Problem 3. Enzyme selection for a batch process Consider a batch reactor where the substrate lactose is being enzymatically hydrolyzed by galactosidase. The data in the table below is for a wild-type enzyme from E.coli and an engineered mutant (REH4). Using the kinetic parameter for both enzymes (on Lactose) in the table below. Assume the following for your calculations: - The milk contains 60g/L of lactose. - The molecular weight of the wild type and mutant enzyme are 540,000 - Both enzyme preparations are 20% pure (only 20% of the mass is active enzyme) - You can source the wild type enzyme for $10/g and the mutant enzyme for $30/g. - You process milk in 1000 L batches. How much of each type of enzyme would be required per batch to remove 80% of the lactose within one hour? How much to remove 95% of the lactose within three hours? Which enzyme would be most effective under each condition? TABLE I Values of kinetic constants and ratios of rate constants for the -galactosidases ND indicates that values were not determined in this study. The intercepts are from app kcot versus ( kcat app kcat)/[A] plots where A is methanol or 2 -mercaptoethanol. The errors given for kcat and Km are standard errors which were obtained by the least squares method described by Cornish-Bowden (1976) assuming simple weighting. plots are also given. The R values (regression coefficients) for each of the plots with acceptor added were all greater than 0.95