Effect of enzyme load on the yield of CG
The influence of the enzyme load on the product yield was investigated as shown in Fig. 4. The enzyme dosage was varied from 5 % to 30 % of the total substrate weight. It was found that the yield of CG gradually increased with the increase of enzyme dosage, likely due to more active sites, a higher probability of enzyme-substrate collision, and a higher reaction rate (Yadav & Devendran, 2012). However, when enzyme load was above 25 %, the yield of CG was almost the same with that of 25 %, likely due to biocatalyst agglomeration and possible diffusional problems of substrates at higher enzyme load (Sun & Hu, 2017). So, the optimal enzyme dosage was selected as 25 %.
Fig. 4. Effect of enzyme load on the yield of CG. Reaction conditions: the molar ratio of CA to glycerol 1:150, reaction temperature 80 oC, 86.7 kpa.