to isolate actinomycetes,Medium LNMS got the highest actinomycetes number of 5.2×105 Cfu/g;while Oat agar got the most actinomycetes species number with 8 kinds.3.Among different areas and different vegetation types,the number of actinomycetes isolated from cultivated land was the highest with 4.65×105 Cfu/g.4.Among different habitats,the proportion of actinomycetes isolated from soil in the Slopes in Caohai,the forests in Huangguoshu and the cave in Shuanghe Cave were above 65%,In a small ecological environment,the proportion of actinomycetes species in the Mizobe was 49%.The maximum proportion of actinomycetes in the caves was 76%.5.At high altitude of 2400 m,the number of actinomycetes were decreased,but the number of rare actinomycetes were increased,such as,Rothia,Nocardiopsis etc.6.The antimicrobial activity of actinomycetes was determined by filter paper method.There were 10 strains of actinomycetes against Escherichia coli and Staphylococcus aureus,with the inhibitory diameter more than 10 mm.In which,3 strains showed the best results with the inhibitory diameter of more than 14 mm against Staphylococcus aureus.There were 12 strains showed antagonist to fungi,and then using the growth rate method.And all the strains exhibited obvious inhibitory effect against 2 kinds of fungi at least.The results showed that the strains of C1 and E4 had good inhibitory effect on bacteria and fungi,and had the prospect of further development.7.Comprehensive analysis of the morphological characteristics,culture characteristics and 16 S rDNA sequence of the strain,the strains with good antagonistic ability 1030,1051,1112,1095,and so on,can be classified into streptomyces.