A smart self-balancing biosystem with reversible competitive adsorption of in-situ anion exchange resin for whole-cell catalysis preparation of lignocellulosic xylonic acid

Xylonic acid (XA) bioproduction via whole-cell catalysis of Gluconobacter oxydans is a promising strategy for xylose bioconversion, which is hindered by inhibitor formation during lignocellulosic hydrolysates. Therefore, it is important to develop a catalytic system that can directly utilize hydrolysate and efficiently produce XA. Determination of the dynamic adsorption characteristics of 335 anion exchange resin resulted in a unique and interesting reversible competitive adsorption between acetic acid-like bioinhibitor, fermentable sugar and XA. Xylose in crude lignocellulosic hydrolysates was completely oxidized to 52.52 g/L XA in unprecedented self -balancing biological system through reversible competition. The obtained results showed that in-situ resin adsorption significantly affected the direct utilization of crude lignocellulosic hydrolysate for XA bioproduction (p <= 0.05). In addition, the resin adsorbed ca. 90 % of XA during bioconversion. The study achieved a multiple functions and integrated system, "detoxification, neutralization and product separation " for one-pot bioreaction of lignocellulosic hydrolysate.