Microbial Production of Bacterial Cellulose Using Chestnut Shell Hydrolysates by Gluconacetobacter xylinus ATCC 53524

Abstract

Bacterial cellulose (BC) is gaining attention as a carbon-neutral alternative to plant cellulose, and as a means to prevent deforestation and achieve a carbon-neutral society. However, the high cost of fermentation media for BC production is a barrier to its industrialization. In this study, chestnut shell (CS) hydrolysates were used as a carbon source for the BC-producing bacteria strain, Gluconacetobacter xylinus ATCC 53524. To evaluate the suitability of the CS hydrolysates, major inhibitors in the hydrolysates were analyzed, and BC production was profiled during fermentation. CS hydrolysates (40 g glucose/l) contained 1.9 g/l acetic acid when applied directly to the main medium. As a result, the BC concentration at 96 h using the control group and CS hydrolysates was 12.5 g/l and 16.7 g/l, respectively (1.3-fold improved). In addition, the surface morphology of BC derived from CS hydrolysates revealed more densely packed nanofibrils than the control group. In the microbial BC production using CS, the hydrolysate had no inhibitory effect during fermentation, suggesting it is a suitable feedstock for a sustainable and eco-friendly biorefinery. To the best of our knowledge, this is the first study to valorize CS by utilizing it in BC production.

Identification and Characterization of Major Flavonoids in Extracts from an Unexplored Medicinal Herb Orostachys fimbriata

“…were epicatechin gallate (about 39% of the TFC), quercetin, and kaempferol. The potential for utilization of resources can be evaluated based on the mass balance [27,28]. Figure 5 shows the mass balance in the overall process of recovering flavonoids from 1000 g (dry basis) of O. fimbriata.…”