葛根淀粉为基质液态发酵生产红曲色素的培养基成分优化

Optimization of Medium Components Producing Hongqu Pigments in Liquid-state Fermentation Using Kudzu Root Starch as Culture Media

葛根淀粉除含淀粉外,还含有丰富的矿物质和黄酮类物质,具有良好的保健功能。红曲色素是红曲霉的次级代谢产物,具有诸多生理活性。若以葛根淀粉为基质发酵生产红曲色素,可将两者的保健功效有机结合。本文探索以葛根淀粉为基质,复配不同碳源、氮源、金属离子,采用红曲霉菌株FZU-MP1501进行液态发酵生产红曲色素。结果显示:以葛根淀粉或籼米粉为基质,两者的红曲色素产量无显著差异。单因素试验表明,以葛根淀粉为碳源时,添加麦芽糖、谷氨酸钠及硫酸亚铁有利于其产色。三因素三水平响应面试验表明,麦芽糖、谷氨酸钠、硫酸亚铁的最佳添加质量浓度为麦芽糖32.50 g/L、谷氨酸钠22.33 g/L、硫酸亚铁0.70 g/L。在此基础上得到最优醇溶性色价为3 591.43 U/g,比优化前提高66.42%,其中黄色价、橙色价、红色价分别提高了104.90%,44.31%和45.19%。葛根淀粉可作为基质,通过液态发酵红曲霉生产红曲色素,且经培养基优化可大幅提高色素产量。

Kudzu root starch contains minerals and flavonoids, which makes it with healthy benefits. Hongqu pigment, as the secondary metabolites of Monascus strains, is a nature food pigment and has been identified to possess numerous physiological activities. Using kudzu root starch as culture media for the fermentation of Hongqu pigment could contribute their health benefits to the final product. In this study, kudzu root starch was used as a major culture, mixing with different carbon source, nitrogen source and metal ions for the production of Hongqu pigment by FZU-MP1501(M.purpureus) in a liquid state fermentation system. The results indicated that there is no significant difference between kudzu root starch and polished rice as the starchy substrate for the Hongqu pigment production. The result of single factor experiment showed that maltose, monosodium glutamate and ferrous sulfate as the carbon source, nitrogen source and metal ions, respectively, would significantly increase the Hongqu pigment production. Response surface experiment result showed that the optimal medium component was as follow: malt sugar 32.50 g/L, monosodium glutamate 22.33 g/L and ferrous sulfate 0.70 g/L. On this basis, the optimized alcohol soluble color value was 3591.43 U/g, which increased by66.42% comparing with the control;the yellow value, orange value and red value increased by 104.90%, 44.31% and104.90%, respectively. In conclusion, the kudzu root starch can be used as a substrate of liquid-state fermentation of Hongqu pigment, and the yield of pigment increased dramatically after optimization of medium components.