Effect of the luxI/R gene on AHL-signaling molecules and QS regulatory mechanism in Hafnia alvei H4

AbstractHafnia alvei H4 is a bacterium subject to regulation by a N-acyl-l-homoserine lactone (AHL)-mediated quorum sensing system and is closely related to the corruption of instant sea cucumber. Studying the effect of Hafnia alvei H4 quorum sensing regulatory genes on AHLs is necessary for the quality and preservation of instant sea cucumber. In this study, the draft genome of H. alvei H4, which comprises a single chromosome of 4,687,151 bp, was sequenced and analyzed and the types of AHLs were analyzed employing thin-layer chromatography (TLC) and high resolution triple quadrupole liquid chromatography/mass spectrometry (LC/MS). Then the wild-type strain of H. alvei H4 and the luxI/R double mutant (ΔluxIR) were compared by transcriptome sequencing (RNA-seq). The results indicate that the incomplete genome sequence revealed the presence of one quorum-sensing (QS) gene set, designated as lasI/expR. Three major AHLs, N-hexanoyl-l-homoserine lactone (C6-HSL), N-butyryl-l-homoserine lactone (C4-HSL), and N-(3-oxo-octanoyl)-l-homoserine lactone (3-oxo-C8-HSL) were found, with C6-HSL being the most abundant. C6-HSL was not detected in the culture of the luxI mutant (ΔluxI) and higher levels of C4-HSL was found in the culture of the luxR mutant (ΔluxR), which suggested that the luxR gene may have a positive effect on C4-HSL production. It was also found that AHL and QS genes are closely related in the absence of luxIR double deletion. The results of this study can further elucidate at the genetic level that luxI and luxR genes are involved in the regulation of AHL.

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Genome sequencing-assisted identification and the first functional validation ofN-acyl-homoserine-lactone synthases from the Sphingomonadaceae family

PeerJ ◽

10.7717/peerj.2332 ◽

2016 ◽

Vol 4 ◽

pp. e2332 ◽

Cited By ~ 5

Author(s):

Han Ming Gan ◽

Lucas K. Dailey ◽

Nigel Halliday ◽

Paul Williams ◽

André O. Hudson ◽

...

Keyword(s):

Quorum Sensing ◽

Thin Layer ◽

Heterologous Expression ◽

Thin Layer Chromatography ◽

Draft Genome ◽

Homoserine Lactone ◽

Acyl Homoserine Lactone ◽

Two Dimensional ◽

Esi Ms ◽

Layer Chromatography

BackgroundMembers of the genusNovosphingobiumhave been isolated from a variety of environmental niches. Although genomics analyses have suggested the presence of genes associated with quorum sensing signal production e.g., theN-acyl-homoserine lactone (AHL) synthase (luxI) homologs in variousNovosphingobiumspecies, to date, noluxIhomologs have been experimentally validated.MethodsIn this study, we report the draft genome of theN-(AHL)-producing bacteriumNovosphingobium subterraneumDSM 12447 and validate the functions of predictedluxIhomologs from the bacterium through inducible heterologous expression inAgrobacterium tumefaciensstrain NTL4. We developed a two-dimensional thin layer chromatography bioassay and used LC-ESI MS/MS analyses to separate, detect and identify the AHL signals produced by theN. subterraneumDSM 12447 strain.ResultsThree predicted luxI homologs were annotated to the locus tags NJ75_2841 (NovINsub1), NJ75_2498 (NovINsub2), and NJ75_4146 (NovINsub3). Inducible heterologous expression of eachluxIhomologs followed by LC-ESI MS/MS and two-dimensional reverse phase thin layer chromatography bioassays followed by bioluminescent ccd camera imaging indicate that the three LuxI homologs are able to produce a variety of medium-length AHL compounds. New insights into the LuxI phylogeny was also gleemed as inferred by Bayesian inference.DiscussionThis study significantly adds to our current understanding of quorum sensing in the genusNovosphingobiumand provide the framework for future characterization of the phylogenetically interesting LuxI homologs from members of the genusNovosphingobiumand more generally the family Sphingomonadaceae.

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Draft Genome Sequence of Nitrobacter vulgaris Strain Ab1, a Nitrite-Oxidizing Bacterium

Genome Announcements ◽

10.1128/genomea.00290-17 ◽

2017 ◽

Vol 5 (18) ◽

Cited By ~ 3

Author(s):

Brett L. Mellbye ◽

Edward W. Davis ◽

Eva Spieck ◽

Jeff H. Chang ◽

Peter J. Bottomley ◽

...

