Glycerol-Assisted Thermal Strategy for Intensifying Bioconversion Performance of Gluconobacter oxydans

Increasing the biotransformation temperature to balance the conditions of saccharification (50°C-60°C) is a crucial measure for intensifying bioprocess competitiveness. The study established a glycerol-assisted thermal strategy to mitigate the damage caused by high temperature on Gluconobacter oxydans. This approach successfully improved bioconversion performance by simultaneously overcoming limitations in catalytic efficiency and cell recovery. With 15 mmol/L glycerol assistance, the proportion of live cells remained at 75.9% after whole-cell catalysis at 37°C for 40 h. Moreover, 570.2 g xylonic acid was accumulated from pure xylose with the average volumetric productivity per round of 14.3 g/L/h, which was 14.5% and 19.6% higher than that of 30°C and 37°C without assistance. Additionally, to validate its practicality, this strategy was further applied to corncob hydrolysate, resulting 216.8 g xylonic acid from 1000 g corncob with the productivity of 4.1 g/h. This work presented an economically viable approach for lignocellulosic biorefinery and offers insights for its further development.