ISOLASI DAN SELEKSI BAKTERI ASAM LAKTAT DARI YOGHURT KEMASAN YANG BERSIFAT ANTIBAKTERI TERHADAP Escherichia coli DAN Salmonella typhi

Abstract

Yoghurt is a fermented product of a group of lactic acid bacteria (LAB) on milk that has been pasteurized. LAB is a group of bacteria that are able to convert carbohydrates (glucose) into lactic acid. LAB produces metabolites that inhibit the growth of pathogenic bacteria. This study aimed to isolate LAB from yoghurt packaging with its inhibitory against bacterial pathogens Escherichia coli and Salmonella typhi. LAB was isolated from 9 samples with 3 brand products and 3 different flavors. Calculation of the total population to the overall LAB samples was obtained between 6.4 × 106 cfu/ml to 2.1 × 107 cfu/ml. In this study, inhibition test of pathogenic bacteria E. coli and S. typhi used samples yoghurt. The method used is the well-agar diffusion. The most effective yoghurt in inhibiting E. coli was yogurt Ab with diameter of inhibiting zone 23.55 mm, while the yogurt sample that had the highest inhibitory zone which is 19.93 mm for S.typhi was yoghurt Ap