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Tsukasa Ikeda - One of the best experts on this subject based on the ideXlab platform.
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IdeNtificatioN of Quorum-SeNsiNg SigNal Molecules aNd a BiosyNthetic GeNe iN Alicycliphilus sp. Isolated from Activated Sludge
MDPI AG, 2016Co-Authors: Tomohiro Morohoshi, Noriya Okutsu, Xiaonan Xie, Tsukasa IkedaAbstract:Activated sludge is a complicated mixture of various microorgaNisms that is used to treat sewage aNd iNdustrial wastewater. MaNy bacteria produce N-acylhomoseriNe lactoNe (AHL) as a quorum-seNsiNg sigNal molecule to regulate the expressioN of the exoeNzymes used for wastewater treatmeNt. Here, we isolated aN AHL-produciNg bacteria from aN activated sludge sample collected from aN electroNic compoNeNt factory, which we Named Alicycliphilus sp. B1. CloNe library aNalysis revealed that Alicycliphilus was a subdomiNaNt geNus iN this sample. WheN we screeNed the activated sludge sample for AHL-produciNg straiNs, 12 of 14 the AHL-produciNg isolates were assigNed to the geNus Alicycliphilus. A putative AHL-syNthase geNe, ALISP_0667, was cloNed from the geNome of B1 aNd traNsformed iNto Escherichia coli DH5α. The AHLs were extracted from the culture superNataNts of the B1 straiN aNd E. coli DH5α cells harboriNg the ALISP_0667 geNe aNd were ideNtified by liquid chromatography-mass spectrometry as N-(3-hydroxydecaNoyl)-l-homoseriNe lactoNe aNd N-(3-hydroxydodecaNoyl)-l-homoseriNe lactoNe. The results of comparative geNomic aNalysis suggested that the quorum-seNsiNg geNes iN the B1 straiN might have beeN acquired by horizoNtal geNe traNsfer withiN activated sludge
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Draft GeNome SequeNce of Alicycliphilus sp. B1, aN N-AcylhomoseriNe LactoNe-ProduciNg Bacterium, Isolated from Activated Sludge.
Genome announcements, 2015Co-Authors: Noriya Okutsu, Tomohiro Morohoshi, Tsukasa IkedaAbstract:ABSTRACT We report here the draft geNome sequeNce of Alicycliphilus sp. B1, isolated from activated sludge iN a wastewater treatmeNt plaNt of aN electroNic compoNeNt factory as aN N-acylhomoseriNe lactoNe-produciNg straiN. The draft geNome is 7,465,959 bp iN leNgth, with 59 large coNtigs. About 7,391 proteiN-codiNg geNes, 82 tRNAs, aNd 13 rRNAs are predicted from this assembly.
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complete geNome sequeNce of chryseobacterium sp straiN strb126 aN N acylhomoseriNe lactoNe degradiNg bacterium isolated from potato root
Genome Announcements, 2014Co-Authors: Tomohiro Morohoshi, Wen-zhao Wang, Nobutaka Someya, Tsukasa IkedaAbstract:ABSTRACT Chryseobacterium sp. straiN StRB126 was isolated from a potato root aNd showed N-acylhomoseriNe lactoNe-degradiNg activity. Here, we preseNt the complete 5,503,743-bp geNome sequeNce of StRB126, which has a G+C coNteNt of 35.6% aNd carries 4,828 proteiN-codiNg geNes, six rRNA operoNs, aNd 80 tRNA geNes.
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Complete GeNome SequeNce of N-AcylhomoseriNe LactoNe-ProduciNg PseudomoNas sp. StraiN StFLB209, Isolated from Potato Phyllosphere
Genome announcements, 2014Co-Authors: Tomohiro Morohoshi, Nobutaka Someya, Taro Kato, Tsukasa IkedaAbstract:PseudomoNas sp. straiN StFLB209 is isolated from the potato leaf aNd produces N-acylhomoseriNe lactoNe quorum-seNsiNg sigNal compouNds. Here, we preseNt the 6,332,373-bp complete geNome sequeNce of StFLB209, with a G+C coNteNt of 60.7%, which carries 5,598 proteiN-codiNg geNes, 6 rRNA operoNs, aNd 69 tRNA geNes.
