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At least 73 records · Page 4Linked to original sources

PubMed2003

Anti-oxidant activities of fucosterol from the marine algae Pelvetia siliquosa.

The anti-oxidant activities of fucosterol isolated from the marine algae Pelvetia siliquosa were investigated. Fucosterol exhibited a significant decrease in serum transaminase activities elevated by hepatic damage induced by CCl4-intoxication in rats. Fucosterol inhibited the sGOT and sGPT activities by 25.57 and 63.16%, respectively. Fucosterol showed the increase in the anti-oxidant enzymes such as hepatic cytosolic superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-px) activities by 33.89, 21.56 and 39.24%, respectively, in CCl4-intoxicated rats. These results suggest that fucosterol possess not only the anti-oxidant, but also the hepatoprotective activities in rats.

Administration, Oral↗

PubMed2005

Proteomic analysis of cadmium-induced protein profile alterations from marine alga Nannochloropsis oculata.

Protein profile alterations following exposure to cadmium were examined in marine alga Nannochloropsis oculata through proteomic analysis. Alterations of the protein expression patterns following 10 muM cadmium treatment were analyzed on 2-dimensional gels. Out of 380 protein spots detected on 2-D gel using Coomassie staining, 11 spots were changed significantly following cadmium treatment. Because of the non-availability of molecular background information on this non-sequenced algal species, cross-species protein identification through ESI-Q-TOF MS/MS was used to identify altered proteins. Two newly induced proteins were identified as malate dehydrogenase orthologue and NADH dehydrogenase orthologue. One suppressed protein was identified to be glyceraldehydes 3-phosphate dehydrogenase A. Protein spot showing a 3-fold increase was identified as mitochondrial NADH: ubiquinone oxidoreductase orthologue. However, we could not find any matches in the database from ESI-Q-TOF MS/MS for the remaining seven proteins, thus only partial peptide sequences of these proteins were found.

Amino Acid Sequence↗

PubMed2002

Removal and recovery of lead using nonliving biomass of marine algae.

Batch equilibrium sorption experiments were used for screening for cost-effective marine algal biomass harvested from the Gulf of Persian. Biosorption of lead by eight brown, green and red marine algae was investigated. Biosorption of lead was rapidly occurred onto algal biosorbents and most of the sorbed metal was bound in <30 min of contact. Three species of brown algae, namely Sargassum hystrix, S. natans and Padina pavonia, removed lead most efficiently from aqueous solution, respectively. The applicability of the Langmuir and Freundlich models for the different biosorbents was tested. An increasing uptake of the metal by biosorbents with increasing pH was demonstrated. Desorption of the adsorbed lead on biosorbent was conducted by decreasing the pH values to lower than 1.0. Removal of lead from Sargassum biomass was successfully achieved by eluting with 0.1M HNO3 for 15 min and a high degree of metal recovery was observed (95%). For optimum operation in the subsequent metal uptake cycle, regeneration of the Sargassum biomass was efficiently performed by 0.1M CaCl2 for 15 min that was total and reversible. In repeated use of biomass experiment, the lead uptake capacity of Sargassum biomass was constantly retained (98%) and no significant biomass damage took place after 10 sorption-desorption cycles.

Adsorption↗

PubMed1994

Cloning, sequencing and expression of dinoflagellate luciferase DNA from a marine alga, Gonyaulax polyedra.

The marine dinoflagellate, Gonyaulax polyedra emits light in a reaction involving the enzymatic oxidation of its tetrapyrrole luciferin by molecular oxygen; its luciferase (LCF) single chain has an estimated molecular mass of 130 kDa, and exhibits a circadian rhythm in its activity. A cDNA expression library in the lambda ZAPII vector was constructed from the polyadenylated RNA isolated from the Gonyaulax cells during the early night phase, the time at which LCF synthesis is believed to be greatest. Of the approx. 1.2 . 10(5) phages from the library screened with antibody against Gonyaulax LCF, 13 positive plaques were obtained. The nucleotide sequences of two of the larger inserts (2.4 kb and 1.6 kb in length), both carrying the poly(A) tail, were determined and found to be identical in the overlapping region. When expressed in Escherichia coli, both cDNA clones produced active luciferase. A Northern hybridization using the cDNA as a probe showed that the length of the lcf mRNA is approx. 4.1 kb, sufficiently long to encode the 130 kDa LCF. Analyses of polymerase chain reaction products, prepared using both the cloned cDNA and Gonyaulax chromosomal DNA as templates, indicated that the cloned region of the luciferase gene does not carry any introns. This represents the first dinoflagellate luciferase to be cloned and sequenced; its deduced amino acid sequence bears no significant homologies with that of any other luciferase, or any other sequence in the data base.

Amino Acid Sequence↗

PubMed2002

Cloning and characterization of an active fragment of luciferase from a luminescent marine alga, Pyrocystis lunula.

Two marine dinoflagellates, Lingulodinium polyedrum and Pyrocystis lunula, emit light in a reaction involving the enzymatic oxidation of its tetrapyrrole luciferin by molecular oxygen. The characteristic properties of P. lunula luciferase have not been clarified, whereas L. polyedrum luciferase, which has three active domains, has been characterized. A cloned partial cDNA of the P. lunula luciferase encodes an active fragment corresponding to part of domain 2 and all of domain 3 of L. polyedrum luciferase. The homology of the amino acid sequence between the two luciferases in domain 3 is about 84.3%. A recombinant His-tagged luciferase fragment containing domain 3 (Mr = 46 kDa) catalyzed the light-emitting oxidation of luciferin (lambdamax = 474 nm). This protein was purified by a single affinity-chromatography procedure. The pH-activity profile and the bioluminescence spectrum of the recombinant enzyme having a third domain are almost identical to those of an extract from P. lunula cultured in vitro. The recombinant enzyme is active at pH 8.0, although the recombinant enzyme derived from the second domain of L. polyedrum luciferase is inactive at pH 8.0. Substitution of Glu-201 by histidine in the third domain of P. lunula luciferase showed a decrease of activity above pH 7.0, suggesting that histidine residues could be responsible for pH-sensitivity in dinoflagellate luciferase.

Amino Acid Sequence↗

PubMed2000

Inhibition of the development of microorganisms (bacteria and fungi) by extracts of marine algae from Brittany, France.

The inhibitory effects of aqueous, ethanolic and dichloromethane fractions from 16 marine algae from the Atlantic shores of North-East Brittany, France, have been investigated against microorganisms frequently associated with immersed surfaces. The extracts were tested in vitro against isolates of marine fungi, bacteria and yeasts potentially involved at different stages in the formation of biofilms in the sea. The high levels of inhibitory activity of nine extracts against marine fungi and Gram-positive bacteria and their apparent absence of toxicity against larvae of oysters and sea urchins suggests a potential for novel active ingredients.

Animals↗

PubMed2003

Lysis of methicillin-resistant Staphylococcus aureus by 2,4-diacetylphloroglucinol produced by Pseudomonas sp. AMSN isolated from a marine alga.

Previously 2,4-diacetylphloroglucinol (DAPG) produced by Pseudomonas sp. AMSN isolated from a marine alga, had demonstrated a high level of anti-methicillin-resistant Staphylococcus aureus (MRSA) comparable with that of vancomycin. In this study, this substance had bacteriolytic activity against MRSA at 1 microg/ml as well as similar activity against Vibrio parahaemolyticus at 24 microg/ml that suggests a novel antibacterial mode of action by this substance. Heat and pH stability tests showed it to be stable at temperatures ranging from 35 to 70 degrees C and at pHs ranging from 2-7. It was not acutely toxic to mice at levels up to 100 mg/kg.

Bacteriolysis↗

PubMed2005

First report on the detection and quantification of arsenobetaine in extracts of marine algae using HPLC-ES-MS/MS.

The detection of arsenobetaine in extracts of marine algae is reported here for the first time. The application of liquid chromatography coupled online with electrospray tandem mass spectrometry in the selected reaction monitoring mode provided improved performance for the detection of low amounts of arsenobetaine in the presence of high amounts of arsenosugars.

Arsenicals↗

PubMed1995

Partial Purification of a Na+ -ATPase from the Plasma Membrane of the Marine Alga Heterosigma akashiwo.

