Method for improving nitrile hydratase activity of bacillus subtilis

Abstract

The invention discloses a method for improving the nitrile hydratase activity of bacillus subtilis. The method comprises the following steps: (1) carrying out slant culture; (2) carrying out seed culture; and (3) carrying out fermentation culture. The method has the advantages that on one hand, the nutrition components in the fermentation medium are changed, namely, the fermentation medium contains Tween-80 0.1-1 g / ml%, NH4Cl 0.1-1 g / ml%, and urea 0.01-1 g / ml%, a glucose-Co<2+> coupling fed batch process is adopted, and a supplementary material formed by mixing glucose and inducer IND is added; on the other hand, the growth environment of bacteria can be controlled, namely, in the fermentation process, by adding ammonium hydroxide, the pH is controlled to be 6.8-7.5, the temperature is controlled to be 25-35 DEG C, the oxygen quantity is maintained to be 1-3 vvm, and thus the purpose of greatly improving the enzymatic activity during the nitrile hydratase fermentation production is achieved.

Description

technical field

[0001] The invention belongs to the technical field of biochemical industry, in particular to a method for improving the activity of bacillus subtilis nitrile hydratase. Background technique

[0002] Nitrile hydratase is an important biocatalytic agent for the production of nicotinamide. At present, there are many reports on the use of nitrile hydratase in microorganisms to biocatalyze nicotinamide: for example, the invention patent with the publication number CN1424402A reports that 3-cyanopyridine is converted into nicotinamide by using the nitrile hydratase produced by Corynebacterium propionici. During the conversion process, when the product concentration is ≥ 5%, use the ultra flow membrane filtration system to discharge the product, and at the same time start to add 3-cyanopyridine and water, and wait for the cumulative concentration of the product to be ≥ 10%, and then discharge the tank at one time; as disclosed The invention patent No. CN1154364A r...