Enhanced ultrafine nanofibril biosynthesis of bacterial nanocellulose using a low-cost material by the adapted strain of Komagataeibacter xylinus MSKU 12

Abstract

Bacterial nanocellulose (BNC) is a renewable and biodegradable biopolymer which has currently received considerable attention due to the rapid increase in environmental issues. In this study, a cost-effective strategy for BNC production was successfully improved in the adapted strain, C30, which was obtained from Komagataeibacter xylinus MSKU 12 by a repetitive cultivation in a low-cost coconut water containing acetic acid and ethanol (CW-AE medium) at 37 °C. The adaptive procedure allowed the strain C30 to be adapted to grow and produce BNC with a higher yield in a limiting nutrient CW-AE medium, than that in a standard HS-AE medium. This strain could produce a high yield of BNC (9.69 g/L dry weight) in a low-cost medium, a modified CW-AE medium supplemented with sucrose and ammonium sulfate. Moreover, SEM images showed that BNC pellicle produced by the strain C30 in the modified CW-AE medium exhibited finer nanofibrils with a narrower range of width compared with those of MSKU 12 while no significant differences in their physicochemical characteristics were detected among these BNCs produced. Therefore, this finding demonstrates, not only the potential strain for the cost-effective BNC production at high temperature, but also the superior ultrafine nanofibrils production useful for further applications.

Keywords: Bacterial nanocellulose; Coconut water; Komagataeibacter xylinus; Low-nutrient adaptation; Ultrafine nanofibrils.