全细胞生物转化二氯丙醇合成环氧氯丙烷的工艺研究

Synthesis of epichlorohydrin by whole-cell biotransformation of 1,3-dichloropropanol

针对传统环氧氯丙烷生产工艺中二氯丙醇皂化过程产生大量高碱度、高含盐量有机废水问题,提出利用生物法转化二氯丙醇合成环氧氯丙烷的绿色工艺。利用表达重组卤醇脱卤酶的大肠杆菌全细胞为生物催化剂,考察了pH、温度、全细胞菌体添加量、底物浓度等对生物转化过程的影响。结果表明,优化的工艺条件为:最适pH为8.3,最适反应温度为45℃,全细胞菌体添加量为10 mg(DCW)/mL,底物浓度为20 mmol/L,在此条件下转化8 h后,1,3-二氯丙醇的最高转化率可达92.3%。全细胞生物催化剂重复反应3次后活力仍保留在80%以上,显示了其良好的应用前景。

In views of the emissions of a large number of high alkalinity and high salinity organic wastewater from the dichloropropanol saponifying process in traditional epichlorohydrin production, a green technology about using biotransformation of dichloropropauol to synthesize epichlorohydrin is presented. With a recombinant E. coli BL21 （DE3） expressing halohydrin dehalogenase as whole-cell biocatalyst, the influences of pH, the temperature of reaction, the amount of cells and substrates concentration are studied in detail. The optimum conditions for biotransformation are as follows ：8.3 of pH, 45℃ of temperature, 10 mg DCW/mL of cells concentration, 20 mmol of substrate concentration. Under the optimal conditions, the conversion rate can reach 92. 3% after 8 hours＇ reaction. The whole-cell biocatalyst has good operational stability, suggesting the more prospective for application.