A Study On Resources And Application Of Soil Actinomycetes From The Eastern Part Of Qinghai Plateau

Qinghai province is located on "the roof of the world" 桻inghai-Tibet Plateau. It' s elevation is very high, and it' s ecological conditions are complicated and distinctive, which decide the unique characteristics of the actinomycete resources in Qinghai. Huangshui Valley located in the east of Qinghai is a miniature of the Qinghai unique ecological environment. In this paper, the actinomycete resources in soil samples were studied systematically by normal methods. The soil samples were collected from Ledu county, Ping' an county, Huzu county, Datong county, Xi' ning city, Huangzhong county, Huangyuan county and Haiyan county. The results were followed.1. The quantity, population and ecological distribution of actinomycetes. More than 1000 strains of actinomycetes in the samples were isolated by spreading the samples on two kinds of agar media. Isolates were identified to genus by domestic conventional procedures(Streptomyces to kind).The results indicated that:㏕he quantity of soil actinomycetes was influenced by several factors. It decreased as elevation of sampling site increased or depth of soil layer deepened, increased as the value of pH increased in 6. 90~8. 62 or the content of organic matters or available nutrients of the soil samples increased, and changed as plant or crop was different. 〢ctinomycete populaion in the vegetable field soil was relatively complex ,and strains tested were classified into eight genera. Streptomyces was the main genus (It* s average percentage was 91. 6%), followed by Micromonospora , Actinomadura and Nocardia. Streptomyces could be classified into 13 kinds, and Aureus(43. 1%), Albosporus(22. 5%) and Griseofucus(16. 5%) occupied the dominant position.Actinomycete population in protectorate field soil(The strains were classified into seven genera) was more complex than opencast field one (The strains were classified into five genera). The composition of Streptomyces in protectorate field was different from opencast field. 〢ctinomycete population in the grain field soil was more simple than vegetable field one. The strains were classified into five genera, and Streptomyces was also the main genus(average 84.5%), followed by Micromonospora , Nocardia and Actinomadura. Streptomyces could be classified into 13 kinds, and Albosporus (34. 3%), Aureus(21. 9%) and Griseofucus(16. 5%) were the main kinds. Actinomycete population in water field (Five genera were isolated) was more complex than the one of dry field (Only four genera were isolated). Streptomyces population in water field,was slightly different from the one in dry field. (4) Accord ing to the type of soil .plant and climate, The composition of actinomycetes in the natural soil samples could be classified into several types as followed: sierozem, castanozem, chernozem, sylvogenic soil, marshy soil, alpine meadow soil, eolian sand soil and salinesoil. Micromonospora was the main genus(53.5%) in the marshy soil, followed by Streptomyces. Streptomyces was the main genus in other soil, and it' s percentage changed from 79.8% to 90.4%. Albosporus, Aureus and Griseofucus were the main kinds of Streptomyces in most natural soil, and few ones' main kinds were Flavus and Griseorubroviolaceus. 〢ctinomycete population was different by different plant or crop. In the four tested crops, actinomycete population in wheat field was more complex than in potato field. In addition, actinomycete population was more and more simple as the depth of the soil layer deepened.2. Study on actinomycetes in saline soil and in salt lake. The actinomycetes in the water, the swamp soil and the lakeside soil of Qinghai Lake and in the salinizating wasteland soil nearby Qinghai Lake were isolated by spreading the samples on three kinds of agar media, in which the content of NaCl was 7%. Isolated were identified by normal methods, and their saline resistance were measured. The results indicated that:(1)There were saline resisting actinomycetes under medium temperature and low temperature culture conditions in swamp soil and lakeside soil of Qinghai...