An intracellular α- D-glucan from clostridium botulinum, type E

Abstract

An intracellular α- D-glucan has been isolated from cultured cells of Clostridium botulinum, type E (Minnesota). The dextrorotatory glucan consumed 1.02 moles of periodate and released 59 mmoles of formic acid per anhydroglucose unit. The fully methylated derivative was composed of 2,3,4,6-tetra- O-methyl- D-glucose (5%), 2,3,6-tri- O-methyl- D-glucose (90%), and 2,3-di- O-methyl- D-glucose (5%). The overall α- D anomeric configuration for the glucosidic linkages in the polymer was assessed by p.m.r. spectroscopy of the methylated derivative. This observation was corroborated by the identification of the partial hydrolysis products as maltose, isomaltose, maltotriose, and maltotetraose by use of g.l.c. and mass spectroscopic analyses of their corresponding permethylated alditols. The results indicate that the α- D-glucan is a ramified molecule composed of branched chains of D-glucopyranosyl residues linked α-(1→4) with α(1→6) linkages at the branch points and an average of about 17 units between branches which favored an amylopectin rather than a glycogen structure. No linear amylose fraction was isolated from the intracellular polysaccharide of the cultured bacillus.