Cutinase-Catalyzed Deacetylation of Poly(vinyl acetate)

Abstract

Poly(vinyl acetate), PVAc, is an industrially important polymer used in adhesives, textile fibers, paper products and coating materials. This paper reports catalytic activities of cutinases from Humicola insolens (HiC), Pseudomonas mendocina (PmC), and Fusarium solani for PVAc hydrolysis. PVAc was distributed as thin films throughout highly porous styrene divinyl benzene beads with known surface area. Cutinase activity for PVAc deacetylation was assayed using a pH-stat to measure NaOH consumption versus time and PVAc concentration was expressed as square meter per milliliter. HiC had maximum initial activity at 70 °C whereas PmC and FsC performed best at 50 and 40 °C, respectively. To limit background chemical hydrolysis, kinetic studies for all three cutinases were performed at pH 7.5. Initial activities for each cutinase at their optimal reaction temperatures were fit by the Michaelis−Menten kinetic model. PmC had the highest affinity for PVAc with Km of 20 m2·mL−1. Furthermore, HiC and FsC had the high...