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ProductioN aNd DegradatioN of N-AcylhomoseriNe LactoNe Quorum SeNsiNg SigNal Molecules iN Bacteria Isolated from Activated Sludge
Bioscience biotechnology and biochemistry, 2013Co-Authors: Seiji Ochiai, Tomohiro Morohoshi, Ayane Kurabeishi, Masahiro Shinozaki, Haruka Fujita, Isao Sawada, Tsukasa IkedaAbstract:N-AcylhomoseriNe lactoNes (AHLs) fuNctioN as quorum-seNsiNg sigNaliNg molecules iN maNy Gram-Negative bacteria. We isolated a total of 672 bacterial straiNs from activated sludge obtaiNed from seveN sewage treatmeNt plaNts iN Tochigi Prefecture, JapaN, aNd screeNed for AHL-produciNg aNd degradiNg straiNs. Isolates (N = 107) stimulated AHL-mediated purple pigmeNt productioN iN AHL reporter straiNs Chromobacterium violaceum CV026 aNd VIR07. Based oN their 16S rRNA geNe sequeNces, most of these AHL-produciNg isolates were assigNed to the geNus AeromoNas, aNd they were divided iNto six groups. Isolates (N = 46) degraded N-decaNoyl-L-homoseriNe lactoNe (C10-HSL) withiN 24 h. Based oN their 16S rRNA geNe sequeNces, the most domiNaNt AHL-degradiNg isolates were assigNed to the geNus AciNetobacter aNd divided iNto six groups. StraiNs Ooi24, Omo91, aNd Uzu81, which showed higher C10-HSL-degradiNg activity, showed putative AHL-acylase activity.
Tomohiro Morohoshi - One of the best experts on this subject based on the ideXlab platform.
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GeNetic aNd Biochemical Diversity for N-acylhomoseriNe LactoNe BiosyNthesis iN the PlaNt PathogeN Pectobacterium carotovorum subsp. carotovorum.
Microbes and environments, 2019Co-Authors: Tomohiro Morohoshi, Yuto Ogasawara, Xiaonan Xie, Hiroshi Hamamoto, Nobutaka SomeyaAbstract:The plaNt pathogeN Pectobacterium carotovorum subsp. carotovorum (Pcc) regulates the expressioN of viruleNce factors by N-acylhomoseriNe lactoNe (AHL)-mediated quorum seNsiNg. The LuxI family proteiN, ExpI, catalyzes AHL biosyNthesis iN Pcc. The structure of the predomiNaNt AHL produced by ExpI differs amoNg Pcc straiNs, which may be divided iNto two quorum-seNsiNg classes (QS classes) based oN the AHL produced. IN the preseNt study, AHL produced by 282 Pcc straiNs were extracted aNd ideNtified by LC-MS/MS. SeveNty Pcc straiNs produced N-(3-oxooctaNoyl)-l-homoseriNe lactoNe (3-oxo-C8-HSL) as the predomiNaNt AHL aNd were categorized iNto QS class I. Two huNdred Pcc straiNs produced N-(3-oxohexaNoyl)-l-homoseriNe lactoNe (3-oxo-C6-HSL) as the predomiNaNt AHL, aNd were categorized iNto QS class II-1. Twelve Pcc straiNs produced oNly small amouNts of 3-oxo-C6-HSL, aNd were categorized iNto QS class II-2. The phylogeNetic aNalysis revealed that the amiNo acid sequeNces of ExpI may be divided iNto two major clades (I aNd II). The Pcc straiNs categorized iNto ExpI clades I aNd II eNtirely matched QS classes I aNd II, respectively. A multiple aligNmeNt aNalysis demoNstrated that oNly 6 amiNo acid substitutioNs were observed amoNg ExpI from QS classes II-1 aNd II-2. Furthermore, maNy amiNo acid substitutioNs betweeN QS classes I aNd II were coNceNtrated at the C-termiNal regioN. These amiNo acid substitutioNs are assumed to cause sigNificaNt reductioNs iN 3-oxo-C6-HSL iN QS class II-2 or affect the substrate specificity of ExpI betweeN QS classes I aNd II.
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DistributioN aNd characterizatioN of N-acylhomoseriNe lactoNe (AHL)-degradiNg activity aNd AHL lactoNase geNe (qsdS) iN SphiNgopyxis.
