Objective: To isolate and evaluate the cytotoxic activity of different actinomycetes species isolated from the Red Sea coast in Sharm el-Sheikh, Egypt.Methods: Forty actinomycetes strains were isolated from different ...Objective: To isolate and evaluate the cytotoxic activity of different actinomycetes species isolated from the Red Sea coast in Sharm el-Sheikh, Egypt.Methods: Forty actinomycetes strains were isolated from different sediments and seawater samples collected from the Red Sea coast in Egypt. Actinomycetes were recognized by morphological and microscopic examinations. Cell viability and cytotoxicity induced by the crude extracts on breast cancer cell lines MDA-MB-231 were assessed using methylene blue assay. The strains with promising cytotoxic activity were identified by sequencing and amplifying the 16 S r RNA genes. The antibacterial activities of the crude extracts were performed using Kirby–Bauer disc diffusion method.Results: The results indicated that five ethyl acetate extracts exhibited cytotoxicity towards breast cancer cell lines MDA-MB-231. The highest cytotoxic activity was found for the ethyl acetate extracts of EGY2 and EGY39. The isolate EGY3 was identified as a new Streptomyces species, while the actinomycete EGY22 was found to be a member of the genus Nocardiopsis sp. The crude extract of the isolate EGY8 showed slightly high antimicrobial activity against different test microorganisms.Conclusions: The results of the present study reveal that marine sediments of the Red Sea are a potent source of novel species of actinomycetes. The isolates may be useful in discovery of novel bioactive compounds and an important step in the development of microbial natural product research.展开更多
Soft corals are an important group of organisms that live in reef ecosystems. In this study, the chemical defense of soft coral Sinularia polydactyla against biofilm-forming bacteria was assessed. The soft coral S. po...Soft corals are an important group of organisms that live in reef ecosystems. In this study, the chemical defense of soft coral Sinularia polydactyla against biofilm-forming bacteria was assessed. The soft coral S. polydactyla was collected from the Obhur creek of the Red Sea and the bioactive compounds were extracted under different conditions using methanol and hexane as solvents. Results revealed that the bioactive compounds produced by the soft coral S. polydactyla were active against the growth, hydrophobicity and extracellular polymeric substances production of the biofilm-forming bacteria. However, the damage or injury in soft coral tissue caused a decrease in the activity against biofilm-forming bacteria. GC-MS analysis revealed that sesquiterpenes were abundant in normal coral sample extract while cembranoids were abundant in damaged coral sample extracts. In general, the results indicated that the soft corals either under stress or with damage may not have a strong chemical defense against the colonizing marine organisms and competitors.展开更多
Objective:To isolate antibacterial potential of sponge endosymbiotic bacteria from marine sponges at Lakshadweep archipelago.Also to identify the potent bacteria by 16s rDNA sequencing and determine the antibacterial ...Objective:To isolate antibacterial potential of sponge endosymbiotic bacteria from marine sponges at Lakshadweep archipelago.Also to identify the potent bacteria by 16s rDNA sequencing and determine the antibacterial activity against clinical pathogens by MIC.Methods: Sponge samples was collected from sub-tidal habitats at Kavaratti Island and identified.The endosymbiotic bacteria were isolated and selected potential bacteria which show antibacterial activity in preliminary screening against clinical pathogens Staphylococcus aureus(S.aureus), Escherichia coli(E.coli),Salmonella typhi(S.typhi),Klebsiella pneumoniea(K.pneumoniea) and Streptococcus sp.by disc diffusion assay.The crude extracts of potential bacteria LB3 was tested against clinical pathogens by MIC.The LB3 strain was identified by 16s rDNA sequencing, 1111 bp was submitted in NCBI(HQ589912) and constructed phylogenetic tree.Results:Sponge sample was identified as Dysidea granulosa(D.granulosa) and potential bacteria LB3 identified as Enterobacter sp TTAG.Preliminary screening of sponge isolates against clinical pathogens,LB3 strain was selected as potential producer of secondary metabolites and crude extract was implies on MIC of LB3 have confirmed with lowest concentration of 5.0 mg/mL in broth medium influence of crude extract on growth inhibitory activity after 5 h of incubation period and completed the inhibitory activity at 15 h.Conclusions:The present study concluded that phylogenetic analysis of endosymbiotic bacteria Enterobacter sp from sponge D.granulosa of Lakshadweep islands showed significant antibacterial activity against clinical bacterial pathogens.展开更多
Objective:To screen the anti-fungal effects and find out the active metabolites from sponge, Sigmadocia carnosa(S.carnosa) against four dermatophytic fungi.Methods:The methanol,ethyl acetate and acetone extract of mar...Objective:To screen the anti-fungal effects and find out the active metabolites from sponge, Sigmadocia carnosa(S.carnosa) against four dermatophytic fungi.Methods:The methanol,ethyl acetate and acetone extract of marine sponge,S.carnosa was examined against Trichaphyton mentagrophytes(T.mentagrophytes),Trichophyton rubrum(T.rubrum),Epidermophyton floccosum(E.floccosum) and Microsporum gypseum(M.gypseum) and qualitative analysed to find out the active molecules.Results:The methanol extract of sponge was expressed significant activity than ethyl acetate and acetone.The minimum inhibitory concentration(MIC) of methanol extract of sponge that resulted in complete growth inhibition of T.mentagrophytes,T.rubrum, E.floccosum and M.gypseum were found to 125,250,250 and 250 μg/mL respectively.But, 100%inhibition of fungal spore germination was observed in T.mentagrophytes at 500 μg/mL concentration followed by T.rubrum,E.floccosum and At.gypseum at 1000 μg/mL concentration. Other two extracts showed weak anti spore germination activity against the tested dermatophyte fungi.Methanol extracts showed presence of terpenoids,steroids,alkaloids,saponins and glycosides.Conclusion:Based on the literature,this is the first study which has conducted to inhibit the growth and spore germination of dermatophytic fungi with S.carnosa.Further research also needs to purify and characterize the secondary metabolites from the sponge,5.carnosa for the valuable source of novel substances for future drug discovery.展开更多
The present study aimed at assessing the antifouling activity of bacteria associated with marine sponges. A total of eight bacterial strains were isolated from the surface of sponge Sigmadocia sp., of them, SS02, SS05...The present study aimed at assessing the antifouling activity of bacteria associated with marine sponges. A total of eight bacterial strains were isolated from the surface of sponge Sigmadocia sp., of them, SS02, SS05 and SS06 showed inhibitory activity against biofilm-forming bacteria. The extracts of these 3 strains considerably affected the extracellular polymeric substance producing ability and adhesion of biofilm-forming bacterial strains. In addition to disc diffusion assay, microalgal settlement assay was carried out with the extracts mixed with polyurethane wood polish and coated onto stainless steel coupons. The extract of strain SS05 showed strong microalgal settlement inhibitory activity. Strain SS05 was identified as Bacillus cereus based on its 16S rRNA gene. Metabolites of the bacterial strains associated with marine invertebrates promise to be developed into environment-friendly antifouling agents.展开更多
