摘要
该文以液态发酵的虎奶菇(Pleurotus tuber-regium,PTR)菌丝体为原料,对PTR菌丝体细胞壁(PTR-MCW)的组分进行分析,并阐明细胞壁骨架结构。采用不同提取强度的溶剂分离MCW的可溶性成分,对各组分进行含量测定、化学成分分析及基本结构表征。结果表明,PTR-MCW主要由4部分组成:热水提多糖和蛋白质复合物的外层,常温碱提的杂多糖部分,热碱提的高度支化杂多糖部分和碱不溶性多糖-几丁质复合物部分,这4种组分在PTR-MCW中的比例为2.06∶22.06∶46.97∶18.95。占主要组分的热碱提多糖经纯化后得到纯多糖MHA-I,单糖组成和甲基化分析表明其糖苷键类型包括T-木糖、T-鼠李糖、T-葡萄糖、1,3-葡萄糖、1,6-葡萄糖、1,4-葡萄糖、1,3,6-葡萄糖、1,4,6-葡萄糖、1,3,6-甘露糖,摩尔比为2.01∶1.00∶27.64∶8.19∶38.22∶20.88∶14.38∶6.98∶3.22,该多糖的分支度(degree of branching,DB)为0.45,FT-IR分析鉴定MHA-I中主要为β-糖苷键。SEC-MALLS分析表明,超支化杂多糖MHA-I的分子量为4.502×10^4 g/mol,回转半径为33.2 nm。电镜结果显示,MHA-I为具有超支化结构的多糖,在干燥的粉末状态下呈现准球形结构。该研究成果为虎奶菇多糖的开发及活性研究提供一定的理论依据。
The edible mushroom Pleurotus tuber-regium(PTR)was fermented to get the mycelium for cell wall component and structure analysis.Several extracted solutions were applied for the isolation of cell wall components,which were then analyzed from aspects of content,chemical composition and structure features.The results indicated that the cell wall structure of PTR mycelium contained four main fractions:an outer fraction of polysaccharide and protein complex which could be extracted using boiling water,an alkali-extractable fraction of heteropolysaccharides(room temperature),a hot alkali-extractable fraction of hyper-branched heteropolysaccharides(80℃)and an alkali-insoluble fraction of glucan-chitin complex.The proportions of these four fractions from outer layer to inner layer in PTR cell wall material were calculated to be 2.06∶22.06∶46.97∶18.95.The purified polysaccharide MHA-I,which was obtained from the main component of MHA,was elucidated by the monosaccharide composition and methylation analysis to be composed of T-Xyl p,T-Rha p,T-Glc p,1,3-Glc p,1,6-Glc p,1,4-Glc p,1,3,6-Glc p,1,4,6-Glc p,1,3,6-Man p in the molar ratio of 2.01∶1.00∶27.64∶8.19∶38.22∶20.88∶14.38∶6.98∶3.22 with DB(degree of branching)value of 0.45,theβ-glycoside bond in MHA-I was identified by FT-IR.SEC-MALLS analysis revealed that the hyper-branched heteropolysaccharide(MHA-I)had a M w of 4.502×10^4 g/mol and R.M.S.radius of 33.2 nm.The results of SEM and TEM indicated that the molecular morphology of MHA-I is hyperbranched structure,which existed in torispherical particles in dried powders.The present research could provide a theoretical basis for development and activity of PTR polysaccharides.
作者
葛梦蝶
代安然
杨崇婧
刘京京
CHEUNG Chi Keung Peter
陈磊
GE Mengdie;DAI Anran;YANG Chongjing;LIU Jingjing;CHEUNG Chi Keung Peter;CHEN Lei(Key Laboratory of Carbohydrate Chemistry and Biotechnology,Ministry of Education,School of Biotechnology,Jiangnan University,Wuxi 214122,China;School of Life Sciences,The Chinese University of Hong Kong,Shatin,New Territories,Hong Kong 999077,China)
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2020年第6期41-48,共8页
Food and Fermentation Industries
基金
国家自然科学基金(21706094)
江苏省自然科学基金(BK2170176)
江苏省“双创博士”项目。
关键词
虎奶菇
菌丝体
细胞壁
多糖
结构鉴定
Pleurotus tuber-regium
mycelium
cell wall
polysaccharide
structural identification
