Method for producing penicillin G acylation enzyme by fermentation by using casein hydrolysate as nitrogen source

Abstract

The invention relates to a method for producing penicillin G acylation enzyme by fermentation by using casein hydrolysate as a nitrogen source, which comprises the following steps: (1) preparing a test tube filled with a slant culture medium and a plate filled with a slant culture medium; (2) inoculating Bacillus cereus 21090 in the slant culture medium in the test tube filled with the slant culture medium under aseptic conditions, and culturing at constant temperature to obtain an activated strain; (3) preparing a bacterium suspension with the cell concentration of 10<8> / mL; (4) breeding the mutant strain of the high-yield penicillin G acylation enzyme by ultraviolet mutagenesis; (5) preparing a Bacillus cereus mutant strain fermentation culture medium from casein hydrolysate and the like; (6) fermenting the penicillin G acylation enzyme to obtain fermented liquor; (7) pretreating the fermented liquor, and concentrating the enzyme solution to obtain a concentrated enzyme solution; (8) preparing a penicillin G acylation enzyme liquid enzyme preparation; and (9) preparation of penicillin G acylation enzyme solid enzyme powder: sequentially adding soluble starch, sodium chloride and glycerol into the PGA (penicillin G acylation enzyme) liquid enzyme preparation, uniformly mixing, and carrying out spray drying to obtain the PGA enzyme powder. The method has the advantages of low cost and high yield.

Description

technical field [0001] The invention relates to a method for producing penicillin acylase, in particular to a method for fermenting and producing penicillin G acylase by using casein hydrolyzate as a nitrogen source. Background technique [0002] Penicillin G acylase (PGA) is an important industrial enzyme widely used to catalyze the production of 6-aminopenicillanic acid (6-APA) from penicillin G and the production of 7-aminodeacetoxycephalosporin from cephalosporin G acid (7-ADCA). 6-APA and 7-ADCA are important raw materials for the production of semi-synthetic penicillins and cephalosporins in the antibiotic industry. [0003] At present, the annual demand for penicillin G acylase exceeds 800 tons, and the annual growth rate is about 10%. However, most of the high-activity penicillin G acylase preparations sold in the domestic market still rely on imports. Since the 1980s in my country, the research on penicillin G acylase has mainly focused on the construction of engi...

AI Technical Summary

Problems solved by technology

On the one hand, the construction of genetically engineered bacteria is complex and cumbersome, and the strains constructed have poor genetic stability

On the other hand, at present, the nitrogen sources in the fermentation medium used to produce penicillin G acylase at home and abroad are mainly peptone, beef extract, yeast extract, etc., which are limited and expensive, and cannot meet the needs of large-scale industrial production.

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