Sodium Nitrite has been widely use as preservative for meats and fish Products, but in recent years there has been considerable interest for searching about natural Food preservatives like Nisin peptide. The aim of this study was to compare the inhibitory effect of two preservatives were Sodium Nitrite and Nisin peptide separately against Staphylococcus Aureus (Staph. A), Escherichia coli (E. coli), and Candida Albicans (C. Albicans) in Mueller Hinton Broth (MHB) at three different pH (7.0- 6.0- 5.5). After that the combination effect between Sodium Nitrite and Nisin was studied in MHB at optimum pH that was concluded from the previous stage. Minimal Inhibitory Concentrations (MIC) and Minimal Bactericidal Concentrations (MBC) of both preservatives were evaluated. FIC values (Fractional Inhibitory Concentration) were calculated after combination between them. The results showed that MIC values of Sodium Nitrite against S. Aureus, E. coli and C. albicans at pH 5.5 were (500- 200- 500) ppm respectively and MIC values of Nisin were (100- 350- 500) ppm respectively, while MIC values of the combination (Sodium Nitrite+ Nisin) against S. A, E. coli and C. albicans were (50- 25- 100) ppm respectively and FIC values of them were (0.39- 0.15- 0.30). On the other hand The results showed that simultaneous use of Nisin with sodium nitrite reduced MIC and MBC of this compound against bacteria and fungi Significantly consequently, this synergistic effect of Nisin could promote in the Future to reduce of the using of Sodium Nitrite in food industry.
