A packed bed reactor filled with the immobilized cells was developed to continuously produce l - alanine from l - aspartic acid . the reactor with100g / l substrate solution had been running for 20 days at 37 在温度37 、底物浓度100g l的条件下，该固定化细胞在填充床反应器中连续运行20天，测得其半衰期为71天。