Objective:To examine the effect of isopod parasite Catoessa boscii(C.boscii)on Carangoides malabaricus(C.malabaricus).Methods:The host fish C.malabaricus infested by C.boscii were collected directly from the trawlers ...Objective:To examine the effect of isopod parasite Catoessa boscii(C.boscii)on Carangoides malabaricus(C.malabaricus).Methods:The host fish C.malabaricus infested by C.boscii were collected directly from the trawlers landed at Parangipettai coast during December 2008 to November2009.Data regarding the total length,width,weight and sex of the host fish were recorded.Effect of infestation on C.malabaricus,the length and weight data were analysed and host specificity of isopods was also examined.Results:During the sampling period,585 C.malabaricus were examined.Among them,218 specimens were found to carry 243 parasites.Three pairs of isopods(one male with one female)were recorded from the host fish and each pair was attached to the tongue in the buccal cavity of the host.Another pair was also found where the male and male,female and female isopod had settled on the tongue in the buccal cavity.Gross lesions observed in the buccal cavity of infested fish showed small pin-holes in the tongue region,through which dactyls of pereopod's penetrating claws dig into the host tissues.The maximum weight loss was reported in females(5.43%)than in males(3.75%)of C.malabaricus.Due to infestation of different isopod parasites in both male and female fish,the effects on the length-weight relationship of C.malabaricus were compared.The rate of increased growth in weight in uninfested female fish was found to be higher than that of the infested.The weight gain is faster in uninfested fish than in the infested fish.Conclusions:From the above mentioned observations,it is clear that the worst of fish on account of the infestation of isopods are the C.malabaricus succumbed to the attack of isopod parasites.Although,the infestation did not cause immediate death,it had affected the normal growth of the host fish.展开更多
Our laboratory study concerns the competitive interaction between two marine rotifer species Bra- chionus plicatilis and Brachionus rotundiformis at five algal ( Nannochloropsis salina) concentrations (0.4*106 to ...Our laboratory study concerns the competitive interaction between two marine rotifer species Bra- chionus plicatilis and Brachionus rotundiformis at five algal ( Nannochloropsis salina) concentrations (0.4*106 to 32.4x106 cells/ml) and at four initial inoculation densities (numerically, 100% B. pli- catilis; 75% B. plicatilis and 25% B. rotundiforrnis, 50% each of the two species; 25% B. plicatilis and 75% B. rotundiformis and 100% B. rotundiforrnis. The initial biomass varied as 0.33 and 0.22 #g/ml for B. plicatilis and B. rotundiformis respectively. Experiments were performed at (25±1)C. Population densities were enumerated and the medium was changed daily up to 8 d in the ex- periment. At the lowest food level tested, B. rotundiformis formed superior competitor than B. plicatilis, regardless of starting inoculation density. Generally when the food concentrations in- creased, B. plicatilis showed a greater increase in biomass than B. rotundiforrnis. B. rotundiformis formed the largest in population growth, regardless of increasing food concentrations. When grown alone, B. plicatilis reached peak abundances of (1.311 5±0.028) and (137.5±0.014) μg/ml at low and high food densities respectively. The corresponding values of B. rotundiformis were 0.724 5±0.016 and 18.15±0.021. The adverse effects of B. rotundiforrnis on the peak abundances of B. plicatilis were observed at the lowest food level and higher initial density. The rate of population growth in controls varied from (0.792±0.162) to (1.482±0.132) ttm/d for B. plicatilis and (0.445~0.041) to (0.856±0.012) μm/d for B. rotundiformis, depending on food level. When both species were intro- duced together, low food levels favoured higher abundance of B. rotundiforrnis than B. plicatilis, suggesting that increased population density of the smaller B. rotundiforrnis was more successfull than larger B. plicatilis in brackish waters. Our work reveals that available food (type and quan- tity) along with starting inoculation density had significant effect on the interspecific competition between marine sibling rotifer species in zooplankton community structure.展开更多
Three species of sponges and a tunicate were collected from Obhur creek of Jeddah coast for this bioactivity study. In order to assess the antifouling efficacy of selected marine organisms, methanolic extracts of thes...Three species of sponges and a tunicate were collected from Obhur creek of Jeddah coast for this bioactivity study. In order to assess the antifouling efficacy of selected marine organisms, methanolic extracts of these organisms were tested against different fouling bacterial forms and II-instar stage of the barnacle, Balanus amphitrite. Antibiosis, bioactivity and followed by multivariate analyses were carried out to check the efficacy of antifouling effect of the selected marine organisms. Principal component analysis revealed the exemplary antifouling efficacy of the sponge extracts of Stylissa sp. observed followed by Hyrtios sp. against bacterial forms in the laboratory study. De-trended correspondence analysis confirmed that the contribution of antifouling efficacy of the selected sponge extracts was observed to be more towards Bacillus sp., Vibrio sp. and Alteromonas sp. Moreover, the efficacy of Hyrtios sp. extract(20.430 μg m L^(-1)) followed by Stylissa sp.(30.945 μg m L^(-1)) showed higher against barnacle instar compared with other extracts in the bioactivity assay. Bray-Curtis cluster analysis under paired linkage categorized all the sponge extracts into one major cluster with 75% similarity, and one outlier tunicate. More than 80% similarity observed between Hyrtios sp. and Stylissa sp. Fourier transform infrared spectroscopy(FTIR) showed that the contribution of major peaks found in the marine organisms were towards sulfones, sulfoxides, cyanates and ketones.展开更多
The present study revealed proliferation of macro-algae modifying coral reef ecosystems in a different manner due to diseases and sedimentations in the Mandapam group of islands in the Gulf of Mannar. Benthic surveys ...The present study revealed proliferation of macro-algae modifying coral reef ecosystems in a different manner due to diseases and sedimentations in the Mandapam group of islands in the Gulf of Mannar. Benthic surveys were conducted with major attack of seven coral reefs diseases with high sedimentation rate, nine species of fleshy macro-algae(Turbinaria ornata, Turbinaria conaides, Caulerpa scalpelliformis, Caulerpa racemosa, Kappaphycus alvarezii, Padina gymnosphora, Sargassum wightii, Ulva reticulata and Calurpa lentillifera) proliferation against major corals life forms(Acropora branching, Acropora digitate, Acropora tabulate, coral massive, coral submassive, coral foliose and coral encrusting). The results confirm that diseased corals most favor to macro-algae growth(15.27%) rather than the sedimentation covered corals(8.24 %). In the degradation of coral life forms, massive corals were more highly damaged(7.05%) than any other forms. Within a short period of time(May to September), coral coverage shrank to 17.4% from 21.9%, macro-algae increased 23.51% and the average sedimentation rate attained 77.52 mg cm^(-2) d^(-1) with persisting coral reef diseases of 17.59%. The Pearson correlation showed that the coral cover decreased with increasing macro-algae growth, which was statistically significant(r =-0.774, n = 100, P < 0.0005). The proliferation of the various macro-algae C. scalpellifrmis, T. ornata, C. racemosa, T. conaides, U. reticulata, S. wightii, K. alvarezii, P. gymnosphora and C. lentillifera increased with percentages of 6.0, 5.8, 5.7, 4.9, 4.2, 3.7, 2.7 and 1.9, respectively. If this trend continues, the next generation of new recruit corals will undoubtedly lead to a phase shift in Gulf of Mannar corals.展开更多
