An Insight into Enzymatic Immobilization Techniques on the Saccharification of Lignocellulosic Biomass

Lignocellulosic biomass (LCB), the most abundant natural polymer across the globe, offers much potential to be a sustainable, non-food-competing carbon source for the production of biofuels and biochemicals. Compared to chemical hydrolysis, enzymatic saccharification of LCB is commonly regarded as less energy-intensive, less toxic, and more environment-benign for efficient, targeted sugar recovery. Nonetheless, the sensitivity of enzymes toward denaturing conditions, poor recyclability, and costs are the bottlenecks for their industrial application. Accordingly, enzyme immobilization has been proposed to address such shortcomings. This review appraises the type of support matrices and enzyme-immobilization techniques, and examines various factors impacting the enzyme immobilization to identify the optimal technique for LCB conversion. Covalent binding of enzymes onto magnetic nanoparticles has been suggested as an excellent immobilization technique in terms of good reusability and improved system stability across changing pH and temperatures. State-of-the-art challenges and future research directions on the enzymatic saccharification of LCB are discussed.