The effect of surfactant on the hydrolysis of coconut husk using cellulase and xylanase enzyme immobilized on chitosan magnetic nanoparticles

This study aimed to investigate the effect of surfactant Tween 80 in the enzymatic hydrolysis of coconut husks by using immobilized cellulase from Aspergillus niger, Trichoderma reesei, and immobilized xylanase. Surfactant is common to enhance the yield of sugar in enzymatic process. However, its application in immobilized enzymes has not been well investigated. Coconut husk is an abundant resource of cellulose that can be converted to reducing sugar which can be utilized to produce various products such as biofuel, lactic acid, 5-hydroxymethyl furfural, and leluvinic acid. Chitosan magnetic nanoparticles as a support in the immobilization process were prepared using the coprecipitation method to obtain particles separated by magnetic field. Cellulase and xylanase were immobilized on magnetic particles through covalent bond directly and with Glutaral dialdehyde (GDA) as cross-linker. The immobilized cellulase and xylanase along with Tween 80 surfactants were applied for the hydrolysis of NaOH pre-treated coconut husk at 55°C for 48 hours. The reducing sugar content were identified with DNS methods. In this study, the highest reducing sugar content obtained from cellulase from A niger, cellulase from T reesei and xylanase were 0.412 mg/ml, 0.532 mg/mL and 1.166 mg/mL, respectively. The concentration of Tween 80 that yielding highest sugar concentration for immobilized cellulase from A niger, cellulase from T reesei and xylanase were 2%, 1% and 2% (w/v), respectively.