冷冻干燥法制备阿特拉津降解菌剂的条件优化

旨在研究通过冷冻干燥法制备出高活性的阿特拉津降解菌剂，并得到最佳工艺条件。采用冷冻干燥法制备阿特拉津降解菌HBT4（Microbacterium sp.）菌剂，通过单因素及正交试验对工艺条件进行优化，其中以菌体存活率为指标。结果表明添加的保护剂的最佳配方为蔗糖10% (w/v)，甘油8 mL/L，脱脂乳15% (w/v)。然后在正交试验中选取4个影响因素，单因素试验结果确定3个水平，得出最佳工艺为：菌液的离心速度为7000 r/min、菌体与冻干保护剂的配比为2:1、冻干过程中装液量为12 mL、冻干的时间为16 h，此时冻干菌体的存活率最高为75.1%。该试验条件下所制备的菌剂存活率高且稳定性较好，为微生物菌剂的工艺化生产及应用奠定基础。

Atrazine Degradation Bacteria Prepared by Freeze-drying Technology: Optimization

The aim of this reserach is to research the preparation of highly active atrazine degradation bacteria by using the freeze-drying method, and get the optimum process conditions. Microbacterium sp.HBT4 agents was prepared by using the freeze-drying method, and the process conditions were optimized by the single-factor method and the orthogonal test, with the survival rate of the bacteria as the index. The results showed that the addition of 10% of sucrose (w/v), 8 mL/L of glycerol, and 15% of skim milk (w/v) was the best combination of freeze-drying protectants for the formula. Four influencing factors were selected in orthogonal experiments, and the single-factormethod results determined three levels. The best results were obtained: the centrifugation speed of the bacteria solution was 7000 r/min; the ratio of bacteria to freeze-dried protection agent was 2:1; the amount of liquid in the freeze-drying process was 12 mL; and the time of freeze-drying was 16 hours. This moment, the highest survival rate of freeze-dried bacteria was 75.1%. The results showed that the bacteria prepared under the experimental conditions had a high survival rate and good stability, thus laying a foundation for the production and application of microbial agents.