Investigation of the polysaccharides synthesis enhancement mechanism from Agaricus bitoquis (Quél.) Sacc Chaidam and its fermentation regulation technology system based on multi-omics technologies

Abstract

The polysaccharides (PS) of Agaricus bitoquis (Quél.) Sacc. Chaidam (ABSC) had attracted the attention of researchers due to their strong anti hypoxia, antioxidant, and anti fatigue activities. Therefore, this article focuses on studying the regulatory channels of exogenous additives-Lycium ruthenicum Murr. Anthocyanin (LRA) to delay fungus cell aging and promote the incremental synthesis of PS from ABSC, and optimizing the regulation system for pilot fermentation experiments. The joint analysis of Ultra High Performance Liquid Chromatography-Quadrupole-Time of Flight Mass Spectrometry (UHPLC-Q-TOFMS) and RNA sequencing (RNA-seq) database elucidates that at the molecular level, the crude extract of LRA inhibits the Telecommunications Association (TCA) cycle, transferring carbon metabolism to the synthesis of polysaccharide precursors (UDP-glucose, UDP-galactose, etc.), promoting the synthesis of PS, promoting the formation of key antioxidant substances (including flavonoids such as quercetin and alginate), improving cell membrane fluidity (saturated fatty acid to unsaturated conversion) and enhancing the degradation of toxic substances (oxidized glutathione), thereby promoting the anti-aging activity and PS synthesis ability of mycelial cells; LRA-adding could enhance the activity in the pilot fermentation of ABSC, which make the mycelia biomass, EPS and IPS production were significantly increased (89.04 %, 65.46 % and 37.64 % respectively) compared with the untreatment control. Based on the optimal fermentation system of PS synthesized in mycelium by adding LRA, Logistic, Gauss, and Asymptotic kinetic equations were used to describe the cell growth, product synthesis and regulatory substrate consumption from ABSC. The correlation coefficients of three models were all above 0.95, indicating a good fit between the experimental values and predicted value, this indicated ABSC fermentation kinetics model could better simulate the actual production process and provide theoretical data for the industrial production of polysaccharides. The results demonstrated that the present proposed LRA intensification approach could be useful to boost up the fermentation of ABSC, which possibly applied to yield increase and fermentation product acquisition of macrofungi.