Prodigiosin-like pigment를 생산하는 해양유래미생물 Zooshikella sp. JE-34의 분리 동정 및 이차대사산물의 생리활성 탐색

Abstract

In last decades marine organisms caught great interest from pharmaceutical companies as sources for noble compounds. Despite its relatively short history, structures of over 5,500 novel secondary metabolites have been determined, of which ca 40 compounds revealed as agriculturally and pharmaceutically active compound. A bacterial strain producing a high concentration of red pigment isolated from sediment that had been collected East China Sea, Which was recorded as JE-34. It was identified as Zooshikella sp. JE-34 as based on the biochemical properties, cellular fatty acids analysis and 16S rRNA gene sequence. The strains were Gram-negative, chemo-organotrophic, aerobic and required NaCl (0.5?8 %) for growth.and major isoprenoid quinone was ubiquinone-9. The predominant cellular fatty acids were saturated and monounsaturated straight-chain fatty acids. The pigment showed characteristics similar to prodigiosin, as it is insoluble in water and has a red colour with a metallic green sheen. Prodigiosin has been reported to be deposited in the cell envelope and not released into the medium; in addition, in its amorphous state it has an appearance of red platelets with a green metallic sheen, and a maximum absorption of 535-540 nm. To date, prodigiosin and its analogues which have been shown to have anticancer, cytotoxic and immunosuppressive activities have been isolated from Serratia marcescens, Psedomonas and Streptomyces species, and chemically synthesized. Nutritional and cultural conditions for the production of prodigiosin-like pigment by this organism under shake-flask conditions have optimized. Similary initial medium pH 6.0, incubation time 4days were found to be optimal. The optimal conditions for the production of prodigiosin-like pigment for carbon, organic and inorganic nitrogen sources were soluble starch and malt extract. The radical scavenging activities of the extracts from Zooshikella sp. JE-34 cell (ZC) and culture broth(ZB) according to extraction solvents and fractions on hydroxyl, alkyl and DPPH radical were investigated using a ESR spectrophotometer and compared with the ESR signal intensity. The extracts exhibited strong scavenging activity on hydroxyl, alkyl and DPPH radical, and the activity increased with increment of concentration of the extracts. The electron donating abilities (EDAs) of ZC acetone extract (ZCAE) and ZC ether soluble fraction (ZCfr.E) were 95.74% and 94.51% at 0.5㎎/㎖ respectively. The hydroxyl radical scavenging ability of the ZC hot water extract (ZC70E) was highest (59.08% at 1㎎/㎖), and alkyl radical scavenging ability was highest in the ZC water extract (84.05% at 1㎎/㎖). From these results, ZC extracts and fractions had strong antioxidant activities. This study was investigated the antimicrobial activity of the culture broth(ZB), and bacterial cell(ZC). ZC and ZB extracts according to extraction solvents and fractions. The antimicrobial activities of ZC and ZB extracts was tested against 18 microorganisms which were fish and human pathogens bacterial species. The extracts showed high activity against Streptococcus iniae, Streptococcus parauberis, Staphylococcus aureus, Propionibacterium acnes, Streptococcus mutans and had poor effect on Serratia marcescens, Proteus mirabilis. Among the various solvent layers, the ZC methanol extraction (ZCME) and ZC diethyl ether soluble fraction (ZCfr.E) showed strong antimicrobial activities.