基于代谢调控优化高产γ-谷维素的苦荞发酵体系

Optimization of High-yield γ-Oryzanol Fermentation System Based on Metabolic Regulation

摘要:

该研究采用紫红曲霉发酵苦荞，在前期研究的基础上，从细胞膜通透性、金属离子浓度与底物诱导三个方面调控其代谢过程，通过响应面法优化高产γ-谷维素的发酵体系。单因素试验表明，超声处理不能促进发酵产物中γ-谷维素的积累，添加表面活性剂（Triton X-100、Tween-80、SDS）、Ca2+离子、Mg2+离子、谷甾醇均对γ-谷维素的富集有正向调节的作用。通过响应面分析得到的调控参数为：Triton X-100添加量3.2‰，Ca2+添加量4.2‰，阿魏酸与谷甾醇配比（阿魏酸:谷甾醇=1:1，W:W）添加0.5‰，此条件下γ-谷维素含量达到2.61 mg/mL，提高至未发酵前的31.62倍、调控前的1.64倍。红曲发酵苦荞产物呈浅红色，具有浓郁的红曲香味，并且通过代谢调控后发酵产物中含有丰富的γ-谷维素，其具有较好的工业开发前景。

Abstract:

In this study, Monascuspurpureus was used to ferment Tartary buckwheat. Based on previous reseaches, the metabolic process was regulated from three aspects: cell membrane permeability, metal ion concentration and substrate induction. The fermentation system with high yield of γ-oryzanol was optimized by the response surface method. The single factor experiment results showed that the accumulation of γ-oryzanol in the fermentation product could not be promoted by ultrasonic treatment, and the addition of surfactants (Triton X-100, Tween-80, SDS), Ca2+, Mg2+, and sitosterol had a positive effect on the accumulation of γ-oryzanol. The control process parameters obtained through response surface optimization were: Triton X-100 was 3.2‰, Ca2+ was 4.2‰, ratio of ferulic acid to sitosterol (ferulicacid: sitosterol=1:1, W:W) was 0.5‰. The content of γ-oryzanol after regulation can reach 2.61 mg/mL, which was increased to 1.64 times of that before regulation, and 31.62 times higher than that of the unfermented blank group. The fermented tartary buckwheat product of Monascuspurpureus was light red with strong red yeast flavor. Furthermore, the fermentation product was rich in γ-oryzanol after metabolic regulation, which has a good industrial development prospect.