RNPP-type quorum sensing regulates solvent formation and sporulation inClostridium acetobutylicum

ABSTRACTThe strictly anaerobic bacteriumClostridium acetobutylicumis well known for its ability to convert sugars into organic acids and solvents, most notably the potential biofuel butanol. However, the regulation of its fermentation metabolism, in particular the shift from acid to solvent production, remains poorly understood. The aim of this study was to investigate whether cell-cell communication plays a role in controlling the timing of this shift or the extent of solvent formation. Analysis of the availableC. acetobutylicumgenome sequences revealed the presence of eight putative RNPP-type quorum sensing systems, here designatedqssAtoqssH, each consisting of RNPP-type regulator gene followed by a small open reading frame encoding a putative signalling peptide precursor. The identified regulator and signal peptide precursor genes were designatedqsrAtoqsrHandqspAtoqspH, respectively. Triplicate regulator mutants were generated in strain ATCC 824 for each of the eight systems and screened for phenotypic changes. TheqsrBmutants showed increased solvent formation during early solventogenesis and hence the QssB system was selected for further characterisation. Overexpression ofqsrBseverely reduced solvent and endospore formation and this effect could be overcome by adding short synthetic peptides to the culture medium representing a specific region of the QspB signalling peptide precursor. In addition, overexpression ofqspBincreased the production of acetone and butanol and the initial (48-hour) titre of heat-resistant endospores. Together, these findings establish a role for QssB quorum sensing in the regulation of early solventogenesis and sporulation inC. acetobutylicum.

Download Full-text

RRNPP-type quorum sensing affects solvent formation and sporulation in Clostridium acetobutylicum

Microbiology ◽

10.1099/mic.0.000916 ◽

2020 ◽

Vol 166 (6) ◽

pp. 579-592 ◽

Cited By ~ 2

Author(s):

Ann-Kathrin Kotte ◽

Oliver Severn ◽

Zak Bean ◽

Katrin Schwarz ◽

Nigel P. Minton ◽

...

Keyword(s):

Quorum Sensing ◽

Clostridium Acetobutylicum ◽

Type Species ◽

Cell Communication ◽

Strictly Anaerobic ◽

Content Type ◽

Reading Frame ◽

Link Type ◽

Solvent Formation ◽

Peptide Precursor

The strictly anaerobic bacterium Clostridium acetobutylicum is well known for its ability to convert sugars into organic acids and solvents, most notably the potential biofuel butanol. However, the regulation of its fermentation metabolism, in particular the shift from acid to solvent production, remains poorly understood. The aim of this study was to investigate whether cell–cell communication plays a role in controlling the timing of this shift or the extent of solvent formation. Analysis of the available C. acetobutylicum genome sequences revealed the presence of eight putative RRNPP-type quorum-sensing systems, here designated qssA to qssH, each consisting of an RRNPP-type regulator gene followed by a small open reading frame encoding a putative signalling peptide precursor. The identified regulator and signal peptide precursor genes were designated qsrA to qsrH and qspA to qspH, respectively. Triplicate regulator mutants were generated in strain ATCC 824 for each of the eight systems and screened for phenotypic changes. The qsrB mutants showed increased solvent formation during early solventogenesis and hence the QssB system was selected for further characterization. Overexpression of qsrB severely reduced solvent and endospore formation and this effect could be overcome by adding short synthetic peptides to the culture medium representing a specific region of the QspB signalling peptide precursor. In addition, overexpression of qspB increased the production of acetone and butanol and the initial (48 h) titre of heat-resistant endospores. Together, these findings establish a role for QssB quorum sensing in the regulation of early solventogenesis and sporulation in C. acetobutylicum .

Download Full-text

RRNPP-type quorum-sensing systems regulate solvent formation, sporulation and cell motility in Clostridium saccharoperbutylacetonicum

Biotechnology for Biofuels ◽

10.1186/s13068-020-01723-x ◽

2020 ◽

Vol 13 (1) ◽

Author(s):

Jun Feng ◽

Wenming Zong ◽

Pixiang Wang ◽

Zhong-Tian Zhang ◽

Yanyan Gu ◽

...

