扁桃斑鸠菊叶促进灵芝胞外多糖高产条件优化及抗氧化活性研究

Optimization of High Yield Conditions and Antioxidant Activity of Ganoderma lingzhi Exopolysaccharide Promoted by Vernonia amygdalina Leaf

胞外多糖(EPS)是灵芝液体发酵的主要活性产物,为提高灵芝胞外多糖含量,在发酵培养基中添加扁桃斑鸠菊叶粉末,采用单因素和正交试验优化发酵条件,红外光谱表征灵芝多糖结构,并分析其抗氧化活性。单因素实验结果表明,扁桃斑鸠菊叶粉末优化的添加量为4 g/L,胞外多糖含量与对照相比提高到167%;正交试验优化的发酵条件为:发酵时间12 d、起始pH5.0、转速120 r/min、扁桃斑鸠菊叶粉末的添加量为4 g/L,在此条件下,胞外多糖含量达到13.05 g/L;红外光谱图表明添加和未添加扁桃斑鸠菊叶粉末的灵芝胞外多糖类型相似;抗氧化活性实验显示扁桃斑鸠菊叶粉末添加对胞外多糖清除ABTS+·的影响较小,但增强了其对·OH、DPPH·清除能力和Fe3+还原能力。扁桃斑鸠菊叶能有效提高灵芝胞外多糖的含量,为灵芝多糖的高效生产提供新思路。

Exopolysaccharide(EPS)is the main active metabolite of Ganoderma lingzhi in liquid fermentation.In order to increase the content of Ganoderma lingzhi EPS,this study added Vernonia amygdala leaf powder to the fermentation medium,and used single factor experiments and orthogonal experiments to optimize fermentation conditions.Fourier transform infrared spectroscopy was used to characterize the structure of Ganoderma lingzhi EPS,then its antioxidant activity was detected.The single factor experiment found that when the optimal addition amount of Vernonia amygdala leaf powder was 4g/L,the content of EPS increased by 167% compared with the control group.The optimum fermentation conditions of the orthogonal experiment were as follows:Fermentation duration was 12 d,initial pH was 5.0,the rotation speed was 120 r/min,and the addition amount of Vernonia amygdala leaf powder was 4 g/L.Under such a condition,the content of EPS could reach 13.05 g/L.The infrared spectra showed that the major absorption peaks of the Ganoderma lingzhi EPS from the addition of Vernonia amygdala leaf powder were similar to those of the EPS from the control group.The antioxidant activity assay showed that the addition of Vernonia amygdala leaf powder had less effect on the scavenging of ABTS+radicals by EPS,but enhanced their ability to scavenge DPPH radicals,OH radicals,and ferric ion reduction.The results showed that Vernonia amygdala leaf could effectively increase the content of EPS in Ganoderma lingzhi,which provided a new idea for the efficient production of polysaccharides in Ganoderma lingzhi.