High-level production of maltobionic acid from high-maltose corn syrup by genetically engineered Pseudomonas taetrolens

Abstract

Highlights Glucose dehydrogenase from Pseudomonas taetrolens could produce maltobionic acid. The glucose dehydrogenase gene was homologously expressed in P. taetrolens . Maltose-oxidizing activity and MBA production titer of P. taetrolens was improved. MBA productivity of the recombinant P. taetrolens was increased to 9.52 g/L/h. High-level production of MBA from HMCS was achieved by the recombinant P. taetrolens .

Valorization of Waste Cooked Rice into Value-Added Maltobionic Acid Using Genetically Engineered Pseudomonas taetrolens

“…However, this enzyme also showed a considerable maltose production titer (87 g/L) and productivity (4.4 g/L/h) at 25 °C. In our previous study, the recombinant P. taetrolens [pDSK-GDH] strain exhibited the highest MBA production ability at 25 °C . Thus, the two-step conversion process from WCR to MBA applied in this study can be reduced to a single-step process by performing simultaneous saccharification and fermentation using Maltogenase L and P. taetrolens [pDSK-GDH] at 25 °C.…”

“…In this study, we successfully produced MBA from WCR via a two-step process: the hydrolysis of WCR into maltose using maltogenic amylase and the conversion of maltose into MBA using recombinant P. taetrolens homologously expressing GDH. In our previous study, this recombinant P. taetrolens could efficiently produce MBA without substrate inhibition up to 200 g/L maltose . Thus, we attempted to produce as much maltose as possible from WCR.…”

“…The cells were cultivated in nutrient broth (NB, 1 g/L beef extract, 2 g/L yeast extract, 5 g/L peptone, and 5 g/L NaCl) containing 10 g/L maltose at 25 °C for 24 h and stored frozen in 50% glycerol at −80 °C. Quinoprotein GDH was homologously expressed in P. taetrolens using plasmid pDSK519, a broad-host range vector for Gram-negative bacteria under the control of the lac promoter, by constructing the resultant plasmid, pDSK-GDH, as described in detail in our previous study …”

“…and Pseudomonas fragi have been published to date. Further, the production titer of MBA was not found to be satisfactory (94.7 g/L) compared with that of LBA (400 g/L). − Recently, we successfully produced MBA from pure maltose or high-maltose corn syrup at a high level (200 g/L) using genetically engineered Pseudomonas taetrolens homologously expressing quinoprotein glucose dehydrogenase (GDH) …”

Efficient Bi-enzymatic synthesis of aldonic acids

“…26 PQQGDH is active towards various monomeric aldoses, di-and oligo-saccharides and accepts structurally different mediators for re-oxidation of the enzyme. 27–34 Here, we demonstrated that thionine (TH) is a stable and efficient redox mediator of PQQGDH in the oxidation scheme coupled with peroxidase allowing for a very high space–time yield for various aldonic acids.…”