Bacterial nanocellulose production: Improvement in productivity and properties via a sustainable medium

High production cost is a significant barrier to commercial bacterial nanocellulose (BNC) production. This study addresses this issue using a low-cost molasses and cheese whey medium via Gluconacetobacter hansenii. The one-factor-at-a-time method investigated the effect of critical factors on BNC production, including total sugar and total protein concentrations (g/L), initial pH, and additives such as ethanol and acetic acid (%(v/v)). The productivity in the HS medium was 0.125 g/L/day, while the low-cost medium without additives achieved a productivity of 0.5275 g/L/day. Although the addition of ethanol decreased the productivity, the inclusion of 0.4 %(v/v) acetic acid increased the productivity to 0.64 g/L/day. Using the low-cost medium with acetic acid led to a 40-fold reduction in production costs compared to the HS medium. Furthermore, transitioning from HS media to the low-cost medium resulted in BNC with thicker fibres, a higher crystallinity index (%) and improved mechanical properties. The ratio of I_α/ I_β in BNC produced in HS media decreased from 1.68 to 1.09 in the low-cost medium. The thermal properties of BNC produced in the low-cost medium also showed slight improvements compared to those in the HS medium. The degree of polymerization significantly increased from 1096 to 1457 in the low-cost medium compared to HS media. These findings highlight the potential of using a low-cost medium to produce BNC with enhanced properties, offering a sustainable and cost-effective alternative to conventional plastics.