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

Abstract

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 and the 9 day. 3-Acetyl benzoyl amide was isolated by ethyl acetate extraction of WA23-4-4 fermentation broth, and its molecular formula was determined as CHNO based on MS, IR, H, andC NMR analyses. The compound showed significant antifungal activity against Candida albicans ATCC 10231 (MIC: 31.25 μg/ml) and Aspergillus niger ATCC 16404 (MIC: 31.25 μg/ml). However, the compound had higher MIC values against Trichophyton rubrum ATCC 60836 (MIC: 500 μg/ml) and Aspergillus fumigatus ATCC 96918 (MIC: 1,000 μg/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.

A minireview of the medicinal and edible insects from the traditional Chinese medicine (TCM)

“…An increasing number of active compounds related to the therapeutic effects of P. americana have been identified in recent years, and at least four active molecules isolated from ‘Xinmailong’ were found to be related to antithrombosis ( Qi et al, 2017 ). In addition, multiple active components from P. americana have been identified as potential drug candidates for wound healing and anti-fungal therapy ( Yun et al, 2017 ; Fang et al, 2018 ; Zhu et al, 2018 ; Yan et al, 2019 ). D-glucosamine and its salts, which are obtained from cockroaches, are employed in dietary supplement products, which have demonstrated positive effects on the treatment of osteoarthritis, knee, and back pain and has an important role in the formation of joints, sinews, bones, heart valves, and respiratory tract ( Bertuzzi et al, 2018 ).…”

Antifungal activity of compounds from Gordonia sp. WA8-44 isolated from the gut of Periplaneta americana and molecular docking studies

“…In our previous studies, we found that P. americana gut-dwelling bacteria generate anti-bacterial chemicals that may be a source of new anti-bacterial compounds [ [17] , [18] , [19] , [20] ]. The current investigation aimed to determine if secondary metabolites generated by Gordonia , isolated from the gut of P. americana , have any anti-fungal effects.…”

Antimicrobial compounds were isolated from the secondary metabolites of Gordonia, a resident of intestinal tract of Periplaneta americana

“…Besides, in the existing research reports of insect microorganisms, most of them focus on pest control, biological agents, ecological protection and ecological diversity, and the study on antimicrobial activity of their secondary metabolites is less (Dantur et al 2015 ; Guo et al 2017 ; Zheng et al 2020 ). Our previous study showed that the endobacteria in the intestinal tract of Periplaneta americana exhibited various antimicrobial activities against all tested pathogens (Fang et al 2018 ; Chen et al 2020 ).…”