Hydrolysis of sunflower seed meal lignocellulosic fraction by free and immobilized cellulases

Abstract

Lignocellulosic biomass is widely abundant in nature and recognized aspotential renewable energy source. Its efficient transformation into bio-basedfuels is enabled only after adequate pretreatment, followed by enzymaticsacharification and microbial fermentation. Hereby we present application of twocellulase preparations – from Aspergillus niger and Trichoderma reesei (Celluclast®)in treating sunflower seed meal lignocellulosic fraction (SSMLF). Temperature andpH optimums of two enzymes were determined – 52 °C and pH4.8 for A. nigercellulase and 55 °C and pH4.5 for Celluclast®. At optimized conditions, milledSSMLF was hydrolyzed by both biocatalysts. With A. niger cellulase higher initialreaction rates were accomplished and yield of 70 mM glucose equivalent wasobtained with 6 % (w/v) of enzyme after 6 hours. On the other hand, applicationof Celluclast® led to lower initial reaction rates and yielded 25 mM of glucoseequivalent with 10 % (v/v) of enzyme. To ensure cost-effective application ofA. niger cellulase, the possibility of its immobilization on different supports wasinvestigated. By using porous methacrylate-based carrier with C6 spacer arm andprimary amino groups – LifetechTM ECR8409, preparation with highest activity wasproduced. This preparation was successfully applied in saccharification of SSMLFand showed unchanged catalytic efficiency comparing to free enzyme