Keyword(s):

Quorum Sensing ◽

Cell Motility ◽

Sensing Systems ◽

Solvent Formation

Download Full-text

Quorum-Sensing Regulation of Antimicrobial Resistance in Bacteria

Microorganisms ◽

10.3390/microorganisms8030425 ◽

2020 ◽

Vol 8 (3) ◽

pp. 425 ◽

Cited By ~ 11

Author(s):

Xihong Zhao ◽

Zixuan Yu ◽

Tian Ding

Keyword(s):

Quorum Sensing ◽

Efflux Pump ◽

Cell Communication ◽

Quorum Quenching ◽

Resistance Mechanisms ◽

Resistant Bacteria ◽

Microbial Resistance ◽

Sensing Systems ◽

Drug Resistant Bacteria ◽

New Strategy

Quorum sensing is a cell-to-cell communication system that exists widely in the microbiome and is related to cell density. The high-density colony population can generate a sufficient number of small molecule signals, activate a variety of downstream cellular processes including virulence and drug resistance mechanisms, tolerate antibiotics, and harm the host. This article gives a general introduction to the current research status of microbial quorum-sensing systems, focuses on the role of quorum-sensing systems in regulating microbial resistance mechanisms, such as drug efflux pump and microbial biofilm formation regulation, and discusses a new strategy for the treatment of drug-resistant bacteria proposed by using quorum quenching to prevent microbial resistance.

Download Full-text

Dialkylresorcinols as bacterial signaling molecules

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1417685112 ◽

2014 ◽

Vol 112 (2) ◽

pp. 572-577 ◽

Cited By ~ 79

Author(s):

Sophie Brameyer ◽

Darko Kresovic ◽

Helge B. Bode ◽

Ralf Heermann

Keyword(s):

Quorum Sensing ◽

Bacterial Species ◽

Cell Communication ◽

Signaling Molecules ◽

Human Pathogen ◽

Human Pathogens ◽

Bacterial Signaling ◽

Sensing Systems ◽

Luxr Homolog ◽

Cell Cell

It is well recognized that bacteria communicate via small diffusible molecules, a process termed quorum sensing. The best understood quorum sensing systems are those that use acylated homoserine lactones (AHLs) for communication. The prototype of those systems consists of a LuxI-like AHL synthase and a cognate LuxR receptor that detects the signal. However, many proteobacteria possess LuxR receptors, yet lack any LuxI-type synthase, and thus these receptors are referred to as LuxR orphans or solos. In addition to the well-known AHLs, little is known about the signaling molecules that are sensed by LuxR solos. Here, we describe a novel cell–cell communication system in the insect and human pathogenPhotorhabdus asymbiotica. We identified the LuxR homolog PauR to sense dialkylresorcinols (DARs) and cyclohexanediones (CHDs) instead of AHLs as signals. The DarABC synthesis pathway produces the molecules, and the entire system emerged as important for virulence. Moreover, we have analyzed more than 90 differentPhotorhabdusstrains by HPLC/MS and showed that these DARs and CHDs are specific to the human pathogenP. asymbiotica. On the basis of genomic evidence, 116 other bacterial species are putative DAR producers, among them many human pathogens. Therefore, we discuss the possibility of DARs as novel and widespread bacterial signaling molecules and show that bacterial cell–cell communication goes far beyond AHL signaling in nature.

Download Full-text

Revised Model for Enterococcus faecalis fsr Quorum-Sensing System: the Small Open Reading Frame fsrD Encodes the Gelatinase Biosynthesis-Activating Pheromone Propeptide Corresponding to Staphylococcal AgrD

Journal of Bacteriology ◽

10.1128/jb.00865-06 ◽

2006 ◽

Vol 188 (23) ◽

pp. 8321-8326 ◽

Cited By ~ 64

Author(s):

Jiro Nakayama ◽

Shengmin Chen ◽

Nozomi Oyama ◽

Kenzo Nishiguchi ◽

Essam A. Azab ◽

...

