Study On Mutagenesis And Liquid Fermentation Of Inonotus Obliquus With Rice Bran And Wheat Bran

Inonotus obliquus is a large medicinal and edible fungus with various active components and pharmacological effects,which has been widely used in food,medicine and cosmetics.Rice bran and wheat bran,as primary by-products of agricultural products in China,have a wide range of sources but low utilization.It's essential to develop a high-value and high-efficiency utilization of rice bran and wheat bran.In this study,Inonotus obliquus strain was improved by mutagenesis,the liquid fermentation of Inonotus obliquus mutant was applied to produce bioactive Inonotus obliquus mycelia and polysaccharides by bio-converted rice bran and wheat bran.And here provided a solution of high-value using rice bran and wheat bran,and high-yield producing Inonotus obliquus raw materials.The main contents and results of this study are as follows:?1?The new strain used in this study was mutated from Inonotus obliquus CFCC83414 strain.An ultra voilet mutated new strain Inonotus obliquus JSU LIUK18 was obtained by 10-time UV mutagenesis and preliminary screening of five generations of plate passage and liquid fermentation respectively.After the liquid fermentation of Inonotus obliquus mutant,the dry weight of mycelium,mycelial polysaccharide,extracellular polysaccharide and residue in 100mL fermentation with 2g rice bran and 3g wheat bran,is 2.005 g,144.160 mg,240.105 mg and0.605g,respectively.For original strain,that is 1.543 g,110.467mg,155.542 mg and0.851 g,respectively.Under the same culture medium and fermentation conditions,compared with the original strain,the dry weight of the mycelium of the Inonotus obliquus JSU LIUK18 increased by 29.9%,the mycelium polysaccharide increased by 30.5%,the extracellular polysaccharide increased by 54.4%,and the residue decreased by 28.9%.?2?Fermentation parameters of a new strain of Inonotus obliquus JSU LIUK18 were investigated including single-factor experiments and optimization of medium components.Through these experiments,the Inonotus obliquus JSU LIUK18 can be used for the high-efficiency conversion of whole rice bran and wheat bran to lay the foundation for large-scale production and could be used to provide the experimental research basis for the subsequent industrial development.With U₁₁?11³?uniform design,rice bran,wheat bran,KH₂PO₄,MgSO₄?7H₂O were optimized by determining the mycelia weight,residue weight,mycelial polysaccharide weight,and exopolysaccharide weight.Four model equations of the four criteria were obtained.The optimum media consists of rice bran,wheat bran,MgSO₄?7H₂O.Other fermentation parameters were selected of temperature of 28?,rotation speed of 150 r/min,natural pH,loading volume of 100mL in 250 mL conical flask,fermentation time of 7 d.The better dry mycelial weight is equal to3.968g when the weight of rice bran is 10g,no wheat bran and KH₂PO₄ are added,the weight of MgSO₄?7H₂O is 0.12g.The optimal weight of mycelial polysaccharide is equal to 470mg when the weight of rice bran,wheat bran,KH₂PO₄ and MgSO₄?7H₂O is 2.5g,7.5g,0g,0.3g,respectively.?3?The uniform design U₂₄?24⁴?was used to build the empirical dynamic equation.The facts included rice bran?the total weight of wheat bran and rice bran is equal to 10g?,KH₂PO₄,MgSO₄?7H₂O in original media of 100mL and fermentation time.The index was the mycelial dry weight of Inonotus obliquus JSU LIUK18.The empirical dynamic equation was obtained.?4?With U₁₆?16³?design table,based on the empirical dynamic equation of mycelial dry weight,each mycelial dry weight in original media of 100mL at a different time was predicted.The theoretical dynamic equations of the Logistic model equation and the regression equations of its parameters of?_m and C_maxax with the weight of rice bran,wheat bran,KH₂PO₄,MgSO₄?7H₂O were obtained.