Chemical And Enzymatic Preparation Of L-ornithine Conditions Discussed

In this paper, the process conditions of preparation of L-ornithine by chemical and enzymatic methods were studied. A simple and convenient method of extracting the L-arginase was found. The structure of the object product was characterized by the infrared spectrum and the optical rotation, and the purity of the object product was analysed by the amino acid analyzer. By designing the orthogonal experiment, the factors of the reactions such as the time, the temperature and so on were discussed, and the best condition of each reaction was determined. The L-ornithine was prepared at pH 9.5 for 5h when the mol ratio for L-arginine to Ba(0H)2 was 1:1.25 by chemical method. The percentage yield was 77.5%. The L-ornithine was prepared at 36℃,and pH 9.5 for 20h by enzymatic method when the mol of L-arginine to the active units of arginase was 1mmol:44units and the mol of MnSCO₄ of to the active units of arginase was 5mmol:880 units. The percentage yield was 78.3%; The best heating temperature of the extraction of the L-arginase was 60℃. The best time of heat preservation was 5min. The quality of bovine liver to the volume of the buffer solution of Tris-HCl was lg:2mL. The active units of the L-arginase extracted were 220 units·mL^-1. At last, the magnification of preparation of the L-ornithine by enzymatic methods was studied simply, which provided the foundation for the factory production.