Highly efficient production of 2-ketobutyrate from 2-hydroxybutyrate by resting cells of Pseudomonas stutzeri DEH130

Resting cells of Pseudomonas stutzeri DEH130 were found to act as biocatalysts to convert 2-hydroxybutyrate (2-HB) into 2-ketobutyrate (2-KA). Two different catalysis mechanisms of 2-KA formation were present in the cells, which were induced by glycolate (GA), and DL-lactate (DL-LA), respectively. The productivity number of 6.52 mmol g⁻¹ cells h⁻¹ was obtained when DL-LA was the sole carbon source and was the highest ever reported.