ISOLATION AND IDENDTIFICATION OF CYCLIC ?-(1,2)-GLUCANS / 微生物学通报

Rhizobium leguminosarum biov.trifolii H954 has been fermented for eight days on the GMS medium.Culture supernatant is extracted by ethanol precipitation,sample is purified by Sephadex G\|50,Sephadex G\|10 and DEAE\|Cellulose chromatoraphy.Gas chromatography(GC), 13 C nuclear magnetic resonance spectroscopy(NMR)and mass spectrometry(MS) analysis indicated that the sample is cyclic,neutral glucan,and composes of glucose linked solely by 1→2 glucosidic bonds.Cyclic glucan has degrees of polymerization ranging form 17 to 22,with a degree of ploymerization of 19 as the major glucan cycles.