球毛壳菌CGMCC 6882利用小麦秸秆发酵生产抗氧化多糖

Production of an antioxidant polysaccharide from wheat straw by Chaetomium globosum CGMCC 6882

针对我国小麦秸秆存在严重浪费和污染环境的现状,该实验采用球毛壳菌CGMCC 6882对小麦秸秆进行发酵,生产一种新型胞外多糖,并对多糖结构和抗氧化活性进行研究。结果显示,球毛壳菌CGMCC 6882以小麦秸秆为碳源发酵所得胞外多糖的单糖组成和摩尔比为鼠李糖∶氨基葡萄糖∶半乳糖∶葡萄糖∶木糖∶果糖∶葡萄糖醛酸=21.46∶1.58∶1.11∶55.15∶36.37∶7.04∶7.34,重均分子质量M w为3.538×10^(4) Da。体外抗氧化实验结果显示,球毛壳菌CGMCC 6882胞外多糖可以有效清除DPPH自由基、羟自由基、超氧阴离子和ABTS阳离子自由基,且清除率与多糖浓度成正相关。多糖质量浓度为5 mg/mL时,对上述自由基的清除率分别达到(83.08±2.58)%、(81.39±1.47)%、(79.38±2.03)%和(85.69±1.62)%。细胞抗氧化实验结果显示,加入多糖实验组的丙二醛酶活水平从(15.8±0.25)μmol/g降低至(7.5±0.31)μmol/g,与多糖浓度成负相关;Caco-2细胞内超氧化物岐化酶、过氧化氢酶和谷胱甘肽过氧化物酶活力水平分别从(147.28±4.82)、(11±1.15)和(18.08±1.96)U/mg增加至(238.89±3.91)、(39.12±0.76)和(41.35±2.18)U/mg,且与多糖浓度成正相关。该实验为小麦秸秆的高效利用提供了重要依据和理论基础。

Due to the serious resource waste and environmental pollution induced by wheat straw in China,wheat straw was used by Chaetomium globosum CGMCC 6882 to produce exopolysaccharide in present work.Meanwhile,the structure of the exopolysaccharide and its antioxidant activity were investigated.Results showed that monosaccharide composition of the polysaccharide produced by C.globosum CGMCC 6882 was rhamnose,glucosamine,galactose,glucose,xylose,fructose and glucuronic acid in a molar ratio of 21.46∶1.58∶1.11∶55.15∶36.37∶7.04∶7.34,and its molecular weight was 3.538×10^(4) Da.Antioxidant assays in vitro revealed that the polysaccharide had strong scavenging effects on DPPH radical,hydroxyl radical,superoxide anions and ABTS radical in a dose-dependent manner.At the concentration of 5 mg/mL,the corresponding scavenging abilities of the polysaccharide were(83.08±2.58)%,(81.39±1.47)%,(79.38±2.03)%and(85.69±1.62)%,respectively.Results of cell antioxidant test showed that the activity of MDA decreased from(15.8±0.25)μmol/g to(7.5±0.31)μmol/g,which was negatively correlated with the concentration of polysaccharide.Furthermore,the activity levels of SOD,CAT and GSH-Px in H 2O 2 induced Caco-2 cells increased from(147.28±4.82),(11±1.15)and(18.08±1.96)U/mg to(238.89±3.91),(39.12±0.76)and(41.35±2.18)U/mg,and those were positively correlated with the concentration of polysaccharide.Overall,this work provides an important reference and theoretical basis for the efficient utilization of wheat straw.