Determination of Activity Optimum Inulinase from Bacteria Screened from Dadih (Curd)

Abstract

Dadih (curd) contains Lactic Acid Bacteria (LAB), most of them are probiotics. Probiotics favour nutritional supplements called prebiotics. One compound that belongs to the prebiotic group is inulin. Inulinase hydrolyses inulin into fructose and FOS. The aim of the study was to determine the optimum activity of inulinase from bacteria screened from dadih (curd) at variation of pH (4.5; 5; 5.5; 6; 7; 8), temperature (20°C, 30°C, 37°C, 45°C) and variation of substrate concentration (0.5%; 1%; 1.5%; 2%; 2.5%). Determination of inulinase activity was determined using Dinitrosalicylic Acid (DNS) reagent method. Absorbance was measured using spectrophotometer at 488 wavelengths. The results obtained from this study were the optimum activity of inulinase (bacterial inulinase degrading inulin) at pH 5.5; temperature 37°C and substrate concentration 2.5%.