Delignification of lignocellulosic biomass by immobilized laccase : a mini review

The production of energy from lignocellulosic biomass has become common interest among the researchers to fully utilize the waste by converting it into valuable energy sources. The main problem is that the lignocellulosic biomass is difficult to hydrolyse due to their recalcitrant and heterogeneous structure. Therefore, a pretreatment or delignification process is required to remove or modify the lignin structure in order to make it more susceptible to the hydrolysis stage. The first part of this paper reviews the current method used in delignification and emphasizes more on the biological treatment which is more eco-friendly and less energy consuming. While the second part focuses on ligninolytic enzymes, laccase which is considered to have great potential in delignification. Due to the limitations of the enzyme in term of operational stability and reusability, the improvements of enzyme after immobilization are discussed briefly. Finally, the future outlooks and challenges on the implementation of immobilized laccase in delignification process are also covered in this review.