摘要
采用乙醇两步沉淀分离木聚糖酶水解残渣的高温自水解液,得到3种不同聚合度范围的木聚糖组分,并就3种木聚糖组分对青春双歧杆菌的增殖效果进行评价。研究结果表明:在180℃、40 min的条件下,高温自水解液中主要含聚合度(Dp)为2~6的低聚木糖(XOS),XOS占水解液中总木聚糖的57.36%,XOS得率为26.54%。乙醇两步沉淀方式可实现木聚糖高温自水解液中不同聚合度范围木聚糖组分的有效分离,分别得到S1(Dp24~122)、S2(Dp7~19)和S3(Dp1~6)这3种木聚糖组分,高聚合度木聚糖组分S1和中等聚合度木聚糖组分S2较难被青春双歧杆菌所利用,增殖效果不明显;XOS纯度高达95.91%的低聚合度木聚糖组分S3对青春双歧杆菌增殖效果最明显,36 h菌体质量浓度达0.25 g/L,菌体增殖倍数达4.72倍,残糖量为43.48%,总有机酸质量浓度达1.96 g/L。
Enzymatic hydrolysis residue of xylan was autohydrolyzed,and the autohydrolysate was then fractionated by two-step ethanol precipitation.The obtained three kinds of xylan fractions with varied degree of polymerization(Dp)were evaluated through in vitro proliferation by Bifidobacterium adolescentis.The autohydrolysis was carried out at 180℃for 40 min to obtain autohydrolysate mainly contained xylooligosaccharides(XOS)with Dp of 2-6.The content of XOS was 57.36%of the xylan in the autohydrolysate,and the yield of XOS was 26.54%of the xylan in the feedstock.Two-step ethanol precipitation could fractionate the xylan in the autohydrolysate into sample S1,S2 and S3,with the range of Dp of 24-122,7-19 and 1-6,respectively.Low Dp of sample S3 contained mainly XOS which was 95.91%and exhibited significant prebiotic activity.After 36 h incubation,the cell concentration was 0.25 g/L,4.72 times of the initial,with the sugar residue of 43.48%,and with the concentration of short-chain fatty acids of 1.96 g/L.
作者
连之娜
王艳娥
罗京
勇强
余世袁
LIAN Zhina;WANG Yan′e;LUO Jing;YONG Qiang;YU Shiyuan(Key Laboratory of Forestry Genetics & Biotechnology,Ministry of Education,Jiangsu Co-innovation Center of Efficient Processing and Utilization of Forest Resources,College of Chemical Engineering,Nanjing Forestry University, Nanjing 210037, China)
出处
《林产化学与工业》
EI
CAS
CSCD
北大核心
2020年第2期33-41,共9页
Chemistry and Industry of Forest Products
基金
江苏省重点研发专项(BF2015007)。
关键词
低聚木糖
高温自水解
聚合度
乙醇沉淀
双歧杆菌
xylooligosaccharide
autohydrolysis
degree of polymerization
ethanol precipitation
Bifidobacterium adolescentis