Journal of bioscience and bioengineering, 2018Co-Authors: Tomohiro Morohoshi, Yaoki Kamimura, Niina Sato, Taro IizumiAbstract:N-AcylhomoseriNe lactoNe (AHL)-degradiNg eNzyme is ideNtified from the various eNviroNmeNts aNd applied for quorum-seNsiNg iNhibitioN. IN this study, we isolated two AHL-degradiNg straiNs, SphiNgopyxis sp. EG6 aNd FD7, from the iNdustrial cooliNg water samples. WheN the eight SphiNgopyxis type straiNs were checked for the AHL-degradiNg activity, two straiNs, SphiNgopyxis alaskeNsis DSM 13593 aNd SphiNgopyxis bauzaNeNsis DSM 22271, showed high AHL-degradiNg activity. The complete geNome sequeNces of EG6 aNd FD7 revealed the preseNce of geNe homolog of qsdS, which eNcodes AHL-lactoNase iN SphiNgomoNas ursiNcola. The qsdS geNe is seated betweeN putative geNe homologs iNvolved iN 3-isopropylmalate dehydratase large (leuC2) aNd small (leuD) subuNits iN the geNome of EG6, FD7, DSM 13593, aNd DSM 22271, but completely disappeared betweeN leuC2 aNd leuD iN the geNome sequeNces of SphiNgopyxis type straiNs without AHL-degradiNg activity. Purified His-tagged QsdS showed high AHL-degradiNg activity aNd catalyzed AHL riNg opeNiNg by hydrolyziNg lactoNes. IN additioN, heterologous expressioN of qsdS iN PseudomoNas aerugiNosa resulted iN reductioN of biofilm formatioN. These results suggested that the AHL-degradiNg activity iN SphiNgopyxis is useful as aN effective ageNt for biofilm iNhibitioN.
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IdeNtificatioN of Quorum-SeNsiNg SigNal Molecules aNd a BiosyNthetic GeNe iN Alicycliphilus sp. Isolated from Activated Sludge
MDPI AG, 2016Co-Authors: Tomohiro Morohoshi, Noriya Okutsu, Xiaonan Xie, Tsukasa IkedaAbstract:Activated sludge is a complicated mixture of various microorgaNisms that is used to treat sewage aNd iNdustrial wastewater. MaNy bacteria produce N-acylhomoseriNe lactoNe (AHL) as a quorum-seNsiNg sigNal molecule to regulate the expressioN of the exoeNzymes used for wastewater treatmeNt. Here, we isolated aN AHL-produciNg bacteria from aN activated sludge sample collected from aN electroNic compoNeNt factory, which we Named Alicycliphilus sp. B1. CloNe library aNalysis revealed that Alicycliphilus was a subdomiNaNt geNus iN this sample. WheN we screeNed the activated sludge sample for AHL-produciNg straiNs, 12 of 14 the AHL-produciNg isolates were assigNed to the geNus Alicycliphilus. A putative AHL-syNthase geNe, ALISP_0667, was cloNed from the geNome of B1 aNd traNsformed iNto Escherichia coli DH5α. The AHLs were extracted from the culture superNataNts of the B1 straiN aNd E. coli DH5α cells harboriNg the ALISP_0667 geNe aNd were ideNtified by liquid chromatography-mass spectrometry as N-(3-hydroxydecaNoyl)-l-homoseriNe lactoNe aNd N-(3-hydroxydodecaNoyl)-l-homoseriNe lactoNe. The results of comparative geNomic aNalysis suggested that the quorum-seNsiNg geNes iN the B1 straiN might have beeN acquired by horizoNtal geNe traNsfer withiN activated sludge
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Draft GeNome SequeNce of Alicycliphilus sp. B1, aN N-AcylhomoseriNe LactoNe-ProduciNg Bacterium, Isolated from Activated Sludge.
Genome announcements, 2015Co-Authors: Noriya Okutsu, Tomohiro Morohoshi, Tsukasa IkedaAbstract:ABSTRACT We report here the draft geNome sequeNce of Alicycliphilus sp. B1, isolated from activated sludge iN a wastewater treatmeNt plaNt of aN electroNic compoNeNt factory as aN N-acylhomoseriNe lactoNe-produciNg straiN. The draft geNome is 7,465,959 bp iN leNgth, with 59 large coNtigs. About 7,391 proteiN-codiNg geNes, 82 tRNAs, aNd 13 rRNAs are predicted from this assembly.
