本文研究了一株具有N-酰基酰化酶（DAA）生产能力的细菌，通过对其酶学特性及固定化酶用于D-氨基酸的生产进行了研究。显示此酶的最适温度为37℃，最适pH7.4，1mmol/L以下的CaCl2，CdCl2，CoCl2，CuCl2，FeCl2，HgCl2， MnCl2，ZnCl2对酶的活性没有影响,在20mmol/L的EDTA条件下仍可保持65%的酶活性。底物特异性显示酶的最佳底物是N-乙酰-D-苯丙氨酸，50mmol/L以上的N-乙酰-D-苯丙氨酸显著抑制酶的活性。利用海藻酸钠固定酶后，在30℃条件下，使用50mmol/L的N-酰基-D-苯丙氨酸底物进行的降解实验显示水解率可以达到84%，转化批次达到6次以上，活性保持达到70小时以上。%This paper analyzes a bacterium possessing the capacity to produce D-aminoacylase (DAA) and its applica-tion in the production of D-amino acid by analyzing its characterization of enzyme and immobilized enzyme. The results show that the optimum temperature of the enzyme is 37℃,the optimum pH is 7.4. Moreover, CaCl2, CdCl2, CoCl2, CuCl2, FeCl2, HgCl2, MnCl2, ZnCl2 under 1mmol/L have no effect on the enzyme activity, it can maintain 65% en-zyme activity under the EDTA condition of 20mmol/L. The substrate specificity shows that the optimum substrate is N-acetyl-D-phenylalanine.N-acetyl-D-phenylalanine above 50mmol/L inhibits the enzyme activity remarkably. Under the condition of 30℃, making use of immobilized DAA of sodium alginate, the degradation experiment using N-ace-tyl-D-phenylalanine shows that the hydrolysis rate can reach to 84%, the converting batches can reach six times or more,and the activity can keep over 70 hours.
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