Production of Bacterial Cellulose by Acetobacter xylinum through Utilizing Acetic Acid Hydrolysate of Bagasse as Low-cost Carbon Source

Abstract

Bacterial cellulose (BC) is a promising and renewable nanomaterial due to its unique structural features and appealing properties. Intensive study on BC preparation has been mainly focused on biosynthesis by certain bacteria, while the high economic costs of fermentation, especially the carbon sources, remain challenges to its application. In this study, bacterial cellulose was synthesized by Acetobacter xylinum with the acetic acid hydrolysate of bagasse used as carbon source. After the bagasse was pretreated by acetic acid, the components in hydrolysate and the removal rate was investigated, and the pretreatment conditions were optimized as follows: temperature of 160 °C, heating time of 60 min, addition of acetic acid of 2.0% (m/m), and solid-to-liquid ratio of 1/5. Prior to Acetobacter xylinum cultivation, the hydrolysate was detoxified by activated carbon. The detoxification process was very efficient for BC production, with a yield up to 2.13 g/L when the dosage of activated carbon was 5% (m/V). Furthermore, the obtained BC was characterized by scanning electron microscopy (SEM), which showed that the ribbons width of BC was between 30 and 80 nm. X-ray patterns showed the crystallinity value was 74.6 % and the crystallinity index (CI%) was 66.5 %, which also evidenced the presence of peaks characteristic of Cellulose I polymorph. In conclusion, it is feasible to produce BC from bagasse hydrolysate. This model of waste recycling could aid in the development of sustainable strategies.

Keywords

• Bacterial cellulose; Acetobacter xylinum; Acetic acid; Bagasse