The quorum‐sensing molecule 2‐phenylethanol impaired conidial germination, hyphal membrane integrity and growth of <i>Penicillium expansum</i> and <i>Penicillium nordicum</i>
C. S. Huang, Y. Qian, Thales Vinícius de Araújo Viana, Henrik Siegumfeldt, Nils Arneborg, Nadja Larsen, Lene Jespersen
Abstract
The aim of the study was to investigate the antifungal effects of a quorum sensing‐molecule, 2‐phenylethanol, against the food spoilage moulds Penicillium expansum and Penicillium nordicum. Conidial germination of the tested Penicillium spp. (three strains in total) were inhibited by treatments with 2‐phenylethanol in a concentration‐dependent manner. Germinated conidia was significantly reduced from 4·4–16·7% at 7·5 mmol l−1 and completely inhibited at 15 mmol l−1 2‐phenylethanol. Integrity of conidial cell membranes was unaffected by 2‐phenylethanol resulting in reversible inhibition pattern of germination. In contrast, membrane permeability of actively growing hyphae was severely compromised, showing 63·5 – 75·7% membrane damage upon treatment with 15 mmol l−1 2‐phenylethanol. The overall inhibitory effect of 2‐phenylethanol on colony development and growth of P. expansum and P. nordicum was additionally confirmed. 2‐phenylethanol inhibits conidial germination and growth of P. expansum and P. nordicum in a nonlethal, reversible and concentration‐dependent manner. The study indicates that 2‐phenylethanol can find potential application as an antifungal agent for biological control of moulds in the food industry.