Lactic Acid Bacteria Producing Sorbic Acid and Benzoic Acid Compounds from Fermented Durian Flesh (Tempoyak) and Their Antibacterial Activities Against Foodborne Pathogenic Bacteria

Antibacterial compounds produced by lactic acid bacteria are believed to replace functions of chemical preservatives. The objectives of this study were to identify lactic acid bacteria, which produced antibacterial compounds, from fermented durian flesh (tempoyak) and to assess antibacterial activities of the isolates. Material and Methods: Two bacterial identification techniques were used, including API 50 CHL kit with supplementary medium and matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF/MS). Results and Conclusion: Four various lactic acid bacteria strains of Lactobacillus buchneri, Lactobacillus plantarum, Lactobacillus brevis I and Lactobacillus acidophilus I were identified using API 50 CHL Kit and five various others of Lactobacillus paracasei DSM 2649, Lactobacillus buchneri DSM 20057T, Lactobacillus parabuchneri DSM 57069, Lactobacillus paracasei DSM 20020 and Lactobacillus farcimini CIP 103136T using MALDI-TOF/MS. Cell-free supernatant extracted from Lactobacillus plantarum, Lactobacillus buchneri, Lactobacillus brevis I and Lactobacillus acidophilus I included strong inhibitory effects against Vibrio cholera O1 (Inaba type), Vibrio cholera O139 (Bengal type), Vibrio parahaemolyticus ATCC 17802, Escherichia coli ATCC 11795, Escherichia coli O157, Salmonella typhimurium ATCC 14028 and a total of 23 serotypes of Salmonella spp. associated with outbreaks of food poisoning from raw chicken, egg shell and water samples. Only Lactobacillus buchneri DSM 20057T was identified by MALDI-TOF/MS as a strain producing sorbic and benzoic acids. This strain can potentially be used as food preservative to decrease growth of foodborne pathogenic bacteria.