Difference Analysis Of Nutritional Characteristics On Three Kinds Of Edible Fungi Mycelium Of Different Nutritional Types

Edible fungi usually include parts species of ascomycota fungi and most species of basidiomycota,belonging to higher macrofungi.There are more than one million species of macrofungi in the world,half of them can be edible.There are five thousands edible fungi and about 300 species have been used.90 species have been cultivated in research level.40 species have been cultivated with economic evaluation,and 20 species have been cultivated as commodity,only eight-ten species are cultivated as industrial production.There are more than 3800 species in China and 938 species have been recorded.However,only 90 species can be artificial cultivated,and most of them can obtain fruiting-body just in laboratory but can not be cultivated extensively.According to nutrition ways,edible fungi can be divided into three types:saprophytic edible fungi,symbiotic edible fungi and concurrent parasitic edible fungi.As far as the species which known can be cultivated,most of them are saprophytic edible fungi such as Lentinus edodes, Flammulina velutipes and Auricularia auricular.Few of them belong to concurrent parasitic edible fungi such as Hericium erinaceum,Armillariella mellea.Because of the special process of growth and development,symbiotic edible fungi can not be cultivated.Although the molecular techniques such as DNA marker and gene transfermation and so on have been apply to breeing,How to breakthrough boundary of cultivated group of edible fungi is still a problem.As a foundational research for application,Lentinus edodes which belongs to saprophytic edible fungi and Leccinum scabrum which belongs to symbiotic edible fungi and Armillariella mellea which belongs to concurrent parasitic edible fungi were selected as research materials.Nutritious conditions of three types of edible fungi mycelium and extracellular enzyme activity were studied, found out the difference of these three nutritional types on demand for different substance and the ability to biodegrade the culture media.From the viewpoint of nutrition physiology study on the mechanism of domestication and cultivation of different edible fungi and provide scientific basis for breaking through boundary of cultivated group of edible fungi.This thesis has done the following researches:1 Selecting optimum nutrition among three kinds of edible fungi mycelium of different nutritional types,it showed that optimal carbon source,nitrogen source and vitamin source of Lentinus edodes are glucose,NH₄Cl and VB₁.Optimal carbon source and nitrogen source of Leccinum scabrum are starch and beef extract,it has no demand for vitamin source.Optimal carbon source,nitrogen source and vitamin source of Armillariella mellea are maltose,yeast extract and VB₆.2 Kinds of extracellular enzyme activity in three types mycelium were analyzed.The results show that the ability decomposing cellulose and lignin of Leccinura scabrum is inferior to others,however,the ability decomposing starch is better than others.Lentinus edodes has higher ability decomposing cellulose than Armillariella mellea.However,Armillariella mellea has higher ability decomposing carbon source such as lignin and starch than Lentinus edodes.All of them have the same ability decomposing protein.3 In the selection range of different types of mycelium in carbon.vitamin and nitrogen source and optimal culture medium,the best selection range of carbon source of the saprophytic edible fungi are glucose,maltose and Starch;the best selection range of nitrogen source are beef extract, yeast extract and NH₄Cl,the best selection range of vitamin source are VB₁,VB₂,VB₆.the optimum medium selected are:potato 200g,glucose 20g,KH₂PO₄ 0.46g,K₂HPO₄ 1g,NH₄Cl 2g,MgSO₄ 0.5g, VB₁ 0.05g,H₂O 1000ml.The best selection range of carbon source of the symbiotic edible fungi are glucose,maltose and starch;the best selection range of nitrogen source are beef extract,KNO₃ and NH₄Cl;it has no demand for vitamin source.The optimum medium selected are:potato 200g,starch 20g,KH₂PO₄ 0.46g,K₂HPO₄ 1g,beef extract 2g,MgSO₄ 0.5g,H₂O 1000ml.The best selection range of carbon source of the concurrent parasitic edible fungi are glucose,maltose and starch;the best selection range of nitrogen source are beef extract,yeast extract and NH₄Cl:the best selection range of vitamin source are VB₂,VB₆,inositol.The optimum medium selected are:potato 200g, maltose 20g,KH₂PO₄ 0.46g,K₂HPO₄ lg,yeast extract 2g,MgSO₄ 0.5g,VB₆ 0.05g,H₂O 1000ml.4 In culture process of saprophytic edible fungi,the choice of carbon and nitrogen source should apt to nutritious substance which have simple structure and are easy to be decomposed and absorbed.It need relatively less kinds of nutritious species.In culture process of concurrent parasitic edible fungi,the choice of carbon and nitrogen source are more extensive,and the structure of nutritious substance can be more complicated,but nutritious species should be more abundant,and should add proper amount of vitamin.For symbiotic edible fungi,although the structure of nutritious substance belonging to carbon source which growth of mycelium demand for can be more simple than others,paying attention to the subtance concentration which mycelium can directly absorb in growth should be lower than others.In culture process of symbiotic edible fungi,it is unnecessary to add exogenous vitamins,but it demands for more species of nutritious substance.If the species of nutritious substance are not enough,it will influence its growth and development,maybe it is one of the reasons why symbiotic edible fungi is difficult to domesticate.