Structural studies of amyloglucan and a soluble glucan produced from starch by Streptococcus sanguis 1 MC 204

Two alpha-D-glucans, produced from amylopectin by an oral isolate Streptococcus sanguis 1 MC 204, were shown to contain both (1----4) and (1----6) linkages. The first alpha-D-glucan (amyloglucan) was adherent and highly insoluble, and methylation analysis, i.r. spectroscopy, and enzymic analyses showed it to be similar to amylopectin but less branched with longer interior and exterior chains. The second polymer was a non-adherent soluble alpha-D-glucan that was similar to amyloglucan but with long exterior chains. These alpha-D-glucans were not synthesised de novo, but were the products of the modification of amylopectin.