Keyword(s):

Quorum Sensing ◽

Genome Sequence ◽

Draft Genome ◽

Homoserine Lactone ◽

Draft Genome Sequence ◽

Nitrifying Bacteria ◽

Acyl Homoserine Lactone ◽

Content Type ◽

Sewage System ◽

Nitrite Oxidizing Bacteria

ABSTRACT Here, we present the 3.9-Mb draft genome sequence of Nitrobacter vulgaris strain Ab1, which was isolated from a sewage system in Hamburg, Germany. The analysis of its genome sequence will contribute to our knowledge of nitrite-oxidizing bacteria and acyl-homoserine lactone quorum sensing in nitrifying bacteria.

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Streptomycin Inhibits Quorum Sensing in Acinetobacter baumannii

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02161-12 ◽

2013 ◽

Vol 57 (4) ◽

pp. 1926-1929 ◽

Cited By ~ 30

Author(s):

Sunil D. Saroj ◽

Philip N. Rather

Keyword(s):

Quorum Sensing ◽

Thin Layer ◽

Acinetobacter Baumannii ◽

Direct Analysis ◽

Homoserine Lactone ◽

Acyl Homoserine Lactone ◽

Content Type ◽

Signal Production ◽

Subinhibitory Concentrations ◽

Layer Chromatography

ABSTRACTStreptomycin at subinhibitory concentrations was found to inhibit quorum sensing inAcinetobacter baumannii. Conditioned medium prepared by growth ofA. baumanniiin the presence of subinhibitory concentrations of streptomycin exhibited reduced activation of two quorum-sensing-regulated genes,abaI, encoding an autoinducer synthase, and A1S_0112. The reduced expression of AbaI resulted in greatly decreased levels of 3-OH-C12-HSL as confirmed by direct analysis using thin-layer chromatography. The effect on acyl-homoserine lactone (AHL) signal production was specific to streptomycin, as gentamicin and myomycin had no significant effect at subinhibitory levels.

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Draft genome sequences of five Proteobacteria isolated from Lechuguilla Cave, New Mexico, USA: Insights into taxonomy and quorum-sensing

10.1101/742460 ◽

2019 ◽

Author(s):

Han Ming Gan ◽

Peter C. Wengert ◽

Hazel A. Barton ◽

André O. Hudson ◽

Michael A. Savka

Keyword(s):

New Mexico ◽

Quorum Sensing ◽

Draft Genome ◽

Homoserine Lactone ◽

Acyl Homoserine Lactone ◽

Genome Sequences ◽

Genomic Resources ◽

Distinct Genus ◽

Genus Two

AbstractGenomic resources remain scarce for bacteria isolated from oligotrophic caves. We sequenced the genomes of five Proteobacteria isolated from Lechuguilla Cave in New Mexico, USA. Genome-based phylogeny indicates that each strain belongs to a distinct genus. Two Rhizobiaceae isolates possess the genomic potential for the biosynthesis of acyl-homoserine lactone.

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Quorum Sensing Bacteria in the Phycosphere of HAB Microalgae and Their Ecological Functions Related to Cross-Kingdom Interactions

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph19010163 ◽

2021 ◽

Vol 19 (1) ◽

pp. 163

Author(s):

Yanchao Zhang ◽

Li Zheng ◽

Shuai Wang ◽

Yangguo Zhao ◽

Xiyuan Xu ◽

...

Keyword(s):

Quorum Sensing ◽

Harmful Algal Blooms ◽

Algal Blooms ◽

Film Formation ◽

Homoserine Lactone ◽

Rrna Gene ◽

16S Rrna Gene Analysis ◽

Signalling Molecules ◽

Film Forming ◽

Layer Chromatography

It has been proven that the relationship between microalgae and bacteria affects the dynamic process of harmful algal blooms (HABs). Microalgae-associated microorganisms widely exist in the phycosphere and play an essential role in algae-bacteria cross-kingdom interactions. Among these processes, quorum sensing (QS), as a communication system of bacteria, is thought to participate in algae-bacteria interactions. However, the species of QS bacteria in the phycosphere and their ecological function are still unknown. In this study, microalgae-associated microorganisms with a QS system were screened by the biosensor method and identified based on 16S rRNA gene analysis. The types and number of acyl-L-homoserine lactone (AHL) signalling molecules produced by QS bacteria were analysed by thin layer chromatography (TLC) bioautography and gas chromatography-mass spectrometer (GC-MS). The film formation, β-dimethylmercaptopropionic (DMSP) degradation and algae growth effects of QS bacteria were investigated. The results showed that 113 QS bacteria were isolated from 842 microalgae-associated bacteria. Detection of AHL molecules in 10 different species of QS bacteria showed that most of them were N-(3-Oxodecanoyl)-L-homoserine lactone (OC10-HSL), N-Octanoyl-L-homoserine lactone (C8-HSL) and N-(3-Oxooctanoyl)-L-homoserine lactone (OC8-HSL). All 10 QS bacteria had film-forming ability, and they could degrade DMSP (except strain E26). The crude metabolic extracts of the 10 QS bacteria can inhibit or promote microalgae growth to different degrees. Our study is helpful to understand the role of microalgae-associated microorganisms with the QS system in algae-bacteria interactions and community succession of HAB microalgae.

