Antimicrobial activity of methanolic extract and fractionated polysaccharide from Loligo duvauceli Orbingy 1848 and Doryteuthis sibogae Adam 1954 on human pathogenic microorganisms

In the present study, in vitro antimicrobial activity of  crude methanolic extract of squid body tissue and fractionated gladius polysaccharide of two squid (Loligo duvauceli and Doryteuthis sibogae) from Cuddalore and Mudasalodai (Southeast Coast of India) landing centre was evaluated. The antimicrobial activity was screened against nine species of clinically isolated human pathogenic bacteria namely Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Vibrio cholerae, V. parahaemolyticus, Staphylococcus aerues, Pseudomonas aeruginosa, Salmonella typhii and Shigella sp. and four fungal strains such as Candida sp., Rhizopus sp., Aspergillus flavus and A. fumigates. Different concentrations such as 25, 50, 75 and 100% were prepared and tested against the microbial strains for their inhibitory activities, using the disc diffusion method. The minimum inhibitory concentration (MIC) of methanolic body tissue extract and fractionated gladius polysaccharide of squid ranged from 60 to 100 mg/ml. The results were discussed in the light of positive and negative control apart from the concentrations tested.   Key words: Antimicrobial activity, squid, gladius, minimum inhibitory concentration (MIC) and pathogenic microorganisms.