Assessment of Extract from Glucose Oxidase-Cellulase Treated Jute Sticks and Green Amaranth Sticks for the Production of Lignocellulose-Based Bioethanol.

Abstract

The possibility that some carbohydrate oxidases are capable of catalytically cleaving glycosidic bonds offers the opportunity for glucose oxidase to achieve the depolymerization of agro wastes required in the production of second-generation bioethanol. The present study aimed to ascertain the effect of glucose oxidase and cellulase isolated from Aspergillus sp. on locally sourced jute sticks and green amaranth sticks for the production of bioethanol. The Box Behnken design was employed to assess the effect of the different concentrations of sucrose, waste extracts and pH on fermentation efficiency, ethanol percent yield, and reducing sugar yield. The selected agro wastes were subjected to fiber detergent analysis, ATR-FTIR, XRD, and SEM. The fermentation broth was subjected to ATR-FTIR analysis. Compared to oven-dried jute extract, the maximum ethanol yield was achieved at 72 hours for 50% broth containing oven-dried green amaranth extract by a difference of 65.6%. Optimization using the Box Behnken design resulted in an increased yield of ethanol (198%), fermentation efficiency (3.86%) and reducing sugar yield (27.97%) at the combination of factor levels of 5% (sucrose concentration), 2.5% (oven-dried green amaranth extract concentration) and pH 4.5. The cleaving of glycosidic bonds in the waste samples was revealed by ATR-FTIR and further confirmed by SEM. With the evidence of the characteristic bands associated with the presence of ethanol in the fermentation broth, it was concluded that the inclusion of glucose oxidase at low concentrations in the presence of cellulase supported the release of reducing sugars required for the production of lignocellulose - based bioethanol.