Inhibiting Effect of Bioactive Metabolites Produced by Mushroom Cultivation on Bacterial Quorum Sensing-Regulated Behaviors

Abstract

Aims: This study aimed to search for novel quorum sensing (QS) inhibitors from mushroom and to analyze their inhibitory activity, with a view to their possible use in controlling detrimental infections. Methods: The bioactive metabolites produced by mushroom cultivation were tested for their abilities to inhibit QS-regulated behavior. All mushroom strains were cultivated in potato-dextrose medium by large-scale submerged fermentation. The culture supernatant was condensed into 0.2 vol 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 results have revealed that, of 102 mushroom strains, the bioactive metabolites produced by 14 basidiomycetes were found to inhibit violacein production, a QS-regulated behavior in C. violaceum. Conclusions: Higher fungi can produce QS-inhibitory compounds.

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

“…Currently, much research aimed at exploring the anticancer, antipathogenic and immune system-enhancing properties of P. igniarius extract. In our former study [18], a P. igniarius metabolite was found to inhibit QS-regulated violacein pigment production in C. violaceum CV026 without interfering with its growth. In microbiology, the bioactive difference is generally attributed to genetic variability.…”

“…Standard disk-diffusion assays were performed according to our previous papers [18,22,23] to detect anti-QS activity of bioactive metabolites from P. igniarius . The protocol is briefly as follows: sterile paper disks (8 mm diameter) were placed on the LB agar plates spread with overnight culture (OD 600 nm = 0.1, 100 µl) of C. violaceum CV026 supplemented with C 6 -HSL at a final concentration of 10 µmol/l.…”

“…However, these furanone compounds consist of halogens that limit their application in humans, making it necessary to search further for effective QS inhibitors from natural products. Increasing evidence implies that certain eukaryotes [13], enzymes [14,15], plants [16,17] and fungi [18,19,20], produce QS-inhibitory compounds. An estimated 75% of polypore fungi that have been tested show strong antimicrobial activity and it is thought that a search for antibacterial secondary metabolites from higher fungi will yield some QS inhibitors through bioassay-directed isolation.…”

Bacterial Quorum Sensing Inhibition Activity of the Traditional Chinese Herbs, <b><i>Ficus carica </i></b>L. and <b><i>Perilla frutescens</i></b>

“…Flask incubation assays [17] were used to quantify anti-QS activity of different extracts from the materials. C. violaceum CV026 was incubated for 18 h and inoculated to OD 600 nm = 0.1 in Erlenmeyer flasks containing LB medium.…”

Quorum quenching: role in nature and applied developments

“…Fungi, especially species of the Ascomycota Penicillium genus produce QSIs, such as patulin or penicillic acid, that contain a furanone core and target the RhlR and the LasR proteins (Rasmussen et al 2005). Some Basidiomycetes, such as Tremella, Auricularia or Phellinus igniarius, may also produce QSIs (Zhu et al 2011(Zhu et al , 2012a.…”