3种益生菌转化纳米硒冻干菌粉工艺研究与形态表征

Research and Morphological Characterization of Three Selenium Probiotics in Transformation of Nano-Selenium Freeze-Dried Bacterial Powder

纳米硒具有低毒、高效的生物活性,采用益生菌转化合成的纳米硒复合益生菌冻干粉具有双重保健功效。实验采用嗜酸乳杆菌、嗜热链球菌及双歧杆菌分别合成纳米硒,然后将转化后的3种富纳米硒益生菌等量混合、冻干后制备成纳米硒益生菌冻干粉,并确定了亚硒酸钠适宜的初始浓度和菌粉理想复合冻干保护剂组成,进而对合成的3种益生菌纳米硒冻干粉进行了结构和性能表征。结果表明,采用双歧杆菌、嗜热链球菌、嗜酸乳杆菌为转化菌时亚硒酸钠适宜初始浓度分别为4、6、6 g/L,理想的复合保护剂组成为海藻糖5%、碳酸氢钠0.8%、低聚木糖12%、蔗糖3%,在此条件下益生菌存活率可达79.6%,益生菌转化的纳米硒为非晶态,呈红色的规则球形颗粒。

Nano selenium has low toxicity and high biological activity.The composite freeze-drying powder of nano selenium and probiotics,which was synthesized by probiotic transformation,has health care effects of both nano selenium and probiotics.In this experiment,Lactobacillus acidophilus,Streptococcus thermophilus and Bifidobacterium were used to synthesize nano selenium respectively,and then the three nano-selenium probiotics were mixed in equal amounts and lyophilized to prepare nano-selenium probiotics.The suitable initial concentration of sodium selenite and the ideal composition of composite freeze-drying protectors were determined,and the structure and properties of the synthesized nano selenium freeze-drying powder were characterized.The results showed that the optimal initial concentration of selenite was 4 g/L,6 g/L and 6 g/L,respectively,when Bifidobacterium,Streptococcus thermophilus and Lactobacillus acidophilus were used as transformation bacteria.The ideal composite protective agent was composed of 5% trehalose,0.8% sodium bicarbonate,12% xylooligosaccharide and 3% sucrose.Under these conditions,the survival rate of probiotics could reach 79.6%.The nano selenium synthesized by probiotics was amorphous state,taken on red and regular spherical particle.