Nematicidal Activity And Active Metabolites Of Lichen And Rare Animal Fecal Actinomycetes

As a species of parasitic nematodes that endanger the world,the annual economic loss is hundreds of billions of dollars.Actinomycetes are the main source of natural antibiotics and have many antibacterial activities.However,the study of actinomycetes derived from special habitats-the lichen and the intestinal tract of rare animals is only just beginning.In this paper,from the perspective of the nematicidal activity of these two kinds of special habitats,the following results are mainly obtained:1.A preliminary screening of 275 strains of actinomycetes from the lichen and theintestinal tract of rare animals was conducted,and a total of 13 strains with a fatalityrate of more than 80% in 8h were detected.Among them,9 strains of actinomyceteswere screened from 87 strains of rare animal fecal actinomycetes,with an active ratio of10.3%,and 4 strains from 188 strains of actinomycetes from lichen,with an active ratioof 2.1%.2.We choosed four different types of culture medium,and the 13 strains werecultured from different nutritional perspectives.In this study,13 strains ofactinomycetes in the above four culture conditions were nematicidal activity tested,and a total of 6 strains with a mortality rate of more than 80% in 24 h.The TLCdetection was performed under different systems,and the richness of the metabolitesof each strain was compared.The results showed that No.61 culture medium was themost abundant metabolite.3.In this paper,the 6 strains of actinomycetes were extracted and concentrated byethyl acetate and n-butanol respectively,and the nematicidal activity was performedwith ethyl acetate and n-butanol.The results showed that Agromyces allii 130935 hadthe highest mortality rate of acetic acid ethyl acetate,which reached 96%.4.The strain A.allii 130935 was fermented for 30 L,and the crude extract of ethylacetate was obtained by 14 g.After column chromatography separation andpurification,four compounds were obtained: MS-1,MS-2,MS-3,MS-4.Thestructure of four compounds was identified by NMR spectrum and MS massspectrometry.The results showed that the activity of compound ms-4 was the highest,with the concentration of 200ug/ml reaching 50% in 24 h.5.In this paper,the bacteria were made from the crude extract of the strain A.allii 130935 and Micromonospora aurantiaca 130826,and the field community experiment was carried out in RenHe at Panzhihua.The results showed that the antibacterial effect of M.aurantiaca 130826 was higher than that of the positive control of avermectin,and the effect was 59.65%.Strain A.allii 130935 has the same protective effect as avermectin.Highlights of this research:1.Six strains of actinomycetes was found to be highly toxic to the Root knot nematode.2.The fermentation liquid of A.allii 130935 of the mortality rate of the crude extract of ethyl acetate was 96% in 24 h.In addition,four compounds were isolated from this phase,and the mortality rate of MS-4 against M.incognita was 50%.3.In the field experiment,it was confirmed that the bactericide made from actinomycete M.aurantiaca 130826 was greater than that of avermectin,which reached 59.65%,which had the potential of bioprotection.