.beta.-1,3-Glucanpolyol, process for preparation thereof, and utilization thereof

.beta.-1,3-glucanpolyol derived from .beta.-1,3-glucan produced by a .beta.-1,3-glucan-producing strain of the genus Pestalotia, said glucanpolyol having the following characteristics [I] and [II]:

• [I] said glucanpolyol comprises a main chain having as repeating units .beta.-1,3-glucopyranose units of the following formula
• .fwdarw.3).beta.-D-Glc (1.fwdarw.
• wherein Glc represents a glucopyranose residual moiety, and bonded thereto, either side chains of formula (B), or both side chains of formulas (A) and (B) below ##STR7## wherein n represents a number of from 0 to 1, and .fwdarw.3) .beta.-D-Glc (1.fwdarw. represents the above main chain, ##STR8## wherein n and .fwdarw.3) .beta.-D-Glc (1.fwdarw. are the same as defined with respect to formula (A), and R represents a groups derived from .beta.-D-glucopyranose of the formula ##STR9## said glucanpolyol has an intrinsic viscosity of about 1 to about 10 and wherein, per 100 .beta.-1,3-glucopyranose units of the main chain, the number of said side chains of formula (B) is about 25 to about 70, and the number of said side chains of formula (A) is 0 to about 45.