Optimization of culture medium composition and fermentation conditions for chitin deacetylase production by Lysinibacillus boronitolerans JM-4

Chitin was the second largest resource in nature, and chitosan obtained by deacetylation from chitin has a broad application prospect. Compared with the commonly used chemical methods, enzymatic deacetylation had the advantages of environmental protection and uniform degree of deacetylation. High quality chitosan with uniform deacetylation degree could be prepared from chitin using chitin deacetylase (CDA) to remove N-acetyl group, which is an environmentally friend process to avoid the use of strong acids and bases. The enzyme-producing conditions of the strain Lysinibacillus boronitolerans JM-4 (LysJM-4) were optimized to improve the CDA-producing capacity. The proportion of medium and fermentation conditions were optimized by single factor experiment. The enzyme production medium consisted of 10 g/L corn starch, 10 g/L beef extract, 5 g/L sodium chloride, and 12 g/L chitin. The optimum fermentation conditions were determined as 7.0 initial pH, 35℃ culture temperature, and 8 % (V/V) inoculation amount. Under these conditions, the CDA enzyme activity could reach 17.77 U/mL after 72 h fermentation. The results were of great significance for the industrial preparation of chitosan by enzymatic method. © (2024), (Bio Tech System). All rights reserved.