Antifungal activity of 3-acetylbenzamide produced by actinomycete WA23-4-4 from the intestinal tract of Periplaneta americana

作者：Fang, Xia; Shen, Juan; Wang, Jie; Chen, Zhi-li; Iin, Pei-bin; Chen, Zhi-yu; Liu, Lin-yan; Zeng, Huan-xiong; Jin, Xiao-bao^*

来源：Journal of Microbiology, 2018, 56(7): 516-523.

DOI：10.1007/s12275-018-7510-z

• Periplaneta americana
• actinomycetes WA23-4-4
• Streptomyces
• 3-acetyl benzoyl amide
• antifungal activity

Actinomycetes are well-known for producing numerous bioactive secondary metabolites. In this study, primary screening by antifungal activity assay found one actinomycete strain WA23-4-4 isolated from the intestinal tract of Periplaneta americana that exhibited broad spectrum antifungal activity. 16S rDNA gene analysis of strain WA23-4-4 revealed close similarity to Streptomyces nogalater (AB045886) with 86.6% sequence similarity. Strain WA23-4-4 was considered as a novel Streptomyces and the 16s rDNA sequence has been submitted to GenBank (accession no. KX291006). The maximum antifungal activity of WA23-4-4 was achieved when culture conditions were optimized to pH 8.0, with 12% inoculum concentration and 210 ml ISP2 medium, which remained stable between the 5(th) and the 9(th) day. 3-Acetyl benzoyl amide was isolated by ethyl acetate extraction of WA23-4-4 fermentation broth, and its molecular formula was determined as C9H9NO2 based on MS, IR, H-1, and C-13 NMR analyses. The compound showed significant antifungal activity against Candida albicans ATCC 10231 (MIC: 31.25 mu g/ml) and Aspergillus niger ATCC 16404 (MIC: 31.25 mu g/ml). However, the compound had higher MIC values against Trichophyton rubrum ATCC 60836 (MIC: 500 mu g/ml) and Aspergillus fumigatus ATCC 96918 (MIC: 1,000 mu g/ml). SEM analysis showed damage to the cell membrane of Candida albicans ATCC 10231 and to the mycelium of Aspergillus niger ATCC 16404 after being treatment with 3-acetyl benzoyl amide. In conclusion, this is the first time that 3-acetyl benzoyl amide has been identified from an actinomycete and this compound exhibited antifungal activity against Candida albicans ATCC 10231 and Aspergillus niger ATCC 16404.

• 出版日期2018-7
• 单位广东药科大学