Study On The Effect Of Weak Magnetic Field On The Liquid Fermentation Of Antrodia Camphorata

In recent years,weak magnetic field can significantly increase the biomass of Saccharomyces and Hericium erinaceus,and it also can increase the production of metabolites such as ethanol,antibiotics,enzymes and polysaccharides,so it receives much concern in the field of physical field assisted microorganism growth and metabolism.A.camphorata is a precious medicinal fungus,because it has many bioactive components such as polysaccharides,triterpenoid,sterols and antioxidants,so it has high application and commercial value.In this paper,we use the weak magnetic field assisted the liquid fermentation of A.camphorata.The effect of weak magnetic field on the liquid fermentation of A.camphorata,was researched from the following aspects,morphological structure of mycelium,cell membrane fluidity,mycelial polysaccharides,mycelial triterpenoid,and the volatile substances of fermentation broth.It provides evidence for the application of weak magnetic field in the liquid fermentation of the rare edible and medical fungi.It will lay a foundation for further study on the mechanism of weak magnetic field.（1）Using mycelium biomass,polysaccharide yield and triterpenoid yields as indexes,the results show that the best fermentation time was 9 days.When the magnetic field intensity was 90 mT,mycelial biomass,polysaccharide yield and three terpenoid yield respectively reach 3.478 g/L,0.01755 g/L and 0.04091 g/L,with the increase of magnetic field intensity,the biomass of mycelium remained stable,there was no significant difference,the yield of polysaccharides yield not increased any more,contraily the triterpenoid yield began to decrease,and reached the lowest when the magnetic field intensity was 180 mT.Therefore,the weak magnetic field of 90 mT showed positive promotion effects on the liquid fermentation of A.camphorata,and the excessive magnetic field may affect the growth and metabolism of myceliuma,thus influence the fermentation of A.camphorata..（2）When the magnetic field intensity was 90 mT,mycelia become more dispersion and better elongation.With the increase of magnetic field intensity,some mycelium was damaged.A certain intensity of weak magnetic field can increase cell membrane fluidity of A.camphorata.,The membrane fluidity is the largest when the magnetic field intensity is 90 mT.Cell membrane fluidity tends to be stable when the magnetic field strength was 120 m T and 180 mT.Combined with the response pattern of mycelial biomass,and conjecture that the change of cell membrane fluidity may be one of the reasons that the weak magnetic field promotes the mycelia biomass of A.camphorata.（3）In the control group,90 mT and 120 mT magnetic field treatment group,polysaccharidesofA.camphoratawerepurificatedtwopolysaccharides（polysaccharide I and polysaccharide II）.The results show that the monosaccharide composition of polysaccharide I was same in the control group and 90 mT magnetic field treatment group,which were contains five monosaccharides,including fructose,mannose,rhamnose,glucose and galactose,but the proportion of monosaccharides is different.The monosaccharide composition in 120 m T magnetic field treatment group contained four monosaccharides,including fructose,rhamnose,glucose and galactose.The monosaccharide composition of Polysaccharide II in each treatment group was fructose,which the content was less.The mycelial polysaccharide of control group,90 m T and 120 m T magnetic field treatment group all showed inhibition on tumor cells（A2780）.The anti-tumor activity of polysaccharides in 90 mT and 120 m T treatment group was all improved,and the polysaccharides in 90 mT treatment group had the best effect of anti-tumor,This may be related to the change in the primary structure on composition and proportion of monosaccharide.According to LC-MS results,the control group,90 mT and 120 mT treatment group contained three majoy triterpenoids,oleanolic acid,lucidenic acid and ganoderic acid C₂.The antioxidant activity results showed that the total antioxidant capacity was improved obviously in weak magnetic field treatment group,but the effect of superoxide anion and hydroxyl radical is not significant.Therefore,the weak magnetic field promoted the total antioxidant activity of triterpenoid was probably related to the proportion of triterpenoid in A.camphorata.（4）The SPME-GC-MS result show that,the broth of control group and treatment groups contain alcohols,esters,aldehydes,ketones,olefins,phenols and other components.Compared with the control group,the content of some volatile substances with antibacterial activity increased in the 90 mT treatment group.Moreover,some volatile substances with antibacterial activity disappeared in the 120mT and 180 mT treatment group.At the same time,it also produces some harmful substances.