冻干高活力纳豆芽胞杆菌菌粉保护剂的筛选和优化

【目的】对冻干高活力纳豆芽胞杆菌菌粉保护剂进行筛选和优化研究,提高菌粉活菌存活率。【方法】采用单因素实验和正交实验设计,通过测定活菌存活率,筛选出最佳保护剂的配方;并研究采用优化后冻干保护剂制备的菌粉在20°C、4°C、25°C下的保存稳定性。【结果】纳豆芽胞杆菌的有效保护剂是:脱脂乳粉、甘露醇、L-抗坏血酸钠。最佳冷冻干燥保护剂配方是:脱脂乳粉10%+甘露醇4%+L-抗坏血酸钠1%,存活率达到91.63%。菌粉在20°C、4°C、25°C下保存12个月后,存活率分别为:88.79%、70.16%和10.52%,说明菌粉在20°C和4°C下保存稳定性较好,25°C下稳定性比较差。【结论】对纳豆芽胞杆菌冻干菌粉保护剂的优化,对纳豆芽胞杆菌的应用、活菌产品的质量稳定及新产品的研发均有一定的指导意义。

Screening and optimization of the cryoprotectants for high active Bacillus natto powder

Objective] Study on the technology of selection and optimization of Bacillus natto freeze-dried powder, in order to increase the survival rates of living bacteria. Methods] Single factor and orthogonal experimental designs were taken to measure the survival cells and then screened the protection agent formulations. And the storage stabilities of optimized lyoprotectant powder prepared at protection agent formulations. And the storage stabilities of optimized lyoprotectant powder prepared at ?20 °C, 4 °C and 25 °C were tested. Results] The effective protecting agents of Bacillus natto were: skimmed milk powder, mannitol, L-sodium ascorbate. The best protectants formula: 10% skim milk powder, 4% Mannitol and 1% L-sodium ascorbate, the results showed that the survival rate could reach to 91.63%. The survival rates of fungus powder conserved at ?20 °C, 4 °C, 25 °C for 12 months were 88.79%, 70.16% and 10.52%, respectively. The storage stability of bacteria powder at ?20 °C and 4 °C were excellent, while that at 25 °C was poor. Conclusion] The freeze-dried powder protective of Bacillus natto was optimized, which provided a guidance for application of Bacillus natto, stabilization of quality of live bacterial product and development of novel live bacterial products.