Issue Archive

Isolation, purification and structure analysis of acidic exopolysaccharide from Rhizobium astragali strain 107

Wu Min, Zhou Beiyun, Song Hongyu, Guo Zhongwu, Wang Laixi

Shanghai Institute of Plant Physiology,The Chinese Academy of Sciences.Shanghai 200032；China

Abstract

The acidic exopolysaccharides (EPS) of R. astragali wild type 107, its Exo~(-) mutant NA02 and R^plasmid transconjugant NAO2 CR^-11) were isolated and purified by acetone precipitation and chromatography. Their composition and structure were also studied using ~(1)H-NMR, infrared spectrum, gas choromatography, TCL. The EPS of R. astragali contained only a high-molecular-weight fraction of EPS, and no low-molecular-weight oligosaccharides were detected. Strain 107 and NA02 (R^-11) produce identical EPS which consists of glucose, galactose, ribose and glucuronic acid and links with #alpha# and #beta# linkages. In contrast, the EPS secreted by mutant NA02 lacks in ribose and the sugar residues were linked by the same #beta# linkages. All of the EPSs contain only acetyl substitutent, and the EPSs^ acidic nature comes from the uronic acid.

Key words: Rhizobium astragali;Isolation;Purification;Exopolysaccharides

Received: 　　Accepted:

Corresponding author: 　　E-mail:

Citing This Article：

Wu Min, Zhou Beiyun, Song Hongyu, Guo Zhongwu, Wang Laixi. Isolation, purification and structure analysis of acidic exopolysaccharide from Rhizobium astragali strain 107. Acta Physiol Sin 1997; 49 (3): (in Chinese with English abstract).