Increased transglycosylation activity of Rhodotorula glutinis endo-beta-glucanase in media containing organic solvent.

The transglycosylation of p-nitrophenyl-beta-D-cellotrioside to cellotetraose catalyzed by endo-1,4-beta-glucanase (cellulase, EC 3.2.1.4) from a psychrotrophic yeast, Rhodotorula glutinis KUJ 2731, was increased by addition of a miscible organic solvent in the reaction mixture. Among various organic solvents tested, acetone was most effective. The transglycosylation activity increased with an increase in acetone concentrations, while hydrolysis activity was suppressed. The transglycosylation preferably occurred at acidic pH with the optimum pH at 2 in 10 mM Gly-HCl buffer. The optimum temperature of transglycosylation was found to be 50 degrees C in the presence of 40% acetone.