岩藻多糖酶产生菌的筛选及其酶解产物的结构表征、抗氧化研究OACSTPCD

In this paper,a strain with fucoidanase activity was successfully isolated from tea leaves through primary screening with a sole carbon source method and detecting with high performance gel permeation chromatography.The fermentation crude enzyme broth of the strain was used for hydrolysis of fucoidan(F)at 50℃for 24 h,and the relative content of low molecular weight fucoidan(LMWF)with a molecular weight of less than 10 kDa was 59.4％.Phylogenetic analysis of the ITS gene sequence of the strain revealed that it was identified as Aspergillus amstelodami.Subsequently,preparation of LMWF by enzymatic hydrolysis of fermentation crude enzyme broth of the strain,and analyzed the sulfate group content,monosaccharide composition,molecular weight and glycosidic bond type of F and LM-WF.The results indicated that the sulfate group contents of F and LMWF were(33.0±0.3)％and(32.4±0.9)％;monosaccharides were mainly composed of fucose and galactose,with a small amount of xylose and glucuronic acid;the molecular weights were 277 kDa and 2 997 Da,respectively;the type of glycosidic bond was α-glycosidic bond.Furthermore,antioxidant activity results of samples before and after hydrolysis demonstrated that the antioxidant activity of LMWF was superior to that of F.The results demonstrated that the LMWF prepared by enzymatic hydrolysis of the fermentation crude enzyme broth of the strain exhibits excellent biological activity,thus providing a foundation for the potential application of fucoidan in food and industrial production.