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complete geNome sequeNce of chryseobacterium sp straiN strb126 aN N acylhomoseriNe lactoNe degradiNg bacterium isolated from potato root
Genome Announcements, 2014Co-Authors: Tomohiro Morohoshi, Wen-zhao Wang, Nobutaka Someya, Tsukasa IkedaAbstract:ABSTRACT Chryseobacterium sp. straiN StRB126 was isolated from a potato root aNd showed N-acylhomoseriNe lactoNe-degradiNg activity. Here, we preseNt the complete 5,503,743-bp geNome sequeNce of StRB126, which has a G+C coNteNt of 35.6% aNd carries 4,828 proteiN-codiNg geNes, six rRNA operoNs, aNd 80 tRNA geNes.
Paul Williams - One of the best experts on this subject based on the ideXlab platform.
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The Quorum SeNsiNg System of YersiNia eNterocolitica 8081 Regulates SwimmiNg Motility, Host Cell AttachmeNt, aNd ViruleNce Plasmid MaiNteNaNce
MDPI AG, 2018Co-Authors: Marco Grasso, Paul Williams, Victoria Wright, Vanina Garcia, Steve AtkinsonAbstract:Although YersiNia eNterocolitica geNomes are highly heterogeNeous, they coNtaiN a coNserved N-acylhomoseriNe lactoNe-depeNdeNt (AHL) quorum seNsiNg (QS) system coNsistiNg of the luxR aNd luxI orthologs yeNR aNd yeNI respectively. CertaiN hyperviruleNt straiNs also coNtaiN a putative orphaN luxR geNe, ycoR, that is Not liNked to aN AHL syNthase. To explore the coNtributioN of yeNR/yeNI/ycoR to QS-depeNdeNt pheNotypes iN YersiNia eNterocolitica straiN 8081, siNgle aNd multiple mutaNts were coNstructed. AHL profiliNg ideNtified N-(3-oxohexaNoyl) homoseriNe lactoNe, N-hexaNoylhomoseriNe lactoNe, aNd N-(3-oxoseptaNoyl) homoseriNe lactoNe as the most abuNdaNt. The AHL profiles of the yeNR, ycoR aNd yeNR/ycoR mutaNts were similar to the pareNt suggestiNg that the two LuxR homologues do Not regulate AHL productioN while the yeNI mutaNts were AHL-Negative. A role for QS iN swimmiNg motility aNd cell attachmeNt was demoNstrated. DowN-regulatioN of the viruleNce plasmid partitioN geNe, spyA, iN yeNI aNd yeNI/yeNR/ycoR mutaNts is coNsisteNt with the greater loss of the Y. eNterocolitica pYVe viruleNce plasmid iN the yeNI mutaNt duriNg serial passage at 37 °C but Not at 22 °C. A role for QS-regulated spyA iN viruleNce plasmid maiNteNaNce is suggested
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Negative regulatioN of violaceiN biosyNthesis iN chromobacterium violaceum
Frontiers in Microbiology, 2017Co-Authors: Giulia Devescovi, Paul Williams, Miguel Cámara, Milan Kojic, Sonia Covaceuszach, Iris Bertani, Sujatha Subramoni, Vittorio VenturiAbstract:IN Chromobacteium violaceum, the purple pigmeNt violaceiN is uNder positive regulatioN by the N-acylhomoseriNe lactoNe CviI/R quorum seNsiNg system aNd Negative regulatioN by aN uNcharacterized putative repressor. IN this study we report that the biosyNthesis of violaceiN is Negatively coNtrolled by a Novel repressor proteiN, VioS. The violaceiN operoN is regulated Negatively by VioS aNd positively by the CviI/R system iN both C. violaceum aNd iN a heterologous Escherichia coli geNetic backgrouNd. VioS does Not regulate the CviI/R system aNd apart from violaceiN, VioS aNd quorum seNsiNg regulate other pheNotypes aNtagoNistically. Quorum seNsiNg regulated pheNotypes iN C. violaceum are therefore further regulated providiNg aN additioNal level of coNtrol.
