Selection of Enzyme Combination, Dose, and Temperature for Hydrolysis of Soybean Meal and White Flakes

The USA produces about 33% of the world soybeans and exports about 15% of the world soybean meal. Traditionally soybean meal is used for livestock feed. In general, soybean meal contains 30% carbohydrates, of which oligosaccharides (stachyose, raffinose, and sucrose) are major constituents. These oligosaccharides can be converted into monosaccharides by enzymes during hydrolysis, and then microorganisms will convert these monosaccharides into ethanol. This study was undertaken with two primary objectives: 1) to select an appropriate enzyme combination (Novozym 960, Celluclast 1.5L, Novozym 188, Cellic CTec, and Cellic HTec) and dose and 2) to fix the hydrolysis temperature for the optimum enzyme combination. White flakes were added along with five different enzyme combinations to identify the best enzyme combination based on sugar recovery. The following enzyme combinations (Novozym 960 + Celluclast 1.5L + Novozym 188 and Novozym 960 + Cellic CTec + Cellic HTec) resulted in comparable sugar recovery. Based on manufacturers recommendations, Novozym 960 + Cellic CTec + Cellic HTec doses were applied to white flakes and meal in order to select an enzyme dose. After fixing the dose, the influence of hydrolysis temperature (50 or 55 C) was evaluated. The selected enzyme combination and dosages were Novozym 960 (0.5 INU/g) + Cellic CTec (6% based on cellulose) + Cellic HTec (0.3% of TS) with a hydrolysis temperature of 55 C.