Fish livers a good source of long-chain polyunsaturated fatty acids and omega 3, are usually discarded as a waste when fish are processed for human consumption in Sudan. Highly fresh <span style="font-family:V...Fish livers a good source of long-chain polyunsaturated fatty acids and omega 3, are usually discarded as a waste when fish are processed for human consumption in Sudan. Highly fresh <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></i></span></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">Triaenodon obesus</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"> and</span><i> </i></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"><i></i></span></i></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">Hipposcarus harid</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span><span><i><span style="font-family:;" "=""> </span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">fish were purchased from Port Sudan fish central market during December 2014. The fatty acid profiles of the livers of these commercially important fish were determined. The polyunsaturated and saturated fatty acids ratio in the livers oil of </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></i></span></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">T. obesus</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> and </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></i></span></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">H. harid</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> was 1:2.2 and 1:1.38, respectively. The Palmatic (16:0), Pentadecenoic (12:0) and Arachidic acids were the highest in both species. The poly chain unsaturated fatty acids Linolenic (18:3n</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">3), Eicosapentaenoic (20:5n</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">3) and Docosahexaenoic (22:6n</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">3) were detected in the liver of both species. The highest values of above poly chain unsaturated fatty acids were detected in </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></i></span></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">T. obesus</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">.</span></i></span></span>展开更多
The Jordan's NAP (national action plan) provides a set of priority actions for the conservation of marine turtles and their habitats in the Gulf of Aqaba, Red Sea. The main threats to the maintenance of stable turt...The Jordan's NAP (national action plan) provides a set of priority actions for the conservation of marine turtles and their habitats in the Gulf of Aqaba, Red Sea. The main threats to the maintenance of stable turtle populations in Jordan range from opportunistic capture to global threats such fishing mortality and from pollution incidents. Jordan's NAP addresses the primary causes of turtle mortality with a series of proposed actions. It includes reducing threats from commercial fisheries, development operations, promoting turtle rescue and rehabilitation along with public awareness activities. It considered also a set of recommendations to reflect the importance of protecting marine turtles in Jordan's Gulf of Aqaba. It includes community participation in conservation, capacity of national agencies to carry out management activities and to enforce legislations. To each priority actions identified in NAP, expected results and performance indicators were defined. Hence, the designation of a level of urgency to each specific priority action allowed a phased approach for implementation, subject to budget and available national capacity. Currently, NAP is performing effectively through an integrated network of national working groups including government and non-governmental organisations and other stakeholders.展开更多
In this study,the coupled torsional-transverse vibration of a propeller shaft system owing to the misalignment caused by the shaft rotation was investigated.The proposed numerical model is based on the modified versio...In this study,the coupled torsional-transverse vibration of a propeller shaft system owing to the misalignment caused by the shaft rotation was investigated.The proposed numerical model is based on the modified version of the Jeffcott rotor model.The equation of motion describing the harmonic vibrations of the system was obtained using the Euler-Lagrange equations for the associated energy functional.Experiments considering different rotation speeds and axial loads acting on the propulsion shaft system were performed to verify the numerical model.The effects of system parameters such as shaft length and diameter,stiffness and damping coefficients,and cross-section eccentricity were also studied.The cross-section eccentricity increased the displacement response,yet coupled vibrations were not initially observed.With the increase in the eccentricity,the interaction between two vibration modes became apparent,and the agreement between numerical predictions and experimental measurements improved.Given the results,the modified version of the Jeffcott rotor model can represent the coupled torsional-transverse vibration of propulsion shaft systems.展开更多
The abundance, distribution and diversity of epibenthic echinoderm were investigated at Dungonab Bay in the Red Sea coastal water of the Sudan. Four permanent line transects were chosen. Eight (30 × 2) square met...The abundance, distribution and diversity of epibenthic echinoderm were investigated at Dungonab Bay in the Red Sea coastal water of the Sudan. Four permanent line transects were chosen. Eight (30 × 2) square metre belt transects along each permanent line transect at 20 metre intervals were used to collect data. The data were subjected to univariate and multivariate analyses. Spatial variations of epibenthic echinoderm abundance were assessed with one-way analysis of variance. Hierarchical agglomerative clustering was used to identify and illustrate the similarities in echinoderm abundance between line transects and between belt transects. Indices of richness (d), diversity (H'), evenness (J') and dominance (C) were used to explain the diversity of epibenthic echinoderm species. The distribution pattern of each echinoderm species was determined in each permanent line transect. A total of 986 individuals were recorded within sixteen species of epibenthic echinoderms in the four line transects. Holothuriidae was the dominant family (5 species and 342 individuals). The most abundant echinoderms species was Pearsonothuria graeffei (77 individuals, about 7.81%). Abundances intra-transects and intra-families were insignificant (f = 1.67, p = 0.183, df = 3 and f = 3.24, p = 0.083, df = 9, respectively). The highest values of Shannon-Wiener diversity index (H'), Pielou evenness index (J'), Margalef species richness index (d), and Simpson Dominance index (C) were 2.738, 0.9875, 2.791 and 0.07159, respectively. The distribution patterns of all species in the study transects varied between clumped and uniform, with the exception of Asthenosoma varium of the Echinothuridae family, which had clumped distribution patterns in all transects. The study concluded that Dungonab Bay supports rich and diverse communities of epibenthic echinoderms.展开更多
