eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2016-06-07 11 Spl.Edn.1 25 29 10.13005/bbra/1387 11731 article R. Muthezhilan 1 K. Balaji 1 K. Gopi 1 A. Jaffar Hussain 2 Department of Marine Biotechnology, AMET University (U/S of UGC Act 1956) Kanathur, Chennai 603112, India. Centre for Marine Bioprospecting, AMET University (U/S of UGC Act 1956) Kanathur, Chennai 603112, India. Nowadays, the pharmaceutical market is growing rapidly and continuously in worldwide but, still the demand for new drug discovery is encouraged. Because, the growth of numbers drug resistant infectious disease and more upcoming disorders to human and animals. In general, the marine animals especially mollusks and their compounds constitute a practically unlimited resource of new active substances. Hence, the present study was carried out to determine the bactericidal activity of Crassostrea madrasensis protein against human pathogens. The edible Oyster Crassostrea madrasensis was collected from Rayapuram lnading centre, Tamil Nadu, India. Immediately it was extracted by using phosphate buffer at three different pH (4, 7 and 9) and all the extracts were screened against six different human pathogens such as Vibrio cholerae, V. parahaemolyticus, Salmonella sp, Shigella sp, Streptococcus sp and Staphylococcus sp by agar well diffusion assay. After 24 hrs of incubation the maximum inhibitory effect was observed against Vibrio parahaemolyticus, Streptococcus sp and Staphylococcus sp and the minimum inhibitory effect was observed against Vibrio cholerae, Salmonella sp and Shigella sp respectively. Whereas checking the minimal inhibitory concentration (MIC), the crude protein extract of Crassostrea madrasensis was inhibited the bacterial strains with the minimum inhibitory concentration of not less than 0.1ml (100¼l). The molecular weight of the crude protein was found from 12.2 to 74.2 kDa and the total protein content of phosphate buffer crude extract of Crassostrea madrasensis was found to be 312 ¼g/ mg. From, the results, the work has suggested to use this commercially available and protein rich (bactericidal) oyster in therapeutics for the development of novel antibiotics against multiple drug resistance (MDR) pathogenic microbes. https://www.biotech-asia.org/vol11_nospl_edn1/purification-of-protein-from-marine-edible-oyster-crassostrea-madrasensis-for-bactericidal-potency/ Crassostrea madrasensis; Human pathogens; Antibacterial activity; Bactericidal activity