GLUCO-OLIGOSACCHARIDE PRODUCTION BY A STRAIN OF ERWINIA-AMYLOVORA

When grown in sorbitol-asparagine-salts medium, cells of Erwinia amylo vora isolate T83 released a mixture of oligosaccharides and lipopolysa ccharide in place of extracellular polysaccharide. The oligosaccharide fraction was usually readily separable from lipopolysaccharide by gel permeation chromatography, but some samples required disaggregation b y preliminary treatment with EDTA. By H-1- and C-13-NMR spectroscopy, methylation analysis and mass spectrometry, the oligosaccharide fracti on was shown to consist of terminal, beta-1,2- and beta-1,2,6-linked D -glucose residues in the ratio 2.2:2.6:1, indicating a branched oligos accharide structure. The purified oligosaccharide fraction was partial ly resolved by gel permeation chromatography into two components conta ining approximately equal amounts of glucose. When grown on pear slice s, isolate T83 produced normal extracellular polysaccharide.