红曲霉产色素发酵条件优化及抑菌性能的测定

Optimization of Fermentation Conditions and Mensuration of Antimicrobial Activities of Monascus Pigment

优化了3株红曲霉(Mg、M6、M8)产红曲色素的发酵条件:接种量5.0%、培养温度30℃、培养时间72 h、初始pH 6.0。选择产色素最高的Mg菌株,用番薯淀粉培养液进行上罐发酵分析,探讨了Mg菌株液体深层发酵过程中色素产量的变化规律,整个发酵过程分为3个阶段:0～40 h是菌体大量生长阶段,色素产量很低;40～90 h是色素生成期,色素生成稳定且产量高;90 h以后菌体生成和产色素能力下降。色素效价最高达到29.71 U.mL-1。测定了色素对大肠杆菌和金黄色葡萄球菌的抑制作用,当培养液中的色素效价为0.9 U.mL-1时,就开始抑制大肠杆菌和金黄色葡萄球菌生长,色素效价达到3.6 U.mL-1时,其抑菌率也不再增大。

The fermentation conditions of Monascus Mg, M6, M8 strains were optimized to produce monascus pigments in this study, h revealed that the optimum fermentation conditions to yield monaseus pigment were inoculation volumes 5.0%, culture temperature 30℃, beginning pH 6.0 and culture time 72 h. It studied that the change regulations of pigment yield by Mg strain in submerged euhure in 3.7 L bioreactor with sweet potato starch culture medium. There were three phases in the fermentation： from 0 to 40 h lots of myeelium grew, the pigment were produced stably and largely in the 40-90 h, after 90 h the mycelium with pigment decreased. The highest pigment yields reached 29.71 U·mL^-1. It also determined antibacterial activities of Monascus pigment to Escheriehia coli and Staphylococcus aureus. It indicated that the growth of Eseheriehia coli and Staphylococcus aureus were inhibited with the pigment level 0.9 U·mL^-1. While the more pigment concentration than 3.6 U·mL^-1 the higher inhibitory rate increased.