细胞转化法生产L-苹果酸的研究

Producing L-Malic Acid by Cell Conversion Process

报道普通变形杆菌细胞转化法生产Ｌ－苹果酸的研究，探讨菌体培养时间和转化反应条件等因素对菌体延胡索酸酶活性的影响、菌体酶的热稳定性和ｐＨ 稳定性． 确定最佳工艺条件和酶的稳定性条件分别为：菌体培养时间７２ ｈ，转化反应温度３５ ℃，底物转化液ｐＨ７．０，转化反应时间３ｈ；温度≤３５ ℃，ｐＨ６．０～７．８． 菌体经过１０ 批次转化反应后，其延胡索酸酶活性仍很稳定，酶活保存率达８７．０％ ．

The production of L malic acid by cell conversion process of Proteus vulgaris is reported with emphasis on its characteristics The studies include the effects of cell culture time and conversion reaction condition on the activity of cell fumarase;and also heat and pH stability of cell fumarase.The optimal technological conditions and the conditions of enzymatic stability are determined respectively as follows:a time of 72 hours for cell culture,a temperature of 35℃ for conversion reaction,an acidity of pH 7 0 for substrate conversion solution,and a time of 3 hours for conversion reaction;a temperature lower than or equal to 35 ℃ and an acidity of pH 6 0～7 8 After the tenth batch conversion reaction,the cell fumarase has a fairly stable acitivity showing a preservation rate up to 87 0%