Antibacterial activities of chemical and biological food preservatives towards food spoilage bacillus among and within species

Food preservatives could cause a wide spectrum of antibacterial efficacies against different spoilage microbial species or strains; however, the mode of variation in antibacterial activities among and within species is still unclear which limits their effective applications in food preservation. In this study, ten thermoresistant spore-forming Bacillus strains as a typical spoilage microbial group were used to evaluate the variances of antibacterial activities of three chemical and three biological food preservatives among these species or strains by the statistical analysis of MIC using SAS 9.2 software. The biological preservatives exhibited much higher anti-bacillus activities compared to the chemical preservatives, and significant variances of MICs were observed among different Bacillus species for chemical preservatives while no variances were observed for biological preservatives. Variances of MICs among different strains in a species were not observed for both chemical and biological preservatives. The possible antibacterial mechanism has also been discussed to encounter food spoilage.