Effect of low-intensity magnetic field on the growth and metabolite of Grifola frondosa in submerged fermentation and its possible mechanisms

This study aimed to investigate the effects of low intensity alternating magnetic field on the submerged fermentation of Grifola frondosa, and its possible mechanism was also explored. Under the optimal shaking flask conditions, amino acids in mycelium with magnetic field treatment significantly increased, and the morphology of mycelium obviously changed. During the scale-up magnetic field-assisted fermentation, Mycelium biomass increased by 12%. The yield of polysaccharides and relative dissolved oxygen in the fermentation broth was higher than in the control group. Transcriptome sequencing results showed that the expression of genes related to amino acid metabolism increased significantly after magnetic treatment. In addition, magnetic field stimulation enhanced the mycelium biomass by upregulation the expression of genes related to cell repair and stress response. This study suggested that applying a magnetic field in submerged fermentation of G frondosa is an innovative approach to produce metabolites.