Abstract：Abstract Based on the morphological, physiological and biochemical characteristics and 16S rDNA sequences analysis, strain AiL3 isolated from mangrove(Acanthus ilicifolius) was identified as Bacillus amyloliquefaciens. Antifungal substance from fermentation of strain AiL3 was deposited by the method of organic solvent extraction and ammonium sulfate, exhibited a high antifungal activity of precipitated by 50% ammonium sulphate precipitation. The results implied that antifungal substance of strains AiL3 was a kind of proteins. It was shown on PDA plates that the development of many pathogens such as Colletotrichum gloeosporioides and Fusarium oxysporum f.sp. cucumerinum was inhibited by the antifungal protein effectively. Their EC50 values were 9.32 and 5.81μg/mL on mycelial growth and conidium germination of C. gloeosporioides. Furthermore, the antagonistic crude protein(20.33μg/mL) could degrade the conidial cell wall and restrain completely the formation of spore.
