Study Of Nutrient Content And Extracellular Enzyme Activity In Substrate During Hericium Erinaceus Growth

The article focuses on various section nutrient content and extracellular enzyme activity (mainly:biomass and pH;the content of total sugar, lignocellulolytic,reducing sugar and free amino acid;the activity of laccase, hemicellulase, carboxymethyl cellulose enzyme and acid protease) in different development stage of Hericium erinaceus by using cottonseed hulls as the mainly substrate. The correlation analysis have been made between nutrient content and extracellular enzyme activity to explore the effect on Hericium erinaceus development.The results indicate that nutrient content and extracellular enzyme activity varied significantly at different section substrate in the same development stage, regardless of the similar trends of them in the whole development process of Hericium erinaceus. However, they change dramatically at its vital development stage. The detail results are as follow:Extracellular enzyme activity:Laccase exhibited high activity when the mycelium first covered the substrate, then its activity decreased and increased after harvesting, its activity summit appeared in the part Ⅰ substrate at the point of primordia formation. Hemicellulase and carboxymethyl cellulose enzyme showed the similar activity trends, their activity were much lower in vegetative growth period than these in reproductive growth period. Both activity summits occurred at the point of primordia formation and harvesting. The activity of them in part Ⅰ substrate was the lowest, carboxymethyl cellulose enzyme activity was much lower than others in the whole process. Acidic protease varied in different part of substrate, it exhibited highly activity at the beginning of mycelium growth, and then decreased, its activity trended to stability in part Ⅱ、Ⅲ、Ⅳ substrate in reproductive growth period. Part Ⅰ、Ⅱ substrate acidic protease activity showed summit at the time of primordia formation as well as summit of part Ⅰ substrate acidic protease activity at harvesting.Nutrient content:①Macromolecule nutrients in matrix:total sugar showed the decreasing trend regardless of the opposite trend of water soluble proteins in the whole growth process of Hericium erinaceus, water soluble proteins begin to increase at the formation of primordia and peak at the time of harvesting. Hericium erinaceus consumed 16.4%lignin and32.6%hemicellulose, despite the little consumption of cellulose.②Micromolecule nutrients:reducing sugar content as well as free amino acid content varied differently, their contents were more at the time of covering the substrate with mycelium and then decreased to the lowest point at the time of primordia formation, which lasting for a stable period. They soared up to the highest point before or at harvesting. They decreased gradually from the bottom to the up of bag.The nucleic acid content, which was used as the test standard of biomass, appeared a gradually increasing trend in the various section substrate during the whole growth period, it soared much higher in the part I substrate than that of other parts. PH value decrease significantly after overgrowth of overgrow in substrate.Partial correlation analysis showed the moderate correlation between laccase activity as well as carboxymethyl cellulose enzyme and reducing sugar content; bivariate correlation exhibited various correlation between carboxymethyl cellulose enzyme activity and hemicellulase activity, between acidic protease activity and laccase activity, carboxymethyl cellulose enzyme activity, soluble protein content, free amino acid content as well as between pH value and water content, biomass and soluble protein content respectively.Conclusion:Nutrient content and extracellular enzyme activity show cetain variation in the growth of Hericium erinaceus, it’s indicate that the change of nutrient content and extracellular enzyme activity related with the development of Hericium erinaceus. The activity of laccase exhibits close relation with primordia formation.The metabolic reactions have significant difference depending on the part of substrate, synthesis reactions occur more frequently than degradation reactions in part I substrate.Nutrient content and extracellular enzyme activity interact with each other, together, they takes effect on the development of Hericium erinaceus.