Improved β-glucan yield using an Aureobasidium pullulans M-2 mutant strain in a 200-L pilot scale fermentor targeting industrial mass production Abstract β-(1→3)-D-glucans with β-(1→6)-glycosidic linked branches are known to be immune activation agents and are incorporated in anti-cancer drugs and health-promoting supplements. β-Glucan concentration was 9.2 g/L in a 200-L pilot scale