scholarly journals Endophytic Actinomycetes: A Novel Source of Potential Acyl Homoserine Lactone Degrading Enzymes

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Surang Chankhamhaengdecha ◽  
Suphatra Hongvijit ◽  
Akkaraphol Srichaisupakit ◽  
Pattra Charnchai ◽  
Watanalai Panbangred
Keyword(s):  
Pathogenic Bacteria ◽  
Sequence Similarity ◽  
Soft Rot ◽  
Quorum Quenching ◽  
Homoserine Lactone ◽  
Amide Bond ◽  
Side Chain ◽  
Signal Molecules ◽  
Endophytic Actinomycetes

Several Gram-negative pathogenic bacteria employN-acyl-L-homoserine lactone (HSL) quorum sensing (QS) system to control their virulence traits. Degradation of acyl-HSL signal molecules by quorum quenching enzyme (QQE) results in a loss of pathogenicity in QS-dependent organisms. The QQE activity of actinomycetes in rhizospheric soil and inside plant tissue was explored in order to obtain novel strains with high HSL-degrading activity. Among 344 rhizospheric and 132 endophytic isolates, 127 (36.9%) and 68 (51.5%) of them, respectively, possessed the QQE activity. The highest HSL-degrading activity was at151.30±3.1 nmole/h/mL from an endophytic actinomycetes isolate, LPC029. The isolate was identified asStreptomycesbased on16S  rRNAgene sequence similarity. The QQE from LPC029 revealed HSL-acylase activity that was able to cleave an amide bond of acyl-side chain in HSL substrate as determined by HPLC. LPC029 HSL-acylase showed broad substrate specificity from C6- to C12-HSL in which C10HSL is the most favorable substrate for this enzyme. In anin vitropathogenicity assay, the partially purified HSL-acylase efficiently suppressed soft rot of potato caused byPectobacterium carotovorumssp.carotovorumas demonstrated. To our knowledge, this is the first report of HSL-acylase activity derived from an endophyticStreptomyces.

Novel bacteria degrading N-acylhomoserine lactones and their use as quenchers of quorum-sensing-regulated functions of plant-pathogenic bacteria

Microbiology ◽  
2003 ◽  
Vol 149 (8) ◽  
pp. 1981-1989 ◽  
Author(s):  
Stéphane Uroz ◽  
Cathy D'Angelo-Picard ◽  
Aurélien Carlier ◽  
Miena Elasri ◽  
Carine Sicot ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Pathogenic Bacteria ◽  
Rhodococcus Erythropolis ◽  
Homoserine Lactone ◽  
Signal Molecules ◽  
In Planta ◽  
Signal Molecule ◽  
Violacein Production ◽  
Regulated Functions

Bacteria degrading the quorum-sensing (QS) signal molecule N-hexanoylhomoserine lactone were isolated from a tobacco rhizosphere. Twenty-five isolates degrading this homoserine lactone fell into six groups according to their genomic REP-PCR and rrs PCR-RFLP profiles. Representative strains from each group were identified as members of the genera Pseudomonas, Comamonas, Variovorax and Rhodococcus. All these isolates degraded N-acylhomoserine lactones other than the hexanoic acid derivative, albeit with different specificity and kinetics. One of these isolates, Rhodococcus erythropolis strain W2, was used to quench QS-regulated functions of other microbes. In vitro, W2 strongly interfered with violacein production by Chromobacterium violaceum, and transfer of pathogenicity in Agrobacterium tumefaciens. In planta, R. erythropolis W2 markedly reduced the pathogenicity of Pectobacterium carotovorum subsp. carotovorum in potato tubers. These series of results reveal the diversity of the QS-interfering bacteria in the rhizosphere and demonstrate the validity of targeting QS signal molecules to control pathogens with natural bacterial isolates.

scholarly journals Identification of Extracellular N-Acylhomoserine Lactone Acylase from a Streptomyces sp. and Its Application to Quorum Quenching