A Na+ -ATPase was partially purified from plasma membranes of the marine alga Heterosigma akashiwo. The plasma membranes of H. akashiwo cells were collected by differential centrifugation with subsequent discontinuous gradient centrifugation. Na+ -ATPase activity was associated with the resultant plasma membrane fraction and was stimulated to the greatest extent in the presence of 100 to 200 mM Na+, 10 mM K+, and 5 mM Mg2+ ions, pH 8.0. The Km value for Na+ ions was 12.2 mM. An apparent Km value for ATP was 880 [mu]M. A 140-kD phosphorylated intermediate was also detected in the same fraction in the presence of both Mg2+ and Na+ ions, and this protein was dephosphorylated upon the addition of K+ ions. We could partially purify the 140-kD protein after solubilization by Suc monolaurate and fractionation by sequential column chromatography on Sephacryl S-300, DEAE-Sepharose CL-6B, and Mono-Q columns. The purified 140-kD polypeptide could also be phosphorylated and be detected after acid sodium dodecyl sulfate-polyacryl-amide gel electrophoresis in the presence of Na+ and Mg2+ ions.

Journal Article↗

PubMed1991

Cytotoxic activity of marine algae and a cytotoxic principle of the brown alga Sargassum tortile.

Partition fractions of hexane, CCl4 and CHCl3 from methanolic extracts of marine algae were each examined for cytotoxic activities against cultured P-388 lymphocytic leukemia cells. Cytotoxic activities were found for partition fractions of 21 species of seaweed. Bioactivity-guided fractionation of the CCl4 partition fraction from Sargassum tortile, exhibiting the most prominent activity, afforded dihydroxysargaquinone (1) and sargatriol (2) previously isolated from this alga. The former was evaluated as a cytotoxic principle, and the latter, showing moderate activity, was suggested to be an artifact derived from 1 during the isolation procedure.

Animals↗

PubMed2007

Antinociceptive properties in mice of a lectin isolated from the marine alga Amansia multifida Lamouroux.

The antinociceptive effects of a lectin (LEC) isolated from the marine alga Amansia multifida were determined in Swiss mice. The LEC (1, 5, and 10 mg/kg) inhibited acetic acid-induced abdominal writhings in a dose-dependent manner after intraperitoneal or oral administration. A partial but significant inhibition of writhings was observed after the combination of LEC (10 mg/kg) with avidin (1 mg/kg), a potent inhibitor of the hemmaglutinant activity of the lectin. However, total writhing inhibition was demonstrable in the group of mice treated with LEC plus mannose (1 mg/kg), as compared to LEC alone or to control groups. Furthermore, avidin and mainly mannose also play a role in antinociception, somehow facilitating the interaction of LEC with its active cell sites. In the formalin test, although both phases of the response were significantly inhibited, the effect of LEC was predominant during phase 2, causing inhibition of licking time that ranged from 48 to 88% after oral (5 and 10 mg/kg) and intraperitoneal (1 to 5 mg/kg) administration. As is the case with morphine, the effect of LEC (2 mg/kg) was reversed by naloxone (2 mg/kg), indicating the involvement of the opioid system. LEC was also effective in the hot-plate test, producing inhibitory responses to the thermal stimulus, and its effects were blocked by naloxone. In the pentobarbital-induced sleeping time, although LEC did not alter the onset of sleep significantly, it increased the time of sleep within the same dose range compared to control. These results show that LEC presents antinociceptive effects of both central and peripheral origin, possibly involving the participation of the opioid system.

Analgesics↗

PubMed1995

Antibiotic activity of marine algae against multi-antibiotic resistant bacteria.

The antibiotic activity of six species of marine algae (Rhodophyta, Phaeophyta and Chlorophyta) against multi-antibiotic resistant (MAR) bacteria was investigated. The study shows that various degrees of activity were present in 18 out of the 24 algal extracts. The highest activity was for Rhodophyta (diameter of the inhibited zone ranged from 10-22 mm), whilst the lowest was for Chlorophyta (8-12 mm). The taxonomic trends were seen between extracts, as the best solvents were found to be ether, methanol and acetone for Rhodophyta, Phaeophyta and Chlorophyta, respectively. The importance of these results on public health are discussed.

Anti-Bacterial Agents↗

PubMed2003

Impact of hypoosmotic challenges on spongy architecture of the cytoplasm of the giant marine alga Valonia utricularis.

