Characterisation of cyclosophorans produced by an acidic polysaccharide-negative mutant of Rhizobium leguminosaram

Abstract

The cyclosophorans produced by the EPS − mutant Rhizobium leguminosarum 8401 pRL1JI pssl :: Tn5 have been isolated and characterised. The cyclic glucans were recovered from the clarified culture broth by absorption and subsequent elution from a charcoal column. Individual ring sizes were identified by fast atom bombardment mass spectrometry and the crude mixture fractionated by HPLC. The spectrum of ring sizes produced is typical of that produced by wild-type R. leguminosarum.