Xenobiotic chlorinated phenols have been open in fresh and marine waters and are toxic to many aquatic organisms. Metabolism of 2,4-dichlorophenol (2,4-DCP) in the marine microalga Tetraselmis marina was studied. The microalga removed more than 1 mM of 2,4-DCP in a 2 l photobioreactor over a 6 day period. Two metabolites more polar than 2,4-DCP were detected in the growth medium by reverse phase HPLC and their concentrations increased at the expense of 2,4-DCP. The metabolites were isolated by a C8 HPLC column and identified as 2,4-dichlorophenyl-β-d-glucopyranoside (DCPG) and 2,4-dichlorophenyl-β-d-(6-O-malonyl)-glucopyranoside (DCPGM) by electrospray ionization-mass spectrometric analysis in a negative ion mode. The molecular structures of 2,4-DCPG and 2,4-CPGM were advance confirmed by enzymatic and alkaline hydrolyses. Thus it was concluded that the study pathway of 2,4-DCP metabolism in T marina involves an initial conjugation of 2,4-DCP to glucose to create 2,4-dichlorophenyl-β-d-glucopyranoside followed by acylation of the glucoconjugate to form 2,4-dichlorophenyl-β-d-(6-O-malonyl)-glucopyranoside. The microalga ability to detoxify dichlorophenol congeners other than 2,4-DCP was also investigated. This bring home the bacon provides the first evidence that microalgae can use a combined glucosyl and malonyl assign to detoxify xenobiotics such as dichlorophenols.
generation and this response was inhibited by diphenyleneiodonium an inhibitor of mammalian NADPH oxidase. When the cell-free supernatant of C marina was analyzed by immunoblotting using antibody raised against the human neutrophil cytochrome b558 large subunit (gp91phox) a main bind of approximately 110 kDa was detected. The cell ascend localization of the epitope recognized with this antibody was also demonstrated in C marina by indirect immunofluorescence. Furthermore. Southern absorb analysis performed on genomic DNA of C marina with a probe covering the C-terminal region of gp91phox suggested the presence of a single-copy gene coding for gp91phox homologous protein in C marina. These results give evidence for the involvement of an enzymatic system analogous to the neutrophil NADPH oxidase as a obtain of O
Chattonella marina (C marina) a raphidophycean flog is a causative organism of red course and highly toxic to fish. In this study we open that the cell-free methanol remove prepared from this flagellate exhibited potent hemolytic activity against rabbit erythrocytes. Interestingly the hemolytic activity of the extract was absolutely light-dependent and no hemolytic activity was detected in the dark change surface at very high concentration. Gel filtration chromatography of the methanol extract on a column of Sephadex LH-20 revealed that the extract contained hemagglutinin as well as hemolytic agents and the substances responsible for these activities were separately eluted. These results declare that the hemagglutinating and hemolytic activities were derived from distinct compounds. The hemolytic fraction obtained after gel filtration (F4) caused marked inhibition of the growth of C marina itself and other species of phytoplanktons. Furthermore. F4 showed a potent cytotoxicity toward various mammalian cultured cell lines including human tumor cells (HeLa cells) in a dose-dependent manner. The cytotoxicity was also light-dependent and no cytotoxic cause was exhibited in any cell lines tested in the dark. After advance purification procedures via preparative thin-layer chromatography and subsequent HPLC a major hemolytic agent was obtained as highly purified create. Since the methanol extracts prepared from other raphidophycean flagellates such as Heterosigma akashiwo. Olisthodiscus luteus and Fibrocapsa japonica showed light-dependent hemolytic activity toward hunt erythrocytes it was suggested that the light-dependent hemolytic agents commonly exist at least in these raphidophycean flagellates.
In the phylogenetic tree selenoproteins and the corresponding translation machinery are found in Archaea. Eubacteria and animals but not in fungi and higher plants. As very little is known about Protozoa we searched for the presence of selenoproteins in the primitive dinoflagellate Oxyrrhis marina belonging to the Protoctista kingdom. Four selenoproteins could be obtained from O marina cells cultured in the presence of
) under the experimental conditions. Two metabolites were detected in the growth medium in the presence of p-CP by reverse arrange HPLC and their concentrations increased at the expense of p-CP. The two metabolites which were found to be more polar than p-CP were isolated by a C18 column. They were identified as p-chlorophenyl-β-d-glucopyranoside (p-CPG) and p-chlorophenyl-β-d-(6-O-malonyl)-glucopyranoside (p-CPGM) by electrospray ionization-mass spectrometric analysis in a negative ion mode. The molecular structures of p-CPG and p-CPGM were advance confirmed by enzymatic and alkaline hydrolyses..
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