Quorum Sensing versus Quenching Bacterial Isolates Obtained from MBR Plants Treating Leachates from Municipal Solid Waste

Abstract

Quorum sensing (QS) is a mechanism dependent on bacterial density. This coordinated process is mediated by the synthesis and the secretion of signal molecules, called autoinducers (AIs). N-acyl-homoserine lactones (AHLs) are the most common AIs that are used by Gram-negative bacteria and are involved in biofilm formation. Quorum Quenching (QQ) is the interference of QS by producing hydrolyzing enzymes, among other strategies. The main objective of the present study was to identify QS and QQ strains from MBR wastewater treatment plants. A total of 99 strains were isolated from two Spanish plants that were intended to treat leachate from municipal solid waste. Five AHL producers were detected using AHL biosensor strains (Chromobacterium violaceum CV026 and Agrobacterium tumefaciens NT1). Fifteen strains of seventy-one Gram-positive were capable of eliminating or reducing at least one AHL activity. The analysis of 16S rRNA gene sequence showed the importance of the Pseudomonas genus in the production of biofilms and the relevance of the genus Bacillus in the disruption of the QS mechanism, in which the potential activity of lactonase or acylase enzymes was investigated with the aim to contribute to solve biofouling problems and to increase the useful lifespan of membranes.

Potential of a Quorum Quenching Bacteria Isolate Ochrobactrum intermedium D-2 Against Soft Rot Pathogen Pectobacterium carotovorum subsp. carotovorum

“…Many QS signal molecule-degrading microbes have been found in nature, including Gordonia sp. (Soler et al, 2018), Bacillus sp. (Dong et al, 2002;Lee et al, 2002;Ulrich, 2004;Soler et al, 2018;Bhatt et al, 2020), Streptomyces sp.…”

“…(Soler et al, 2018), Bacillus sp. (Dong et al, 2002;Lee et al, 2002;Ulrich, 2004;Soler et al, 2018;Bhatt et al, 2020), Streptomyces sp. (Park et al, 2005;Devaraj et al, 2017), Micromonospora sp.…”

Acyl homoserine lactone-mediated quorum sensing in the oral cavity: a paradigm revisited

“…Since QQ strategies do not interfere directly with bacterial growth, the probabilities of inducing tolerance or resistance against these mechanisms are lower 37,38 . Previous studies have already reported the successful approach of using QS inhibitors to control different types of bacterial biofilms 35,[39][40][41][42] . Therefore, the confirmation of a possible role of AHL-type QS signals in dental plaque formation would open new perspectives in the prevention and treatment of oral diseases.…”

Use of Quorum Sensing Inhibition Strategies to Control Microfouling

“…Over the last years, interfering with QS bacterial communication systems has been proposed as a promising mechanism to prevent the development of different types of bacterial biofilms [ 11 , 12 , 13 , 14 , 15 ]. Commonly, the term “quorum quenching” (QQ) refers to the enzymatic inactivation of QS processes [ 16 ], while the more general term “quorum sensing inhibition” (QSI) is preferred to describe the chemical disruption of the cell-to-cell communication system caused by QS inhibitory compounds [ 17 ].…”

“…Using QQ enzymes that can degrade the AHLs produced by Gram-negative bacteria has been suggested as a novel anti-biofouling strategy [ 25 , 26 , 27 ], and a few studies have evaluated the effect of QQ enzymes on the ecology of multispecies biofilms [ 14 , 28 , 29 , 30 ]. QQ strategies have been successfully applied to control biofouling in membrane bioreactors (MBRs) for wastewater treatment [ 11 , 15 ] and to reduce biocorrosion [ 28 ], as they are associated with deep changes in the microfouling community [ 28 ]. This effect could be observed even in in vitro oral biofilm models dominated by Gram-positive species [ 14 ].…”