布拉氏酵母发酵山药多糖的分离鉴定与体外生物活性探究

Isolation,Identification and Biological Activity of Fermented Chinese Yam Polysaccharides by Saccharomyces boulardii

目的:探究通过布拉氏酵母发酵怀山药,来提高发酵怀山药多糖(Fermented Chinese yam polysaccharides,FCYP)的多糖含量以及生物活性。方法:采用苯酚-硫酸法、考马斯亮蓝法及福林酚法分别检测FCYP和未发酵怀山药多糖(Unfermented Chinese yam polysaccharides,UCYP)中多糖、总蛋白和多酚的含量;用高效液相色谱、紫外和红外光谱分析发酵怀山药多糖的单糖组成以及理化性质;对比分析布拉氏酵母发酵前后怀山药多糖的体外抗氧化活性和免疫调节活性。结果:相较于UCYP(383.03±12.57 mg/g),FCYP中的多糖含量得到显著提高(480.71±5.93 mg/g,P<0.001);红外光谱分析发现FCYP在3279和1636 cm^(-1)处具有多糖典型官能团(O-H和C-O);FCYP的单糖组成以半乳糖和甘露糖为主,二者质量百分比分别为48.70%和16.19%;此外,体外抗氧化实验结果显示,FCYP在1.0~5.0 mg/mL浓度范围内具有良好的DPPH自由基清除能力,并且FCYP在5.0 mg/mL浓度下的还原力显著高于UCYP(P<0.05);免疫调节结果显示,FCYP的促RAW264.7细胞增殖活性和促NO产生能力优于UCYP。结论:布拉氏酵母发酵处理怀山药是一种有效的提高多糖含量与生物活性的方法。本研究可为发酵怀山药多糖天然抗氧化产品的开发提供依据。

Objective:To improve the polysaccharide content and biological activities of the fermented Chinese yam polysaccharides(FCYP)by fermentation with Saccharomyces boulardii.Methods:The contents of polysaccharides,total protein and polyphenols of FCYP and unfermented Chinese yam polysaccharides(UCYP)were determined by phenol-sulfuric acid method,coomassie bright blue method and folin-ciocalteu method,respectively.The monosaccharide composition and physicochemical properties of FCYP and UCYP were determined by ultraviolet spectrum analysis,high performance liquid chromatography and Fourier transform infrared spectroscopy.Then the antioxidant activity and immunomodulatory activity were compared and analyzed.Results:Compared with UCYP(383.03±12.57 mg/g),the polysaccharide content in FCYP was significantly increased(480.71±5.93 mg/g,P<0.001).The Fourier transform infrared spectroscopy analysis showed that FCYP had typical polysaccharide functional groups(O-H and C-O)at 3279 and 1636 cm^(−1),respectively.The monosaccharide composition of FCYP was mainly galactose and mannose,with the mass percentage of 48.70%and 16.19%,respectively.In addition,the results of antioxidant activity in vitro showed that FCYP had the best DPPH free radical scavenging activity in the concentration range of 1.0~5.0 mg/mL.And the reducing power of FCYP at 5.0 mg/mL was significantly higher than that of UCYP(P<0.05).Finally,the results of immunomodulatory activity showed that FCYP showed good enhanced cell proliferation activity and promoted NO production in RAW264.7 cells.Conclusion:It was an effective method to improve the polysaccharide content and biological activity of Chinese yam by fermentation with Saccharomyces boulardii.This study would provide a basis for the development of natural antioxidant products of fermented polysaccharides of Chinese yam.