ABSTRACT
Curdlan is insoluble but swells in water. It is soluble in alkaline solution, formic acid, dimethyl sulfoxide, aqueous saturated urea or thiourea, and 25% potassium iodide. Studies on the formation of a complex with Congo red by measuring the circular dichroism suggested two kinds of binding in alkaline media. Curdlan is soluble in cadoxen. It seems to contain minor helical portions but, for the most part, has a random coil conformation. Curdlan is produced by secondary metabolism in the sense that it is associated with the stationary phase of growth. An approximate 6.0 pH is the most suitable for curdlan production by a cell suspension. Cells can produce curdlan from sugars even at low concentrations of inorganic salts, if the suspension is adjusted to a pH value of about 6 to 7 in these conditions. Certain amounts of succinoglycan produced by the organisms of Agrobacterium and Rhizobium may be accumulated in soil, because these organisms are widely distributed in soil.
