Single-batch, homogeneous phase depolymerization of cellulose catalyzed by a monocomponent endocellulase in ionic liquid [BMIM][Cl]

The stability and enzymatic activity of an industrial, recombinant cellulase dissolved either in 1-butyl-3-methylimidazolium chloride [BMIM][Cl] or in mixtures of [BMIM][Cl]/aqueous buffer have been investigated and the results are here reported. The preparation used was a recombinant monocomponent endocellulase from Trichoderma reesei or EGIII (now renamed Cel12A), commercially referred to as IndiAge® Super GX Plus. The key parameters studied were: the effect of temperature in the range between 75 and 90 °C, the enzyme stability at 75 °C and the ability of EGIII to hydrolyze cellulose in the presence of [BMIM][Cl]. This cellulase preparation turns out to be more stable and active in pure ionic liquid rather than in buffer. These results indicate that the recombinant, monocomponent endocellulase from T. reesei is a suitable biocatalyst for the depolymerization of cellulose in [BMIM][Cl] and it therefore opens the way to a possible one-pot process based on a homogeneous phase, enzyme-catalyzed depolymerization of cellulose.