Abstract: In this paper, artificial neural network (ANN), which can simulate an enzymatic hydrolysis process based on self-learning, was applied to study the optimum conditions for enzymatic preparation of antibacterial peptides from Pinctada fucata muscle with flavourzyme. The hydrolysis of Pinctada fucata muscle by flavourzyme was simulated and optimized using a three-hierarchy ANN structure. The antimicrobial activity of Pinctada fucata muscle hydrolysates was tested by cylinder-plate method. The results demonstrated that the peptide A was obtained after 4 h of hydrolysis under the conditions of pH 7.0, 55 ℃, 7:5 material/liquid ratio and 1.6% enzyme/substrate ratio, which showed the strongest antibacterial activity against Salmonella typhimurium with an inhibition zone diameter of 14.20 mm and an average peptide chain length of 2.6. Four-hour hydrolysis under the conditions of pH 7.0, 55 ℃, 3:2 material/liquid ratio and 1.7% enzyme/substrate ratio generated the peptide B, which had the strongest antibacterial activity against Shigella dysenteriae with an inhibition zone diameter of 23.42 mm and an average peptide chain length of 2.8. The peptide C was obtained under the conditions of pH 6.5, 60 ℃, 7:5 material/liquid ratio, 2.5% enzyme/substrate ratio and 4 h hydrolysis, which displayed the strongest antibacterial activity against L.monocytogenes with an inhibition zone diameter of 16.60 mm and an average peptide chain length of 2.5. The three peptides also had strong antibacterial activity against Escherichia coli and Staphyloccocus aureus with an inhibitory rate ranged of 74.3%－80.8%. The application of ANN for optimizing antibacterial peptides preparation from Pinctada fucata muscle overcomes many shortcomings such as low purity and low extraction efficiency and can therefore provide technical supports for the development and exploitation of antibacterial peptides derived from Pinctada fucata muscle.

Key words: Pinctada fucata muscle, antimicrobial peptides, production, artificial neural network optimization