长根菇液体深层发酵制备多糖条件优化及体外抗氧化活性研究

Optimization of polysaccharides preparation by liquid-submerged fermentation of from Oudemansiella radicata and antioxidant activity in vitro

中文关键词:  长根菇  液体深层发酵  胞外多糖  抗氧化活性

英文关键词:Oudemansiella radicata  liquid-submerged fermentation  extracellular polysaccharides  antioxidant activity

中文摘要:

      目的 优化长根菇液体深层发酵产胞外多糖的培养基成分, 考察其基本结构特征和体外抗氧化活性。方法 以长根菇液体深层发酵胞外多糖质量浓度为评价指标, 先分别筛选出液体培养基最适碳源、氮源、生长因子, 再通过单因素、响应面实验对最佳发酵培养基条件进行优化, 对胞外多糖进行分离和纯化后, 利用红外光谱扫描法分析其基本结构, 最后通过羟基自由基(OH·)、1,1-二苯基-2-三硝基苯肼自由基(1,1-diphenyl-2-picrylhydrazyl free radical, DPPH·)清除能力和铁离子(Fe3+)还原能力等考察其体外抗氧化活性。结果 长根菇液体培养基最佳培养条件为: 可溶性淀粉24 g/L、牛肉粉1.9 g/L、维生素B1 0.03 g/L, 在此条件下长根菇液体深层发酵胞外多糖质量浓度为384.72 μg/mL; 红外光谱表明: 胞外多糖含有主要官能团O-H、C-H、C=O、C-O, 另外还存在吡喃环结构; 体外抗氧化研究表明: 长根菇液体深层发酵胞外多糖具有较好的体外抗氧化活性, 但其抗氧化能力均低于维生素C, 胞外多糖对OH·、DPPH·的清除能力和Fe3+还原能力的半抑制浓度(half maximal inhibitory concentration, IC50)分别为0.68、1.00和8.46 mg/mL。结论 本研究确定了长根菇液体深层发酵产多糖的最佳培养基, 且制备的多糖具有较好的体外抗氧化活性, 可为长根菇进一步研究和利用提供理论参考。

英文摘要:

      Objective To optimize the composition of the medium for the production of extracellular polysaccharide by liquid-submerged fermentation of Oudemansiella radicata, and investigate its basic structural characteristics and antioxidant activity in vitro. Methods Taking the extracellular polysaccharides concentration of the Oudemansiella radicata as the evaluation index, the optimal carbon source, nitrogen source and growth factor of the liquid medium were screened, and then the optimal fermentation medium conditions were optimized by single-factor and response surface experiments. After the separation and purification of extracellular polysaccharides, the basic structure was analyzed by infrared spectroscopy, and the antioxidant activity in vitro was investigated by hydroxyl radicals (OH·), 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·) scavenging ability and iron ion (Fe3+) reduction ability. Results The optimal culture conditions for the liquid medium of Oudemansiella radicata were: Soluble starch 24 g/L, beef powder 1.9 g/L, vitamin B1 0.03 g/L, and the mass concentration of extracellular polysaccharides was up to 384.72 μg/mL under this optimized condition. Infrared spectroscopy showed that extracellular polysaccharides contained the main functional groups O-H, C-H, C=O, C-O, and there was also pyranoid ring group; In vitro antioxidant studies showed that the extracellular polysaccharide by liquid-submerged fermentation of Oudemansiella radicata had good antioxidant activity in vitro, but their antioxidant capacity was lower than that of vitamin C, and the half maximal inhibitory concentration (IC50) of extracellular polysaccharides on OH·, DPPH· scavenging ability and Fe3+ reduction ability were 0.68, 1.00 and 8.46 mg/mL, respectively. Conclusion The extracellular polysaccharide by liquid-submerged fermentation of Oudemansiella radicata has high polysaccharides content and good antioxidant activity in vitro, which can provide theoretical reference for further research and utilization of Oudemansiella radicata.