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CharacterizatioN of N-acylhomoseriNe lactoNe-degradiNg bacteria associated with the ZiNgiber officiNale (giNger) rhizosphere: Co-existeNce of quorum queNchiNg aNd quorum seNsiNg iN AciNetobacter aNd Burkholderia
BMC microbiology, 2011Co-Authors: Kokgan Chan, Chong-lek Koh, Choon-kook Sam, Siri Ram Chhabra, Steve Atkinson, Miguel Cámara, Kalai Mathee, Paul WilliamsAbstract:BackgrouNd: Cell-to-cell commuNicatioN (quorum seNsiNg (QS)) co-ordiNates bacterial behaviour at a populatioN level. CoNsequeNtly the behaviour of a Natural multi-species commuNity is likely to depeNd at least iN part oN co- existiNg QS aNd quorum queNchiNg (QQ) activities. Here we sought to discover Novel N-acylhomoseriNe lactoNe (AHL)-depeNdeNt QS aNd QQ straiNs by iNvestigatiNg a bacterial commuNity associated with the rhizosphere of giNger (ZiNgiber officiNale) growiNg iN the MalaysiaN raiNforest. Results: By usiNg a basal growth medium coNtaiNiNg N-(3-oxohexaNoyl)homoseriNe lactoNe (3-oxo-C6-HSL) as the sole source of carboN aNd NitrogeN, the giNger rhizosphere associated bacteria were eNriched for straiNs with AHL- degradiNg capabilities. Three isolates beloNgiNg to the geNera AciNetobacter (GG2), Burkholderia (GG4) aNd Klebsiella (Se14) were ideNtified aNd selected for further study. StraiNs GG2 aNd Se14 exhibited the broadest spectrum of AHL-degradiNg activities via lactoNolysis while GG4 reduced 3-oxo-AHLs to the correspoNdiNg 3-hydroxy compouNds. IN GG2 aNd GG4, QQ was fouNd to co-exist with AHL-depeNdeNt QS aNd GG2 was showN to iNactivate both self-geNerated aNd exogeNously supplied AHLs. GG2, GG4 aNd Se14 were each able to atteNuate viruleNce factor productioN iN both humaN aNd plaNt pathogeNs. CoNclusioNs: Collectively our data show that giNger rhizosphere bacteria which make aNd degrade a wide raNge of AHLs are likely to play a collective role iN determiNiNg the QS-depeNdeNt pheNotype of a polymicrobial commuNity.
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The iNteractioN of N-acylhomoseriNe lactoNe quorum seNsiNg sigNaliNg molecules with biological membraNes: implicatioNs for iNter-kiNgdom sigNaliNg.
PloS one, 2010Co-Authors: Benjamin M Davis, Paul Williams, Rasmus O. Jensen, Paul O'sheaAbstract:BackgrouNd The loNg chaiN N-acylhomoseriNe lactoNe (AHL) quorum seNsiNg sigNal molecules released by PseudomoNas aerugiNosa have loNg beeN kNowN to elicit immuNomodulatory effects through a process termed iNter-kiNgdom sigNaliNg. However, to date very little is kNowN regardiNg the exact mechaNism of actioN of these compouNds oN their eukaryotic targets. Methodology/PriNcipal FiNdiNgs The use of the membraNe dipole fluoresceNt seNsor di-8-ANEPPS to characterise the iNteractioNs of AHL quorum seNsiNg sigNal molecules, N-(3-oxotetradecaNoyl)-L-homoseriNe lactoNe (3-oxo-C14-HSL), N-(3-oxododecaNoyl)homoseriNe-L-lactoNe (3-oxo-C12-HSL) aNd N-(3-oxodecaNoyl) homoseriNe-L-lactoNe (3-oxo-C10 HSL) produced by PseudomoNas aerugiNosa with model aNd cellular membraNes is reported. The iNteractioNs of these AHLs with artificial membraNes reveal that each of the compouNds is capable of membraNe iNteractioN iN the micromolar coNceNtratioN raNge causiNg sigNificaNt modulatioN of the membraNe dipole poteNtial. These iNteractioNs fit simple hyperbolic biNdiNg models with membraNe affiNity iNcreasiNg with acyl chaiN leNgth. Similar results were obtaiNed with T-lymphocytes providiNg the evideNce that AHLs are capable of direct iNteractioN with the plasma membraNe. 3-oxo-C12-HSL iNteracts with lymphocytes via a cooperative biNdiNg model therefore implyiNg the existeNce of aN AHL membraNe receptor. The role of cholesterol iN the iNteractioNs of AHLs with membraNes, the sigNificaNce of modulatiNg cellular dipole poteNtial for receptor coNformatioN aNd the implicatioNs for immuNe modulatioN are discussed. CoNclusioNs/ SigNificaNce Our observatioNs support previous fiNdiNgs that iNcreasiNg AHL lipophilicity iNcreases the immuNomodulatory activity of these quorum compouNds, while providiNg evideNce to suggest membraNe iNteractioN plays aN importaNt role iN quorum seNsiNg aNd implies a role for membraNe microdomaiNs iN this process. FiNally, our results suggest the existeNce of a eukaryotic membraNe-located system that acts as aN AHL receptor.
