Phytochemical Constituency Profiling and Antimicrobial Activity Screening of Seaweeds Extracts Collected from the Bay of Bengal Sea Coasts

Abstract

AbstractSeaweeds are able to produce a great variety of secondary metabolites that are characterized by a broad spectrum of biological activities. Two seaweeds species, namelyHypnea musciformisandEnteromorpha intestinalis werestudied to evaluate the phytochemical constituency and antimicrobial activities. First of all, crude extracts of both sea weeds were prepared by two different extraction methods (soaking and water bath) using different solvents. Phytochemicals profiling results revealed the presence of bioactive compounds (flavonoids, alkaloids, tannin, saponin and phenols) in both seaweed extracts. Quantification results for ethanolic extracts ofH. musciformis and E. intestinalisestimated 51 mg and 43 mg tannins in per gram of dried samples and flavonoids contents were found 67 mg and 57 mg/g mg QE/g respectively. Total phenolic contents were determined in terms of gallic acid equivalent (GAE).H. musciformisexhibited higher amount of phenolics (59 ± 0.0002 mg GAE/g) thanE. intestinalisextracts (41 ± 0.0002 mg GAE/g). In antimicrobial activity test, ethanol extractsof H. musciformisandE. intestinaliswere found 10 mm of inhibition diameter against all of the bacterial strains. Besides, methanol extracts ofE. intestinaliswere more susceptible toStaphylococcus aureus and Pseudomonaswhich was close to the inhibition diameter (>15 mm) of the mainstream antibiotic; Gentamicin. Moreover,Klebsiella sp. was found more susceptible to ethanol and methanol extracts of Hypnea musciformisas it showed inhibition zone greater than 15 mm. Both Seaweed extracts possessed higher amount of phytochemicals and showed promising antimicrobial activities when compared with the standards.