Isolation And Bioactivity Of Endophytic Fungi From Glycyrrhiza Uralensis And Angelica Sinensis

Endophytic fungi are widely found in plants,and a complex micro-ecological relationship exists between plant endophytes and plants.Endophytic fungi have the wide prospects and potential in medicine,agriculture,etc,because they can produce the compounds that similar or same with host itselves.In this research,to study the metabolite activity of its endophytic fungi and its relationship with the growth of licorice,we select glycyrrhiza uralensis and angelica sinensis as the materials.A total of 30 endophytic fungi were isolated from the roots of glycyrrhiza and angelicae sinensis by using the tissue block separation method,and 16 strains of endophytic fungi were identified by morphology and microscopic features,which were divided into 8genera,they were respectively Mucor?1strain?,Fusarium?6 strains?,Aspergillus?3strains?,Helminthosporium?1strain?,Cephalosporium?2strains?,Penicillium?1strain?,Graphium?1st rain?,Trichoderma?1strain?.From shake flask fermentation of endophytic fungi,a total of90 samples of ethyl acetate extract?EAE?,n-butanol extract?NBE?and methanol extract?MME?were obtained.And then,we research the antibacterial activity,antioxidant activity,?-Glycosidase inhibitory activity,screening of insect-resistant activity and the relationship between endophytic fungi and glycyrrhiza uralensis fisch in 90 samples.The results of antibacterial activity showed that there were 39 samples exhibiting antibacterial activity about againsting Staphylococcus aureus,which accounting for 43.3%of the total number of samples.there were 36 samples exhibiting antibacterial activity about againsting Pseudomonas aeruginosa,which accounting for 40%of the total number of samples,there were 39 samples exhibiting antibacterial activity about againsting Klebsiella pneumoniae,which accounting for 43.3%of the total number of samples,there were 32 samples exhibiting antibacterial activity about againsting E.coli which accounting for 35.6%of the total number of samples,there were 25 samples exhibiting antibacterial activity about againsting Bacillus licheniformis which accounting for 27.8%of the total number of samples.And there were a total of 7 samples with a diameter of inhibition of more than 16mm.Among them,the sample GC-R-108?MME?had the strongest antibacterial activity against P.aeruginosa with the minimum inhibitory concentration of0.312 mg/m L,the sample DG-R-110?NBE?had the strongest antibacterial activity against Klebsiella pneumoniae with a minimum inhibitory concentration of 5 mg/mL,the sample DG-R-104?NBE?has the strongest antibacterial activity against Escherichia coli with a minimum inhibitory concentration of 1.25 mg/m LThe results of antioxidant activity showed that there were a total of 61 samples showed hydroxyl radical scavenging activity,which accounting for 67.8%of the total number of samples,and a total of 3 samples cleared over 30%.of which GC-R-109?EAE?has the highest activity with an IC₅₀ value of 0.0912 mg/m L.A total of 81 samples showed clear DPPH free radical activity,accounting for 90%of the total number of samples,of which DG-R-103?EAE?had the strongest scavenging capacity,and its IC₅₀ value was 0.041mg/m L.A total of 51 samples showed total reducing power,accounting for 56.7%of the total number of samples,and V_C equivalents greater than 80?g/mg with 3 samples,of which sample DG-R-111?EAE?has the highest total reducing power with an equivalent concentration of 87.97?g/mg and an EC₅₀ value of 0.062 mg/mL.The results of?-Glycosidase inhibitory activity showed that at a sample concentration of 1 mg/m L,a total of 6 samples had inhibitory rates of more than 80%,which are respectively GC-R-104?EAE?,GC-R-111?EAE?,DG-R-101?EAE?,GC-R.-108?NBE?,DG-R-102?MME?and DG-R-105?MME?,of which the inhibition rates were 87.83%,84.56%,84.57%,80.22%,86.74%,and 80.22%,respectively,and the activities were weaker than the inhibition rate of guaiapine at the same concentration.The results of contact test showed that when the sample concentration is 10 mg/m L,there were a total of 33 samples exhibited strong contact activity against tribolium castaneum?corrected mortality rate>70%?,and accounting for 36.67%of the total number of samples.There were a total of 30 samples showed strong contact activity against nicotiana tabacum,and accounting for 33.33%of the total number of samples.Among them,DG-R-101?MME?and DG-R-101?EAE?were the best samples for the contact toxicity of T tribolium castaneum and nicotiana tabaci,with LC₅₀ values of 0.742 mg/mL.The repellent test showed that when the initial concentration is 10000ppm,the repellency rate is greater than 90%.Samples with the activity level of V have ethyl acetate,n-butanol,and methanol sites of 7,5,and 6,accounting for 23.3%,16.67%,and 20%of the total number of samples,respectively.A total of 30 endophytic fungi of glycyrrhiza and angelica were fed back to the licorice tissue culture bottle to observe the relationship between endophytic fungi and glycyrrhiza uralensis.The results showed that after 42 days,there were no deaths in 4 treated groups,they were GC-R-104,GC-R-112,DG-R-112,and DG-R-113.We also studied the relationship between fermentation broth and growth of licorice though fermenting the four strains of endophytic fungi in PD medium.,concentrating and then quantifying bacteria back to the licorice tissue culture bottle.The results showed that compared with the blank control group,there was no significant difference in the water content,plant height,and fresh/leaved leaves of licorice in the fermentation broth treatment groups after 42 days of recovery,however,the treatment group of fermentation broth GC-R-104 and DG-R-113 slowed the growth of licorice roots.The fermentation broth GC-R-104 significantly reduced the chlorophyll content in the licorice leaves.The GC-R-112treatment group significantly increased the licorice SOD activity,and the four endophytic fungal fermentation broth groups significantly reduced the MDA content in the licorice leaves.GC-R-112,DG-R-112 significantly reduced the soluble sugar content of licorice,but the content of glycyrrhizic acid was significantly enhanced;GC-R-104 and DG-R-112treatment groups significantly reduced the soluble sugar content in the lower part of the licorice.