The effects of cell free supernatants of Lactobacillus reuteriATCC55730 and Lactobacillus plantarum FI8595 against selected fish spoilage and foodborne pathogen microorganisms were investigated. For detection of the antimicrobial effect of cell free supernatants from two Lactobacillus strains,
four food-borne pathogens (Salmonella Paratyphi A NCTC13, Staphylococcus aureus ATCC29213, Klebsiella pneumoniae ATCC700603, and
Listeria monocytogenesATCC19112) and three fish spoilage bacteria (Proteus mirabilis, Enterococcus faecalis and Pseudomonas luteola) were used.
The agar well diffusion method was performed to determine the antimicrobial effects. The cell free supernatants of both L. reuteri and L. plantarum
were effective on fish spoilage bacteria tested. Especially, E. faecalis showed high sensitivity against both CFS obtained from L. plantarum and L.
reuteri with 16.75 and 22.75 mm inhibition zone diameter, respectively. The CFS of L. reuteri exerted a strong ability to inhibit the growth of all foodborne pathogens. The highest antibacterial effect of CFE of L.reuteri was observed on S. aureus, with the diameter of 26.50 mm inhibition zone.