An efficient enzymatic production of N-acetyl-d-glucosamine from crude chitin powders

Abstract

In this study, we present an efficient affinity adsorption–enzymatic reaction integrated approach to produce N-acetyl-D-glucosamine (GlcNAc) from crude chitin powders (CP). Chitinase was first purified from the crude enzyme mixture by affinity adsorption on the CP substrate, with ∼92.7% recovery of the enzyme achieved within 10 minutes in the presence of 20 g L⁻¹ of CP under optimized conditions. The chitinase then efficiently converted 40 g L⁻¹ of CP to 39.3 g L⁻¹ of GlcNAc in a batch enzymatic reaction for 4 days, achieving nearly 100% conversion of the substrate CP. The product GlcNAc was easily separated from hydrolysates after destaining, concentrating, crystallizing and drying processes with a high purity of 98%. In addition, the chitinase can be conveniently reused for several batches by the affinity adsorption–enzymatic reaction approach, giving an average yield of 29.6 g L⁻¹ of GlcNAc based on 30 g L⁻¹ of CP as the substrate.