Researches On Mass Production Process Of Adventitious Roots Of Panax Ginseng And On Saponin-producing Fungal Endophytes

Ginseng(Panax ginseng)is a Chinese traditional valuable medicine.Wild ginseng resources are depleted due to the long-term over-excavation and the serious damage to ecological environment of forest.Now,the cultivated ginseng occupied the market.However,cultivated ginseng has the following disadvantages such as low medicinal value,pesticide pollution,heavy metal pollution,competition for land,many other issues,etc.To protect the wild ginseng resources and meet the market demand,this study was tried to use the bioreactor technology to produce a large amount of ginseng with high quality.At the same time,the genes expression levels about saponins accumulation in ginseng roots under MeJA inducement were investigated.The results may provide a basis for theoretical support and scientific and technical support for further optimization of extracting saponins produced by the bioreactor.At last,the possibility of saponins production by endophytic fungi was explored.The aim of selecting endophytic fungi was to look for alternative sources of the active ingredients in ginseng and to provide an effective reference for using the resources of other medicinal plants.(1)This experiment was the investigation of the suitable cultivation parameters of the 10-L bioreactor.And by fixed ventilation and vaccination amount,1000-L bioreactor was used to enlarge ginseng roots cultivation based on 10-L bioreactor results.The results showed that when the basic medium was 1/2MS medium,plus IBA 5 mg/L,sucrose 20g/L,inoculation amount 5 g/L,and the ventilation as 0.1×media volume min-1,etc.as the basic parameters,ginseng adventitious roots accumulated saponins mostly.The success of the 600-L culture system showed that these parameters were feasible in a large reaction tank.The amplification of 1600%was obtained when adventitious ginseng roots were cultivated in 600-L cultivation system seven weeks later.The saponins amounted to 14 mg/g.(2)The genes were selected before panaxadiol synthesis in the triterpenoid saponins biosynthetic pathway as the research objects to clear the relationship between genes expression level and the total saponins accumulation amount.The results showed that there was a detention by the MeJA inducement from the gene expression level to the saponin accumulation amount.After 3-12 hour MeJA induction,the genes began to express.The saponins accumulation occurred at 24 hour inducement.MeJA induction caused the changes of all target genes.More genes showed the trend from the increase to the decrease.Only the expression level of IPI showed negative regulation to the MeJA induction.The experimental results showed that MeJA treatment increased the saponins mainly by increasing DS expression and reducing IPI expression.The expressions of other genes seemed to increase the triterpenoid saponins,but they were not main factors.(3)Thirty-eight and 96 endophytic fungal strains were isolated from ginseng and Aralia elata.Endophytic fungi isolated from Panax ginseng belonged to nine genera.The dominant genera was Nectria,Aspergillus and Penicillum.Of the endophytic fungi isolated from Aralia elata,twelve genera were identified.The dominant genera was Diaporthe and Alteraria.According to the vanillin-perchloric acid method,many endophytic fungi had color reaction.The highest saponin concentration was Pg27(0.181mg/ml)among endophytic fungi isolated from Panax ginseng.There was a very high total saponins expression amount in G22(2.049 mg/ml).From HPLC results,Rb2 and Re could be detected in G22 cultivation liquid.G22 seemed to hold the ability to produce saponins and genesosides.The antimicrobial activity results showed that P11 and Pg42-1 could inhibited Klebsiella pneumoniae ACCC10498.These might be potential medical resources for curing the pneumonia.