Antimicrobial Properties and Lactase Activities from Selected Probiotic Lactobacillus brevis Associated With Green Cacao Fermentation in West Sumatra, Indonesia

Abstract

Lactase activity is very important enzyme for Lactose Intolerant people. The lactic acid bacteria selected for use as Probiotic bacteria should be able to tolerate many organotoxic or heavy metal toxicities in intestine at least for 90 minute, attach to the epithelium, and grow in the lower intestinal tract before they can start providing any health benefits. The Green varieties of cacao fruits were used for cacao bean fermentation. The cacao bean covers with white pulp containing fructose, e.g. 42 mg/g, glucose 24 mg/g and sucrose 21 mg/g, as carbon source of Lactic Acid Bacteria (LAB). Screening of LAB was carried out after 24-36 h during spontaneous fermentation. This paper aims to find potential LAB resistant acid pH and producing potential antimicrobial and showing high protease/lactase activities. The medium of de Man, Ragosa, and Sharpe (MRS) were used to screen LAB, and 63 colonies were found. The screening of isolates is based on LAB survival growth in acid pH ranges (2.0; 2.5 and 3.0) and body temperature (37°C). For Antimicrobial experiments were used pathogen bacterial E. coli and Salmonela (Unand Collection) as indicator strain. Six isolate were conformed as strong antimicrobial and selected as potential for producing protease (lactase) using specific Triple Sugar Iron Agar (TSIA) medium. The isolate G3 and G6 were selected for further enzyme protease delivered with 2% Skim Milk as a protein subsrate. The results showed, the maximum amount of protease activity potential from isolate G6 in acid pH (3.0) were calculated as 0.0088 and protease activity 1.1795 Unit/mL, while the optimum of protease activity was found at pH (6.0) calculated protease activity 3.150 Unit/mL. This study could explain the possibility of using potential isolate G6 LAB as Probiotic for dairy or food Industry and supplement tablet. There is no report so far concerning this topic and potential isolate G6, with high antimicrobial or wide pH of protease. The study will continue to purify antimicrobial Bacteriocin and amino acid structure determination. The G6 isolate was 95% polymorphism with Lactobacillus brevis.