Molecular Identification And Liquid Fermentation Of Tricholoma Mongolicum And Application Of Mycelium Metabolite

Tricholoma mongolicum Imai known as nutritional value edible fungi is mainly distributed in the Mongolia Plateau steppe region. In recent years, wild Tricholoma mongolicum resources have endangered due to environmental pollution and overexploitation. What’s more the artificial cultivation of Tricholoma mongolicum has not yet obtain substantial breakthrough. Thus their genetic resources, fermentation technology and product application should be researched.In this paper,16strains fungi including Tricholoma mongolicum with deferent resources were identified in molecular level using ISSR identification technology. Then Tricholoma mongolicum liquid fermentation process and formula of mushroom sauce were optimized using single factor experiment and orthogonal test. Furthmore, the extraction processes of intracellular polysaccharide were established with response surface methods. Growth-promoting effect of intracellular polysaccharide on Lactobacillus acidophilus was analyzed to explore its prebiotics effect.The results were stated as follows:Two suitable primers were screened from12known microsatellite sequence primers. ISSR identification technology for Tricholoma mongolicum was established.2. The optimal liquid fermentation process of Tricholoma mongolicum was studied by using the single factor experiment and orthogonal experiment according to the yield of intracellular and extracellular polysaccharide. The optimal culture medium was2%yeast extract,0.3%KH2PO4,3%glucose, and0.3%MgSO4. The optimal fermentation condition was12%inoculums,25℃,150r/min, and pH6.5. Under the conditions, the production of intracellular and extracellular polysaccharide are1.180g/L and1.078g/L, respectively.3. The extraction of intracellular polysaccharide from Tricholoma mongolicum was studied by the response surface method. The highest content of polysaccharides (7.36%) was extracted by hot water at85℃with solid to liquid ratio of1:32g/mL for2.2h. In addition, the ultrasonic-assisted hot water extraction increased the yield to more than12.92%.4. The effects of intracellular polysaccharide on Lactobacillus acidophilus in fermented milk were studied compared with inulin. The highest number of living bacterium was obtained at the concentration of0.6%polysaccharide (1.05×1010cfumL-1), which is equal of3%inulin (1.51×1010cfu·ml-1). The viscosity value of Lactobacillus acidophilus fermented milk also reached the maximum and higher than the control. And the lowest pH values (5.02and4.98respectively) were observed at the concentration of0.6%polysaccharide and3%inulin. The results showed intracellular polysaccharide had positive effect on the growth of Lactobacillus acidophilus and the polysaccharide may be potential prebiotics.5. Mushroom sauce was made from mycelium and auxiliary condiment (salt, saccharose, aginomoto and citric acid). With orthogonal experiments, the flavor, color, and mouth feel of mushroom sauce was evaluated. At the same time, physical and chemical indexes, and microbial indexes were discussed. The optimal culture medium was3%salt,2.8%saccharose,0.5%aginomoto and0.2%citric acid.