Isolation, Identification And Antibacterial Effect Of Endophytic Fungi From Lonicera Japonica Thunb

Endophytic fungi are fungi that live in healthy plant tissues and organs at a certain stage or at all stages.The study found, the same or similar active components of the host can be synthesized by some endophytic fungi. At the same time,there are many kinds of endophytic fungi,such as species diversity, abundant metabolites,and so on,so it becomes the source of new active compounds,in agriculture and medicine and other fields has great application potential.In this study,the medicinal plants of Lonicera maackii as experimental materials,carried out the L.maackii endophytic fungi separation and identification,screening of antimicrobial strains,optimization of fermentation conditions and molecular biological identification of antimicrobial strains.The results of the study mainly include the following aspects:1 、 Using tissue isolation method,47 strains of endophytic fungi were isolated from L.maackii roots,branches,leaves and fruits.33 strains can produce spores in 47 strains of endophytic fungi,14 strains did not produce spores after induction of spore. By morphological identification,33 strains of spore endophytic fungi belong to 2 classes,3 orders,4 families,8 genera,the Fusarium was the dominant genus.2、Preliminary screening of antibacterial effect of 47 strains of endophytic fungi by block method.Screening 15 strains have antibacterial effects for more than 1 kinds of pathogenic bacteria.The 15 strains were screened by the plate hole well diffusion method,the results showed that the Y6 strains isolated from the leaf tissues had a strong inhibitory effect.3、The optimum carbon source and nitrogen source were studied by single factor experiment of Y6.The best carbon source was maltose,the best concentration was 30g/L,the best nitrogen source was wheat bran,the best concentration was 20g/L.The fermentation conditions were optimized by response surface experiment,the optimum combination of fermentation conditions is 31.09℃,pH6.82,liquid loading 124.78 mL. The best condition is compared with the original condition, results show,the optimal condition of the fermentation broth was close to the maximum predicted value of the inhibition zone diameter,compared with the original fermentation conditions,it increased by 11.35%.4、The ITS sequence of strain Y6 was analyzed. Blast analysis was carried out with the nuclein sequence of GenBank.Constructing phylogenetic tree using MEGA5.05,the results showed that the strain Y6 was identified as Chaetomium globosum sp.