Optimization of culture conditions for the bioconversion of vitamin D sub(3) to 1a,25-dihydroxyvitamin D sub(3) usingPseudonocardia autotrophica ID 9302

• Published in: Biotechnology and bioprocess engineering 2006-10, Vol.11 (5), p.408-413
• Main Authors: Kang, Dae-Jung, Lee, Hong-Sub, Park, Joon-Tae, Bang, Ji Sun, Hong, Soon-Kwang, Kim, Tae-Yong
• Format: Article
• Language: English
• ISSN: 1226-8372; 1976-3816
• DOI: 10.1007/BF02932307

We assessed the ability of aPseudonocardia sp. from soil samples to bioconvert vitamin D sub(3). The optimal culture conditions for the bioconversion of vitamin D sub(3) to active 1a,25-dihydroxyvitamin D sub(3) were investigated by varying the carbon and nitrogen sources, the metal salt concentrations, the initial pH, and the temperature. Microbial transformations were carried out with the addition of vitamin D sub(3) dissolved in ethanol. They were sampled by extraction with methanol-dichloromethane and the samples were examined by HPLC. Optimum culture conditions were found to be 0.4% yeast extract, 1% glucose, 3% starch, 1% fish meal, 0.2% NaCl, 0.01% K sub(2)HPO sub(4), 0.2% CaCO sub(3), 0.01% NaF, and pH 7.0 at 28C. The optimal timing of the addition of vitamin D sub(3) for the production of calcitriol byPseudonocardia autotrophica ID 9302 was concurrent with the inoculation of seed culture broth. Maximum calcitriol productivity and the yield of bioconversion reached a value of 10.4 mg/L and 10.4% respectively on the 7th day in a 75 L fermenter jar under the above conditions.