The antioxidant mechanism of exopolysaccharides' synthesis from Agaricus bitorquis (Quel.) Sacc. Chaidam under the influence of Lycium ruthenicum Murr. anthocyanin extract

Agaricus bitorguis (Quel.) Sacc. Chaidam is a rare wild edible macro-fungus that grows underground at high altitudes. In this study, the mechanism of exopolysaccharide synthesis (secretion) was studied with the help of changes in the antioxidant metabolism of mycelial cells, by adding Lycium ruthenicum Murr. (black wolfberry) anthocyanins (LRA). Lycium ruthenicum Murr. significantly affect the molar ratio and apparent structure of monosaccharides, antioxidant channels, polysaccharide synthesis, and the growth of Agaricus bitorguis (Quel.) Sacc. Chaidam. We observed that the upregulation of the flavonoid/isoflavone anabolic pathway was linearly correlated to the levels of antioxidants, such as quercetin and daidzein. Overexpression of cytochrome metabolism P450 in the xenobiotic pathway decreased the content of toxic components, such as benzopyrene and aflatoxin. Lycium ruthenicum Murr. improved the oxidative environment and the antioxidant activity in the cells, effectively reduced oxidative damage in the process of cell growth and polysaccharide synthesis, and accelerated polysaccharide synthesis. In addition, the antioxidant channels of mycelial cells, such as the content of ROS, MDA, and the activity of PPO decreased rapidly, and the activities of CAT, SOD, and POD enzymes significantly increased. The decreased and increased expression of these proteins corresponded to the peak period of bacterial biomass and polysaccharide yield (72 h). This indicated that Lycium ruthenicum Murr. could significantly improve the antioxidants in the mycelial cells, increasing the production of biomass and polysaccharides.{GRAPHIACAL ABSTRACT}