ISOLATION AND TESTING OF ANTIMICROBIAL ACTIVITY OF LACTIC ACID BACTERIA FROM CASSAVA FERMENTATION (MANIHOT ESCULENTA) IN INHIBITING ESCHERICHIA COLI AND SALMONELLA TYPHI

Lactic acid produced by lactic acid bacteria can lower the medium pH, inhibiting the contamination from putrefactive bacteria and killing pathogenic bacteria. Lactic acid bacteria can be isolated from various sources, including cassava which is obtained by fermentation process and called as cassava tape. Lactic acid bacteria from cassava tape are a probiotic that has potency to improve intestinal physiological function. Its presence can prevent the growth of pathogenic bacteria such as Salmonella typhi and Escherichia coli. This research aims to measure the ability of lactic acid bacteria isolates from cassava tape in inhibiting Escherichia coli and Salmonella typhi. This study was carried out from April to August 2023 in Bacteriology Laboratory of the Health Polytechnic, Ministry of Health in Medan. The cassava tape was originated from Sukaramai Market in Medan. The ability of Lactic Acid Bacteria against the pathogenic bacteria is measured by the inhibition zone's size. This study obtained 4 types of lactic acid bacteria isolates. The lactic acid bacteria isolate had inhibition zone against Escherichia coli and Salmonella typhi, 1.36 cm and 1.26 cm, respectively. People are recommended to consume cassava tape as a healthy food because it can suppress the growth of Escherichia coli and Salmonella typhi bacteria.
Keywords: Cassava Tape, Escherichia Coli, Salmonella Thypi, Lactic Acid Bacteria.