The Substance Base Of Active Antifungal Ingredients From Lysinibacillus Fusiformis He14

Bacillus spp.are extensively distributed with a great diveristy,of which the secondary metabolites have various biological activities.In this study,an antagonist bacterium viz.Lysinibacillus fusiformis He14 from Dendrobii Caulis was studied and found that its fermentation broth had antagonistic effect on pathogenic fungi via.preliminary screening experiments.In order to analyze the antifungal mechanism in He14 fermentation broth,the following works have been done:1.The experiments of antifungal activities were carried out with the strain He14,and the results showed that the fermentation broth of He14 inhibited the growth of several plant pathogenic fungi as well as two animal pathogenic fungi.Considering the inhibition rate of the fermentation broth on pathogenic fungi and the growth rate of pathogenic fungi,Botrytis cinerea was selected as an indicator to detect the activity.The stabilities of He14 and its fermentation broth were tested with temperature,acid,alkali and UV.It was found that the bioactive substance in the fermentation broth had genetic stability,temperature stability,pH stability and UV stability.2.Via the screening test,the best pretreatment of He14 fermentation broth was using macroporous adsorption resin LX-60;Through further isolation and purification of the crude extract of the fermentation broth,10 monomeric compounds were finally isolated.The structures of 5 compounds were determined respectively by spectral techniques(MS,¹H-NMR,¹³C-NMR)combining with the comparison results of SicFinder Scholar and Antibase databases,and they were Triphenylmethanol?compound 1?,Palmitic Acid?compound 2?,3,3'-Diindolymethane?compound 4?,Pyrrolo[1,2-a]pyrazine-1,4-dione?compound 8?and Phenylacetic acid?compound 10?.3.Compound 8 and compound 10 showed inhibition effects on the pathogenic fungi via antifungal activity screening.Compound 10 had a strong inhibitory effect on Phytophthora infestans,in which it dissolved the hypha of the fungi.In addition,an active mixture?was isolated by silica gel column chromatography,it inhibited the growth of Botrytis cinerea,Phytophthora infestans and Trichophyton mentagrophytes.In summary,the antifungal activity and stability of the fermentation broth of the strain He14were studied.Meanwhile,through isolating its bioactive ingredients,two compounds with antifungal effects were isolated and their chemical structures were identified.It provided reference data to optimize the process of the separation and purification of such compounds.