Objective:To search for new sources of safe and inexpensive antioxidants,the leaf,root and rhizome of Enhalus acoroides(E.acoroides) were screened for the first time for their antioxidant activities.Methods:Samples of...Objective:To search for new sources of safe and inexpensive antioxidants,the leaf,root and rhizome of Enhalus acoroides(E.acoroides) were screened for the first time for their antioxidant activities.Methods:Samples of leaf,root and rhizome from E.acoroides were tested for total phenolic content,proanthocyanidins and in vitro antioxidant activity in terms of total antioxidant assay,DPPH assay and FRAP assay.Results:The leaf sample was found to have high levels of phenolic(0.323±0.028 mg TAE/g) and proanthocyanidins(0.570 0±0.000 3 mg TAE/g) when compared to root and rhizome.The leaf samples exhibited higher total antioxidant activity (11.770±0.026 mg Ascorbic acid equivalent/g),higher percentage of DPPH radical scavenging activity(25.76±0.04) and higher reducing power(18.060±0.073) in terms of mg GAE/g.In addition, there was a significant correlation between total phenolic content and total antioxidant activity (R^2=0.923),DPPH assay(R^2=0.509).FRAP assay(R^2=0.994).Similarly,significant correlation was found between the proanthocyanidin and total antioxidant activity(R^2=0.977),DPPH assay (R^2=0.464) and the FRAP assay(R^2=0.998).Conclusions:These results suggested that E.acoroides have strong antioxidant potential.Further study is necessary for isolation and characterization of the active antioxidant agents,which can be used to treat various oxidative stress-related diseases.展开更多
Objective:To evaluate the larvicidal and pupicidal potential of the methanolic extracts from Moringa oleifera(M.oleifera) plant seeds against malarial vector Anopheles stephensi(A.stephensi) mosquitoes at different co...Objective:To evaluate the larvicidal and pupicidal potential of the methanolic extracts from Moringa oleifera(M.oleifera) plant seeds against malarial vector Anopheles stephensi(A.stephensi) mosquitoes at different concentrations(20,40,60,80 and 100 ppm).Methods:M.oleifera was collected from the area of around Bharathiar University,Coimbatore.The dried plant materials were powdered by an electrical blender.From each sample,100 g of the plant material were extracted with 300 mL of methanol for 8 h in a Soxhlet apparatus.The extracts were evaporated to dryness in rotary vacuum evaporator to yield 122 mg and 110 mg of dark greenish material(residue) from Arcang amara and Ocimum basilicum,respectively.One gram of the each plant residue was dissolved separately in 100 mL of acetone(stock solution) from which different concentrations, i.e.,20,40,60,80 and 100 ppm were prepared.Results:Larvicidal activity of M.oleifera exhibited in the first to fourth instar larvae of the A.stephensi,and the LC_(50) and LC_(90) values were 57.79 ppm and 125.93 ppm for the first instar,63.90 ppm and 133.07 ppm for the second inslar,72.45 ppm and 139.82 ppm for the third instar,78.93 ppm and 143.20 ppm for the fourth instar,respectively. During the pupal stage the methanolic extract of M.oleifera showed that the LC_(50),and LC_(90) values were 67.77 ppm and 141.00 ppm,respectively.Conclusions:The present study indicates that the phytochemicals derived from M.oleifera seeds extracts are effective mosquito vector control agents and the plant extracts may be used for further integrated pest management programs.展开更多
Objective:To evaluate the antimicrobial activity of Turbinaria conoides(T.conoides).Padina gymnospora(P.gymnospora) and Sargassum tenerrimum against human bacterial and fungal pathogens.Methods:The antimicrobial activ...Objective:To evaluate the antimicrobial activity of Turbinaria conoides(T.conoides).Padina gymnospora(P.gymnospora) and Sargassum tenerrimum against human bacterial and fungal pathogens.Methods:The antimicrobial activities of the extracts against various organisms were tested by using disc diffusion method.Results:The methanol extract showed the better result than the other extracts.Whereas,the strong antibacterial inhibition was noted in methanol extracts of P.gymnospora against Bacillus subtilus(26.33±1.86) and the mild inhibition of ethanol extracts from T.conoides against Klebsiella pneumoniae(2.33±0.51).Acetone extraction of P. gymnospora had strong antifungal inhibition against Cryptococcus neoformans(23.00±1.78), and acetone extract of T.conoides had mild inhibition against Aspergillus niger(3.00±0.89). Conclusions:The seven different solvent extracts of seaweeds used in the present study have shown significant bacterial action.Further,a detailed study on the principle compound in the seaweeds which is responsible for antimicrobial activity is still needed and it can be achieved by using advanced separation techniques.展开更多
Objective:To evaluate the antibacterial activity of Halophila stipulacea(H.stipulacea), Cymodocea serrulata(C.serrulata) and Halodule pinifolia(H.pinifolia) against seven human bacterial pathogens.Methods:The antibact...Objective:To evaluate the antibacterial activity of Halophila stipulacea(H.stipulacea), Cymodocea serrulata(C.serrulata) and Halodule pinifolia(H.pinifolia) against seven human bacterial pathogens.Methods:The antibacterial activities of the extracts on the various test organisms using disc diffusion method and Minimum Inhibitory Concentraction(MIC).Results: Methanol and chloroform extracts of all the three seagrasses were active against all the tested pathogens,whereas the hexane extract of seagrasses was not active against Staphylococcus aureus (S.aureus).Antibacterial activity of three seagrass screened,was in the order of H.pinifolia 】 H.stipulacea.】 C.serrulata.Conclusions:This antibacterial studies can further investigated on seagrasses for purification of bioactive substance and its possible utility in disease control.展开更多
Objective:In vitro antioxidant activities of three selected Indian seaweeds viz.,Halimeda tuna(H.tuna),Turbinaria conoides(T.conoides) and Gracilaria foliifera(G.foliifera) were evaluated.Methods:Total antioxidant act...Objective:In vitro antioxidant activities of three selected Indian seaweeds viz.,Halimeda tuna(H.tuna),Turbinaria conoides(T.conoides) and Gracilaria foliifera(G.foliifera) were evaluated.Methods:Total antioxidant activity,total phenolic content,and reducing power of crude methanol and diethyl ether extracts were determined.Results:Total phenolic content and total antioxidant activity were higher(1.231±0.173 mg GAE/g,1.675±0.361 mg GAE/g) in T.conoides respectively.Reducing power of crude methanol extract increased with concentrations of the extract.The Fourier transform-infra red spectrum analysis revealed the presence of polyphenolic signals.The seaweed extracts displayed moderate antioxidant activity compared to gallic acid standard.Conclusions:The seaweeds could be considered for curing diseases from oxidative deteriorations.展开更多
Objective:To investigate the antimicrobial activity of the tissue extracts of Babylonia spirata(B.spirala)against nine bacterial and three fungal patliogeiis.Methods:Crude extract of gastropod was tested for inhibitio...Objective:To investigate the antimicrobial activity of the tissue extracts of Babylonia spirata(B.spirala)against nine bacterial and three fungal patliogeiis.Methods:Crude extract of gastropod was tested for inhibition of bacterial and fungal growth.Antibacterial assay was carried out by disc diffusion method and in vitro antifungal activity was determined against Czapex Dox agar.The antimicrobial activity was measured accordingly based on the inhibition zone around the disc impregnated with gastropod extract.Molecular size of muscle protein was determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE).And fourier transform infrared spectroscopy(FT1R)spectro photometry analysis was also studied.Results:The maximum inhibition zone(12 mm)was observed against Pseudomonas aeruginosa in the crude ethanol extract of B.spirata and the minimum inhibition zone(2 mm)was noticed against Staphylococcus aureus in the crude methanol extract of B.spirala.Water extract of B.spirala showed the highest activity against Vibrio parahaemolyticus,Staphylococcus aureus and Candida albicans.Ethanol,acetone,methanol,chloroform and water extracts showed antimicrobial activity against almost all the bacteria and fungus.Compared with water extracts,ethanol and methanol extracts showed higher activity against all pathogens.The molecular weight of protein of the gastropod sample ranged from 2-110 kDa on SDS-PAGE.FTIR analysis revealed the presence of bioactive compounds signals at different ranges.Conclusions:The research shows that the great medicinal value of the gastropod muscle of B.spirata may be due to high quality of antimicrobial compounds.展开更多
