Effects of Inorganic Salts on Enzymatic Saccharification Kinetics of Lignocellulosic Biomass for Biofuel Production

Abstract

Utilization of agricultural waste, or lignocellulosic biomass, is one of the strategies to reduce the environmental problem caused by combustions after harvesting seasons. Biorefining process to convert lignocellulose to value-Added biochemicals and biofuels has been developed. Inorganic salt pretreatments improve enzymatic saccharification efficiency. However, salt residues inhibit activities of cellulase enzyme. In this work, the inhibitory effects of two types of inorganic salts, NaCl and KCl, on commercial cellulase enzyme, Accellerase 1500, were studies using the Michaelis-Menten model. The kinetic properties, in terms of Km and Vm, on three types of cellulose substrates, including CMC, Avicel, and sugarcane bagasse, were calculated based on Lineweaver-Burk plot. The obtained kinetic values showed that Vm of Accellerase 1500 reduced to 58.21% and 81.25% with the presence of 0.5 M KCl when using CMC and Avicel as substrates, respectively. On the other hand, the Km values of cellulases were also reduced with the presence of NaCl and KCl, suggesting the accessibility of enzymes to substrates. Additionally, sugar yields obtained from sugarcane baggase as substrates for biofuel production were also increased with the presence of 1M NaCl and 1M KCl. © 2021 ACM.