[Studies on actinomycete flora and resources in the plateau lakes in Yunnan]

During the period of 1983 to 1987 mud and water samples were collected from 12 larger lakes on the Yunnan Plateau. The actinomycetes in both sediment and water samples were investigated. Strains producing metabolites were screened by various procedures. The results are as follow: 1. The number and composition of actinomycetes in a lake were found to have relation to the physical and chemical features of the water-body. On the basis of the number and generic diversity of actinomycetes, lakes were thus divided into four groups. 2. Micromonospora occupied a notable domonance in benthic samples taken from all 12 lakes. This is a conspicuous characteristics of actinomycete flora in these lakes. 3. The population of actinomycetes in Lakes Qilu, Yilong and Datun ranges from 2991 to 3542 X 10(3)/g dry wt. of mud. 4. Strains of Actinomadura, Microtetraspora, Micropolyspora, Saccharomonospora and Saccharopolyspora were isolated. These genera were not previously reported in similar studies abroad. In addition, five species were considered to be new to science: Micromonospora phaeovirida Jiang et Xu, 1985 Saccharomonospora yunnanensis Jiang et Xu, 1985 Microtetraspora flavorosea Jiang et Xu, 1986 Actinomadura chenghaiensis Jiang et Xu, 1986 Actinomadura viridoflava Jiang et Xu, 1986 5. Studies indicate that actinomycetes possibly play an important role in the decomposition of chitin, cellulose and some toxic substances in lakes. 6. As freshwater resources, actinomycetes produce various useful metabolites such as fibrinolysine, and milk-clotting enzyme.