Optimization Of Culture Conditions And Submerged Liquid Fermentation Process Of Armillaria Mellea

Gastrodia elata is a valuable Chinese herbal medicine.Armillaria mellea,a symbiont of G.elata,plays an important role in G.elata growth.At present,the production of A.mellea mostly adopts solid inoculation and solid fermentation,which shows several disadvantages such as low efficiency,long production cycle,and so on.Sawtooth oak and oriental white oak are the main woods A.mellea growth needs.However,some problems largely remain unsolved in this industry,such as narrow selection range of species,serious waste,and so on.In order to optimize the production process of A.mellea,improve the production efficiency of A.mellea,expand the selection range of woods,and explore the possibility of pear and apple trees as production materials.This study explored submerged liquid fermentation-based liquid fermentation technology of A.mellea.Pear and apple trees were used as culture medium materials and with G.elata growth to assess their performance.This will provide reference for the development of the technology of A.mellea production and G.elata cultivation.In this study,production of A.mellea strain M6 was selected as the object,and the optimal medium for the strain was selected by plate culture and shake flask fermentation.Based on the results of shake flask fermentation,the fermentation process and high biomass production conditions of this strain were optimized by submerged liquid fermentation.The submerged liquid fermentation product was used as the liquid strain to inoculate in the cultivation bottle,and the most suitable culture medium for the strain was screened.In order to verify the feasibility of apple trees in G.elata production,mature A.mellea M6 cultivation bottle were used for G.elata cultivation.At the same time,the growth rate of A.mellea YN3862 was evaluated by plate culture,and the high-density fermentation process of this strain was explored in a 200 L fermenter.The main results are as follows.The optimal medium for the mother culture of A.mellea M6: sawdust of 100 g/L,wheat bran of 100 g/L,glucose of 20 g/L,beef extract of 5 g/L,and agar of 15 g/L.The optimal liquid medium: glucose of 1%,sucrose of 2%,silkworm chrysalis meal of 3%,Mg SO4·7H2O of 0.075%,KH2PO4 of 0.15%,and ethanol of 1%.The optimal fermentation conditions: inoculation amount of 5%,dissolved oxygen of 20%,p H 5-6,rotation speed of 150 r/min,and 28 ?.In this fermentation condition,the maximum dry weight of mycelium was 23.63 g/L.A.mellea YN3862 presents fast germination,large extension area,and good growth performance.The optimal fermentation conditions: inoculation amount of 5%,dissolved oxygen of 55%.In fermentation for 0-24 h,24-36 h,36-48 h,and 48-144 h,the rotational speeds were set as 60,80,120,150 r/min,respectively.In this fermentation condition,the dry weight of mycelium can reach up to 25.14 g/L,achieving high density fermentation.Pear trees were selected as the main raw materials for A.mellea M6 cultivation.The optimal cultivation medium: pear wood of 70%,wheat bran of 30%,glucose of0.6%,potato powder of 6%.Changing as the main raw material of apple trees,the optimal formula: apple woods of 70%,auxiliary material of 30%(corn cob/wheat bran/no addition),glucose of 0.4%,potato liquid of 2%.The rhizomorph of A.mellea are white and thick when they grew in the cultivation medium composed of above formula,and with many branches in short growth time.Moreover,for apple tree as the material,the effects of different planting methods on the growth of G.elata were explored.The results showed that the growth of G.elata could be effectively promoted by A.mellea,demonstrating that apple tree could replace other tree species and be used as the material of cultivation medium used for A.mellea growth.This study explored the submerged liquid fermentation technology used for production of A.mellea strain M6 and honeyring strain YN3862.The results will be useful for the production of A.mellea and the development of the plant-products industry of G.elata.