| The objective of this project was to isolate and purify the antimicrobial peptides from hen's egg white ovalbumin. Ovalbumin hydrolysate obtained by treatment with trypsin showed bactericidal as well as bacteriostatic activity against Gram-positive bacteria (Bacillus subtilis) and Gram-negative bacteria (Escherichia coli D-31) whereas ovalbumin itself didn't show any antimicrobial activity. Two antimicrobial peptides were isolated by chromatography. One peptide, with relative molecular mass of 20 kDa, showed bactericidal activity of 31% and 36% and bacteriostatic activity of 21% and 25% for E. coli D-31 and Bacillus subtilis, respectively. Another peptide, with a relative molecular mass of 15 kDa, showed bactericidal activity of 46% and 56% and bacteriostatic activity of 32% and 38% for E. coli D-31 and Bacillus subtilis, respectively. Conjunction of these two peptides increased its bactericidal activity by 78% and 83% and bacteriostatic activity by 61% and 80% in case of E. coli D-31 and Bacillus subtilis, respectively. These peptides act synergistically to inhibit the growth and inactivate the cells of E. coli D-31 and Bacillus subtilis. |