The ultrastructure of the several micrometers thick cytoplasmic layer of the giant marine alga Valonia utricularis displays characteristics which are apparently linked with the capability of this alga to regulate turgor pressure. Transmission and scanning electron microscopy of cells prefixed in different ways, including a protocol that allows prefixation of the alga in a turgescent state, revealed a highly dendritic network of cytoplasmic strands connecting and enveloping the chloroplasts and the nuclei. Innumerable vacuolar entities are embedded in the network, giving the cytoplasm a spongy appearance. Vacuolar perfusion of turgor-pressure-clamped cells with prefixation solution containing tannic acid presented evidence that these vacuolar entities together with the huge central vacuole form a large unstirred continuum. In contrast to the tonoplast, the plasmalemma followed smoothly the lining of the cell wall, even at the numerous cell wall ingrowths. Sucrose, but not polyethylene glycol 6000, induced chloroplast clustering. Acute hypoosmotic treatment (established by reduction of external NaCl or by replacement of part of the external NaCl by equivalent osmotic concentrations of sucrose or polyethylene glycol 6000) resulted in a local relocation of the chloroplasts and cytoplasm towards the central vacuole. This effect did not occur when the relatively low reflection coefficients of these two osmolytes were taken into account. The increase in spacing between the spongy cytoplasm and the plasmalemma by chloroplast relocation (viewed by confocal laser scanning microscopy) was associated with a speckled appearance of the affected surface area under the light microscope. As indicated by electron microscopy, hypoosmotically induced chloroplast relocation resulted from disproportionate swelling of the vacuolar entities located close to the plasmalemma. The cytoskeleton in the cytoplasm and the mucopolysaccharide network in the central vacuole apparently resisted swelling of these compartments. This finding has the important consequence that relevant hydrostatic pressure gradients can be built up throughout the entire multifolded vacuolar space. This gradient could represent the trigger for turgor pressure regulation which is manifested electrically first in the tonoplast.

Chlorophyta↗

PubMed2026

Vibrio phycocola sp. nov. and Vibrio phycohabitans sp. nov., Isolated from the Phycosphere of Marine Algae.

Two Gram-stain-negative, facultatively aerobic, oxidase- and catalase-positive, motile (by means of a polar flagellum) rod-shaped bacterial strains, designated BS-M-Sm-2T and MA40-2T, were isolated from marine algae. Growth was optimal at pH 7.0-8.0 and 2.0-3.0% (w/v) NaCl, with temperature optima of 25°C for BS-M-Sm-2T and 25-30°C for MA40-2T. Ubiquinone-8 was the sole respiratory quinone. The major fatty acids common to both strains were C16:0, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c), while BS-M-Sm-2T additionally contained C12:0 and C14:0. The predominant polar lipids were phosphatidylethanolamine and phosphatidylglycerol, with diphosphatidylglycerol also detected in strain MA40-2T. The DNA G+C contents of strains BS-M-Sm-2T and MA40-2T were 44.2 and 39.8 mol%, respectively. The 16S rRNA gene sequence similarity, average nucleotide identity (ANI), and digital DNA-DNA hybridization (dDDH) values between the two strains were 93.8%, 71.4%, and 23.2%, respectively. Phylogenetic and phylogenomic analyses placed both strains within the genus Vibrio, forming distinct lineages. Comparisons with closely related Vibrio type strains yielded ANI and dDDH values below 91.6% and 44.3%, respectively, further supporting their classification as novel species. Genome analyses revealed genes potentially involved in algal symbiosis, including those for polysaccharide degradation and vitamin biosynthesis. Based on comprehensive genomic, phylogenetic, phenotypic, and chemotaxonomic evidence, strains BS-M-Sm-2T and MA40-2T represent two novel species, for which the names Vibrio phycocola sp. nov. (BS-M-Sm-2T =KACC 24066T =DSM 119941T) and Vibrio phycohabitans sp. nov. (MA40-2T =KACC 24064T = DSM 119942T) are proposed.

RNA, Ribosomal, 16S↗

PubMed2002

Paraliobacillus ryukyuensis gen. nov., sp. nov., a new Gram-positive, slightly halophilic, extremely halotolerant, facultative anaerobe isolated from a decomposing marine alga.

