Optimization on the synthesis of bacterial nano cellulose (BNC) from banana peel waste for water filter membrane applications

Abstract

Abstract This research reports the optimization of the synthesis of bacterial nano cellulose (BNC) from banana peel waste media of Kepok bananas (Musa paradisiaca L.) using Gluconacetobacter xylinus bacteria in a fermentation process for use in water filter membrane applications. Bacterial nanocellulose (BNC) synthesis was successfully accomplished under conditions of pH 4, 0.5% urea, and varying sucrose contents (5%, 10% and 15% (w/v)). The higher sucrose content causes the pH of the banana peel extract solution to decrease at the end of Day 8 and 10 due to the metabolic activity of bacteria, which produces acetic acid. A bacterial growth pH range of 3.93–4.26 was obtained. The Optical Density (OD) values tend to increase with respect to fermentation time due to the growth of BNC-forming bacteria. The higher the added sucrose content, the higher the total amount of the acid obtained as the G. Xylinus bacteria produces acetic acid in its metabolic processes. BNC thickness is directly proportional to the increase in sucrose level but does not increase proportionally with the increase in sucrose levels from 5%, 10% (two times), and 15% (three times). The sucrose level at 5% (w/v) produces most optimal results. Optimal incubation time was obtained on Day 6, which had the highest rate of increase in thickness in addition to the supporting pH, OD value and total acid factors. The TEM analysis shows that the BNC surface morphology tends to be the same among all sucrose level (5%, 10% and 15% (w/v)). The difference can only be seen in the density of the nanocellulose. The nanocellulor nanofiber produced from banana peels has diameter sizes between 30–50 nm which potentially be used in water filter membrane application.