Objective:To study the antimicrobial,hemolytic activity and immunomodulatory activity of fish epidermal mucus and their chemical constituents from Cynoglossus arel(C.arel) and Alius caelatus(A.caelatus).Mucus plays an...Objective:To study the antimicrobial,hemolytic activity and immunomodulatory activity of fish epidermal mucus and their chemical constituents from Cynoglossus arel(C.arel) and Alius caelatus(A.caelatus).Mucus plays an important role in the prevention of colonization by parasites,bacteria and fungi.Methods:Epidermal mucus was obtained from two marine fishes,lyophilized and the chemical composition of epidermal mucus was analysed by FT-IR analysis.The in vitro antimicrobial activity against human pathogens(fungi,gram positive and gram-negative bacteria) and also the hemolytic activity and immunomodulatory activity were determined.Results:Totally ten human pathogens were tested against the fish mucus.Out of the ten pathogens,five pathogens have proved to be sensitive to the mucus.Maximum zone of inhibition was observed against Vibrio cholera(V.cholera)(9 mm and 2 mm in diameter),followed by Staphylococcus aureus(S.aureus) with a inhibition zone of(6 mm and 3 mm),Streptococcus areus(S.areus)(5 mm and 4 mm),Vibrio parahemolyticus(V.parahemolyticus)(4 mm and 5 mm) respectively.Conclusions:The present investigation has revealed that positive progresses in the fish mucus extracts against human pathogens and hemolytic activity.But further efforts are required for the purification and isolation of the active antimicrobial compounds in order to establish their possible applications.展开更多
基金Supported by the Egyptian Science and Technology Development fund(STDF)(Grant No.4930)
文摘Objective: To isolate and evaluate the cytotoxic activity of different actinomycetes species isolated from the Red Sea coast in Sharm el-Sheikh, Egypt.Methods: Forty actinomycetes strains were isolated from different sediments and seawater samples collected from the Red Sea coast in Egypt. Actinomycetes were recognized by morphological and microscopic examinations. Cell viability and cytotoxicity induced by the crude extracts on breast cancer cell lines MDA-MB-231 were assessed using methylene blue assay. The strains with promising cytotoxic activity were identified by sequencing and amplifying the 16 S r RNA genes. The antibacterial activities of the crude extracts were performed using Kirby–Bauer disc diffusion method.Results: The results indicated that five ethyl acetate extracts exhibited cytotoxicity towards breast cancer cell lines MDA-MB-231. The highest cytotoxic activity was found for the ethyl acetate extracts of EGY2 and EGY39. The isolate EGY3 was identified as a new Streptomyces species, while the actinomycete EGY22 was found to be a member of the genus Nocardiopsis sp. The crude extract of the isolate EGY8 showed slightly high antimicrobial activity against different test microorganisms.Conclusions: The results of the present study reveal that marine sediments of the Red Sea are a potent source of novel species of actinomycetes. The isolates may be useful in discovery of novel bioactive compounds and an important step in the development of microbial natural product research.
基金King Abdulaziz City for Science and Technology (KACST) for providing financial assistance to this study (No. PS-37-988)
文摘Soft corals are an important group of organisms that live in reef ecosystems. In this study, the chemical defense of soft coral Sinularia polydactyla against biofilm-forming bacteria was assessed. The soft coral S. polydactyla was collected from the Obhur creek of the Red Sea and the bioactive compounds were extracted under different conditions using methanol and hexane as solvents. Results revealed that the bioactive compounds produced by the soft coral S. polydactyla were active against the growth, hydrophobicity and extracellular polymeric substances production of the biofilm-forming bacteria. However, the damage or injury in soft coral tissue caused a decrease in the activity against biofilm-forming bacteria. GC-MS analysis revealed that sesquiterpenes were abundant in normal coral sample extract while cembranoids were abundant in damaged coral sample extracts. In general, the results indicated that the soft corals either under stress or with damage may not have a strong chemical defense against the colonizing marine organisms and competitors.
文摘Objective:To isolate antibacterial potential of sponge endosymbiotic bacteria from marine sponges at Lakshadweep archipelago.Also to identify the potent bacteria by 16s rDNA sequencing and determine the antibacterial activity against clinical pathogens by MIC.Methods: Sponge samples was collected from sub-tidal habitats at Kavaratti Island and identified.The endosymbiotic bacteria were isolated and selected potential bacteria which show antibacterial activity in preliminary screening against clinical pathogens Staphylococcus aureus(S.aureus), Escherichia coli(E.coli),Salmonella typhi(S.typhi),Klebsiella pneumoniea(K.pneumoniea) and Streptococcus sp.by disc diffusion assay.The crude extracts of potential bacteria LB3 was tested against clinical pathogens by MIC.The LB3 strain was identified by 16s rDNA sequencing, 1111 bp was submitted in NCBI(HQ589912) and constructed phylogenetic tree.Results:Sponge sample was identified as Dysidea granulosa(D.granulosa) and potential bacteria LB3 identified as Enterobacter sp TTAG.Preliminary screening of sponge isolates against clinical pathogens,LB3 strain was selected as potential producer of secondary metabolites and crude extract was implies on MIC of LB3 have confirmed with lowest concentration of 5.0 mg/mL in broth medium influence of crude extract on growth inhibitory activity after 5 h of incubation period and completed the inhibitory activity at 15 h.Conclusions:The present study concluded that phylogenetic analysis of endosymbiotic bacteria Enterobacter sp from sponge D.granulosa of Lakshadweep islands showed significant antibacterial activity against clinical bacterial pathogens.
基金Funded by University Grants Commission(UGC),New Delhi.(grant No.U.G.C.No.33-384/2007(SR)
文摘Objective:To screen the anti-fungal effects and find out the active metabolites from sponge, Sigmadocia carnosa(S.carnosa) against four dermatophytic fungi.Methods:The methanol,ethyl acetate and acetone extract of marine sponge,S.carnosa was examined against Trichaphyton mentagrophytes(T.mentagrophytes),Trichophyton rubrum(T.rubrum),Epidermophyton floccosum(E.floccosum) and Microsporum gypseum(M.gypseum) and qualitative analysed to find out the active molecules.Results:The methanol extract of sponge was expressed significant activity than ethyl acetate and acetone.The minimum inhibitory concentration(MIC) of methanol extract of sponge that resulted in complete growth inhibition of T.mentagrophytes,T.rubrum, E.floccosum and M.gypseum were found to 125,250,250 and 250 μg/mL respectively.But, 100%inhibition of fungal spore germination was observed in T.mentagrophytes at 500 μg/mL concentration followed by T.rubrum,E.floccosum and At.gypseum at 1000 μg/mL concentration. Other two extracts showed weak anti spore germination activity against the tested dermatophyte fungi.Methanol extracts showed presence of terpenoids,steroids,alkaloids,saponins and glycosides.Conclusion:Based on the literature,this is the first study which has conducted to inhibit the growth and spore germination of dermatophytic fungi with S.carnosa.Further research also needs to purify and characterize the secondary metabolites from the sponge,5.carnosa for the valuable source of novel substances for future drug discovery.
