The conformation of cinerean, a microbial beta-(1,3)x(1,6)-D-glucan produced by the fungus Botrytis cinerea, was investigated in H2O, NaOH, and DMSO by small-angle X-ray scattering (SAXS) and small-angle neutron scattering(SANS). The native cinerean is a wormlike chain with a large persistence length. By treatment with ultrasound rodlike fragments are formed. In aqueous solution cinerean has a multihelical conformation. in solutions with NaOH the cinerean multihelix disentangles into its single strands. These strands show the structure factor of a random coil. With scattering methods the transition between helix and coil was examined as a function of the pH value. SAXS measurements of the macroscopic scattering cross-section beyond the Guinier region yield directly the fractions alpha and (1-alpha) of the single molecular strands in the "rod" or the "coil" state, respectively. The fraction alpha as a function of the pH value shows a narrow transition region at 0.15 N NaOH, which suggests a cooperative transition. The helix-coil transition is irreversible. A gel appears after neutralization of the solution. This gel is formed by multihelical rods acting as cross-links in a network of the molecular strands. In the organic solvent dimethyl sulfoxide (DMSO) a helix-coil transition was observed as well. For this measurement neutron scattering was used since the contrast between cinerean and DMSO for X-rays is very low.