Role of extracted bacteriocins from standard isolates as biological preservatives against isolated pathogenic bacteria from different types of fresh meat

Due to the increasing demand for the high quality of meat products, long shelf life, and minimum processing, therefore, this study aimed to evaluate the antimicrobial activity of the two standard strains Lactobacillus delbrukii subspp delbrukii )PTCC 1333( and Lactobacillus fermentum (PTCC 1744) on the most common isolated bacteria from meat. In this study, 50 meat samples including red meat, minced meat, and fish were purchased from different areas of Shiraz city. The samples were transferred to the lab and cultivated in Nutrient Broth as well as blood agar. Then the isolates were purified and the most common isolates identified using biochemical tests. The inhibitory activity of the two strains lactobacillus supernatant against the most common isolates was investigated by the good diffusion agar method. As well as to prevent the inhibitory effects of organic acids and H2O2, the supernatant was treated with sodium hydroxide and catalase enzyme. Finally, the most common isolates were identified by PCR molecular technique. Common bacteria were reported by the molecular test as Escherichia coli (16.6%), Enterobacter cloacae (16.6%), Hafnia alvei (50%), and Aeromonas salmonicida (16.6%). The greatest effect of lactic acid bacteria on Escherichia coli, Hafnia alvei, and Aeromonas salmonicida was observed. Among the two standard strains of lactobacillus, Lactobacillus delbrukii has a greater effect on isolated bacteria. The supernatant of the two lactobacilli, without neutralizing with Sodium Hydroxide and catalase, had antimicrobial activity against the most common isolates.