The Antimicrobial Effect Of Clove Essential Oil And Nisin Against Listeria Monocytogenes

Listeria monocytogenes is a kind of important food-borne pathogens and can cause zoonoses. Thus preventing food from being contaminated by Listeria monocytogenes is a significant task. Natural bacteriostatic agent is more and more popular compared to synthetic bacteriostatic agents. The aim of this study was to research the antimicrobial effect of Clove essential oil and Nisin against Listeria monocytogenes. In addition, the antimicrobial mechanism was also discussed. In this paper, the research contents are divided into the following several parts:1 The minimal inhibitory concentration (MIC) of Clove essential oil and Nisin were determined.Double dilution method was used to determine the minimal inhibitory concentration of Clove essential oil and Nisin. Results showed that the minimal inhibitory concentration of Clove essential oil was 0.04%, the minimal inhibitory concentration of Nisin was 333.3 IU/g. The concentration gradient of the Clove essential oil was 0.04%,0.08%,0.12%; the concentration gradient of Nisin was 400 IU/g,800 IU/g.2 The antimicrobial effect of Clove essential oil and Nisin against Listeria monocytogenes in TSB-YE.Results showed that Clove essential oil, Nisin for inhibition of Listeria monocytogenes were significantly different (P<0.05), Clove essential oil and Nisin combined with interaction (P<0.05). The antimicrobial action of Clove essential oil increased with the rising of concentration. The antimicrobial action of Nisin increased with the rising of concentration. The effect of combination of Clove essential oil and Nisin was best.3 The antimicrobial effect of Clove essential oil and Nisin against Listeria monocytogenes in ground beef.According to the colony count results, the antimicrobial action of Clove essential oil increased with the rising of concentration both in 4? and 20?. The antimicrobial action of Nisin was same with that of Clove essential oil. The effect of combination of Clove essential oil and Nisin was best. Based on beef meat quality, at the end of the storage (4? and 20?), beef present different metamorphic degree of corruption. The control group had strong stale smell and dark color. The treatment group had lighter degree of metamorphism. The treatment of combination of Clove essential oil 0.08% and Nisin 800 IU/g had Clove smell and red color. And its ground beef was almost fresh.4 The morphological ultrastructure of Clove essential oil and Nisin against Listeria monocytogenes by transmission electron microscopy (TEM)Results suggested that Clove essential oil and Nisin can destroy the cell wall, cell membrane and cell contents. The treatment of combination of Clove essential oil and Nisin had the most significant influence. The effect of the combination of Clove essential oil and nisin were cell wall had been dissolved, the cell membrane was damaged, cell contents scattered degradation and was uneven.5 Analysis of protein profiles of Clove essential oil and Nisin against Listeria monocytogenes by SDS-PAGE.Results depicted that the Thalli protein contention of treatment groups were lower than that of control. May be, bacteriostatic agent destruct the cell structure, resulting in leakage of proteins inside cells. And bacteriostatic agent may be seriously affected the normal bacterium protein metabolism. Futhermore, bacteriostatic agent may be destroy bacterium protein and inhibit protein synthesis. The treatment of combination of Clove essential oil and Nisin had the most significant influence.