A Monolithic Hybrid Cellulose-2.5-Acetate/Polymer Bioreactor for Biocatalysis under Continuous Liquid-Liquid Conditions Using a Supported Ionic Liquid Phase

Mesoporous monolithic hybrid cellulose-2.5-acetate (CA)/polymer supports were prepared under solvent-induced phase separation conditions using cellulose-2.5-acetate microbeads 8-14m in diameter, 1,1,1-tris(hydroxymethyl)propane and 4,4-methylenebis(phenylisocyanate) as monomers as well as THF and n-heptane as porogenic solvents. 4-(Dimethylamino)pyridine and dibutyltin dilaurate (DBTDL), respectively, were used as catalysts. Monolithic hybrid supports were used in transesterification reactions of vinyl butyrate with 1-butanol under continuous, supported ionic liquid-liquid conditions with Candida antarctica lipaseB (CALB) and octylmethylimidazolium tetrafluoroborate ([OMIM+][BF4-]) immobilized within the CA beads inside the polymeric monolithic framework and methyl tert-butyl ether (MTBE) as the continuous phase. The new hybrid bioreactors were successfully used in dimensions up to 2x30cm (V=94mL). Under continuous biphasic liquid-liquid conditions a constant conversion up to 96% was achieved over a period of 18days, resulting in a productivity of 58molmg(-1)(CALB)min(-1). This translates into an unprecedented turnover number (TON) of 3.9x10(7) within two weeks, which is much higher than the one obtained under standard biphasic conditions using [OMIM+][BF4-]/MTBE (TON=2.7x10(6)). The continuous liquid-liquid setup based on a hybrid reactor presented here is strongly believed to be applicable to many other enzyme-catalyzed reactions.