文摘The present study aimed at assessing the antifouling activity of bacteria associated with marine sponges. A total of eight bacterial strains were isolated from the surface of sponge Sigmadocia sp., of them, SS02, SS05 and SS06 showed inhibitory activity against biofilm-forming bacteria. The extracts of these 3 strains considerably affected the extracellular polymeric substance producing ability and adhesion of biofilm-forming bacterial strains. In addition to disc diffusion assay, microalgal settlement assay was carried out with the extracts mixed with polyurethane wood polish and coated onto stainless steel coupons. The extract of strain SS05 showed strong microalgal settlement inhibitory activity. Strain SS05 was identified as Bacillus cereus based on its 16S rRNA gene. Metabolites of the bacterial strains associated with marine invertebrates promise to be developed into environment-friendly antifouling agents.
基金Financially supported by Department of Science and Technology(Grant No:SR/FF/LS-088/2007)Ministry of Environment&Forest,Government of India(Grant No:22-18/2008-CS-I)
文摘Objective:To examine the effect of isopod parasite Catoessa boscii(C.boscii)on Carangoides malabaricus(C.malabaricus).Methods:The host fish C.malabaricus infested by C.boscii were collected directly from the trawlers landed at Parangipettai coast during December 2008 to November2009.Data regarding the total length,width,weight and sex of the host fish were recorded.Effect of infestation on C.malabaricus,the length and weight data were analysed and host specificity of isopods was also examined.Results:During the sampling period,585 C.malabaricus were examined.Among them,218 specimens were found to carry 243 parasites.Three pairs of isopods(one male with one female)were recorded from the host fish and each pair was attached to the tongue in the buccal cavity of the host.Another pair was also found where the male and male,female and female isopod had settled on the tongue in the buccal cavity.Gross lesions observed in the buccal cavity of infested fish showed small pin-holes in the tongue region,through which dactyls of pereopod's penetrating claws dig into the host tissues.The maximum weight loss was reported in females(5.43%)than in males(3.75%)of C.malabaricus.Due to infestation of different isopod parasites in both male and female fish,the effects on the length-weight relationship of C.malabaricus were compared.The rate of increased growth in weight in uninfested female fish was found to be higher than that of the infested.The weight gain is faster in uninfested fish than in the infested fish.Conclusions:From the above mentioned observations,it is clear that the worst of fish on account of the infestation of isopods are the C.malabaricus succumbed to the attack of isopod parasites.Although,the infestation did not cause immediate death,it had affected the normal growth of the host fish.
文摘Our laboratory study concerns the competitive interaction between two marine rotifer species Bra- chionus plicatilis and Brachionus rotundiformis at five algal ( Nannochloropsis salina) concentrations (0.4*106 to 32.4x106 cells/ml) and at four initial inoculation densities (numerically, 100% B. pli- catilis; 75% B. plicatilis and 25% B. rotundiforrnis, 50% each of the two species; 25% B. plicatilis and 75% B. rotundiformis and 100% B. rotundiforrnis. The initial biomass varied as 0.33 and 0.22 #g/ml for B. plicatilis and B. rotundiformis respectively. Experiments were performed at (25±1)C. Population densities were enumerated and the medium was changed daily up to 8 d in the ex- periment. At the lowest food level tested, B. rotundiformis formed superior competitor than B. plicatilis, regardless of starting inoculation density. Generally when the food concentrations in- creased, B. plicatilis showed a greater increase in biomass than B. rotundiforrnis. B. rotundiformis formed the largest in population growth, regardless of increasing food concentrations. When grown alone, B. plicatilis reached peak abundances of (1.311 5±0.028) and (137.5±0.014) μg/ml at low and high food densities respectively. The corresponding values of B. rotundiformis were 0.724 5±0.016 and 18.15±0.021. The adverse effects of B. rotundiforrnis on the peak abundances of B. plicatilis were observed at the lowest food level and higher initial density. The rate of population growth in controls varied from (0.792±0.162) to (1.482±0.132) ttm/d for B. plicatilis and (0.445~0.041) to (0.856±0.012) μm/d for B. rotundiformis, depending on food level. When both species were intro- duced together, low food levels favoured higher abundance of B. rotundiforrnis than B. plicatilis, suggesting that increased population density of the smaller B. rotundiforrnis was more successfull than larger B. plicatilis in brackish waters. Our work reveals that available food (type and quan- tity) along with starting inoculation density had significant effect on the interspecific competition between marine sibling rotifer species in zooplankton community structure.
基金funded by the Deanship of Scientific Research(DSR),King Abdulaziz University,Jeddah,under grant no.429/150/1433
文摘Three species of sponges and a tunicate were collected from Obhur creek of Jeddah coast for this bioactivity study. In order to assess the antifouling efficacy of selected marine organisms, methanolic extracts of these organisms were tested against different fouling bacterial forms and II-instar stage of the barnacle, Balanus amphitrite. Antibiosis, bioactivity and followed by multivariate analyses were carried out to check the efficacy of antifouling effect of the selected marine organisms. Principal component analysis revealed the exemplary antifouling efficacy of the sponge extracts of Stylissa sp. observed followed by Hyrtios sp. against bacterial forms in the laboratory study. De-trended correspondence analysis confirmed that the contribution of antifouling efficacy of the selected sponge extracts was observed to be more towards Bacillus sp., Vibrio sp. and Alteromonas sp. Moreover, the efficacy of Hyrtios sp. extract(20.430 μg m L^(-1)) followed by Stylissa sp.(30.945 μg m L^(-1)) showed higher against barnacle instar compared with other extracts in the bioactivity assay. Bray-Curtis cluster analysis under paired linkage categorized all the sponge extracts into one major cluster with 75% similarity, and one outlier tunicate. More than 80% similarity observed between Hyrtios sp. and Stylissa sp. Fourier transform infrared spectroscopy(FTIR) showed that the contribution of major peaks found in the marine organisms were towards sulfones, sulfoxides, cyanates and ketones.
基金the National Remote Sensing Center, ISRO-Hyderabad for providing financial supports
文摘The present study revealed proliferation of macro-algae modifying coral reef ecosystems in a different manner due to diseases and sedimentations in the Mandapam group of islands in the Gulf of Mannar. Benthic surveys were conducted with major attack of seven coral reefs diseases with high sedimentation rate, nine species of fleshy macro-algae(Turbinaria ornata, Turbinaria conaides, Caulerpa scalpelliformis, Caulerpa racemosa, Kappaphycus alvarezii, Padina gymnosphora, Sargassum wightii, Ulva reticulata and Calurpa lentillifera) proliferation against major corals life forms(Acropora branching, Acropora digitate, Acropora tabulate, coral massive, coral submassive, coral foliose and coral encrusting). The results confirm that diseased corals most favor to macro-algae growth(15.27%) rather than the sedimentation covered corals(8.24 %). In the degradation of coral life forms, massive corals were more highly damaged(7.05%) than any other forms. Within a short period of time(May to September), coral coverage shrank to 17.4% from 21.9%, macro-algae increased 23.51% and the average sedimentation rate attained 77.52 mg cm^(-2) d^(-1) with persisting coral reef diseases of 17.59%. The Pearson correlation showed that the coral cover decreased with increasing macro-algae growth, which was statistically significant(r =-0.774, n = 100, P < 0.0005). The proliferation of the various macro-algae C. scalpellifrmis, T. ornata, C. racemosa, T. conaides, U. reticulata, S. wightii, K. alvarezii, P. gymnosphora and C. lentillifera increased with percentages of 6.0, 5.8, 5.7, 4.9, 4.2, 3.7, 2.7 and 1.9, respectively. If this trend continues, the next generation of new recruit corals will undoubtedly lead to a phase shift in Gulf of Mannar corals.
