Screening Antimicrobial Peptides from Hydrolysates of Sunflower Seed Meal Protein Hydrolyzing with Proteases

Antimicrobial peptides were obtained from the protein of sunflower seed meal (SSM) treated with three kinds of proteases. Only the hydrolysate of sunflower seed meal protein (SSMP) treated by pepsin could appear zones of inhibition on the MRS agar plates for Escherichia coli, Staphylococcus aureus and Bacillus subtillis, and the hydrolysates obtained by trypsin and papain were with little antimicrobial activities. Three fractions of peptides of SSMP hydrolysis by pepsin with molecular weight (MW) <3500 Da (P1), 3500 Da to 5000 Da (P2), and >5000 Da (P3) were obtained by dialysis separation. The zones of inhibition tests of the three fractions showed that all the three fractions possessing antimicrobial activities exhibited the inhibition zones, but their inhibitory activities were distinctly lower in comparison with the unseparated ones.