Process Biochemistry, Vol.82, 1-9, 2019
Bacterial cellulose grows with a honeycomb geometry in a solid-state culture of Gluconacetobacter xylinus using polyurethane foam support
The polyurethane foam (PUF) allowed the growth of Gluconacetobacter xylinus for prompt production of bacterial cellulose (BC) due to high water storage capacity that let high water activity, as well as diffusion of oxygen through the PUF pores. PUF was studied in two sizes cut (0.13 cm(3)) and minced (0.08 cm(3)). Additionally, the study assessed the level of inoculum on the growth and the formation of BC. The highest yield of BC was 2.46 g L-1 of cellulose achieved with cut foam and 15% inoculum at 96 h. Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD) and solid state C-13 cross polarization and magic angle spinning nuclear magnetic resonance (CP/MAS NMR) analyses evidence crystalline structure type I for the produced microbial cellulose. According to scanning electron microscopy (SEM) analysis, the bacteria synthesized the biopolymer as a biofilm adhered to the solid support; thereby BC displays a honeycomb geometry.