Pre-treatment, Physicochemical Properties and Production of Bioethanol from Rice Husk using Fungi Isolated from Waste Dumpsite in Kaduna, Nigeria

Abstract

This research is based on the pre-treatment and physicochemical characterization of rice husk and production of Bioethanol from rice husk using fungal isolates obtained from waste dump sites in Kaduna Nigeria. Standard procedures were followed. The results revealed a reduction in lignin (from 21.40 to 12.08%), hemicellulose (22.04-18.92%), protein (14.56-8.56%) and ash (1.31-1.04%) contents which resulted to an increase in the cellulosic fraction (49.55-58.29%) of the rice husk.. A significant difference (p<0.05) was observed in the reducing sugar concentrations of the 50g substrate concentration using Aspergillus niger SIF2 (0.60±0.30mg/ml), Aspergillus flavus CMXY22565 (0.56±0.29mg/ml) and a consortium (1.17±0.82mg/ml) of both organisms after 120 hours of enzymatic hydrolysis. The results also revealed a significant yield (p<0.05) in bioethanol production using Pichia kudriavzevii IPBCC.y.161552 (4.91±2.51%), Saccharomyces cerevisiae FJI (5.39±2.87%) and a consortium (9.02±4.83%) of both organisms. There was an increase in temperature and titratable acidity and a decrease in pH and specific gravity. The FTIR revealed a high ethanol content of 68% from the bioethanol produced from the 50g substrate concentration hydrolysed and fermented using a consortium of molds and yeasts. The results therefore suggest that bioethanol can be produced from rice husk with maximum yields obtained using a consortium of Aspergillus niger SIF2 and Aspergillus flavus CMXY22565 for hydrolysis as well as a consortium of Saccharomyces cerevisiae FJI and Pichia kudriavzevii IPBCC.y.161552 for fermentation.

Keywords

• Bioethanol;
• rice husk;
• fungi;
• hydrolysis;
• fermentation