Trametes sp. as a source of biopolymer cross-linking agents: laccase induced gelation of ferulated arabinoxylans.

This study examined the feasibility of using Trametes sp. grown under drought conditions to catalyze the covalent cross-linking of ferulated arabinoxylans. The rate of polymerization of ferulated arabinoxylans solutions at 0.5% (w/v) was dose dependent on the laccase concentration in the system. Above 1.2 nkat laccase/mg ferulated arabinoxylan, the rate of cross-linking reached a plateau, suggesting that the reaction reached saturation. For 2% (w/v) ferulated arabinoxylans treated with laccase (1.6 nkat/mg ferulated arabinoxylan), stable gels were formed after 4 h at 25 degrees C, with cross-linking contents (diferulic and triferulic acid) contents of 0.03 and 0.015 microg/mg ferulated arabinoxylan, respectively. This study demonstrated that Trametes sp. can be a source of biopolymer cross-linking enzymes like laccase.