Antagonistic properties of seagrass associated Streptomyces sp.RAUACT-1:A source for anthraquinone rich compound

Objective:To identify the antibacterial potential of seagrass(Syringodium isoetifoliutn) associate microbes against bacterial pathogens.Methods:Eumeration of microbial associates were analyzed with leaf and root samples of Syringodium isoetifolium.MIC and MBC were calculated for bacterial pathogens with microbial associates.Phylogenetic and GC-MS analysis were calculated for Actinomycetes sp.(Act01) which was the most potent.Results:Of the isolated microbial associates phosphatase producing bacterial isolates were identified as maximum [(26l.78±35.09) CFU×10~4/g]counts in root sample.Of the selected microbial isolates Actinomycete sp(Act01) showed broad spectrum of antibacterial activity against antibiotic resistant and fish bacterial pathogens.Phylogenetic analysis of Act01 showed maximum identities(99%) with the Streptomyces sp.(GU5500072).The 16s rDNA secondary structure of Act01 showed the free energy values as -366.3 kkal/mol.The GC-MS analysis Act01 showed maximum retention value with 23.742 RT and the corresponding chemical class was identified as 1,4-dihydroxy-2-(3- hydroxybutyl)-9,10-anthraquinone 9,10-anthrac.Conclusions:In conclusion,Streptomyces sp. (GU045544.1) from Syringodium isoetifolium could be used as potential antibacterial agent.

Bioactivity of seagrass against the dengue fever mosquito Aedes aegypti larvae

Objective:To identify the larvieidal activity of the seagrass extracts.Methods:Seagrass extracts,Syringodium isoelifolium(.S.isoetifolium),Cymodocea serrulata and Hulophila beccarii,were dissolved in DMSO to prepare a graded series of concentration.Batches of 25 early 4th instars larvae of Aedes aegypti(Ae.aegypti) were transferred to 250 ml.enamel bowl containing199 mL of distilled water and 1 mL of plant extracts(0.01 mg- 0.1 mg).After 24 h the mortality rate was identified with the formulae[(%of lest mortality-%of control mortality)/(100-%of control morlality)]× 100.Each experiment was conducted with three replicates and a concurrent control group.A control group consisted of 1 mL of DMSO and 199 mL of distilled water only.Results:The root extract of S.isoelifolium showed maximum larvicidal activity with minimum concentration of extract of LC_(50)= 0.0604 ± 0.0040)μg/mL with lower confidence limit(LCL)-upper confidence limit(UCL) =(0.051-0.071) and LC_(90)=0.0972 μg/mL followed by leaf extract of S.isoelifolium showed LC_(50)=(0.062 ± 0.005)μ'g/mL.The regression equation of pool and leaf extract of S.isoelifolium for4th instar larvae were Y =4.909- 1.32x(R^2= 0.909) and Y= 2.066+ 1.2x(R^2 =0.897) respectively.The results of the preliminary photochemical constituents shows the presence of saponin,steroids,terpenoid,phenols,protein and sugars.Conclusions:from the present study the ethanolic extracts of seagrass of S.isoelifolium possesses lead compound for development of larvieidal activity.