Objective:To evaluate the antimicrobial activity of Actinomycetes species isolated from marine environment.Methods:Twenty one strains of Actinomyceteswere isolated from samples of Royapuram, Muttukadu, Mahabalipuram s...Objective:To evaluate the antimicrobial activity of Actinomycetes species isolated from marine environment.Methods:Twenty one strains of Actinomyceteswere isolated from samples of Royapuram, Muttukadu, Mahabalipuram sea shores and Adyar estuary. Preliminary screening was done using cross-streak method against two gram-positive and eight gram-negative bacteria.The most potent strains C11 and C12 were selected from which antibacterial substances were extracted. The antibacterial activities of the extracts were performed using Kirby-Bauer disc diffusion method. Molecular identification of those isolates was done.Results:All those twenty one isolates were active against at least one of the test organisms. Morphological characters were recorded. C11 showed activity againstStaphylococcusspecies(13.0暲0.5 mm),Vibrio harveyi(11.0暲0.2 mm),Pseudomonas species(12.0暲0.3 mm). C12 showed activity against Staphylococcus species(16.0暲0.4 mm),Bacillus subtilis(11.0暲0.2 mm),Vibrio harveyi(9.0暲0.1 mm),Pseudomonas species(10.0暲0.2 mm). 16S rRNA pattern strongly suggested that C11 and C12 strains were Streptomyces species.Conclusions:The results of the present investigation reveal that the marineActinomycetesfrom coastal environment are the potent source of novel antibiotics.Isolation, characterization and study of Actinom ycetescan be useful in discovery of novel species of Actinomy cetes.展开更多
Background:Mosquito is a big threat to the human health.Mosquito-borne diseases cause millions of death to the human beings.Hence,a permanent solution is eagerly to be established to control its excessive growth in st...Background:Mosquito is a big threat to the human health.Mosquito-borne diseases cause millions of death to the human beings.Hence,a permanent solution is eagerly to be established to control its excessive growth in stagnant water.Portulaca oleracea Linn is a natural larvicidal agent,which contains active ingredients such as linolenic acid,linoleic acid(omega-3 fatty acids).These bioactive compounds may be responsible for its larvicidal properties on mosquito.Objective:The present study is focussed on identifying the bioactive compounds,such as linolenic acid,through GC-MS,and analyzing the larvicidal efficacy of Portulaca oleracea L.against Culex quinquefasciatus and Anopheles stephensi larvae.Methods:Preliminary phytochemical analysis,total protein content,total carbohydrate content,total phenol content,total flavonoid content and GC-MS analysis exhibited the presence of rich phytoconstituents in Portulaca oleracea.DPPH analysis was carried out to analyze the antioxidant potential of plant extract.Larvicidal activity and histological change were detected to evaluate the efficacy of Portulaca oleracea L.on the Culex quinquefasciatus and Anopheles stephensi larvae.Results:Aqueous and ethanol leaf extracts of Portulaca oleracea L.against both Culex quinquefasciatus and Anophe-les stephensi larvae,showed a very good larvicidal activity at 500μg/mL among the various concentrations.His-tological damages of mosquito larvae were observed when treated with the Portulaca oleracea L.extract,and provided further evidence for its larvicidal activity.Conclusion:This study concluded that the plant Portulaca oleracea L.contained many useful bioactive compounds,can be a strong larvicidal agent against both Culex quinquefasciatus and Anopheles stephensi larvae.The molecular mechanism for the larvicidal activity will be identified in future studies.展开更多
文摘Objective:To evaluate the antimicrobial activity of Actinomycetes species isolated from marine environment.Methods:Twenty one strains of Actinomyceteswere isolated from samples of Royapuram, Muttukadu, Mahabalipuram sea shores and Adyar estuary. Preliminary screening was done using cross-streak method against two gram-positive and eight gram-negative bacteria.The most potent strains C11 and C12 were selected from which antibacterial substances were extracted. The antibacterial activities of the extracts were performed using Kirby-Bauer disc diffusion method. Molecular identification of those isolates was done.Results:All those twenty one isolates were active against at least one of the test organisms. Morphological characters were recorded. C11 showed activity againstStaphylococcusspecies(13.0暲0.5 mm),Vibrio harveyi(11.0暲0.2 mm),Pseudomonas species(12.0暲0.3 mm). C12 showed activity against Staphylococcus species(16.0暲0.4 mm),Bacillus subtilis(11.0暲0.2 mm),Vibrio harveyi(9.0暲0.1 mm),Pseudomonas species(10.0暲0.2 mm). 16S rRNA pattern strongly suggested that C11 and C12 strains were Streptomyces species.Conclusions:The results of the present investigation reveal that the marineActinomycetesfrom coastal environment are the potent source of novel antibiotics.Isolation, characterization and study of Actinom ycetescan be useful in discovery of novel species of Actinomy cetes.
文摘Background:Mosquito is a big threat to the human health.Mosquito-borne diseases cause millions of death to the human beings.Hence,a permanent solution is eagerly to be established to control its excessive growth in stagnant water.Portulaca oleracea Linn is a natural larvicidal agent,which contains active ingredients such as linolenic acid,linoleic acid(omega-3 fatty acids).These bioactive compounds may be responsible for its larvicidal properties on mosquito.Objective:The present study is focussed on identifying the bioactive compounds,such as linolenic acid,through GC-MS,and analyzing the larvicidal efficacy of Portulaca oleracea L.against Culex quinquefasciatus and Anopheles stephensi larvae.Methods:Preliminary phytochemical analysis,total protein content,total carbohydrate content,total phenol content,total flavonoid content and GC-MS analysis exhibited the presence of rich phytoconstituents in Portulaca oleracea.DPPH analysis was carried out to analyze the antioxidant potential of plant extract.Larvicidal activity and histological change were detected to evaluate the efficacy of Portulaca oleracea L.on the Culex quinquefasciatus and Anopheles stephensi larvae.Results:Aqueous and ethanol leaf extracts of Portulaca oleracea L.against both Culex quinquefasciatus and Anophe-les stephensi larvae,showed a very good larvicidal activity at 500μg/mL among the various concentrations.His-tological damages of mosquito larvae were observed when treated with the Portulaca oleracea L.extract,and provided further evidence for its larvicidal activity.Conclusion:This study concluded that the plant Portulaca oleracea L.contained many useful bioactive compounds,can be a strong larvicidal agent against both Culex quinquefasciatus and Anopheles stephensi larvae.The molecular mechanism for the larvicidal activity will be identified in future studies.
