Screening And Identification On The Microorganism With Potential Applications From The East Sea

Since the specific living environment, marine microorganisms have unique heredity background and metabolite pathways, and synthesize some distinct antibiotics in structures. Therefor it has significance for antibiotics screening from marine microorganism. And the marine microorganisms have attracted considerable attention because of chemical unique, rich physiological properties and thus potential as important drugs of their metabolites.Many kinds of samples, including 14 seawater samples and 10 sea mud samples were collected from East Sea from Longitude 120°to 123°, North latitude 28°to 31°.the depth of the sea mud samples is 20m to 260m.the depth of the seawater samples is 2m to 5m. It is greatly influenced by the composition of medium and culture condition on the production of the metabolites with antimicrobial activity and the growth of marine microorganism.1260 strains marine bacteria were isolated from the seawater,.1151 strains marine bacteria and 168 strains marine fungi were isolated from the sea mud.The isolated bacteria is identified through morphological, physiological and biochemical experiment and no.19 for seawater samples and no.76 for sea mud samples,16S rRNA sequence analysis and phylogenetic analysis.for assessing the microbial species diversity of-the East China Sea.16S rRNA sequence analysis for 95 marine bacteria show that the most of bacteria isolate from seawater samples are Halomonas yet belong to different race. the bacteria isolate from sea mud have different species,they belong to 14 species icluding Bacillus(47),Halomona(5), Brevibacterium(3),Shewanella(3),Pseudomonas(4),Pantoea(1),Dietzia(1),Planococcus(1),Marinib acillus(2), Sphingopyxis(1), Salegentibacter(2), Roseobacter(3), Flexibacter(2), Hoeflea(1).47 of them are Bacillus, accounted for 62%. Inferring that Bacillus is the main species in sea mud from the East China Sea.there are 14 race in the 47 Bacillus, Inferring that the diversity and richness of species of Bacillus in sea mud of the East China Sea.Their antibiotic activities against six microorganisms(Bacillus subtilis,Staphylococcus aureus,Escherichia coli,Pseudomonas aeruginose,Enterobacter aerogenes,Candida albicans) from 95 marine bacteria were assayed by Agar block method and Oxford Cup method. The results show that two of them have antibiotic activities against Staphylococcus aureu,one of them have antibiotic activities against Bacillus subtilis.In this study, a pair of degenerate oligonucleotide primers, disigned for amplification A domain in NRPSs, had been employed to screen NRPSs gene fragments from the bacteria isolate from the East China Sea. Our purpose was to develop a method to access NRPSs gene diversity in sea and get 3 bacteria could amplified A domain This would open up the possibilities of the secondary metabolites and as the basis for a search for attractive antibiotic biosynthesis genes that could be used in the heterogenous expression and combinatorial biosynthesis. Furthermore, the amplified NRPSs gene fragments can also be used as homologous hybridization probes to detect the clones harbored NRPSs gene clusters.