Method for preparing nitrite reductase from flammulina velutipes

Abstract

The invention relates to a method for preparing nitrite reductase from flammulina velutipes and belongs to the technical field of a food enzyme biotechnology. The method comprises washing, draining and freeze-drying fresh flammulina velutipes, crushing the flammulina velutipes at a low temperature, screening the flammulina velutipes powder through a sieve of 60-100 meshes, carrying out extraction through an ultrasonic-assisted wall-dissolution enzyme method, carrying out salting-out, carrying out dialysis desalination, carrying out concentration to obtain a crude enzyme solution, carrying out separation purification through a DEAE-SepharoseFast Flow and dextrane gel G-150 chromatographic column, collecting a protein with enzyme activity, and carrying out dialysis, PEG20000 embedding and concentration, and freeze-drying to obtain nitrite reductase. The method provides a new idea for preparation of nitrite reductase, can be used in the field of fermented foods such as pickles, bacon and pickle development and reduces the content of nitrite in the product.

Description

[0001] 1. Technical field

[0002] The invention relates to a method for preparing nitrite reductase from Flammulina velutipes, belonging to the field of food enzyme biotechnology.

[0003] 2. Background technology

[0004] Nitrite is one of the common chemical pathogenic sources. It is the precursor of strong carcinogen nitrosamines. After ingestion, it can react with secondary amines in the human body to form nitrosamines, which can induce various cancers; Excessive intake of nitrite can also cause methemoglobinemia, leading to asphyxia due to hypoxia. In recent years, due to the extensive use of nitrogen fertilizers and the use of industrial wastewater and domestic sewage to irrigate farmland, the nitrite pollution of agricultural land has intensified, resulting in excessive nitrite in agricultural products such as vegetables, fruits, grains, and feed; on the other hand, traditional pickled products, meat, etc. Products will accumulate or introduce nitrite during processing...