Ultrastructure of Curdlan

1. Introduction During the studies on Alcaligenes faecalis var. myxogenes 10C3, Harada and co-workers found that a spontaneous mutant, 10C3K produces an insoluble exocellular polysaccharide (1). This polysaccharide is entirely composed of D-glucosyl residues which are connected almost exclusively by β-(1→3)-linkages. This and the similar glucan formed by some strains of Agrobacterium are named Curdlan because they form irreversibly, resilient gel when heated in water. Because of interesting and specific properties of the gel, curdlan has many potential uses not only in food industry but also as a film, a fiber, a support for immobilizing enzymes and a binding agent in tobacco product etc. (2). Besides these, an antitumor activity(3) has been reported. In connection with these uses the conformation of curdlan molecule in solution and in gel and the ultrastructure of aggregates of curdlan molecules are considered very important. This paper deals with conformational studies on curdlan molecules by