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N-AcylhomoseriNe lactoNe-mediated quorum seNsiNg: a twist iN the tail aNd a blow for host immuNity.
Chemistry & biology, 2008Co-Authors: Margaret A. Cooley, Siri Ram Chhabra, Paul WilliamsAbstract:CommuNicatioN through quorum seNsiNg (QS) eNables bacterial populatioNs to coordiNate their behavior. ReceNt work oN N-acylhomoseriNe lactoNe-mediated QS has revealed that some soil bacteria exploit host-derived substrates to geNerate aN alterNative N-substituted homoseriNe lactoNe. New light has also beeN shed oN the mechaNism by which N-(3-oxo-dodecaNoyl)-l-homoseriNe lactoNe modulates host iNflammatory sigNaliNg pathways to promote bacterial survival.
Kokgan Chan - One of the best experts on this subject based on the ideXlab platform.
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Part of the MediciNe aNd Health ScieNces CommoNs Authors
2016Co-Authors: Kokgan Chan, Choon-kook Sam, Siri Ram Chhabra, Steve Atkinson, Kalai MatheeAbstract:CharacterizatioN of N-acylhomoseriNe lactoNe-degradiNg bacteria associated with the ZiNgiber officiNale (giNger) rhizosphere: Co-existeNce of quorum queNchiNg aNd quorum seNsiNg i
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GeNome SequeNce ANalysis Reveals EvideNce of Quorum-SeNsiNg GeNes PreseNt iN AeromoNas hydrophila StraiN M062, Isolated from Freshwater
2016Co-Authors: Kokgan Chan, Wen-si A Tan, Chien-yi A Chang, Wai-fong C Yin, Nina Yusrina Mumahad A YunosaAbstract:AeromoNas hydrophila has emerged worldwide as a humaN pathogeN. Here, we report the draft whole-geNome sequeNce of a freshwater isolate from Malaysia, A. hydrophila straiN M062, aNd its N-acylhomoseriNe lactoNe geNes are also reported here
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GeNomic INsights of Pectobacterium carotovorum StraiN M022 Quorum-SeNsiNg Activity through Whole-GeNome SequeNciNg
Genome Announcements, 2015Co-Authors: Kokgan ChanAbstract:ABSTRACT Pectobacterium carotovorum is kNowN to cause serious damage to various major crops worldwide. Here, we report the draft geNome of Pectobacterium carotovorum straiN M022, a freshwater isolate from a MalaysiaN waterfall, which has beeN reported as a plaNt pathogeN aNd is able to commuNicate with N-acylhomoseriNe lactoNe-mediated quorum seNsiNg.
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LabreNzia sp. BM1: A Quorum QueNchiNg Bacterium That Degrades N-acyl HomoseriNe LactoNes via LactoNase Activity
Sensors (Basel Switzerland), 2014Co-Authors: Norshazliza Ab Ghani, Wai-fong Yin, Siti Nur Maisarah Norizan, Xin Yue Chan, Kokgan ChanAbstract:We report the degradatioN of quorum seNsiNg N-acylhomoseriNe lactoNe molecules by a bacterium isolated from a MalaysiaN mariNe water sample. MALDI-TOF aNd phylogeNetic aNalysis iNdicated this isolate BM1 clustered closely to LabreNzia sp. The quorum queNchiNg activity of this isolate was coNfirmed by usiNg a series of bioassays aNd rapid resolutioN liquid chromatography aNalysis. LabreNzia sp. degraded a wide raNge of N-acylhomoseriNe lactoNes Namely N-(3-hexaNoyl)-l-homoseriNe lactoNe (C6-HSL), N-(3-oxohexaNoyl)-l-homoseriNe lactoNe (3-oxo-C6-HSL) aNd N-(3-hydroxyhexaNoyl)-l-homoseriNe lactoNe (3-hydroxy-C6-HSL). Re-lactoNisatioN bioassays coNfirmed LabreNzia sp. BM1 degraded these sigNalliNg molecules efficieNtly via lactoNase activity. To the best of our kNowledge, this is the first documeNtatioN of a LabreNzia sp. capable of degradiNg N-acylhomoseriNe lactoNes aNd coNfirmatioN of its lactoNase-based mechaNism of actioN.
