Study On Effects Of Liquid Fermentation Conditions On The Mycelium Morphology And Main Metabolites Yield

Poria is a type of fungus being often parasitic on the tree roots of pinus densiflora and masson pine in pinaceae plants,and it is a common Chinese medicine and has utilities for excreting dampness,diuresis,tonifying spleen and so on.Cultivating and producing Poria by liquid submerged fermentation can not be restricted by conditions of region,climate,plant diseases and insect pests,etc.With a short period and a large output,it is easy to realize industrial production and has broad development and application prospect.Its major metabolite are triterpenoids and polysaccharides,among which pachymaran has functions of regulating immunity,anti^tumor,anti^mutagenic and so on,and triterpenoid compounds have functions of regulating immune,anti^tumor,anti^convulsants,antiⁱnflammatory and so on.Correlational researches showed that mycelium morphology in the process of fermentation of filamentous fungi is related to accumulation of metabolite.Based on such theory,this paper studies the relation between mycelium morphology and metabolite through regulating and controling the poria cocos liquid state fermentation condition.During the progress of studying tuckahoe's liquid fermentation,when we change the fermentation conditions and analyze the mycelium morphology which is fermented in each condition through the software of IPP,we can find that the mycelium morphology and the amount of metabolite accumulation change remarkably.In the case of unchanged basal medium,the components and culture conditions of culture medium respectively are:glucose concentration is 60 g/L,peptone concentration is 20 g/L,corn flour concentration is 20 g/L,the KH₂PO₄ concentration is 3 g/L,the MgSO₄ concentration is 1g/L,the VB₁ concentration is 8 mg/L,and the liquid volume is 70 mL;inoculation amount is 6%;pH is5;the temperature is 28?;the speed of revolution is 150 r/min;when it has fermented for seven days,the major form of the mycelium displays the medium^sized fungus ball with a rough surface,the diameter of which is 0.8².5 mm.At the moment,the mycelium is conducive to the accumulation of the exopolysaccharide under the liquid state fermentation of tuckahoe.On the basis of the invariant basic culture medium,the culture medium and culture conditions of components are: 20g/L glucose,10 g/L peptone,8 g/L maize flour,2g/L KH₂PO₄,1 g/L MgSO₄,6 mg/L VB₁,the amount of fluid in 50 mL,6% inoculated quantity,pH 5.5,the temperature of 26?,the speed of 130 r/min,fermentation for 11 days.When it is under these circumstances,mycelium morphology becomes the medium^sized fungus ball with the smooth surface in 0.8².5 mm diameter range,and at this time it is good for the accumulation of poria cocos intracellular triterpene.The research invovled the shapes of liquid fermentation poria cocos mycelia and the changes of main metabolites production in different months.The result indicated that the mycelial morphology fermented in different months and the yield of the major metabolites had significant differences.Thereinto,the quantity of the medium^sized fungus balls of mycelium which were fermented in February and in liquid state fermentation was smaller.The biomass and the yield of major metabolites were lower;In the mycelium in August,the quantity of the medium^sized pellets is relatively high,and the biomass and the outputs of its main metabolites including the exopolysaccharides,the water^soluble intracellular polysaccharides,alkali^soluble intracellular polysaccharides and total intracellular triterpenes are all relatively high,respectively up to 18.56 g/L,0.91g/L,14.69%,44.09%and 8.81%;And when the relation between mycelium morphology and metabolites equally showed the medium^sized and shaggy pellet form,it can facilitate the accumulation of exopolysaccharides and intercellular polysaccharides.The medium^sized and smooth pellet form can facilitate the accumulation of intercellular triterpenoids.