Effect of fucoidan from Turbinaria ornata against marine ornamental fish pathogens

Objective:To evaluate the antimicrobial capacity of fucoidan from the brown seaweed Turbinaria ornata against the marine ornamental fish bacterial pathogens.Methods:Fucoidan was isolated by the ethanol extraction method and the functional groups were identified by Fourier Transform Infrared Spectroscopy analysis.Subsequently,structural characterization was done by 1H NMR analysis.In vitro antibacterial activity of fucoidan was performed by the agar plate diffusion method and Minimum Inhibitory Concentration.Results:The characteristic C-0-S bending vibration of sulfate substituent the axial C-4 was observed at 839 cm^(-1).Characterisitic signal of the fucoidan was detected in a different ppm of 1H NMR analysis.The maximum antibacterial activity(16.23±0.11)mm was obtained for Vibrio parahaemolyticus and the minimum activity(5.1±0.24)mm was recorded for Yersinia enterocolitica.The Minimum Inhibitory Concentration value was recorded between 2.5 to 10 mg/mL to the respective pathogens.Conclusions:The present study proved that fucoidan possessed the significant antibacterial activity against the tested fish bacterial pathogens.It could be further used as a natural antibiotic in an aquaculture system to control the bacterial diseases.However,the present study suggested that the further in vivo study is required to get the better understanding of the mode of action of fucoidan.

Ecological and biochemical analyses of the brown alga Turbinaria ornata(Turner)J.Agardh from Red Sea coast,Egypt

Objective:To study ecological parameters and biochemical composition of brown seaweed,Turbinaria ornata(T.ornata)collected from Hurghada shores,Red Sea coast of Egypt during September,October and November,2015.Methods:T.ornata and its associated seaweeds were collected,identified and their abundances were estimated.Water of collection site was analyzed physicochemically as well as qualitative and quantitative analyses of phytoplankton.T.ornata was analyzed for protein,total carbohydrate,lipids,alginic acid,agar,pigments,minerals and heavy metals.Results:The results showed that macroalgal species recorded along Hurghada shores belong to Phaeophyta,Rhodophyta and Chlorophyta.At collection site,the moderate temperature,slight alkaline pH,low turbidity,high dissolved oxygen and valuable nutrient content of saline water exerted the massive growth of T.ornata with maximum abundance(24%)during October.The phytoplankton community was quite diverse with a maximum numbers of taxa(104.2×10^(8) cell/L)recorded during October.Analysis of T.ornata alga powder showed that high soluble carbohydrate(2.80±0.10 mg/g dry/weight)and chlorophyll c(0.0017±0.0001 mg/g fresh weight)contents were recorded during September;while high contents of protein(37.70±0.60 mg/g dry weight),lipids(3.10±0.06 mg/g dry weight),polysaccharides(agar and alginates),carotenoids(0.0160±0.0004 mg/g fresh weight),minerals and heavy metals were recorded during November.Conclusions:The study revealed that physicochemical analyses of water were varied slightly during the three months and suitable for the growth of T.ornata.It contains high amount of most biochemical constituents during October.

Evaluation of antibacterial activity of the brown Seaweed Turbinaria ornata(Turner)J.Agardh from Egypt

Objective:To investigate the potential antibacterial activities of ethanol extracts of Turbinaria ornata(T.ornata),Oleic acid(OA)and palmitic acid(PA)extracted from T.ornata as well as mixtures of OA and PA(1:1)against some bacterial species.Methods:Brown seaweed T.ornata was collected from Hurghada shores,Red Sea coast of Egypt.OA and PA were extracted from T.ornata.Ethanol extracts of T.ornata,OA,PA and mixtures of these two fatty acids(1:1)were tested for their antibacterial activities against Escherichia coli,Bacillus cereus,Bacillus subtilis,Klebsiella pneumonia and Staphylococcus aureus by the disc diffusion method.Results:Ethanol extracts of T.ornata,OA,PA and mixtures of OA and PA(1:1)showed antibacterial activities that increased significantly(least significant difference at 0.05 level)with increasing concentrations against all tested bacteria.Different concentrations of ethanol extracts of T.ornata and extracted OA showed its highest activity against Bacillus subtilis,while PA and mixtures of PA and OA(1:1)showed its highest activity against Bacillus cereus.The maximum inhibition activities were shown for mixtures of OA and PA(1:1).Scanning electron microscope showed that mixtures of OA and PA(1:1)caused plasmolysis and reduction in cell size of Escherichia coli.Conclusions:Different concentrations of T.ornata and its fatty acids showed activities against all tested bacteria.Therefore,it is a potential source of natural antimicrobial compounds.

