Microbial enzymes racemization preparation method of DL-alanine

Abstract

The invention relates to a microbial enzymes racemization preparation method of DL-alanine, comprising the following steps: preparing a substrate, adjusting the PH value of the substrate to eight by ammonia or sulphuric acid, canning the obtained substrate in flasks, inoculating microorganisms saved on an inclined plane to the substrate by picking one loop of microorganisms with a transfering loop, culturing the substrate for 24h at 30 DEG C by a rotary shaker of which the rotation rate is 110rpm, merging the above cell supernatant, adding the cell supernatant in a substrate solution, reacting at 30 DEG C at PH value of 7.0 when a polarimeter is used to measure the specific rotation of the reaction system every hour, continuing to react when the specific rotation is zero and heating up to60-100 DEG C, destaining for 30min by adding active carbon, filtering, and vacuum concentrating and crystallizing by a rotary film evaporator to obtain the DL-alanine finished goods. The invention has the advantages of accessible raw materials, simple production process and mild conditions, and can greatly reduce the production cost of DL-alanine.

Description

technical field

[0001] The present invention relates to a method for producing DL-alanine. Background technique

[0002] At present, the production process of DL-alanine at home and abroad mainly uses the reaction of acetaldehyde and hydrocyanic acid to generate cyanohydrin, which is reacted with ammonia to obtain cyanamide, which is hydrolyzed under alkaline conditions to generate amino acid sodium, which is The crude product of aminopropionic acid was obtained by exchange, and the finished product was obtained by recrystallization with water or ethanol. Alanine can also be synthesized from raw materials such as ether, ammonium chloride, and sodium cyanide. However, these synthetic methods all use cyanide, which is highly toxic, difficult conditions, serious waste problems, long synthetic routes and low yields. In addition, aminopropionic acid can also be produced by the chlorination method. This method uses propionic acid chlorination to obtain chloropropionic acid, and ...