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Draft Genome Sequences of Five Proteobacteria Isolated from Lechuguilla Cave, New Mexico, USA, and Insights into Taxonomy and Quorum Sensing

Microbiology Resource Announcements ◽

10.1128/mra.00913-19 ◽

2019 ◽

Vol 8 (40) ◽

Cited By ~ 1

Author(s):

Han Ming Gan ◽

Peter C. Wengert ◽

Hazel A. Barton ◽

André O. Hudson ◽

Michael A. Savka

Keyword(s):

New Mexico ◽

Quorum Sensing ◽

Draft Genome ◽

Homoserine Lactone ◽

Acyl Homoserine Lactone ◽

Genome Sequences ◽

Genomic Resources ◽

Distinct Genus ◽

Genus Two

Genomic resources remain scarce for bacteria isolated from oligotrophic caves. We sequenced the genomes of five Proteobacteria isolated from Lechuguilla Cave in New Mexico. Genome-based phylogeny indicates that each strain belongs to a distinct genus. Two Rhizobiaceae isolates possess genomic potential for the biosynthesis of acyl-homoserine lactone.

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N-(3-Hydroxyhexanoyl)-l-Homoserine Lactone Is the Biologically Relevant Quormone That Regulates the phz Operon of Pseudomonas chlororaphis Strain 30-84

Applied and Environmental Microbiology ◽

10.1128/aem.01354-07 ◽

2007 ◽

Vol 73 (22) ◽

pp. 7443-7455 ◽

Cited By ~ 34

Author(s):

Sharik R. Khan ◽

Jake Herman ◽

Jessica Krank ◽

Natalie J. Serkova ◽

Mair E. A. Churchill ◽

...

Keyword(s):

Quorum Sensing ◽

Wild Type Strain ◽

Homoserine Lactone ◽

Pseudomonas Chlororaphis ◽

Biologically Relevant ◽

Sensing Systems ◽

Major Species ◽

Phenazine Production ◽

Chain Lengths ◽

Layer Chromatography

ABSTRACT Phenazine production by Pseudomonas fluorescens 2-79 and P. chlororaphis isolates 30-84 and PCL1391 is regulated by quorum sensing through the activator PhzR and acyl-homoserine lactones (acyl-HSLs) synthesized by PhzI. PhzI from P. fluorescens 2-79 produces five acyl-HSLs that include four 3-hydroxy species. Of these, N-(3-hydroxyhexanoyl)-HSL is the biologically relevant ligand for PhzR. The quorum-sensing systems of P. chlororaphis strains 30-84 and PCL1391 have been reported to produce and respond to N-(hexanoyl)-HSL. These differences were of interest since PhzI and PhzR of strain 2-79 share almost 90% sequence identity with orthologs from strains 30-84 and PCL1391. In this study, as assessed by thin-layer chromatography, the three strains produce almost identical complements of acyl-HSLs. The major species produced by P. chlororaphis 30-84 were identified by mass spectrometry as 3-OH-acyl-HSLs with chain lengths of 6, 8, and 10 carbons. Heterologous bacteria expressing cloned phzI from strain 30-84 produced the four 3-OH acyl-HSLs in amounts similar to those seen for the wild type. Strain 30-84, but not strain 2-79, also produced N-(butanoyl)-HSL. A second acyl-HSL synthase of strain 30-84, CsaI, is responsible for the synthesis of this short-chain signal. Strain 30-84 accumulated N-(3-OH-hexanoyl)-HSL to the highest levels, more than 100-fold greater than that of N-(hexanoyl)-HSL. In titration assays, PhzR30-84 responded to both N-(3-OH-hexanoyl)- and N-(hexanoyl)-HSL with equal sensitivities. However, only the 3-OH-hexanoyl signal is produced by strain 30-84 at levels high enough to activate PhzR. We conclude that strains 2-79, 30-84, and PCL1391 use N-(3-OH-hexanoyl)-HSL to activate PhzR.