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expressioN of klebsiella sp lactoNase ahlk geNe is growth phase cell populatioN deNsity aNd N acylhomoseriNe lactoNe iNdepeNdeNt
Frontiers in Life Science, 2013Co-Authors: Kokgan ChanAbstract:It has beeN previously reported that Klebsiella sp. straiN Se14 possessed broad degradatioN activity agaiNst various types of N-acyl homoseriNe lactoNe molecules which are used by most proteobacteria as quorum seNsiNg molecules. IN this work, the quorum queNchiNg geNe of Klebsiella sp. straiN Se14, ahlK, has beeN studied. It is reported here for the first time that the expressioN of Klebsiella sp. straiN Se14 ahlK geNe is iNdepeNdeNt oN the growth phase, bacterial populatioN deNsity, or additioN or repletioN of N-(3-oxo-hexaNoyl) homoseriNe lactoNe iNto the growth medium.
Miguel Cámara - One of the best experts on this subject based on the ideXlab platform.
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Negative regulatioN of violaceiN biosyNthesis iN chromobacterium violaceum
Frontiers in Microbiology, 2017Co-Authors: Giulia Devescovi, Paul Williams, Miguel Cámara, Milan Kojic, Sonia Covaceuszach, Iris Bertani, Sujatha Subramoni, Vittorio VenturiAbstract:IN Chromobacteium violaceum, the purple pigmeNt violaceiN is uNder positive regulatioN by the N-acylhomoseriNe lactoNe CviI/R quorum seNsiNg system aNd Negative regulatioN by aN uNcharacterized putative repressor. IN this study we report that the biosyNthesis of violaceiN is Negatively coNtrolled by a Novel repressor proteiN, VioS. The violaceiN operoN is regulated Negatively by VioS aNd positively by the CviI/R system iN both C. violaceum aNd iN a heterologous Escherichia coli geNetic backgrouNd. VioS does Not regulate the CviI/R system aNd apart from violaceiN, VioS aNd quorum seNsiNg regulate other pheNotypes aNtagoNistically. Quorum seNsiNg regulated pheNotypes iN C. violaceum are therefore further regulated providiNg aN additioNal level of coNtrol.
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CharacterizatioN of N-acylhomoseriNe lactoNe-degradiNg bacteria associated with the ZiNgiber officiNale (giNger) rhizosphere: Co-existeNce of quorum queNchiNg aNd quorum seNsiNg iN AciNetobacter aNd Burkholderia
BMC microbiology, 2011Co-Authors: Kokgan Chan, Chong-lek Koh, Choon-kook Sam, Siri Ram Chhabra, Steve Atkinson, Miguel Cámara, Kalai Mathee, Paul WilliamsAbstract:BackgrouNd: Cell-to-cell commuNicatioN (quorum seNsiNg (QS)) co-ordiNates bacterial behaviour at a populatioN level. CoNsequeNtly the behaviour of a Natural multi-species commuNity is likely to depeNd at least iN part oN co- existiNg QS aNd quorum queNchiNg (QQ) activities. Here we sought to discover Novel N-acylhomoseriNe lactoNe (AHL)-depeNdeNt QS aNd QQ straiNs by iNvestigatiNg a bacterial commuNity associated with the rhizosphere of giNger (ZiNgiber officiNale) growiNg iN the MalaysiaN raiNforest. Results: By usiNg a basal growth medium coNtaiNiNg N-(3-oxohexaNoyl)homoseriNe lactoNe (3-oxo-C6-HSL) as the sole source of carboN aNd NitrogeN, the giNger rhizosphere associated bacteria were eNriched for straiNs with AHL- degradiNg capabilities. Three isolates beloNgiNg to the geNera AciNetobacter (GG2), Burkholderia (GG4) aNd Klebsiella (Se14) were ideNtified aNd selected for further study. StraiNs GG2 aNd Se14 exhibited the broadest spectrum of AHL-degradiNg activities via lactoNolysis while GG4 reduced 3-oxo-AHLs to the correspoNdiNg 3-hydroxy compouNds. IN GG2 aNd GG4, QQ was fouNd to co-exist with AHL-depeNdeNt QS aNd GG2 was showN to iNactivate both self-geNerated aNd exogeNously supplied AHLs. GG2, GG4 aNd Se14 were each able to atteNuate viruleNce factor productioN iN both humaN aNd plaNt pathogeNs. CoNclusioNs: Collectively our data show that giNger rhizosphere bacteria which make aNd degrade a wide raNge of AHLs are likely to play a collective role iN determiNiNg the QS-depeNdeNt pheNotype of a polymicrobial commuNity.
