Efficient production of D-glucosaminic acid from D-glucosamine by Pseudomonas putida GNA5

D-glucosaminic acid was produced efficiently from glucosamine by oxidative fermentation using a newly isolated strain, Pseudomonas putida GNA5. After optimization of the fermentation process, 51.5 g L^-1 D-glucosaminic acid was produced from an initial concentration of 60 g L^-1 D-glucosamine-HCl after 72 h of oxidative fermentation, which corresponded to a molar yield of 95.4%. This production process is potentially of considerable economic significance because very few by-products were detected. Furthermore, D-glucosaminic acid was accumulated stably during the oxidative fermentation process without the addition of an inhibitor of D-glucosaminic acid breakdown, even though D-glucosamine was exhausted. These results suggest that the mechanisms of D-glucosaminic acid-related metabolism differ between Pseudomonas putida GNA5 and the strain Pseudomonas genera, which was previously reported to produce D-glucosaminic acid.