Effect of LF-AMF on the production of EPS by liquid fermentation of P.
The objective of this study was to investigate the effect of low
frequency alternating magnetic field (LF-AMF) on the production of
extracellular polysaccharide (EPS) by submerged liquid fermentation of
Pleurotus citrinopileatus. The fermentation conditions optimized by
central composite design method were as follows: fermentation time of 6
d, temperature of 28 ℃, shaking speed of 150 r/min, and inoculum amount
of 8 %. Under these conditions, a LF-AMF was applied to the liquid
fermentation of P. citrinopileatus. When the intensity of LF-AMF was 40
Gs, the initial intervention time was 24 h after inoculation, and the
treatment time was 6 h at one time, the mycelium biomass of P.
citrinopileatus increased by 11.30 ± 0.33 %, and the EPS yield
increased by 23.09 ± 1.52 % compared with the fermentation without
LF-AMF treatment. The morphology of mycelium after LF-AMF treatment was
observed by scanning electron microscopy. It was found that the surface
of mycelium was wrinkled and the structure of mycelium was loose, which
might be more conducive to the production of EPS.