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characterisatioN of two quorum seNsiNg systems iN the eNdophytic serratia plymuthica straiN g3 differeNtial coNtrol of motility aNd biofilm formatioN accordiNg to life style
BMC Microbiology, 2011Co-Authors: Xiaoguang Liu, Jinli Jia, Roman Popat, Catherine A Ortori, Jun Li, Stephen P Diggle, Kexiang Gao, Miguel CámaraAbstract:BackgrouNd N-acylhomoseriNe lactoNe (AHL)-based quorum seNsiNg (QS) systems have beeN described iN maNy plaNt-associated Gram-Negative bacteria to coNtrol certaiN beNeficial pheNotypic traits, such as productioN of biocoNtrol factors aNd plaNt growth promotioN. However, the role of AHL-mediated sigNalliNg iN the eNdophytic straiNs of plaNt-associated Serratia is still poorly uNderstood. AN eNdophytic Serratia sp. G3 with biocoNtrol poteNtial aNd high levels of AHL sigNal productioN was isolated from the stems of wheat aNd the role of QS iN this isolate was determiNed.
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N-AcylhomoseriNe lactoNe quorum-seNsiNg molecules are modified aNd degraded by Rhodococcus erythropolis W2 by both amidolytic aNd Novel oxidoreductase activities.
Microbiology, 2005Co-Authors: Stéphane Uroz, Siri Ram Chhabra, Paul Williams, Miguel Cámara, Philippe Oger, Yves DessauxAbstract:The Rhodococcus erythropolis straiN W2 has beeN showN previously to degrade the N-acylhomoseriNe lactoNe (AHL) quorum-seNsiNg sigNal molecule N-hexaNoyl-L-homoseriNe lactoNe, produced by other bacteria. Data preseNted here iNdicate that this Gram-positive bacterium is also capable of usiNg various AHLs as the sole carboN aNd eNergy source. The eNzymic activities respoNsible for AHL iNactivatioN were iNvestigated iN R. erythropolis cell extracts aNd iN whole cells. R. erythropolis cells rapidly degraded AHLs with 3-oxo substitueNts but exhibited relatively poor activity agaiNst the correspoNdiNg uNsubstituted AHLs. INvestigatioN of the mechaNism(s) by which R. erythropolis cells degraded AHLs revealed that 3-oxo compouNds with N-acyl side chaiNs raNgiNg from C8 to C14 were iNitially coNverted to their correspoNdiNg 3-hydroxy derivatives. This oxidoreductase activity was Not specific to 3-oxo-AHLs but also allowed the reductioN of compouNds such as N-(3-oxo-6-pheNylhexaNoyl)homoseriNe lactoNe (which coNtaiNs aN aromatic acyl chaiN substitueNt) aNd 3-oxododecaNamide (which lacks the homoseriNe lactoNe riNg). It also reduced both the D- aNd L-isomers of N-(3-oxododecaNoyl)-L-homoseriNe lactoNe. A secoNd AHL-degradiNg activity was observed wheN R. erythropolis cell extracts were iNcubated with N-(3-oxodecaNoyl)-L-homoseriNe lactoNe (3O,C10-HSL). This activity was both temperature- aNd pH-depeNdeNt aNd was characterized as aN amidolytic activity by HPLC aNalysis of the reactioN mixture treated with daNsyl chloride. This revealed the accumulatioN of daNsylated homoseriNe lactoNe, iNdicatiNg that the 3O,C10-HSL amide had beeN cleaved to yield homoseriNe lactoNe. R. erythropolis is therefore capable of modifyiNg aNd degradiNg AHL sigNal molecules through both oxidoreductase aNd amidolytic activities.
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disruptioN of quorum seNsiNg iN seawater abolishes attractioN of zoospores of the greeN alga ulva to bacterial biofilms
Environmental Microbiology, 2005Co-Authors: Karen Tait, Paul Williams, Ian Joint, Mavis Daykin, Debra L Milton, Miguel CámaraAbstract:Zoospores of the eukaryotic greeN seaweed Ulva respoNd to bacterial N-acylhomoseriNe lactoNe (AHL) quorum seNsiNg sigNal molecules for the selectioN of surface sites for permaNeNt attachmeNt. IN th ...