文摘Fish livers a good source of long-chain polyunsaturated fatty acids and omega 3, are usually discarded as a waste when fish are processed for human consumption in Sudan. Highly fresh <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></i></span></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">Triaenodon obesus</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"> and</span><i> </i></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"><i></i></span></i></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">Hipposcarus harid</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span><span><i><span style="font-family:;" "=""> </span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">fish were purchased from Port Sudan fish central market during December 2014. The fatty acid profiles of the livers of these commercially important fish were determined. The polyunsaturated and saturated fatty acids ratio in the livers oil of </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></i></span></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">T. obesus</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> and </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></i></span></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">H. harid</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> was 1:2.2 and 1:1.38, respectively. The Palmatic (16:0), Pentadecenoic (12:0) and Arachidic acids were the highest in both species. The poly chain unsaturated fatty acids Linolenic (18:3n</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">3), Eicosapentaenoic (20:5n</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">3) and Docosahexaenoic (22:6n</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">3) were detected in the liver of both species. The highest values of above poly chain unsaturated fatty acids were detected in </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></i></span></span></span><i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">T. obesus</span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></span></i></span></span></i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">.</span></i></span></span>
文摘The Jordan's NAP (national action plan) provides a set of priority actions for the conservation of marine turtles and their habitats in the Gulf of Aqaba, Red Sea. The main threats to the maintenance of stable turtle populations in Jordan range from opportunistic capture to global threats such fishing mortality and from pollution incidents. Jordan's NAP addresses the primary causes of turtle mortality with a series of proposed actions. It includes reducing threats from commercial fisheries, development operations, promoting turtle rescue and rehabilitation along with public awareness activities. It considered also a set of recommendations to reflect the importance of protecting marine turtles in Jordan's Gulf of Aqaba. It includes community participation in conservation, capacity of national agencies to carry out management activities and to enforce legislations. To each priority actions identified in NAP, expected results and performance indicators were defined. Hence, the designation of a level of urgency to each specific priority action allowed a phased approach for implementation, subject to budget and available national capacity. Currently, NAP is performing effectively through an integrated network of national working groups including government and non-governmental organisations and other stakeholders.
基金supported by the Scientific and Technological Research Council of Turkey(TUBITAK)2214-A International Doctoral Research Fellowship Programmewhile experiments were performed at the Wuhan University of Technology。
文摘In this study,the coupled torsional-transverse vibration of a propeller shaft system owing to the misalignment caused by the shaft rotation was investigated.The proposed numerical model is based on the modified version of the Jeffcott rotor model.The equation of motion describing the harmonic vibrations of the system was obtained using the Euler-Lagrange equations for the associated energy functional.Experiments considering different rotation speeds and axial loads acting on the propulsion shaft system were performed to verify the numerical model.The effects of system parameters such as shaft length and diameter,stiffness and damping coefficients,and cross-section eccentricity were also studied.The cross-section eccentricity increased the displacement response,yet coupled vibrations were not initially observed.With the increase in the eccentricity,the interaction between two vibration modes became apparent,and the agreement between numerical predictions and experimental measurements improved.Given the results,the modified version of the Jeffcott rotor model can represent the coupled torsional-transverse vibration of propulsion shaft systems.
文摘The abundance, distribution and diversity of epibenthic echinoderm were investigated at Dungonab Bay in the Red Sea coastal water of the Sudan. Four permanent line transects were chosen. Eight (30 × 2) square metre belt transects along each permanent line transect at 20 metre intervals were used to collect data. The data were subjected to univariate and multivariate analyses. Spatial variations of epibenthic echinoderm abundance were assessed with one-way analysis of variance. Hierarchical agglomerative clustering was used to identify and illustrate the similarities in echinoderm abundance between line transects and between belt transects. Indices of richness (d), diversity (H'), evenness (J') and dominance (C) were used to explain the diversity of epibenthic echinoderm species. The distribution pattern of each echinoderm species was determined in each permanent line transect. A total of 986 individuals were recorded within sixteen species of epibenthic echinoderms in the four line transects. Holothuriidae was the dominant family (5 species and 342 individuals). The most abundant echinoderms species was Pearsonothuria graeffei (77 individuals, about 7.81%). Abundances intra-transects and intra-families were insignificant (f = 1.67, p = 0.183, df = 3 and f = 3.24, p = 0.083, df = 9, respectively). The highest values of Shannon-Wiener diversity index (H'), Pielou evenness index (J'), Margalef species richness index (d), and Simpson Dominance index (C) were 2.738, 0.9875, 2.791 and 0.07159, respectively. The distribution patterns of all species in the study transects varied between clumped and uniform, with the exception of Asthenosoma varium of the Echinothuridae family, which had clumped distribution patterns in all transects. The study concluded that Dungonab Bay supports rich and diverse communities of epibenthic echinoderms.
文摘Objective:To search for new sources of safe and inexpensive antioxidants,the leaf,root and rhizome of Enhalus acoroides(E.acoroides) were screened for the first time for their antioxidant activities.Methods:Samples of leaf,root and rhizome from E.acoroides were tested for total phenolic content,proanthocyanidins and in vitro antioxidant activity in terms of total antioxidant assay,DPPH assay and FRAP assay.Results:The leaf sample was found to have high levels of phenolic(0.323±0.028 mg TAE/g) and proanthocyanidins(0.570 0±0.000 3 mg TAE/g) when compared to root and rhizome.The leaf samples exhibited higher total antioxidant activity (11.770±0.026 mg Ascorbic acid equivalent/g),higher percentage of DPPH radical scavenging activity(25.76±0.04) and higher reducing power(18.060±0.073) in terms of mg GAE/g.In addition, there was a significant correlation between total phenolic content and total antioxidant activity (R^2=0.923),DPPH assay(R^2=0.509).FRAP assay(R^2=0.994).Similarly,significant correlation was found between the proanthocyanidin and total antioxidant activity(R^2=0.977),DPPH assay (R^2=0.464) and the FRAP assay(R^2=0.998).Conclusions:These results suggested that E.acoroides have strong antioxidant potential.Further study is necessary for isolation and characterization of the active antioxidant agents,which can be used to treat various oxidative stress-related diseases.
