| Deep-sea environment, accounting for 49% of the Earth's surface, is considered the present species of the planet's most resource-rich areas. Deep-sea micro-organisms live in the high-pressure, low temperature (some regions in high-temperature such as hydrothermal mouth), anaerobic, extreme pH, high salt concentration, high metal concentrations, no light, oligotrophic, high-halogen and other special extreme enviroment. Because of its environment specificity, deep-sea microbes have some specific metabolic pathways and genetic background, their secondary metabolites have peculiar, novel chemical structures, and diverse characteristics. Special structure of natural products are very important to enhance drugs'specificity and effectiveness, reduce drugs'side effects, prevent drugs'resistance, they also have important scientific significance on lead compounds discovery and drug study of new targets, new mechanism.Since the 60s'20th century, the concern in the development of marine natural products is growing,961 new compounds were isolated from marine in 2007, there was an increase of 24% from the number of compounds reported for 2006. Marine microbial natural products development became a hot spot, its growth rate is much higher than sponge which was the most large part of marine natural compounds. In 2007 the number of compounds from marine organisms got five-fold increase to the average number from 1965 to 2005, above 60% increase to 2006.In our study,deep sea sedimental samples collected by the 20th voyage of Chinese Ocean No.1 ship were used to isolate and identify deep sea originated fungus and 110 strains have been obtained. These strains belonged to 15 genus,50% of them,55 stains, are Penicillium or Aspergillus. These 55 stains just belonged to 10 different species. Antitumor and antibacterial activity analysis of second metabolites of 100 fungi were performed by CCK-8 method and agar diffusion method. Results showed that deep sea originated fungi possess good antitumor and antibacterial activity,49% strains indicate cytotoxical activities,26% stains showed significant anti Escherichia coli activities and 32% against Bacillus subtilis,5% against Candida albicans,21% inhibited Staphlococcus aureus growth. the bioactivity related to culture medium and tumor cell type. HPLC analysis of 20 fungus second metabolism product fingerprints indicated map changes with culture medium. These results could be useful to next isolation of bioactive compounds from deep sea originated fungus second metabolism product.The deep-sea bacterium Shewanella piezotolerans WP3 and Shewanella psychrophila WP2 used in this study was isolated from deep-sea sediments of 1914m depth in west Pacific. Cytotoxic activity analysis of second metabolism products of them were detected through CCK-8 method. Study on impacts of temperature, pressure and phage on cytotoxic activity of Shewanella piezotolerans WP3 second metabolism product were also conducted. Results showed that Shewanella piezotolerans wp3 second metabolism product had strong cytotoxic activity to tumor cells, and low temperature could enhance this activity. Pressure could reduce cytotoxic activity at most optimal temperature and had almost no effect on this activity at low temperature on the contrary. Meanwhile, phage had no effect on cytotoxic activity. HPLC analysis of Shewanella piezotolerans WP3 second metabolism product fingerprints indicated map changes at different temperature.Based on the analysis of cytotoxic activity, by chromatographic separation, mass spectrometry, nuclear magnetic resonance technology, two compounds of wp3 fermentation extract have been isolated and identified, but the two compounds showed no cytotoxic activity, further work will focus on the active compound isolation of WP3 secondary metabolites to explore the possible relationship between the compounds and the environmental adaptability of WP3. |
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