Growth And Cell Transformation And Resting Cell Transformation At The Same Time Used As A Study Of The Hydroxylation Of Nicotinic Acid

6-hydroxynicotinic acid is a useful intermediate for synthesis of agrochemicals, Pharmaceuticals or other chemicals. It is difficult to add hydroxyl to form 6-hydroxynicotinic acid by chemic method. So we can get 6-hydroxynicotinic acid by a more effective way, that is bio-transformation. The current technology for microbial hydroxylation of nicotinic acid is a two-stage procedure of induced-cultivation/resting cells transformation. By which persons needed to first cultivate bacteria with hydroxylation activity by nicotinic acid as an inducer for obtaining of a large amount of cells, and then used the resting cells to convert the nicotinic acid to 6-hydroxynicotinic acid to avoid degrading of 6-hydroxynicotinic acid while cultivating. In this study, we reported that both growing culture and resting cells can transform nicotinic acid to 6-hydroxynicotinic acid, then in these two periods, we can both get the products. Through this method, the yield of the product was increased greatly.A strain named Pseudonomas putida NA-1 which transformed nicotinic acid into 6-hydroxynicotinc acid efficiently was isolated in our lab. When it was cultivated in the 1% (w/v) nicotinic acid ferment medium, we could get 62.6 mmol product at the most, then it will slowly degrade, but still remain 50% after 48 hours. So this strain has a slower ability to degrade the product than the strains Serratia marcescens and Pseudomonas fluorescens reported abroad. If we kept adding nicotinic acid to the medium, we could get continuously accumulated products—6-hydroxynicotinic acid. We put the strain to different concentrations of nicotinic acid in ferment medium, Themolar transformable ratio was the highest when the nicotinic acid was l%(w/v). During the cultivation period, we found the pH kept growing up. By set a contrast (not adjust the pH while cultivating), we found it was better to adjust pH during the cultivate period if we continuously add nicotinic acid to keep l%(w/v) concentration.Through the research, we found that the resting cell of the strain had the greatest transformable ratio in the l%(w/v) nicotinic acid transformable liquid. So we thought whether the strain could degrade 6-hydroxynicotinic acid. After the study, we got that low concentration of the product was degraded slowly, but high concentration of the product prohibited the degradation. Combine the raw material with the product, we found that the existence of nicotinic acid could keep on transforming to 6-hydroxynicotinic acid, and prohibit the degradation of the product. And we did not find apparent affect of fermentation transformation on the hydroxylation activity of resting cells.The final results showed that both growing culture and resting cells of pseudomonas putida NA-1 could be combined for production of 6-hydroxynicotinic acid. Therefore the inducer was saved and extra fermentation transformation besides resting cells transformation could be utilized for production of 6-hydroxynicotinic acid. So that, the production yield of 6-hydroxynicotinic acid from nicotinic acid was raised greatly.