A slightly halophilic, extremely halotolerant, alkaliphilic, and facultatively anaerobic rod bacterium was isolated from a decomposing marine alga collected in Okinawa, Japan. The isolate, designated O15-7(T), was Gram-positive, endospore-forming, catalase-positive, menaquinone-7-possessing bacterium that is motile by peritrichous flagella. The isolate was an inhabitant of marine environments; the optimum NaCl concentration for growth was 0.75-3.0% (w/v) with a range of 0-22.0%, and the optimum pH was 7.0-8.5 with a range of 5.5-9.5. Catalase was produced in aerobic cultivation but not in anaerobic cultivation. Carbohydrate, sugar alcohol or a related carbon compound was required for growth. In aerobic cultivation, the isolate produced pyruvate, acetate and CO(2) from glucose, and in anaerobic cultivation, it produced lactate, formate, acetate and ethanol with a molar ratio of approximately 2 : 1 : 1 for the last three products. No gas was produced anaerobically. Lactate yield per consumed glucose was markedly affected by the pH of the fermentation medium: 51% at pH 6.5 and 8% at pH 9.0. The cell-wall peptidoglycan contained meso-diaminopimelic acid. Phylogenetically, the isolate occupied an independent lineage within the group composed of the halophilic/halotolerant/alkaliphilic and/or alkalitolerant species in Bacillus rRNA group 1 with the highest 16S rRNA gene sequence similarity of 95.2% to the genus Gracilibacillus. For this isolate, Paraliobacillus ryukyuensis gen. nov., sp. nov. was proposed. The type strain, O15-7(T) (G+C535.6 mol%), has been deposited in the DSMZ, IAM, NBRC, and NRIC (DSM 15140(T)=IAM 15001(T)=NBRC 10001(T)=NRIC 0520(T)).

Bacteria, Anaerobic↗

PubMed2001

Cadmium(II) removal from aqueous solutions by pre-treated biomass of marine alga Padina sp.

In this study, the adsorption properties of a pre-treated biomass from marine alga Padina sp., a biomass collected from Surin Island, Thailand, for removal of cadmium(II) ions from aqueous solutions was investigated. Batch and column experiments were conducted to determine the adsorption properties of the modified biomass. At a pH of 5, the maximum removal capacity of the biomass is 0.53 mmol/g. The kinetics of cadmium(II) adsorption were fast with 90% of adsorption taking place within 35 min. This study demonstrated that the pre-treated biomass of Padina sp. could be used as an efficient biosorbent for the treatment of cadmium(II)-bearing wastewater streams.

Adsorption↗

PubMed2005

A CARD-FISH protocol for the identification and enumeration of epiphytic bacteria on marine algae.

A CARD-FISH protocol was developed and applied to analyse surface-associated bacteria on the marine algae Ulva lactuca, Delisea pulchra, Corallina officinalis, Amphiroa anceps, Porphyra sp. and Sargassum linearifolium. The combination of Alexa(546)-labelled tyramide as the reporter molecule with SYBR Green II counterstain allowed for superior detection of the hybridised probe fluorescence against plant tissue from which pigment autofluorescence has been reduced.

Bacteria↗

PubMed1999

Screening of lipase inhibitors from marine algae.

The possible presence of an inhibitor of pancreatic lipase (triacylglycerol acylhydrolase, EC 3.1.1.3) was screened in 54 marine algae. An active inhibitor, caulerpenyne, was purified from an extract of Caulerpa taxifolia, using ethyl acetate extraction, followed by successive chromatographies on ODS and silica gel columns. The purified inhibitor was identified by thin-layer chromatography, infrared and nuclear magnetic resonance spectroscopy. Caulerpenyne competitively inhibited lipase activities using emulsified triolein and dispersed 4-methylumbelliferyl oleate (4-MU oleate) as substrates. The concentrations producing 50% inhibition against triolein and 4-MU oleate hydrolysis were 2 mM and 13 microM, respectively. In vivo, oral administration of corn oil with or without caulerpenyne to rats demonstrated a reduced and delayed peak plasma triacylglycerol concentration with caulerpenyne.

Administration, Oral↗