基于微生物固态发酵豆粕转化大豆异黄酮的研究

大豆异黄酮具有较高的营养价值和生理保健功能，现已广泛应用到食品、饲料和医药等领域中。为了研究EM菌、枯草芽孢杆菌ATCC 6633和植物乳酸杆菌ATCC 8014单独和混合发酵对大豆异黄酮 (Soybean insoflavones, SIF)转化效率的研究，本实验将接种量的接种水平全部考虑进去建立微生物固态发酵和菌种组合的方法，通过真空密封发酵和高效液相色谱(High performance liquid chromatography, HPLC)分析方法研究大豆异黄酮中糖苷转化为苷元的效率，此外，还研究了饲料发酵后的干物质含量和在优化条件下样品的重复性研究。结果表明，三种微生物的单独发酵都比混合发酵的效果好，在7 d后枯草芽孢杆菌ATCC 6633单独发酵的效果最好，其苷元含量占大豆异黄酮的比例达到64.56%，且样品重复性和稳定性较高，从而为工业化发酵转化SIF提供一定的理论基础和参考依据。

Biotransformation of Soybean Isoflavone by Microbial Solid-state Fermentation

Soybean insoflavones (SIF) are rich in nutritional value and heathy benefit, which had been widely applied in various fields including food, feed, medicine and so on. To extend the application of SIF for industrialization production, the efficacy of biotransformation of SIF by microbial solid-state fermentation was studied using EM strains, Bacillus subtilis ATCC 6633 and Lactobacillus planetarium ATCC 8014 for single and mixed fermentation. Effects of combined strains and incubation size were investigated for improve the biotransformation efficiency of SIF through vacuum sealed fermentation. The repeatability of the samples was also investigated under the optimized fermentation conditions. The results demonstrated that the single strain-mediated fermentation resulted in higher biotransformation efficacy than that with mixed strains, and the ratio of aglycone in total SIF content reached 64.56% after 7 d by solid-state fermentation with Bacillus subtilis ATCC 6633. The fermentation had high repeatability and stability.