PRODUCTION OF 6-HYDROXYNICOTINIC ACID FROM NICOTINIC-ACID BY RESTING CELLS OF PSEUDOMONAS-FLUORESCENS TN5

Resting cells of Pseudomonas fluorescens TN5 catalyze the hydroxylation at the 6-position of nicotinic acid to produce 6-hydroxynicotinic acid. We optimized the reaction and culture conditions for the production of 6-hydroxynicotinic acid from nicotinic acid by using P. fluorescens TN5 resting cells. The addition of molybdenum and iron ions and nicotinic acid as an inducer to the culture medium significantly enhanced the formation of the hydroxylation enzyme. The supply of oxygen was important for the enhancement of hydroxylation activity. Under the optimum conditions, 98.7% of the added 1.4 M nicotinic acid was converted to 6-hydroxynicotinic acid, and the highest yield was 191 g of 6-hydroxynicotinic acid per liter of reaction mixture containing 7.43 g dry weight of cells in 45 h at 35 degrees C.