红曲霉-金钗石斛双向发酵工艺优化

Optimization of Bidirectional Fermentation Conditions of Monascus sp.and Dendrobium nobile

红曲霉(Monascus sp.)代谢产物具有很强的抗氧化性,是天然的抗氧化剂重要来源。金钗石斛是中国传统中药材,具有很多生物活性,结合红曲霉与中草药材双向发酵有望增强其抗氧化能力和改变代谢通路,为探究筛选最佳的金钗石斛-红曲霉发酵条件,提高双向发酵代谢产物的抗氧化活性,采用ABTS法、DPPH法和抗脂质过氧化法三种体外抗氧化模型,通过单因素实验确定影响抗氧化活性的发酵条件,然后设计了四因素三水平正交实验,确定了最优发酵条件为:接种量10%、料水比1:0.7、培养时间16 d和温度(28±1)℃。在此条件下,石斛红曲的脂质过氧化抑制率为69.32%,DPPH自由基清除率为45.65%,ABTS+自由基清除率90.63%,比单独红曲霉发酵代谢产物的抗氧化性分别提高了13.04%,14.10%,29.07%,比金钗石斛的抗氧化性分别提高了42.48%,44.99%,74.63%。可为新型双向发酵的抗氧化产品的开发提供一定的依据。

Monascus sp.is an important resource of natural antioxidant with strong antioxidant capability.The bidirectional fermentation of M.sp.and Chinese herbaceous herbs can be expected to enhance its antioxidant ability and change the metabolic pathways.Dendrobium nobile is a traditional Chinese medicinal material with many biological activities.In order to screen the best fermentation conditions of D.nobile and Monascus sp.to improve the antioxidant activity of metabolites of bidirectional fermentation,three antioxidative modes in vitro were adopted:ABTS+free radical scavenging,DPPH free radical scavenging,and inhibiting lipid peroxidation.Moreover,the fermentation conditions affecting antioxidant activity were determined by single factor experiment,and then the orthogonal experiment with four factors and three levels was designed.Finally,the optimum fermentation conditions were determined as follows:Inoculum size 10%,ratio of material to water 1:0.7,culture time 16 days,and temperature(28±1)℃.Under these conditions,the inhibition rate of lipid peroxidation,the scavenging rate of DPPH and the scavenging rate of ABTS+were 69.32%,45.65%and 90.63%respectively.These data were increased by 13.04%,14.10%,and 29.07%respectively than the metabolic products of M.sp.,and were 42.48%,44.99%,74.63%higher than Dendrobium nobile respectively.This study can lay a foundation for the development of a new antioxidant of bidirectional fermentation.