The invention discloses a preparation, separation and purification method of
glucan oligosaccharide, and belongs to the technical field of active
oligosaccharide preparation. The preparation, separation and purification method comprises the following steps: adding
alcaligenes faecalis into a
fermentation culture medium, fermenting to prepare beta-1, 3-
glucan, adding beta-1, 3-
glucanase when the
viscosity of
fermentation liquor reaches a certain value, and simultaneously controlling the temperature to promote enzymolysis, so that the beta-1, 3-
glucan with high
polymerization degree is hydrolyzed into
oligosaccharide, and separating and purifying the oligosaccharide. The material
liquid viscosity is reduced, and the
mass transfer is improved, so that the single-
batch fermentation yield is improved. Meanwhile, sugars with different
polymerization degrees are separated through a graded
alcohol precipitation process, part of impurities are removed, and the product purity is improved. According to the method, the enzymolysis reaction is directly carried out in the
fermentation process, so that the steps of
polysaccharide extraction and enzymolysis are simplified, the production
energy consumption is reduced, and the yield and the production benefit of the final product are improved.