Threshold effect on whole-cell catalysis of extra hyperviscous biosystem
by a sealed oxygen supply biotechnology
Abstract
The end-product concentration and productivity are critical issues in
economic competition between biotechnological commercials and the
chemical engineering industry. The prominent contradiction between
high-titer products and the large-scale oxygen demand for aerobic
biocatalysis leads to hyperviscosity, mass transport bottleneck in
[dynamically changing](javascript:;) polyphase biosystems, and
severe foaming problems. In this study, an intensification strategy for
the whole-cell catalytic preparation of high-titer xylonic acid by
Gluconobacter oxydans in a sealed-compressed oxygen supply
bioreactor is propose. Multi-scale control factors are quantitatively
studied to determine the biochemical parameter thresholds, and
theoretically calculated the optimal production performance based on
threshold effect. Finally, 650.8 g/L xylonic acid is obtained with a
maximum productivity of 41.7 g/L/h with a catalytic performance of
95.8%, compared with the theoretical calculations. The intensification
strategy for the oxygen transfer threshold effect overcome the stubborn
obstacles of obligate aerobic catalysis, while providing a sustainable
value-added pathway for fermentative lignocellulose.