不同菌种发酵对铁皮石斛多糖及其生物活性的影响

Effects of Different Strains Fermentation on Polysaccharide and Biological Activity of Dendrobium candidum

为筛选出可增强铁皮石斛活性的菌种,以铁皮石斛粗多糖水提液为原料,采用6种常用菌种进行纯种发酵。测定发酵前后多糖含量、还原糖含量、多糖分子量、还原糖分子量4个指标并追踪发酵过程中发酵液的体外抗氧化活性和体外降血糖活性。结果显示:发酵可以提高铁皮石斛的抗氧化活性和体外降血糖活性,还原糖含量降低,除曲霉外,其余菌种发酵后多糖含量和多糖分子量均有所下降。面包酵母发酵后,发酵液抗氧化活性最强,对DPPH、OH、ABTS自由基的清除率依次为29.5%、38.2%和31.2%,相比未发酵空白分别提高了56.9%、60.5%和63.4%。红曲霉发酵后其发酵液对α-葡萄糖苷酶和α-淀粉酶的抑制活性最强,依次为26.3%和22.6%,相对发酵空白分别提高了78.9%和86.8%。

In order to screen out the strains that can enhance the activity of Dendrobium candidum,the water extract of crude polysaccharide from Dendrobium candidum are used as the raw materials,and six kinds of common strains are used for pure fermentation.Four indexes such as polysaccharide content,reducing sugar content,polysaccharide molecular weight and reducing sugar molecular weight before and after fermentation are determined and the antioxidant activity and hypoglycemic activity in vitro of the fermentation broth during fermentation are tracked.The results show that fermentation could increase the antioxidant activity and hypoglycemic activity in vitro of Dendrobium candidum,and the content of reducing sugar decreases.The content of polysaccharide and the molecular weight of polysaccharide decrease after fermentation of the other strains except for Aspergillus.After being fermented by bread yeast,the antioxidant activity of the fermentation broth is the strongest,and the DPPH,OH and ABTS free radicals'scavenging rate is 29.5%,38.2%and 31.2%respectively,which is 56.9%,60.5%and 63.4%respectively higher than that of the unfermented blank group.After being fermented by Monascus,the fermentation broth has the strongest inhibitory activity onα-glucosidase andα-amylase,which is 26.3%and 22.6%respectively,and is increased by 78.9%and 86.8%respectively.