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Table 2 Equations used for calculating glucose yield, Y glucose (% g glucose/g cellulose) (equation 1) and enzyme productivity, P enztot (g glucose/mg enzyme protein) (equation 2)

From: Enzymatic lignocellulose hydrolysis: Improved cellulase productivity by insoluble solids recycling

  Equation
Yglucose (equation 1) Y glucose = C gluc final C gluc initial ) V final M cellulose tot 1.11
Penztot (equation 2) P enztot = 0 N C gluc final n C gluc initial n V final n 0 N M enz n
  1. For Yglucose equation 1: The glucose yields were calculated based on the total present cellulose in each hydrolysis round. C gluc final is the final glucose concentration in the liquor fraction, C gluc initial is the initial glucose concentration, V final is the final volume of the liquor fraction, and M cellulose tot is the total mass of cellulose present at the beginning of the hydrolysis. For the recycle rounds this included both cellulose from the fresh substrate and cellulose which was carried over in the insoluble solids. The amount of cellulose carried over from the previous recycle round was calculated by subtracting the glucose produced in the previous recycle round and assuming conservation of cellulose in the system. The glucose yields were calculated based on the total present cellulose in each hydrolysis round. It was assumed that all cellulose not converted to glucose remained evenly distributed with the insoluble fraction (for the 15% TS experiment, the amount of liquid removed was approximately 12 g (± 2 g) depending on recycle conditions. This amount was only a function of the efficiency of centrifugation).
  2. For P enztot equation 2: M enz n is the mass of enzyme protein added for each recycle round n, and N is the total number of recycles. The other symbols are as explained for equation 1.