Keyword(s):

Amino Acid ◽

Quorum Sensing ◽

Amino Acid Sequence ◽

Enterococcus Faecalis ◽

Cysteine Protease ◽

Open Reading Frame ◽

Reading Frame ◽

Sensing System ◽

Quorum Sensing System ◽

Small Open Reading Frame

ABSTRACT Gelatinase biosynthesis-activating pheromone (GBAP) is an autoinducing peptide involved in Enterococcus faecalis fsr quorum sensing, and its 11-amino-acid sequence has been identified in the C-terminal region of the 242-residue deduced fsrB product (J. Nakayama et al., Mol. Microbiol. 41:145-154, 2001). In this study, however, we demonstrated the existence of fsrD, encoding the GBAP propeptide, which is in frame with fsrB but is translated independently of fsrB. It was also demonstrated that FsrB′, an FsrD segment-truncated FsrB, functions as a cysteine protease-like processing enzyme to generate GBAP from FsrD. This revised model is consistent with the staphylococcal agr system.

Download Full-text

Convection - Diffusion model of talking bacteria

10.1101/101931 ◽

2017 ◽

Author(s):

Sarangam Majumdar ◽

Subhoshmita Mondal

Keyword(s):

Mathematical Model ◽

Diffusion Coefficient ◽

Quorum Sensing ◽

Biological System ◽

Numerical Scheme ◽

Cell Communication ◽

Threshold Concentration ◽

Communication Process ◽

Convection Diffusion ◽

Sensing Systems

abstractQuorum sensing is cell to cell communication process through chemical signals formally known as autoinducers. When the concentration of quorum sensing molecules reached threshold concentration bacteria are in active state or quorum state. In this article, we propose a mathematical model of quorum sensing systems and study this biological system numerically. Moreover, we compare the different numerical scheme with the batch culture ofP.aeruginosa. We observed a negative diffusion coefficient which plays an important role in the quorum sensing mechanism.

Download Full-text

Faculty Opinions recommendation of A cell-cell communication signal integrates quorum sensing and stress response.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717995806.793476388 ◽

2013 ◽

Author(s):

Fergal O'Gara

Keyword(s):

Stress Response ◽

Quorum Sensing ◽

Cell Communication ◽

Communication Signal ◽

A Cell ◽

Cell Cell

Download Full-text

Quorum Sensing – A Stratagem for Conquering Multi-Drug Resistant Pathogens

Current Pharmaceutical Design ◽

10.2174/1381612826666201210105638 ◽

2020 ◽

Vol 26 ◽

Author(s):

Madison Tonkin ◽

Shama Khan ◽

Mohmmad Younus Wani ◽

Aijaz Ahmad

Keyword(s):

Drug Resistance ◽

Quorum Sensing ◽

Virulence Factors ◽

Biofilm Formation ◽

Cell Communication ◽

Natural Compounds ◽

Quorum Sensing Inhibitors ◽

Communication Technique ◽

Multicellular Organisms ◽

Chemical Strategies

: Quorum sensing is defined as cell to cell communication between microorganisms, which enables microorganisms to behave as multicellular organisms. Quorum sensing enables many collaborative benefits such as synchronisation of virulence factors and biofilm formation. Both quorum sensing as well as biofilm formation encourage the development of drug resistance in microorganisms. Biofilm formation and quorum sensing are causally linked to each other and play role in the pathogenesis of microorganisms. With the increasing drug resistance against the available antibiotics and antifungal medications, scientists are combining different options to develop new strategies. Such strategies rely on the inhibition of the communication and virulence factors rather than on killing or inhibiting the growth of the microorganisms. This review encompasses the communication technique used by microorganisms, how microorganism resistance is linked to quorum sensing and various chemical strategies to combat quorum sensing and thereby drug resistance. Several compounds have been identified as quorum sensing inhibitors and are known to be effective in reducing resistance as they do not kill the pathogens but rather disrupt their communication. Natural compounds have been identified as anti-quorum sensing agents. However, natural compounds present several related disadvantages. Therefore, the need for the development of synthetic or semi-synthetic compounds has arisen. This review argues that anti-quorum sensing compounds are effective in disrupting quorum sensing and could therefore be effective in reducing microorganism drug resistance.

Download Full-text