功能性红曲固态发酵工艺优化

Optimization of solid-state fermentation technology of functional Monascus

为提高功能性红曲中酸式Monacolin K的产量,优化红曲的固态发酵工艺。以紫色红曲菌(Monascus purpureus)为发酵菌株进行固态发酵,以酸式Monacolin K产量为评价指标,采用单因素和响应面试验对其发酵条件进行优化,通过扫描电镜观察添加L-蛋氨酸后的形态变化。结果表明,最佳发酵条件为装料量100 g/500 m L,大豆粉添加量2.3%,甘油添加量2.5%、L-蛋氨酸添加量0.1%、接种量16.0%,变温发酵24 d(即前3 d 30℃培养,后21 d 20℃低温培养,并在低温发酵第4天加入L-蛋氨酸)。此优化条件下,酸式Monacolin K产量平均值为21.00 mg/g,比优化前(2.95 mg/g)提高了85.95%。添加L-蛋氨酸能使红曲霉菌丝体更为粗壮,细胞壁、细胞膜的通透性增加,产物积累形成的反馈抑制程度降低,从而使Monacolin K产量得到提升。该研究通过优化功能性红曲发酵工艺,有效地提高了红曲米中酸式Monacolin K的产量。

To increase the yield of acidic Monacolin K in functional Monascus,the solid-state fermentation technology was optimized.Using Monascus purpureus as the fermentation strain to perform solid-state fermentation and acid Monacolin K yield as the evaluation index,the fermentation conditions were optimized by single factor and response surface tests the morphological changes of Monascus with L-methionine addition were observed by scanning electron microscopy.The results showed that the optimal fermentation conditions were as follows:loading volume 100 g/500 ml,soybean powder 2.3%,glycerol 2.5%,L-methionine 0.1%,and inoculum 16.0%,variable temperature fermentation 24 d(30℃for the first 3 d and 20℃for the last 21 d,L-methionine was added on the 4th day of low temperature stage).Under the optimal conditions,the average yield of acidic Monacolin K was 21.00 mg/g,which was 85.95%higher than that before optimization(2.95 mg/g).It was found that the addition of L-methionine made the mycelium of Monacolin more robust,the permeability of cell wall and cell membrane increased,and the feedback inhibition of product accumulation was reduced,resulting in increased Monacolin K production.In this study,by optimizing the fermentation process of functional Monascus,the yield of acid Monacolin K in red kojic rice was effectively increased.