Investigation Of Co-culture Of Endophytic Aspergillus Fumigatus Sps-02 And Fusarium Oxysporum Sps-03 And Their Secondary Metabolites

Microorganisms are one of the important sources of natural lead drug.In view of the natural interactions among microorganisms,simulating the competition of nutrient and space among microbial populations is considered to be the main metabolic pathway for the induction of active secondary metabolites.Co-culture of microorganisms has become an important method to enhance production potency and find new compounds,which is a hot issue in industry,agriculture,medicine,food and environmental protection.This paper mainly focused on bioactive secondary metabolites from mixed fermentation of two endophytic strains Aspergillus fumigatus(sps-02)and Fusarium oxysporum(sps-03)which firstly isolated from the healthy leaves of Artemisia annua Linn,in order to obtain more active natural products.Aspergillus fumigatus is widespread in the world and its host plants include Artemisia annua,Eucommia ulmoides,Cynodon dactylon,Gloriosa superba,Ficus carica and Melia Azedarach.These endophytic fumigates tend to be consistent in microbial morphology and can adapt to high temperature(30-40 ° C).In addition,their chemical constituents have been reported.Host plant studies of endophytic Fusarium oxysporum include Malus pumila,Buddleja and Juniperus recurva.Fusarium oxysporum from Malus pumila and Buddleja mainly reported the activities of their crude extract and that one active metabolite was found in Fusarium oxysporum from Juniperus recurva.In this study,antimicrobial assay was used to screen the first coculture condition :Using liquid Chashi’s liquid culture medium(Czapek’s Dox Agar).The two fungi cultured alone for 3 days,then sps-02 and 03 mixed at the ratio of 1: 4 for 7 days.The yield of crude extract of fermentation broth(60 L)was respectively 0.339 g/L.On the basis of the first co-culture conditions,HPLC analysis was performed to obtain a second co-culture condition: Using liquid Chashi’s liquid culture medium.The two fungi cultured alone.After 3 days,2 ml of the sps-03 broth was added to a 500 ml flask containing 250 ml of sps-02 broth then coculturing for 7 days.Fermentation to 50 L,extraction of total metabolites,yield 0.040 g / L.Six compounds had been identified by spectroscopic techniques(ESI-MS,1H-NMR,etc.)They are 9-ethyladenine-1-oxide(1)、Tyrosine(2)、Tryptophan(3)、diisobutyl phthalate(4)、Tricycloalternarene 3b(7)Tricycloalternarene(5-6).Compound 5 and 6 are still in the identification.This study provides a reference for the co-culture of microorganisms and the separation of their secondary metabolites,especially the use of "One Strain Many Compounds"(OSMAC)research idea.We may use this research idea to obtain more active natural products.