文摘Objective:To evaluate the larvicidal and pupicidal potential of the methanolic extracts from Moringa oleifera(M.oleifera) plant seeds against malarial vector Anopheles stephensi(A.stephensi) mosquitoes at different concentrations(20,40,60,80 and 100 ppm).Methods:M.oleifera was collected from the area of around Bharathiar University,Coimbatore.The dried plant materials were powdered by an electrical blender.From each sample,100 g of the plant material were extracted with 300 mL of methanol for 8 h in a Soxhlet apparatus.The extracts were evaporated to dryness in rotary vacuum evaporator to yield 122 mg and 110 mg of dark greenish material(residue) from Arcang amara and Ocimum basilicum,respectively.One gram of the each plant residue was dissolved separately in 100 mL of acetone(stock solution) from which different concentrations, i.e.,20,40,60,80 and 100 ppm were prepared.Results:Larvicidal activity of M.oleifera exhibited in the first to fourth instar larvae of the A.stephensi,and the LC_(50) and LC_(90) values were 57.79 ppm and 125.93 ppm for the first instar,63.90 ppm and 133.07 ppm for the second inslar,72.45 ppm and 139.82 ppm for the third instar,78.93 ppm and 143.20 ppm for the fourth instar,respectively. During the pupal stage the methanolic extract of M.oleifera showed that the LC_(50),and LC_(90) values were 67.77 ppm and 141.00 ppm,respectively.Conclusions:The present study indicates that the phytochemicals derived from M.oleifera seeds extracts are effective mosquito vector control agents and the plant extracts may be used for further integrated pest management programs.
基金Supported by University Grants Commission,New Delhi.India
文摘Objective:To evaluate the antimicrobial activity of Turbinaria conoides(T.conoides).Padina gymnospora(P.gymnospora) and Sargassum tenerrimum against human bacterial and fungal pathogens.Methods:The antimicrobial activities of the extracts against various organisms were tested by using disc diffusion method.Results:The methanol extract showed the better result than the other extracts.Whereas,the strong antibacterial inhibition was noted in methanol extracts of P.gymnospora against Bacillus subtilus(26.33±1.86) and the mild inhibition of ethanol extracts from T.conoides against Klebsiella pneumoniae(2.33±0.51).Acetone extraction of P. gymnospora had strong antifungal inhibition against Cryptococcus neoformans(23.00±1.78), and acetone extract of T.conoides had mild inhibition against Aspergillus niger(3.00±0.89). Conclusions:The seven different solvent extracts of seaweeds used in the present study have shown significant bacterial action.Further,a detailed study on the principle compound in the seaweeds which is responsible for antimicrobial activity is still needed and it can be achieved by using advanced separation techniques.
文摘Objective:To evaluate the antibacterial activity of Halophila stipulacea(H.stipulacea), Cymodocea serrulata(C.serrulata) and Halodule pinifolia(H.pinifolia) against seven human bacterial pathogens.Methods:The antibacterial activities of the extracts on the various test organisms using disc diffusion method and Minimum Inhibitory Concentraction(MIC).Results: Methanol and chloroform extracts of all the three seagrasses were active against all the tested pathogens,whereas the hexane extract of seagrasses was not active against Staphylococcus aureus (S.aureus).Antibacterial activity of three seagrass screened,was in the order of H.pinifolia 】 H.stipulacea.】 C.serrulata.Conclusions:This antibacterial studies can further investigated on seagrasses for purification of bioactive substance and its possible utility in disease control.
基金University Grants Commission, New Delhi,India for providing the financial assistance for the work
文摘Objective:In vitro antioxidant activities of three selected Indian seaweeds viz.,Halimeda tuna(H.tuna),Turbinaria conoides(T.conoides) and Gracilaria foliifera(G.foliifera) were evaluated.Methods:Total antioxidant activity,total phenolic content,and reducing power of crude methanol and diethyl ether extracts were determined.Results:Total phenolic content and total antioxidant activity were higher(1.231±0.173 mg GAE/g,1.675±0.361 mg GAE/g) in T.conoides respectively.Reducing power of crude methanol extract increased with concentrations of the extract.The Fourier transform-infra red spectrum analysis revealed the presence of polyphenolic signals.The seaweed extracts displayed moderate antioxidant activity compared to gallic acid standard.Conclusions:The seaweeds could be considered for curing diseases from oxidative deteriorations.
文摘Objective:To investigate the antimicrobial activity of the tissue extracts of Babylonia spirata(B.spirala)against nine bacterial and three fungal patliogeiis.Methods:Crude extract of gastropod was tested for inhibition of bacterial and fungal growth.Antibacterial assay was carried out by disc diffusion method and in vitro antifungal activity was determined against Czapex Dox agar.The antimicrobial activity was measured accordingly based on the inhibition zone around the disc impregnated with gastropod extract.Molecular size of muscle protein was determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE).And fourier transform infrared spectroscopy(FT1R)spectro photometry analysis was also studied.Results:The maximum inhibition zone(12 mm)was observed against Pseudomonas aeruginosa in the crude ethanol extract of B.spirata and the minimum inhibition zone(2 mm)was noticed against Staphylococcus aureus in the crude methanol extract of B.spirala.Water extract of B.spirala showed the highest activity against Vibrio parahaemolyticus,Staphylococcus aureus and Candida albicans.Ethanol,acetone,methanol,chloroform and water extracts showed antimicrobial activity against almost all the bacteria and fungus.Compared with water extracts,ethanol and methanol extracts showed higher activity against all pathogens.The molecular weight of protein of the gastropod sample ranged from 2-110 kDa on SDS-PAGE.FTIR analysis revealed the presence of bioactive compounds signals at different ranges.Conclusions:The research shows that the great medicinal value of the gastropod muscle of B.spirata may be due to high quality of antimicrobial compounds.
文摘Objective:To study the antimicrobial,hemolytic activity and immunomodulatory activity of fish epidermal mucus and their chemical constituents from Cynoglossus arel(C.arel) and Alius caelatus(A.caelatus).Mucus plays an important role in the prevention of colonization by parasites,bacteria and fungi.Methods:Epidermal mucus was obtained from two marine fishes,lyophilized and the chemical composition of epidermal mucus was analysed by FT-IR analysis.The in vitro antimicrobial activity against human pathogens(fungi,gram positive and gram-negative bacteria) and also the hemolytic activity and immunomodulatory activity were determined.Results:Totally ten human pathogens were tested against the fish mucus.Out of the ten pathogens,five pathogens have proved to be sensitive to the mucus.Maximum zone of inhibition was observed against Vibrio cholera(V.cholera)(9 mm and 2 mm in diameter),followed by Staphylococcus aureus(S.aureus) with a inhibition zone of(6 mm and 3 mm),Streptococcus areus(S.areus)(5 mm and 4 mm),Vibrio parahemolyticus(V.parahemolyticus)(4 mm and 5 mm) respectively.Conclusions:The present investigation has revealed that positive progresses in the fish mucus extracts against human pathogens and hemolytic activity.But further efforts are required for the purification and isolation of the active antimicrobial compounds in order to establish their possible applications.