海藻酸钠-微晶纤维素在SETR中包埋纳豆芽孢杆菌的固定化研究

目的 考察海藻酸钠-微晶纤维素在新型软弹式反应器(soft elastic tubular reactor, SETR)中对菌株的包埋作用。方法 使用海藻酸钠(sodium alginate, SA)与微晶纤维素(microcrystalline cellulose, MC)制成海藻酸钠-微晶纤维素水凝胶(microcrystalline cellulose/sodium alginate microcapsule, SA-MC)并包埋纳豆芽孢杆菌, 以光学显微镜形态、微球直径为指标, 单因素法优化SA与MC的配比和包埋时间; 并对优化好的SA-MC进行pH溶胀实验; 应用24 r/min的挤压频率进行发酵, 观察SA-MC在该过程中对pH的影响。结果 SA与MC以1:3的比例混合, 包埋时间1 h效果最佳; SA-MC对pH的响应并不敏感, 可用于发酵环境对菌株的包埋和保护; 与空白相比, SA-MC在SETR发酵环境中对pH有缓冲效果。结论 在SETR环境中SA-MC包埋纳豆芽孢杆菌表现较好的包埋作用。后续将进一步优化包埋材料的配方, 并对不同发酵参数的影响规律进行深入研究。本研究为天然材料包埋益生菌, 并旨在为SETR的应用推广提供理论支持。

Immobilization study on the encapsulation of Bacillus subtilis subsp. Natto in SETR by sodium alginate-microcrystalline cellulose

Objective To investigate the effect of sodium alginate-microcrystalline cellulose on the encapsulation of bacterial strains in an unconventional soft elastic tubular reactor (SETR). Methods Sodium alginate (SA) and microcrystalline cellulose (MC) were used to make a hydrogel (SA-MC) encapsulating with Bacillus subtilis subsp. natto, and the ratio of SA to MC and the encapsulation time were optimized by a single-factor method using light microscope morphology and microsphere diameter as indicators. Results The best results were obtained when SA and MC were mixed in the ratio of 1:3 and immobilized for 1 h. SA-MC was not sensitive to pH and could be used for encapsulation and protection of strains in the fermentation environment; SA-MC had a buffering effect on pH in the SETR fermentation environment compared to the control group. Conclusion SA-MC showed good performance in encapsulating Bacillus subtilis subsp. natto in SETR environment. The formulation of the embedding material will be further optimized and the effect of different fermentation parameters will be investigated in depth. The present study aims to provide theoretical support for the application of SETR by embedding probiotic bacteria with natural materials