Biosynthetic relation between the soluble and insoluble dextrans produced by Leuconostoc mesenteroides NRRL B‐1299

The structures and properties of bacterial dextrans vary with the organism [1,2] and certain bacteria elaborate simultaneously two or more dextrans that differ in structure and water solubility [3]. As little is known of the manner by which more than one dextran type is produced by a single organism it was of interest to examine the simultaneous synthesis of two dextrans by Leuconostoc mesenteroides NRRL B-1299 [3 ]. The data presented here show that both dextrans are synthesised by structure-bound dextransucrase and that a large proportion, at least, of the insoluble dextran acts as a precursor of the water-soluble dextran.