| Since penicillin was found by Flemming, more than 350 kinds of antibiotics were used in clinical application, which made many infectious diseases under control; however, with the wide application of antibiotics and the development of bacterial drug resistance, looking for new antibiotics becomes more and more important. Marine microorganism, for their special survival environment, high pressure, high salinity, low temperature and lack of oxygen, developed the unique metabolic ways, which made them become an important resource of marine bioactive substances and new antibiotics that have the new special structure, compared with the terrestrial microorganism, and be capable of antibacterial, antitumor and antivirus. Antibacterial test were carried on the 196 strains of marine bacterium,34 strains of marine Actinomycetes and 22 strains of marine Fungi isolated from seawater , sea mud , sponge, kelp and several fish intestinal from Zhoushan coastal by double agar plate method and filter paper method. Strain NF19,a1,X6,X7,B2,B5 were screened for their good inhibition Identified by the 16S rRNA and physiology and biochemistry features, the strain NF19 belongs to L.salivarius of lactobacillus, the strain a1,X6 belong to Streptomyces roseus of Streptomyces, the strain B2,B5 belong to Streptomyces sp., the strain X7 belongs to Streptomyces roseofulvus of Streptomyces.Fermentation condition research shows the best cultivation coditions of strain NF19 are 50ml medium in 250ml shaken flask,rotary rate 120rpm, 25℃,pH7.2,inoculation doses per cent 8, up to 48h,and the best cultivation coditions of strain a1,X6,X7,B2,B5 are 50ml medium in 250ml shaken flask, rotary rate 120rpm, 25℃,pH7.0, inoculation doses per cent 2,up to 96h. Analysis of salt tolerance shows the best inhibitory effect of strain X6 is at 5% of the sodium chloride concentration,another five strains is at 3% of the sodium chloride concentration.
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