Study On Fermentation Process Of Microbial Method Manufacturing Nicotinamide

A kind of B clan vitamin, mainly existing in the animal, nicotinamide is the necessary componentof NAD and NADP, and it is an effective treatment and can cure pellagra; there are three specification ofgoods which names are food, medicine and animal feed, and it can be primarily applied in feed additive,which can promote the disease resist and prevention ability of domestic animals. With the change of dietarypattern of people which has turned into Animals from plould like, nicotinamide which is used for feedadditive has a broad market prospect.Producing nicotinamide by microbial method has the following advantages: mild reactionconditions, high conversion rate, good product quality and minor pollution. Enzyme activity wassettled as detection parameters in this experiment, and this article had studied the contents which were thescreening of high yield nitrile hydratase bacterial strain, the optimization of fermentation conditions, andthe optimization of fermentation medium. In the end, the results indicated that:(1) It had studied the mutagenic effect of Norcardia sp.HD9611respectively, that themutagenesis conditions were ultraviolet rays, microwave and diethyl sulfate. At last, it had determined thebest mutation conditions which are ultraviolet rays, power15w, irradiation distance is35cm, irradiationtime90s, microwave, irradiation intensity,60%, irradiation time,80s, and diethyl sulfate, concentration0.8%,40min. On this basis, strategy of composite mutagenesis was designed, as a result, a high yieldnitrile hydratase mutant strain HD1220with enzyme activity of1066.4U/mL was obtained, this value was25.0percent higher than the original strain. We had observed the cell shape of the mutant strain, which wasbranching, or moniliform arrangement, and determined growth curve of the mutant strain.(2) By method of single factor and orthogonal test, we had optimized producing enzyme offermentation conditions of the mutant strain HD1220. Finally, it had determined that the optimizedfermentation conditions were: seed cultivation time of35h, inoculating quantity of6%, liquid mediumvolume of30mL, initial pH of8.0, fermentation temperature of26℃, speed of220r/min.(3) By method of single factor and response surface, we had studied the the four factors of carbonsource, nitrogen source, metal ion and inductive agent. Finally, it had determined that seed fermentationculture medium composition of: glucose of18.43g/L, yeast extract of9.33g/L, cobalt ions of12.81mg/L, urea of7g/L.