Production of D-glucosaminic acid by fermentation with pseudomonas putida

Strain GNA5 producing D-glucosaminic acid from D-glucosamine was isolated from soil samples. It was identified as Pseudomonas putida based on the assay of Biology Automated Microbiology Identification System and analysis of 16S ribosomal DNA sequence. P. putida GNA5 could grow in the medium containing high concentration of D-glucosamine, and D-glucosaminic acid was stably accumulated in the oxidative fermentation process. The preliminary optimized culture medium composition (g/L) for the production of D-glucosaminic acid with P. putida GNA5 was obtained as follows: D-glucosamine-HCl 30, glucose 5, urea 5, KH₂PO₄2, MgSO₄-7H₂O 0.5, CaCO₃ 10, pH 7.0. After 48 h fermentation in this medium, the concentration of D-glucosaminic acid reached 25.5 g/L. with molar yield of 93.9%. P. putida GNA5 exhibited efficient conversion ability of D-glucosamine to D-glucosaminic acid and low degradation ability of D-glucosaminic acid. It shows considerable economic significance in development of D-glucosaminic acid producing process.