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Aims: Equol is a nonsteroidal oestrogen of the isoflavone class. We investigated the antibacterial ability of equol with respect to the growth rate, toxin production and spore‐forming abilities of Clostridioides difficile BI/027/NAP1. Methods and Results: Isoflavones, or female hormones, were added to bacterial culture, which was grown at 35°C. The absorbance of the culture was measured at various time points for evaluating the growth inhibition. The toxin levels in the media and morphological changes were also assessed. To evaluate the influence of equol on the sporulation of C. difficile, cells were collected at various time points from the equol‐supplemented culture and the number of spores was counted. Our results show that equol inhibits bacterial growth in a concentration‐dependent manner. However, it does not inhibit the production of toxin by C. difficile. Other isoflavones and female hormones did not inhibit the C. difficile growth. At the 14th day, approximately 600 spores were present in the control medium and only six were seen in the equol‐containing medium. Conclusion: Our results suggest that equol may directly inhibit the C. difficile growth in a concentration‐dependent manner and spore formation. Significance and Impact of the Study: This is the first report on the antimicrobial ability of equol. [ABSTRACT FROM AUTHOR]

Aims: The aim of this study was to evaluate the influence of environmental conditions on the antifungal activity of the Bacillus sp. CCMI 1053 cultures. Methods and Results: The electrospray ionization mass spectra (ESI-MS) analysis was used to detect the active peptides produced by Bacillus amyloliquefaciens CCMI 1051 cultures in a glucose-containing medium to which four different nitrogen sources were added. The cultures produced different patterns of Bacillus sporulation and distinct antifungal activity of the cell-free culture broths. Conclusions: The highest sporulation obtained corresponds to higher antifungal activity when it is formed after 3 days of microbial growth. The antifungal activity against Trichoderma harzianum CCMI 783 is more influenced by the concentration on the nitrogen source than the culture time of incubation. The association of nitrogen concentration and the time of incubation is particularly relevant in the expression of the antifungal activity. Significance and Impact of the Study: The present findings allow the reduction of the use of chemical pesticides and to limit some plant diseases. The association of the nitrogen source and the time of incubation is a novelty, which would improve the production of secondary metabolites. Both economical and environmental benefits arise from the study. [ABSTRACT FROM AUTHOR]