A Study On Resource And Application Of Soil Actinomycetes From Southeastern Of Xizang

Fifty soil samples were obtained from Tibet southeast as Linzhi, SeJila mountain, Milin, Gong Bu-jiang-da and Mila mountain. These samples from different vegetation and altitude represented different geographic environments such as Primeva forests, alpine meadow, marsh, field, secondary forest, Wasteland and Farmland meadow. Mesothermal and Psychrophilic actinomycetes isolated based on multiple cultural media were studied their properties, for example, the quantity, composition, chemophysiology and antimicrobial activity and so on. All of these actinomycetes were identified to genus and stretomyces were identified to group based on the morphological characters. Several high antagonism strains were selected for further tests such as pathogenic mechanism, the optimal fermentation condition, greenhouse trial, identifications and the width of antagonisms. We found that: first, the soil actinomycetes from Tibet southeast showed that 564 isolations based on the 5 kinds of cultural media can be identified to genus. The number of mesothermal actinomycetes on gause's synthetic agar is more than on glycerol arginine agar, and Psychrophilic actinomycetes on soil extraction agar is more than glucose asparagine agar. The number of mesothermal actinomycetes were successively down on fieldland, Wasteland, secondary forest, dependency, Primeva forests ,agrarian meadow, sub-alpine meadow, marsh and alpine meadow, the number of colonies in each geographic environments as mentioned above were 1553.1×10~3,1479×10~3,1473.3×10~3,820.0×10~3,537.7×10~3,184.3×10~3,19.5×10~3,9.0×10~3, and 4.8×10~3 per gram soil respectively.Second, these actinomycetes from Tibet southeast soil were attributed to nine genus as Stretomyces,Norcardia, etc. the actinomycetes were affluent most in field, whose kinds can reach 7, and there were just 2 kinds of genus in agrarian meadow. Actinosynnema which was from in field was first reported in the home. The isolations attributed to different 12 groups of streptomyces in each Sampling area, Griseorubroviolaceus and Albosporu were dominant, the streptomyces sp. were accounted for 90.5% in whole actinomycetes isolations. The result of physiological and biochemical characteristics indicated that 58.7% of mesothermal actinomycetes could use Gelatin liquefaction and 72.0% of mesothermal actinomycetes could produce Milk-clotting enzyme, these isolations did not had much starch and casein hydrolysis ability, which were 22.7% and 25.3% individually.