OPTIMIZATION OF BACTERIOCIN PRODUCTION BY LACTIC ACID BACTERIA FROM SPENT COFFEE GROUND HYDROLYSATE

OPTIMIZATION OF BACTERIOCIN PRODUCTION BY LACTIC ACID BACTERIA FROM SPENT COFFEE GROUND HYDROLYSATE

The instant coffee industry produces a considerable amount of spent coffee ground (SCG) as a residue that could be potentiallyutilized as a renewable lignocellulosic biomass feedstock for the production of bacteriocin. Bacteriocins have attracted muchattention from academia and industry because of their possible applications as non-toxic additives in food preservation andprevention of food spoilage from food-borne pathogenic bacteria. The objective of this study was to evaluate the possibility ofproducing bacteriocin by Lactobacillus plantarum BCRC 10069 and Lactobacillus paracasei LCW23 using SCG as feedstock. Thebacteriocin produced by L. plantarum and L. paracasei showed significant inhibitory activity against Gram-positive (Bacilluscereus) and Gram-negative bacteria (Escherichia coli). Response Surface Methodology (RSM) was used to optimize the factorsinvolving in bacteriocin production such as pH, glucose concentration, and cysteine concentration. The optimum conditions forbacteriocin production from L. plantarum were found to be 15 mg/mL of SCG concentration, 0.059% (w/v) of cysteine content, andpH 7.1; while the optimum conditions for L. paracasei were 19.1 mg/mL of SCG concentration, 0.062% (w/v) of cysteine content,and pH 7.08. Under the optimal culture conditions, the specific activities of produced bacteriocins could respectively reach 1163AU/mg and 1920 AU/mg after 24 h of inoculation.