2-Aminoimidazoles as potent inhibitors of contaminating brewery biofilms

Abstract

Cleaning and disinfection protocols are not always able to remove biofilm microbes present in breweries, indicating that novel anti-biofilm strategies are needed. The preventive activities of three in-house synthesized members of the 2-aminoimidazole class of anti-biofilm molecules were studied against 17 natural brewery biofilms and benchmarked against 18 known inhibitors. Two 2-aminoimidazoles belonged to the top six inhibitors, which were retested against 12 defined brewery biofilm models. For the three best inhibitors, tannic acid (n° 1), 2-aminoimidazole imi-AAC-5 (n° 2), and baicalein (n° 3), the effect on the microbial metabolic activity was evaluated. Here, the top three inhibitors showed similar effectiveness, with baicalein possessing a slightly higher efficacy. Even though the 2-aminoimidazole was the second-best inhibitor, it showed a lower biocidal activity than tannic acid, making it less prone to resistance evolution. Overall, this study supports the potential of 2-aminoimidazoles as a preventive anti-biofilm strategy.

Keywords:

• 2-aminoimidazole
• inhibitor
• brewery
• biofilm
• screening
• benchmarking

Disclosure statement

No potential conflict of interest was reported by the author(s).

Acknowledgements

The authors thank G. Hooyberghs for chemical synthesis of the 2-aminoimidazoles and D. De Coster for excellent experimental assistance.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by the KU Leuven Research Fund (C32/17/020 and C24/18/046), by the Institute for the Promotion of Innovation through Science and Technology in Flanders under grant IWT-SBO 120050 (NEMOA), by FWO-Vlaanderen under grant 3G046318 and grant FWO-SBO S007019N (Bisceps) and by VLAIO under grant HBC.2017.0816 BARATom. E.V.d.E. acknowledges the support of RUDN University Program 5–100.