米曲霉菌体细胞固定化及DL-蛋氨酸的光学拆分

Immobilization of High Activity Aminoacylase-producing Aspergillus Oryzae Cells Applied for Resolution of DL-Methionine

用亚硝基胍对产氨基酰化酶的米曲霉 ( Aspergillus oryzae) 30 42进行诱变 ,经过筛选获得诱变菌株30 42 - 5 ,再进行自然分离后得到了一株高产菌株 30 42 - 5 - 5 a,其自由酶活力提高了 2 15 .7% .采用此菌株进行了固定化细胞酶法拆分 DL -蛋氨酸 ( DL - Met)的研究 ,得到了最好的固定化条件为 8%明胶包埋 ,0 .1%戊二醛交联 12 h.制得的固定化细胞酶活力为 81.99u/ g.固定化细胞酶的最适作用温度为 6 5℃ ,最适作用 p H为 8.0 .用固定化细胞装柱 ,将连续拆分得到的产物用离子交换法进行分离精制 ,L -蛋氨酸盐酸盐的得率为理论产值的 6 9.4%

Aspergillus oryzae 3042 was mutated with NTG, then separated and purified.High\|producer of animoacylase (3042\|5\|5a) was selected from many mutants. The animoacylase activity of the mutant 3042\|5\|5a for resolving DL\|Methionine was 215.7% higher than that produced by wild type strain, and could reach to 478.3 u/mL. Mycelium pellets of 3042\|5\|5a was immobilized by crosslinking of 8% gelatina and 0.1% glutaraldehyde. The enzyme activity of immobilized cells was 81.99 u/g. The optimal pH and temperature for aminoacylase of immobilized cells were 8.0 and 65℃,respectively. The immobilized cells were used for continuous resolution of N\|Ac\|DL\|Met and the yield of L\|Met was 69.4%.