Screening And Characterization On Marine Actinomycetes

Ocean Marine actinomycetes have its unique metabolic pathway and can synthesize some new antibiotics in the special environment. So the study on Marine actinomycetes is very importment for the production of new physiological active compounds. In this paper ocean actinomycetes were separated and screened from sea water and muds of Dalian coast. The ocean actinomycetes were also classified. Their fermentation conditions which produce antibacterial activities were also optimized. The main conclusions are as follows:1.33actinomycetes strains were isolated from acquisition samples of dalian Xinghaiwan,Heishijiao, Xiajiahezi area,and showed sea mud contained rich actinomycetes resources.2. The33actinomycete strains were described from morphological characteristics, and identified with the reference of Bergey’s Manual of Systemaic Bacteriology; the33strains were basicly thought to be actinomycete Streptomyces.3. The33strains were first screened by agar drilling method. Seven strains were found which can produce antimicrobial active substances, and three strains D09, D25, D30had the broad-spectrum antimicrobial activity, the D09was the most significant.The seven actinomycete strains of D09, D10, D12, D19, D25, D30and D31which had the bacteriostatic effect were also tested by physiological and biochemical characteristics.4. The fermentation condition was optimized and the best carbon source was soluble starch, the best nitrogen source was potassium nitrate. The fermentation formula which set up by orthogonal test was soluble starch15g/L, KNO31g/L, K2HPO4·H2O0.25g/L, MgSO4·7H2O0.25g/L. The best fermentation conditions producing antibacterial activity substancefor D09were that the optimal initial pH value for7, bacteria age for48h, inoculated quantity for10%, culture at25℃and sample loading capacity of10%.