The Role of Glyceraldehyde-3-Phosphate Dehydrogenase in 2-Ketogluconic Acid Industrial Production Strain Pseudomonas plecoglossicida JUIM01

The full-length <i>gapA</i> gene (1002 bp) was cloned from <i>Pseudomonas plecoglossicida</i> JUIM01, an industrial strain used for 2-ketogluconic acid (2KGA) production. The protein encoded by <i>gapA</i> (designated Gap) was predicted to be a canonical NAD(P)-dependent glyceraldehyde-3-phosphate dehydrogenase that catalyzes the interconversion between glyceraldehyde-3-phosphate and 1,3-bisphosphoglycerate. Bioinformatics analyses and electrophoretic mobility shift assays suggested that <i>gapA</i> is regulated by the transcription factor HexR. Through the knockout and complementation of the gene, along with shake-flask experiments and fermentation in bioreactors, this study demonstrated that the deletion of <i>gapA</i> increased the 2KGA production, sugar-acid conversion rate, molar yield, and productivity of <i>P. plecoglossicida</i> JUIM01 by 5.7-6.6% without affecting cell growth, highlighting the mutant's significant industrial potential.