Evaluation of phenolic contents and antioxidant activities of brown seaweeds belonging to Turbinaria spp.(Phaeophyta,Sargassaceae) collected from Gulf of Mannar

Objective:To evaluate the antioxidant activities and total phenolic contents of brown seaweeds belonging to Turbinaria spp.[Turbinaria conoides(T.conoides)and Turbinaria ornata(T.ornata)collected from Gulf of Mannar of southeastern coast of India in various in vitro systems.Methods:The antioxidant activity was evaluated using different in vitro systems,viz.,I,I-diphenyl-2-picrylhydrazyl(DPPH),2,2'-azino-bis-3 ethylbenzothiozoline-6-sulfonic acid diammonium salt(ABTS),H_20_2/H0 radical scavenging,Fe^(2+)ion chelating ability,and reducing potential.Folin-Ciocalteu method was used to determine the total phenolic content of the extracts,and the results were expressed as mg of gallic acid equivalents(GE)/g of the seaweed extracts.Thiobarbituric acid-reactive substances assay was employed to assess the ability of the seaweed extracts to inhibit lipid oxidation.Results:Ethyl acetate(EtOAc)fraction of T.conoides registered significantly higher phenolic content(105.97 mg GE/g)than that of T.ornata(69.63 mg GE/g).Significantly higher antioxidant potential as determined by DPPH(64.14%)radical scavenging activity was registered in EtOAc fraction of T.ornata.A higher ABTS(?)radical scavenging(IC_(50)3.16μg/mL),Fe^(2+)chelating(IC_(50)0.46 mg/mL),H_2O_2 scavenging(IC_(50)4.25 mg/mL),lipid peroxidation inhibitory(TBARS,IC_(50)0.21 mg/mL),and reducing abilities(IC_(50)52.67 mg/mL)(P<0.05)were realized in EtOAc fraction of T.ornata than other fractions.Conclusions:This study indicated the potential use of T.conoides and T.ornata as candidate species to be used as food supplements/functional foods to increase shelf-life of food items for human consumption,and nutraceuticals to deter deleterious free radical-induced life-threatening diseases.

拟小叶喇叭藻和喇叭藻多糖对α-葡萄糖苷酶活性的影响

目的研究喇叭藻多糖对α-葡萄糖苷酶抑制活性。方法采用热水提取从拟小叶喇叭藻(Turbinaria conoides)和喇叭藻(Turbinaria ornata)中获得水溶性多糖TCP和TOP,并采用硫酸-苯酚法测定其总糖含量;用改良的咔唑法测定其糖醛酸含量;用Folin-酚法(Lowry法)测定其蛋白含量;用高效液相色谱法(HPLC)测定其单糖组成;用离子色谱法(IC)测定其硫酸根含量;用高效凝胶渗透色谱与多角度激光散射仪联用法(HPGPC-MALLS)测定其平均分子量;用PNPG显色法测定TCP和TOP对α-葡萄糖苷酶抑制活性。结果 TCP和TOP具有良好的α-葡萄糖苷酶抑制活性,IC50值分别为204.1和113.2μg·mL^(-1),效果优于阿卡波糖(220.3μg·mL^(-1))。初步动力学研究表明其均为混合型抑制方式。结论热水提取自拟小叶喇叭藻和喇叭藻的多糖具有良好的α-葡萄糖苷酶抑制活性。