Evaluation of Antibacterial and Sanitizing Activity of Lactobacillus Plantarum Against Staphylococcus Aureus in Stored Citrus Lanatus (Melon) Drink

Abstract

The main study objective was to isolate and characterize some lactic acid bacteria from some fermented foods and evaluate their ability to produce antagonistic effect against some food- borne pathogens as biopreservatives in the form of protective cultures or their metabolites. Isolation and Identification of Lactobacillus species from some fermented drinks was carried out on six different food types in triplicates following standard procedures. Following Isolation and Identification by biochemical and molecular methods, the antimicrobial activity of the Lactobacillus isolates in three different densities (1.5 × 108 cfu/mL, 2.1 × 108 cfu/mL and 3.0 × 108 cfu/ml) were evaluated against Escherichia coli, Salmonella typhi, Salmonella typhimurium and Staphylococcus aureus isolated from some foods. Sanitizing activity of L.plantarum against S.aureus in melon drink was evaluated at the time intervals of 0, 24 and 48 hours respectively. Results of Isolation and Identification revealed the isolate to be L. plantarum. Antibacterial activity of different densities of Lactobacillus showed that for 1.5 × 108 cfu/ml and 2.1 × 108 cfu/ml densities, the highest zone of inhibition produced were 17.00 ± 0.57 and 24.66 ± 0.88 against S. typhi and the least (6.66 ± 0.66) against E. coli. For 3.0 x 108 cfu/ml density, the highest zone of inhibition was 35.33 ± 0.88 against S. typhi and the least was 9.66 ± 1.66 against coli. Statistical analysis revealed significant difference (P<0.05) in the antimicrobial activity of three different densities of Lactobacillus against the tested bacterial isolates. Results of sanitizing activity of L.plantarum against S.aureus revealed 3.52 Log10cfu/ml reduction after 24hours of storage. Conclusively, Lactobacillus plantarum could be employed as a biopreservative in stored melon drink.