ASSESSMENT OF PROBIOTIC CHARACTERISTICS OF LATILACTOBACILLUS CURVATUS AND LEUCONOSTOC MESENTEROIDES FROM INDIAN FERMENTED NON-DAIRY FOODS

Abstract

Fermented foods are being broadly explored for different strains of lactic acid cultures which can enhance the organoleptic and nutritional quality of food and promote health of the consumer. Current study emphasizes on the isolation, screening, identification of lactic acid bacteria (LAB) with probiotic properties from non-dairy traditionally fermented Indian foods. In this study, isolation of LAB was performed from fermented cooked whole wheat extract. Total 33 isolates were obtained that displayed Gram positive character, catalase and oxidase negative test and showing γ-hemolysis pattern. The selected isolates were identified based on 16S rRNA sequencing after screening for their probiotic characters. The isolate ‘GC03’ was identified as Latilactobacillus curvatus (100% similarity) and isolate ‘GC04’ as Leuconostoc mesenteroides subsp. mesenteroides (99.35 % similarity) with type strain. Survivability of isolates in gastric environment was evaluated by acid and bile tolerance. Highest percent survivability at pH 2 was seen at 17.16 % and 21.11 % for Latilactobacillus curvatus and Leuconostoc mesenteroides respectively. Also, Lat. Curvatus GC03 showed 35.02 % bile tolerance at 0.3% bile whereas, Leuconostoc mesenteroides GC04 28.63 % tolerance. Isolates were tolerant up to 8% NaCl concentration and tolerate temperatures up to 45°C. The significant antibacterial and antibiofilm activity of cell-free supernatants of both the LAB against Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and Escherichia coli was observed. The isolates exhibited typical probiotic characters (acid and bile tolerance) along with considerable antibacterial and anti-biofilm activity and could be exploited further for their potential in human endeavour.