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Characterisation of Quorum Sensing System and Its Role in Global Regulation in Hafnia alvei

10.1101/812727 ◽

2019 ◽

Author(s):

Jia Yi Tan ◽

Wah-Seng See-Too ◽

Peter Convey ◽

Kok-Gan Chan

Keyword(s):

Cell Division ◽

Quorum Sensing ◽

Nutrient Uptake ◽

Genome Sequence ◽

Opportunistic Pathogen ◽

Homoserine Lactone ◽

Accession Number ◽

Hafnia Alvei ◽

Link Type

AbstractQuorum sensing (QS) is a regulatory process achieved via cell-to-cell communication that involves release and detection of autoinducers (AIs), and which occurs in a wide range of bacteria. To date, QS has been associated to events of pathogenesis, biofilm formation, and antibiotic resistance in clinical, industrial, and agricultural contexts. The main objective of this study was to characterise the role of N-Acyl homoserine lactone (AHL) type QS in Hafnia alvei FB1, a bacterial strain isolated from frozen vacuum-packed fish paste meatballs, via identification of QS core genes using a genomic approach, followed by comparative transcriptomic profiling between QS-deficient mutants and wild-type strains. H. alvei FB1 is known to produce two types of AHLs, namely, N-(3-oxohexanoyl) homoserine lactone (3OC6-HSL) and N-(3-oxooctanoyl) homoserine lactone (3OC8-HSL). The complete genome sequence of strain FB1 was obtained and a single gene for AHL synthase (halI) and its cognate receptor (halR) were identified. QS-deficient mutants of FB1 were constructed via the λ-Red recombineering method. Removal of the QS genes in strain FB1 affected mainly mechanisms in cell division and nutrient uptake, as well as resistance to a number of antibiotics, which are crucial for survival, adaptation and colonisation of both food and the host gut environment.Impact statementThe Hafnia genus is known as opportunistic pathogen in both nosocomial and community-acquired infections, however, involvement and mechanism of pathogenesis of Hafnia in infection diseases is uncertain. We investigate the role of the signalling molecule, N-acyl homoserine lactones (AHLs), in a Hafnia alvei strain, since AHLs play important roles in pathogenicity, survival or adaptation in other pathogen. This comparative transciptomic study has revealed that AHLs are involved in mechanisms in cell division and nutrient uptake, as well as resistance to a number of antibiotics, which are crucial for survival, adaptation and colonisation of both food and the host gut environment. This finding provides insight and possible strategy to combat this opportunistic pathogen.Data summaryGenome sequence is deposited in NCBI GenBank under accession number CP009706. The transcriptomic data, have been deposited in the Gene Expression Omnibus (GEO) database (https://www.ncbi.nlm.nih.gov/gds) under accession number GSE93000.

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Insights into the Genome Sequences of an N -Acyl Homoserine Lactone Molecule Producing Two Pseudomonas spp. Isolated from the Arctic

Genome Announcements ◽

10.1128/genomea.00767-16 ◽

2016 ◽

Vol 4 (4) ◽

Cited By ~ 3

Author(s):

Akhilandeswarre Dharmaprakash ◽

Dinesh Reghunathan ◽

Krishnakutty C. Sivakumar ◽

Manoj Prasannakumar ◽

Sabu Thomas

Keyword(s):

Quorum Sensing ◽

Draft Genome ◽

Homoserine Lactone ◽

The Arctic ◽

Acyl Homoserine Lactone ◽

Cold Environments ◽

Sensing System ◽

Quorum Sensing System ◽

First Time

We report for the first time the draft genome sequence of two psychrotrophic Pseudomonas species, Pseudomonas simiae RGCB 73 and Pseudomonas brenneri RGCB 108, from the Arctic that produce more than one acyl homoserine lactone molecule of varied N -acyl length. The study confirms the presence of a LuxR-LuxI (type) mediated quorum-sensing system in both the Pseudomonas species and enables us to understand the role of quorum sensing in their survival in extremely cold environments.

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Draft Genome Sequence ofChromobacterium violaceumStrain CV017

Genome Announcements ◽

10.1128/genomea.00080-16 ◽

2016 ◽

Vol 4 (2) ◽

Cited By ~ 5

Author(s):

Xiaofei Wang ◽

Kara C. Hinshaw ◽

Stuart J. Macdonald ◽

Josephine R. Chandler

Keyword(s):

Quorum Sensing ◽

Genome Sequence ◽

Draft Genome ◽

Homoserine Lactone ◽

Chromobacterium Violaceum ◽

Draft Genome Sequence ◽

Acyl Homoserine Lactone

We announce the draft genome sequence forChromobacterium violaceumstrain CV017, used as a model and tool to understand acyl-homoserine lactone-dependent quorum sensing. The assembly consists of 4,774,638-bp contained in 211 scaffolds.

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