Recycling of Calotropis gigantea waste fiber by enzymatic hydrolysis to produce bioethanol

Abstract

Background/Objectives: Recycling is an functional option for municipal and industrial waste management. Recycling not only helps the industry to reduce environmental pollution, it allows production of raw materials from useful waste for a wide variety of products. This study recycled cellulose from Calotropisgigantea fibers as a useful material in nature. Methods/Statistical Analysis: Enzymatic hydrolysis as an eco-friendly process is used for recycling fiber by cellulase and beta-glucosidase enzymes at pH=4.8 and 45°C and 24, 48, 72, 84 and 96 hours. The ability of these enzymes is evaluated for hydrolysis of cellulose and the effect of time on the progress of hydrolysis. The effect of alkaline pretreatment is evaluated on the efficiency of conversion of cellulose into glucose. Then, the sugar solution with the highest efficiency of hydrolysis was fermented by 15g/l commercial baker's yeast at 30°C for 72 hours and the result is measured. Findings: The best results are obtained by enzymatic hydrolysis of pretreated Calotropis gigantea fibers hydrolyzed in the presence of both cellulase and beta-glucosidase for 84 hours. Applications/Improvements: Efficiency of both hydrolysis and fermentation is high for the pretreated Calotropis gigantea fibers and alkaline pretreatment multiplied the efficiency of hydrolysis.