Springer, Bioprocess and Biosystems Engineering, 10(36), p. 1327-1338, 2012
DOI: 10.1007/s00449-012-0835-9
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Cellulase from Trichoderma reesei (Celluclast 1.5 L, Novozyme) was immobilized by sol-gel encapsulation, using binary or ternary mixtures of tetramethoxysilane (TMOS) with alkyl- or aryl-substituted trimethoxysilanes as precursors. Optimization of immobilization conditions resulted in 92 % recovery of total enzymatic activity in the best immobilized preparate. The immobilized cellulase exhibiting the highest activity, obtained from tetramethoxysilane and methyltrimethoxysilane precursors at 3:1 molar ratio, was investigated in the hydrolysis reaction of microcrystalline cellulose (Avicel PH101). Although the optimal values did not change significantly, both temperature and pH stabilities of the sol-gel entrapped cellulase improved compared to the native enzyme. Immobilization also conferred superior resistance against the inactivation effect of glucose. Reuse of the sol-gel entrapped cellulase showed 40 % retention of the initial activity after five batch hydrolysis cycles, demonstrating the potential of this biocatalyst for large-scale application.