Bioprocess Intensification for Whole-Cell Catalysis of Catabolized Chemicals with 2,4-Dinitrophenol Uncoupling

A basic scheme of using 2,4-dinitrophenol (2,4-DNP) as an uncoupler between electron transport chain and oxidative phosphorylation for the biochemical regulation of Gluconobacter oxydans (G. oxydans) is raised. Under the weakly acidic environment, the lipophilic 2,4-DNP as an uncoupling agent destroys the electrochemical proton (H+) gradient in mitochondria, which leads to a loss of the driving force for adenosine triphosphate (ATP) synthesis. Based on the main enzyme system of G. oxydans, four typical substrates were studied for exploring the biochemical effects of uncoupling on the cells. As a result, it was found that under uncoupling conditions, cells receive a feedback signal of ATP deficiency, which promotes the utilization of catabolized substrates such as sorbitol and glucose through the substrate level phosphorylation pathway in order to make up for the deficiency of ATP. The proposal of strategy has a further understanding of the basic biochemical knowledge of G. oxydans and lays a theoretical foundation for the directional regulation of G. oxydans.