Production Of Nicotinamide By Biological Catalyst

A kind of B clan vitamin, naturally existing in the animal liver and kidney, yeast and rice chaff, nicotinamide is the necessary component of NAD and NADP. It can be applied in the treatment of pellagra and used as a vitamin supply for human body. When used as feed additive, it can promote the disease resist and prevention ability of domestic animals. With the limits of production ability and scale, large quantity of nicotinamide is imported to meet the domestic needs.The optimization of ferment, preparation of immobilized cells, optimization of bioconversion and extraction of nicotinamide were studied in this paper. The fermentation technology 3-cyanopyridine hydratase were optimized by orthogonal experimental design and other methods. An optimized fermentation technology was obtained as follows: the fermentation media were 3.0% glucose, 1.0% yeast extracts, 0.05% MgSO4, 0.1% urea, 0.05%KH2PO4, 0.05% K2HPO4 and 10 ppm additive; 5% (v/v) seed; temperature, gas flow rate, pressure and agitating rate were controlled with different periods in 80 h fermentation time. Under the technology, 3-cyanopyridine hydratase activity in culture broth was increased 2 times, reached 12000000U/hr.mL.To prepare the immobilized cells, a machine was designed and manufactured. The preparation of immobilized cells was greatly accelerated with it.The effects of various factors especially feeding ways of substrate and conversion models onthe bioconversion rate of 3-cyanopyridine to nicotinamide with immobilized cells were studied. The transformation times of immobilized cells was raised from originally 3 times to 6-7 times with the results.The separation technology was investigated in the paper, especially the crytalization. The recovery rate for the crytalization was 88.6%. And the total recovery rate was 88.5%.