Abstract: Nisin is antibacterial multipeptide produced by certain strain of lactococcus lactis. It is a high-efficiency and nonpoisonous effect natural biopreservative. Nisin is effective against Gram-positive bacterium, however, there is no effect on the inhibition of Gram-negative bacterium and yeast. Poly-lysine, a kind of a peptide polymerized by the amid e bond between α-carboxyl and ε-amino groups, shows a wide rang of antimicrobial activity, water solubility, high safety, stability at high temperatures and wide pH range. Nisin and Poly-lysine in extending the shelf life of prawn was studied in this paper. The results showed that, the effect of Nisin, and related factors on the quality of the prawn had been investigated with orthogonal test, sense assess and microbiological analysis. Therefore, the optimum processing for preserving prawn with Nisin has been determined.
Keywords: Nisin; Poly-L-lysine; antimicrobial activity; orthogonal test