食品科学 ›› 2021, Vol. 42 ›› Issue (14): 70-77.doi: 10.7506/spkx1002-6630-20200323-350

• 生物工程 • 上一篇    下一篇

人工神经网络结合遗传算法优化保护剂提高罗伊氏乳杆菌抗冻性能

潘海博,覃璐琪,黄燕婷,梁晓琳,黄国宏,聂梦琳,饶川艳,梅丽华,李全阳   

  1. (1.广西大学轻工与食品工程学院,广西 南宁 530004;2.广西职业技术学院食品与生物技术学院,广西 南宁 530226)
  • 发布日期:2021-07-27
  • 基金资助:
    国家自然科学基金面上项目(31871802);南宁市重点研发计划项目(20172141)

Artificial Neural Network-Genetic Algorithm-based Optimization of the Formulation of Lyoprotectants to Improve the Freezing Resistance of Lactobacillus reuteri

PAN Haibo, QIN Luqi, HUANG Yanting, LIANG Xiaolin, HUANG Guohong, NIE Menglin, RAO Chuanyan, MEI Lihua, LI Quanyang   

  1. (1. College of Light Industry and Food Engineering, Guangxi University, Nanning 530004, China;2. School of Food and Biotechnology, Guangxi Vocational & Technical College, Nanning 530226, China)
  • Published:2021-07-27

摘要: 为提高新筛选的罗伊氏乳杆菌LTR1318冷冻干燥过程中的抗冻性能,通过单因素试验先筛选出影响乳酸菌冻干存活率的4 个主要因素:脱脂乳、谷氨酸、低聚果糖和山梨糖醇。再利用Box-Behnken试验设计不同保护剂组合下的菌株冻干存活率为训练集和测试集,构建径向基函数人工神经网络模型,模型拟合度可达0.984 4。结合遗传算法对神经网络的拟合结果进行50 次迭代寻优后,得到的最佳保护剂配方为脱脂乳10.90%、谷氨酸1.20%、低聚果糖1.30%和山梨糖醇0.80%。验证此条件下的冻干存活率为(95.74±5.07)%。经过人工神经网络结合遗传算法优化保护剂组合的策略,菌株在冻干过程中的乳酸脱氢酶和β-半乳糖苷酶的酶活力分别提高了53.19%和3.53 倍,是正常培养条件下酶活力的78.25%和86.43%。此外,冷休克蛋白基因的相对表达量小幅上调8.29%。通过采取上述策略,本研究探索出一种新型益生菌的冻干工艺,为乳酸菌冻干制剂的制备和真空冷冻干燥技术的进一步应用提供参考和指导。

关键词: 罗伊氏乳杆菌;人工神经网络;遗传算法;生物信息学;冷胁迫;抗冻性能

Abstract: In order to improve the freezing resistance of Lactobacillus reuteri LTR1318 during freeze-drying, four lyoprotectant ingredients, namely skim milk, glutamic acid, fructo-oligosaccharide and sorbitol were identified as main factors affecting the freeze-drying survival rate of this strain by single factor experiments. The survival rates of freeze-dried cells with different protectant combinations designed by Box-Behnken design were used for training and testing to construct a radial basis function neural network model whose fitting degree was 0.984 4. The genetic algorithm was used to optimize the fitting results of neural network with 50 iterations, and the optimal lyoprotectant composition was obtained as follows: skim milk 10.90%, glutamic acid 1.20%, fructo-oligosaccharide 1.30% and sorbitol 0.80%. The optimized formulation gave a freeze-drying survival rate of (95.74 ± 5.07)%. The activities of lactate dehydrogenase and β-galactosidase in freeze-dried L. reuteri with the lyoprotectant increased by 53.19% and 353% compared to the control without the lyoprotectant, respectively, which accounted for 78.25% and 86.43% of the enzyme activities under normal culture conditions, respectively. In addition, the relative expression of cold shock protein gene was slightly increased by 8.29%. The lyoprotectant developed in this study could be a new promising probiotic lyoprotectant. Our results provide a reference and guidance for the development of freeze-dried preparations of lactic acid bacteria and more extensive applications of vacuum freeze-drying technology.

Key words: Lactobacillus reuteri; neural network; genetic algorithm; bioinformatics; cold stress; freezing resistance

中图分类号: