Production and characterization of bacterial cellulose before and after enzymatic hydrolysis

Abstract

Bacterial cellulose (BC) is produced by bacteria such as Gluconacetobacter xylinus. It has unique structural and mechanical properties and is highly pure as compared to plant cellulose. In this study, BC was produced in Hestrin-Schramm (HS) medium. G. xylinus produced an average dry yield of 1.4 ± 0.09 g/L BC after 9 days of fermentation period. Scanning Electron Microscopy (SEM) analysis confirmed BC to be highly structured while Fourier Transform infrared spectroscopy (FTIR) analysis indicated that the absorption peaks at 3000 – 3700, 2800 – 2970 and 1023 – 1024 cm-1 were derived from –OH bending, -CH stretching and C-C/C-OH/C-H ring vibrations. X-Ray Diffraction (XRD) revealed a high purity of BC indicating type I cellulose with high crystalline nature. The solid state 13C Nuclear magnetic resonance (NMR) spectroscopy of the untreated BC sample also indicated high crystallinity while the cellulase treated BC sample was different, but dominated by a polysaccharide signal between 55 and 110 ppm. The results suggest the prospects of the production and recycling of biopolymers from bacterial sources.   Key words: Bacterial cellulose, Scanning Electron Microscopy (SEM), Fourier Transform infrared spectroscopy (FTIR), X-Ray Diffraction (XRD), Nuclear magnetic resonance (NMR), cellulase enzyme.