Quorum Sensing Signalling and Biofilm Formation of Brewery-Derived Bacteria, and Inhibition of Signalling by Natural Compounds

Abstract

Bacteria use quorum sensing signalling in various functions, e.g. while forming biofilms, and inhibition of this signalling could be one way to control biofilm formation. The aim of this study was to evaluate the production of signalling molecules and its correlation with the biofilm formation capability of bacteria isolated from brewery filling process. A further aim was to study berry extracts and wood-derived terpenes for their possible quorum sensing inhibitory effects. Out of the twenty bacteria studied, five produced short-chain and five long-chain AHL (acyl homoserine lactone) signalling molecules when tested with the Chromobacterium violaceum CV026 reporter bacterium. Production of AI-2 (autoinducer-2) signalling molecules was detected from nine strains with the Vibrio harveyi BB170 bioassay. Over half of the strains produced biofilm in the microtitre plate assay, but the production of AHL and AI-2 signalling molecules and biofilm formation capability did not directly correlate with each other. Out of the 13 berry extracts and wood-derived terpenes screened, four compounds decreased AHL signalling without effect on growth. These were betulin, raspberry extract and two cloudberry extracts. The effect of these compounds on biofilm formation of the selected six bacterial strains varied. The phenolic extract of freeze-dried cloudberry fruit caused a statistically significant reduction of biofilm formation of Obesumbacterium proteus strain. Further experiments should aim at identifying the active compounds and revealing whether quorum sensing inhibition causes structural changes in the biofilms formed.

Mining ofluxSgenes from rumen microbial consortia by metagenomic and metatranscriptomic approaches

“…Because previous studies indicated that AI-2-mediated QS is associated with biofilm formation in gut, oral, marine and brewery microbial communities (Kolenbrander et al 2010;Christiaen et al 2014;Liaqat et al 2014;Priha et al 2014), it is likely that many of the luxS genes collected in the present study, not only from R. albus but also from other bacteria, are probably involved in biofilm formation on feed particles for fiber degradation.…”

“…Ecological studies of rumen microbial communities showed that biofilm formation commences with the adhesion of initial colonizers, mainly cellulose-and starch-degrading bacteria, to the feed particles, and their end-products are used as substrates of other colonizers for developing biofilm (Minato & Suto 1976, 1978Cheng et al 1984;McAllister et al 1994). Because previous studies indicated that AI-2mediated QS is associated with biofilm formation in gut, oral, marine and brewery microbial communities (Kolenbrander et al 2010;Christiaen et al 2014;Liaqat et al 2014;Priha et al 2014), it is likely that many of the luxS genes collected in the present study, not only from R. albus but also from other bacteria, are probably involved in biofilm formation on feed particles for fiber degradation.…”

Plant Phenolics and Phenolic-Enriched Extracts as Antimicrobial Agents against Food-Contaminating Microorganisms

“…Moreover, blueberry extract was outstanding in the inhibition of quorum sensing related swarming motility in P. aeruginosa and E. coli O157:H7 pathogens. Berry phenolic extracts, namely those from raspberry and cloudberry, were the most effective C. violaceum AHL signaling inhibitors in the study of Priha et al [113]. In addition, the cloudberry extract reduced the biofilm formation of the common brewery contaminant bacterium, Obesumbacterium proteus at the concentrations of 25 and 50 mg/L.…”

Inhibitory Activity of Tea Polyphenols on Biofilm Development of Shewanella putrefaciens

“…Similarly, the phenolic extract of freeze‐dried cloudberry fruit led to a statistically significant reduction of biofilm formation of Obesumbacterium proteus (Priha et al . ).…”

“…Meanwhile, the compact threedimensional structures in a mature biofilm might hinder the diffusion of these compounds into the biofilm (Sandasi et al 2008). Similarly, the phenolic extract of freeze-dried cloudberry fruit led to a statistically significant reduction of biofilm formation of Obesumbacterium proteus (Priha et al 2014).…”