A novel sec-butyl-β-d-cellobioside and sec-butyl-β-d-glucoside biosynthesized by immobilized β-glucosidase of Fusarium solani with surfactant properties

Abstract

The immobilization of Fusarium solani β-glucosidase (FBgl1) on chitosan was performed to improve biocatalyst performance. Compared with free FBgl1, the immobilized biocatalyst exhibited a shift of the optimal temperature, a conservation of the optimum pH with high residual activity at extreme acidic pH and an improved thermal stability. The immobilized enzyme was reusable up to 12 cycles. The FBgl1 immobilization enhanced its glucose and organic solvent tolerance. The free form of FBgl1 was unable to synthesize alkylglucosides, while the immobilized one was able to react using butanol as alcohol and either cellobiose or glucose as glucoside. The alkylglucosides were characterized by nuclear magnetic resonance as sec-butyl-β-d-glucoside and sec-butyl-β-d-cellobioside. It is worth noting that this last glucomolecule is synthesized for the first time using an enzymatic process. These butylglucosides exhibited a typical surfactant behavior (surface tension 26−35 mN/m and critical micellar concentration 250−1000 mg/L).