Directing cell catalysis of glucose to 2-keto-d-gluconic acid using Gluconobacter oxydans NL71

2-Keto- d -gluconic acid (2-KGA) is a high-value-added product from lignocellulosic straw-based biorefining process obtained via cell catalysis using Gluconobacter oxydans ( G. oxydans ); nonetheless, the economical production has some limitations because of the formation of undesirable mixture products of keto-gluconic acid from glucose. In this study, it was demonstrated that pulse addition of hydrogen peroxide (H 2 O 2 ) to synthetic media was beneficial to improve the conversion rate of glucose to 2-KGA by 1.47-fold in G. oxydans . Moreover, some lignocellulosic degradation compounds served as substitute and played the role of H 2 O 2 on corn stover hydrolysate for the production of 2-KGA. By conducting qRT-PCR analysis, eight dehydrogenase genes were identified in G. oxydans , which were responsible for regulating 2-KGA production. Moreover, most of the identified genes were found to produce membrane-bound glucose dehydrogenase and gluconate 2-dehydrogenase, and were up-regulated by adding H 2 O 2 or degradation compounds. These up-regulated genes could be responsible for directing cell catalysis of glucose to 2-KGA in G. oxydans .