IDENTIFICATION AND APPRAISAL OF CRUDE PROTEIN EXTRACTS FROM SOUTH INDIAN MARINE EDIBLE BIVALVES FOR THEIR POTENTIAL BACTERICIDAL PROPERTY

Abstract

Objectives: The crude protein extracts of edible marine invertebrates Pitar erycina and Donax cuneatus collected from the coastal area of South India were evaluated for its antimicrobial potency against broad spectrum of bacterial pathogens.

Methods: The crude proteins were extracted from the flesh with 5percent cold acetic acid and buffers at acidic, neutral and basic pH. The crude was partially purified by ammonium sulfate precipitation method and the precipitate was stored at -20ËšC still evaluation. The antimicrobial property was assessed by well diffusion method. Both the edible oyster extracts showed inhibitory effects against the tested bacterial and fungal strains.

Results: The maximum zone of 24mm was observed with Donax cuneatus acidic extract against Bacillus subtilis and a minimum of 17mm zone was observed against Pseudomonas aeruginosa, Salmonella typhi, Shigella flexneri. The Pitar erycina acidic extract showed the maximum activity against E.coli  and Shigella flexneri  with 17mm and 15mm zone respectively. The antimicrobial potency of buffer extracts of the two bivalves was comparingly low with that of the acidic extracts. 1.23mg/ml protein was estimated in Donax cuneatus acidic extract.

Conclusion: The crude extracts of protein from edible bivalves showed potent bactericidal property against highly pathogenic species, which may helps to find a safe novel protein/peptide antibiotic.

Keywords:  Edible bivalve, Marine invertebrate, Antimicrobial Assay, Antimicrobial Peptides