Evaluation of Anti-Quorum-Sensing Activity of Fermentation Metabolites from Different Strains of a Medicinal Mushroom, Phellinus igniarius

Abstract

Aims: This study aimed to evaluate the different abilities of various Phellinus igniarius strains inhibiting quorum sensing (QS), to search for novel QS inhibitors from them and to analyze their inhibitory activity, with a view to their possible use in controlling infections. Methods: The bioactive metabolites produced by P. igniarius cultures were tested for their abilities to inhibit QS-regulated behavior. All P. igniarius strains were cultured in potato-dextrose medium by large-scale submerged fermentation. The culture supernatant was condensed into 0.2-fold volumes by freeze drying. The condensed supernatant was sterilized by filtration through a 0.22-µm membrane filter and added to Chromobacterium violaceum CV026 cultures, which were used to monitor QS inhibition. Inhibitory activity was measured by quantifying violacein production using a microplate reader. Results: The bioactive metabolites produced by 10 P. igniarius strains could inhibit violacein production, a QS-regulated behavior in C. violaceum. Furthermore, these strains could be roughly categorized into three groups on the basis of their inhibitory activities. Conclusions:P. igniarius strains can produce QS-inhibitory compounds and have different abilities to inhibit QS.