Antimicrobial activity of red seaweed Gracilaria corticata against human pathogenic bacterial strains

Abstract

Recent microorganisms have developed resistance to existing available antibiotics, thereby thriving to an emerging need for new generation of antibiotics. Since seaweeds provide a rich source of bioactive molecules, the present study aimed to investigate its antibacterial potential against clinically important microorganism. Red seaweed namely Gracilaria corticata collected from different coastal regions of Gulf Of Mannar Sea shore, Thoothukudi, India were used. For microbiological testing of the seaweed extracts, agar disc diffusion method was used. The zone of inhibition was measured for all the different crude algal extracts against eight strains of microorganisms including four Gram positive bacteria including Staphylococcus aureus, Bacillus subtilis, Streptococcus pneumonia, Enterococcus faecalis and four Gram negative bacteria including Pseudomonas aeruginosa, Klebsiella pneumonia, Proteus mirabilis and Salmonella typhi that cause diseases in human beings, animals and plants. Crude extracts prepared from Acetone, Chloroform, Ethanol and Methanol extraction procedures revealed that methanol extraction procedure have a wide range of antibacterial activity against all the test pathogens. The overall antibacterial activity assessed from the above results indicates the presence of active constituents in the extractions of seaweeds which can be explored for the production of significant molecules which could be used in pharmaceutical industry.