Curdlan consists of β-(1,3)-linked glucose residues and forms elastic gels upon heating in aqueous suspension.

[2] Extracellular and capsular polysaccharides are produced by a variety of pathogenic and soil-dwelling bacteria.

Curdlan is a neutral β-(1,3)-glucan, perhaps with a few intra- or interchain 1,6-linkages, produced as an exopolysaccharide by soil bacteria of the family Rhizobiaceae.

[4] A putative operon contains crdS (Q9X2V0, family GT2, Pfam PF13632), encoding β-(1,3)-glucan synthase catalytic subunit,[5] flanked by two additional genes.

A membrane-bound phosphatidylserine synthase, encoded by pssAG, is also necessary for maximal production of curdlan of high molecular mass.