Improving the remaining activity of lignocellulolytic enzymes by membrane entrapment

The production of bioethanol by the conversion of lignocellulosic waste has attracted much interest in recent years because of its low cost and great potential availability. However, the high cost of the enzyme required for this conversion is often considered to be the major bottleneck in the commercial lignocellulosic ethanol industry. In this work, the hydrolysis of rice straw by free and entrapped lignocellulolytic enzymes (cellulase, xylanase and laccase) was carried out at pH 5.5 and 37 °C. The hydrolysis of rice straw by enzymes entrapped in a membrane produced a higher monosaccharide content: 601.05 mg/g rice straw for entrapped enzymes vs. 465.46 mg/g rice straw for free enzymes. This study has shown that enzyme entrapment is an important technique for the efficient use and reuse of enzymes in industrial applications and also for the rapid separation of saccharide products from the reaction medium, thus improving the remaining enzymatic activities.