Study Of Morchella Fermented Broth And Exopolysaccharides

Morchella is a kind of rare edible fungi which has many sanitarian functions to health of body and mind. So, it is favored by the consumers. With the maturity of submerged fermentation technology, the fermentation product of Morchella has a favorable development prospect.This article mainly had analyzed the relationship among the exopolysaccharides, mycelial biomass and endo-polysaccharides of Morel.It elaborated the main nutritional components about fermented Morel liquid and Morchella culture medium. The value of Morchella fermented liquid was obtained the affirmation.Then it had studied the acute toxicity and genetic toxicology of fermented Morel liquid. It also found that Morchella fermented liquid(exopolysaccharides of Morchella) could alleviate physical fatigue. The functionality of fermented Morel liquid had been confirmed. Finally the paper had optimized the extraction process parameters of the Morchella exopolysaccharide. The exopolysaccharides of Morel were separated and purified under the two kinds of different carbon source, in order to analyze the two kinds of exopolysaccharides. The data of possible Morchella exopolysaccharides senior structures were described by software. The main research contents were as follows:1. Two kinds of common fermentation medium were filtrated with Morchella exopolysaccharides extractive yield and mycelial biomass as the indexes. Formula for the best medium wasâ… medium(potato 100 g, sugar 30 g, peptone 1g, yeast extract 5g,Mg SO4 0.5g, KH2PO4 0.5g, water 1000 m L, p H value of nature). Under the condition,Morchella mycelia biomass could reach 11.803g/L and the production of exopolysaccharide could reach 1.465 g/L. On the premise of Morchella mycelia biomass and endo-polysaccharides yield, the termination time of liquid culture was the seventh day. After calculation, the proportion of Morchella exopolysaccharides extractive yield and mycelial biomass was 3:20, the proportion of Morchella exopolysaccharides extractive yield and endo-polysaccharides yield was 10:3. Results showed that the Morchella fermented broth had the vital significance.2. The data of acute toxinology experiment and genetic toxicology experiment were analyzed by SPSS 20.0 software and Student’s t test was performed. The analysis results were negative. So the Morchella fermented broth was preliminary proved non-toxic. Finally, mouse physical fatigue model demonstrated that and Morchella fermentation broth( Morchella exopolysaccharides) had the ability to relieve physical fatigue. Nevertheless, Morchella medium had no such function.3. The single factor experiments of concentrated temperature, ultimate ethanol concentration, precipitation and precipitation temperature were shown. After these,the Morchella exopolysaccharide extraction process was optimized by using theDesign- Expert 8.0.4 software with Morchella exopolysaccharides extractive yield and mycelial biomass as the indexes(guaranteeing the premise of Morchella mycelia biomass and endo-polysaccharides yield). And then, the Morchella exopolysaccharide extraction technology conditions had been determined as temperature 70℃, ethanol concentration 77%, precipitation temperature 4℃ and precipitation time 19 h by building a quadratic multinomial regression model. At this point, Morchella exopolysaccharide extraction quantity could reach 2.027 g/L. At last, the two kinds of Morchella exopolysaccharides gotten from different carbon source liquid medium,had been separated and purified. Through the preparation of Morchella exopolysaccharides named EXPnâ… and EXPnâ…¡ by high performance liquid chromatography(HPLC), the molecular weight of EXPnâ… and EXPnâ…¡were2.036×106Da and 2.238×106Da.4. Morchella exopolysaccharides EXPnâ… and EXPnâ…¡are canary, yellow powder,light in quality, odorless, tasteless, soluble in water especially in hot water, insoluble in organic solvent like anhydrous ethanol, acetone, n-butanol, diethyl ether,chloroform; do not contain nucleic acid, protein, pigment and uronic acid; belong to non starch polysaccharide. Infrared spectroscopy analysis revealed that the majority of cyclization patterns of Morchella exopolysaccharides EXPnâ… and EXPnâ…¡are glucopyranoside, main bonds in sugar chain are α glycosidic bond and β glycosidic bond, containing acetyl. Morchella fermentation broth exopolysaccharides does not contain acylamino, which makes it different from Morchella intracellular polysaccharide. 1H-NMR and HSQC atlas analysis of nuclear magnetic resonance indicated main structure of Morchella exopolysaccharides. EXPnâ… is comprised ofα-1â†'4 glucose as main chain, α-1â†'6, β-1â†'6, α-1â†'3, β-1â†'3 galactose or mannose as branch chain. EXPnâ…¡is comprised of α-1â†'6 glucose as main chain, α-1-4, β-1â†'4galactose or mannose as branch chain. The different carbon source in culture medium should account for distinct difference in structure link of Morchella exopolysaccharides. Finally, the conjunction of Chem Bio Office software and chemical analysis provided a theoretical basis for the following higher-order structure study of Morchella exopolysaccharides.