13-13: Enzyme recovery after enzymatic hydrolysis of treated sugarcane bagasse

Reuse and recycle waste could minimize the environmental problems linked to its accumulation and decreased use of fossil fuels. This work aims to improve the process of enzymatic hydrolysis of cane sugar and reduce the cost of enzyme. Sugarcane bagasse was treated by hydrothermal treatment. All hydrolysis assays were performed with a laboratory made enzyme mixture maintaining the ratio BGU/FPU equal to three, at 50°C, 100 g/L and 10 FPU/g. Concerning hydrolysis kinetics within 14 hours was enough to hydrolyze 68% of initial biomass. These results showed that glucose concentration above 6 g/L begins to inhibit β-glucosidase activity. Until 14 hours of enzymatic hydrolysis it was observed that the FPase activity was reduced by 70%, while the β-glucosidase activity remained stable. The enzyme recovered after 14 hours of hydrolysis can be reused for a new batch with partial supplementation of enzyme. The washing factor (dilution) was evaluated on diafiltration process, and it was possible to observe and concludes that, washing fivefold was enough to get a glucose concentration of 3.71 g /L, which is out of β-glucosidase inhibition range. The reuse of enzyme without diafiltration process during the four cycles of hydrolysis achieved to a loss of 7% in grams of glucose/FPU when compared with reuse of the enzyme using a 30 kDa membrane on diafiltration process. However washing out in all four cycles it was possible to obtain a gain of 13% in grams of glucose/FPU. All data were compared regarding a batch process without enzyme recovery.