Improved thermostable polyvinyl alcohol electrospun nanofibers with entangled naringinase used in a novel mini-packed bed reactor.

Abstract Polyvinyl alcohol (PVA) electrospun nanofibers were produced using an electrospinning technique. Key parameters (e.g. collectors, distance from needle tip to collector, among others) that influence the structure and morphology of fibers were optimized. The naringinase entrapped in PVA nanofibers retained over 100% of its initial activity after 212 h of operation, at 25 °C. Chemical crosslinking with several boronic acids further increased the hydrolysis temperature (up to 85 °C) and yielded nanofibers with thermal stability up to 121 °C. A mini packed bed reactor (PBR) developed to establish the feasibility for continuous enzymatic operation, ran for 16 days at 45 °C. Highest naringenin biosynthesis was attained at a flow rate of 10 mL h −1 . Highest volumetric (78 mol L −1  h −1 ) and specific (26 mol h −1  g enzyme −1 ) productivities were attained at 30 mL h −1 . The activity of NGase in electrospun nanofibers remained constant for almost 16 days of operation at 10 mL h −1 .