Enhanced In Vitro Cascade Catalysis of Glycerol into Pyruvate and Acetoin by Integration with Dihydroxy Acid Dehydratase from Paralcaligenes ureilyticus

Recently, an in vitro enzymatic cascade was constructed to transform glycerol into the high-value platform chemical pyruvate. However, low activity of dihydroxy acid dehydratase from Sulfolobus solfataricus (SsDHAD) limited efficiency. In this study, reduction pyruvate catalyzed by d-lactate dehydrogenase Pseudomonas aeruginosa PAO1 used assay activities dehydratases. Dihydroxy Paralcaligenes ureilyticus (PuDHT) identified as most efficient candidate for glycerate dehydration. After optimization catalytic temperature cascade, comprising alditol oxidase Streptomyces coelicolor A3, PuDHT, and catalase Aspergillus niger, 20.50 ± 0.27 mM consumed 4 h produce 18.95 0.97 with a productivity 12.15-fold higher than previous report using SsDHAD. The further coupled decarboxylase Zymomonas mobile production another compound, acetoin. Acetoin at concentration 8.52 0.12 produced 21.62 0.19 1.42 0.02 h?1.