利用扁桃斑鸠菊叶发酵生产蛹虫草胞外多糖的条件及其抗氧化活性

Production of antioxidative exopolysaccharides of Cordyceps militaris with Vernonia amygdalina leaves in substrate

摘要:

蛹虫草胞外多糖具有增强免疫力、抗疲劳等药理活性，有极高的保健价值。为高效地获取蛹虫草胞外多糖，本研究通过向发酵培养基中添加适量的扁桃斑鸠菊叶粉末，来提高蛹虫草发酵液中胞外多糖的产量，并对优化得到的胞外多糖红外吸收光谱和化学抗氧化活性进行了研究。实验结果表明，液体发酵最优条件为：扁桃斑鸠菊叶粉末添加量8 g/L、发酵时间9 d、pH 6.5、接种量5.0 mL，在此条件下，蛹虫草胞外多糖的产量可达(5.24±0.28) mg/mL，与未添加扁桃斑鸠菊叶的空白组相比，胞外多糖产量提高了约205.20%；红外分析与抗氧化活性实验结果显示，扁桃斑鸠菊叶对蛹虫草生产的胞外多糖结构和活性影响较小。该研究结果表明扁桃斑鸠菊叶能够有效地提高蛹虫草胞外多糖的产量，为蛹虫草胞外多糖的高效生产提供了新思路。

Abstract:

Cordyceps militaris exopolysaccharides (EPS) have many pharmacological activities such as boosting immunity and antifatigue. To obtain EPS efficiently, we added moderate Vernonia amygdalina leaf powder as inducer to the fermentation medium to promote the production of Cordyceps militaris EPS and studied the infrared absorption spectrum and antioxidant activities of the EPS after optimization. The optimum liquid fermentation conditions were as follows: addition of Vernonia amygdalina leaf powder of 8 g/L, fermentation duration of 9 d, initial pH of 6.5, inoculation quantity of 5.0 mL. Under such a condition, the yield of Cordyceps militaris EPS reached (5.24±0.28) mg/mL, increased by 205.20% compared to the control group without adding Vernonia amygdalina leaf powder. Results of infrared analysis and antioxidant activity showed that the Vernonia amygdalina leaves had little effect on the structure and activities of Cordyceps militaris EPS. The results of this research suggest that Vernonia amygdalina leaf can enhance the production of Cordyceps militaris EPS effectively, and provides a novel method for efficient production of EPS in Cordyceps militaris.