This Review highlights how we can build upon the relatively new and rapidly developing field of research into bacterial quorum sensing (QS). We now have a depth of knowledge about how bacteria use QS signals to communicate with each other and to coordinate their activities. In recent years there have been extraordinary advances in our understanding of the genetics, genomics, biochemistry, and signal diversity of QS. We are beginning to understand the connections between QS and bacterial sociality. This foundation places us at the beginning of a new era in which researchers will be able to work towards new medicines to treat devastating infectious diseases, and use bacteria to understand the biology of sociality.

/pdf/progress-in-and-promise-of-bacterial-quorum-sensing-research-2lqmzuae82.pdf

Progress in and promise of bacterial quorum sensing research

Quorum sensing is a process of bacterial cell-to-cell chemical communication that relies on the production, detection and response to extracellular signalling molecules called autoinducers. Quorum sensing allows groups of bacteria to synchronously alter behaviour in response to changes in the population density and species composition of the vicinal community. Quorum-sensing-mediated communication is now understood to be the norm in the bacterial world. Elegant research has defined quorum-sensing components and their interactions, for the most part, under ideal and highly controlled conditions. Indeed, these seminal studies laid the foundations for the field. In this Review, we highlight new findings concerning how bacteria deploy quorum sensing in realistic scenarios that mimic nature. We focus on how quorums are detected and how quorum sensing controls group behaviours in complex and dynamically changing environments such as multi-species bacterial communities, in the presence of flow, in 3D non-uniform biofilms and in hosts during infection.

/pdf/bacterial-quorum-sensing-in-complex-and-dynamically-changing-aei9j5536l.pdf

Bacterial quorum sensing in complex and dynamically changing environments.

https://arrow.tudublin.ie/cgi/viewcontent.cgi?article=1167&context=schfsehart

A Comprehensive Review on Pre-treatment Strategy for Lignocellulosic Food Industry Waste: Challenges and Opportunities

Nutrients removal and recovery in bioelectrochemical systems: A review

g-C3N4/carbon dot-based nanocomposites serve as efficacious photocatalysts for environmental purification and energy generation: A review

The bacterium Pseudomonas aeruginosa is an opportunistic human pathogen that uses a quorum sensing signal cascade to activate expression of dozens of genes when sufficient population densities have been reached. Quorum sensing controls production of several key virulence factors, including secreted proteases such as elastase. Cooperating groups of bacteria growing on protein are susceptible to social cheating by quorum-sensing defective mutants. A possible way to restrict cheater emergence is by policing where cooperators produce costly goods to sanction or punish cheats. The P. aeruginosa LasR-LasI quorum sensing system controls genes including those encoding proteases and also those encoding a second quorum-sensing system, the RhlR-RhlI system, which controls numerous genes including those for cyanide production. By using RhlR quorum sensing mutants and cyanide synthesis mutants, we show that cyanide production is costly and cyanide-producing cooperators use cyanide to punish LasR-null social cheaters. Cooperators are less susceptible to cyanide than are LasR mutants. These experiments demonstrate policing in P. aeruginosa, provide a mechanistic understanding of policing, and show policing involves the cascade organization of the two quorum sensing systems in this bacterium.

https://www.pnas.org/content/pnas/112/7/2187.full.pdf

Meizhen Wang

Papers

Quorum sensing and policing of Pseudomonas aeruginosa social cheaters

Improving production of volatile fatty acids from food waste fermentation by hydrothermal pretreatment

Enhancement of acidogenic fermentation for volatile fatty acid production from food waste: Effect of redox potential and inoculum.

Acidogenic fermentation characteristics of different types of protein-rich substrates in food waste to produce volatile fatty acids.

Where are signal molecules likely to be located in anaerobic granular sludge