2005 ◽  
Vol 71 (5) ◽  
pp. 2632-2641 ◽  
Author(s):  
Sun-Yang Park ◽  
Hye-Ok Kang ◽  
Hak-Sun Jang ◽  
Jung-Kee Lee ◽  
Bon-Tag Koo ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Pathogenic Bacteria ◽  
Quorum Quenching ◽  
Homoserine Lactone ◽  
Amino Acid Sequences ◽  
Amide Bond ◽  
Mass Spectrometry Analysis ◽  
Penicillin G ◽  
Spectrometry Analysis ◽  
Acyl Chains

ABSTRACT N-Acylhomoserine lactones (AHLs) play an important role in regulating virulence factors in pathogenic bacteria. Recently, the enzymatic inactivation of AHLs, which can be used as antibacterial targets, has been identified in several soil bacteria. In this study, strain M664, identified as a Streptomyces sp., was found to secrete an AHL-degrading enzyme into a culture medium. The ahlM gene for AHL degradation from Streptomyces sp. strain M664 was cloned, expressed heterologously in Streptomyces lividans, and purified. The enzyme was found to be a heterodimeric protein with subunits of approximately 60 kDa and 23 kDa. A comparison of AhlM with known AHL-acylases, Ralstonia strain XJ12B AiiD and Pseudomonas aeruginosa PAO1 PvdQ, revealed 35% and 32% identities in the deduced amino acid sequences, respectively. However, AhlM was most similar to the cyclic lipopeptide acylase from Streptomyces sp. strain FERM BP-5809, exhibiting 93% identity. A mass spectrometry analysis demonstrated that AhlM hydrolyzed the amide bond of AHL, releasing homoserine lactone. AhlM exhibited a higher deacylation activity toward AHLs with long acyl chains rather than short acyl chains. Interestingly, AhlM was also found to be capable of degrading penicillin G by deacylation, showing that AhlM has a broad substrate specificity. The addition of AhlM to the growth medium reduced the accumulation of AHLs and decreased the production of virulence factors, including elastase, total protease, and LasA, in P. aeruginosa. Accordingly, these results suggest that AHL-acylase, AhlM could be effectively applied to the control of AHL-mediated pathogenicity.

scholarly journals Characterization and Complete Sequence of Lactonase Enzyme fromBacillus weihenstephanensisIsolate P65 with Potential Activity against Acyl Homoserine Lactone Signal Molecules

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Masarra Mohammed Sakr ◽  
Khaled Mohamed Anwar Aboshanab ◽  
Mohammad Mabrouk Aboulwafa ◽  
Nadia Abdel-Haleem Hassouna
Keyword(s):  
Pathogenic Bacteria ◽  
Quorum Quenching ◽  
Homoserine Lactone ◽  
Complete Sequence ◽  
Crude Enzyme ◽  
Signal Molecules ◽  
Acyl Homoserine Lactone ◽  
Crude Enzyme Extract ◽  
Synthetic Standard ◽  
Ph Range

Acyl homoserine lactones (AHLs) are the most common class of quorum sensing signal molecules (autoinducers) that have been reported to be essential for virulence of many relevant pathogenic bacteria such asPseudomonas aeruginosa. New approach for controlling infections of such bacteria is through quorum quenching. In this study, the acyl homoserine lactone inhibitory activity of the crude enzyme from aBacillus weihenstephanensis-isolate P65 was characterized. The crude enzyme was found to have relatively high thermal stability and was stable in pH range 6 to 9. The crude enzyme extract was found to have lactonase activity of 36.3 U/mg total protein. Maximum enzyme activity was achieved within a range of 28–50°C and pH 6–9. None of the metals used enhanced the activity neither did EDTA inhibit it. However, a concentration of 10 mM Fe+2reduced the activity to 73.8%. Catalytic activity and kinetic constants were determined using hexanoyl homoserine lactone as a substrate. Studying enzyme substrate specificity using synthetic standard signals displayed broad spectrum of activity. The enzyme was found to be constitutive. Isolation and complete nucleotide sequence of the respective lactonase gene were done and submitted to the Genbank database under accession code KC823046.

scholarly journals Quorum Quenching by an N-Acyl-Homoserine Lactone Acylase from Pseudomonas aeruginosa PAO1

2006 ◽  
Vol 74 (3) ◽  
pp. 1673-1682 ◽  
Author(s):  
Charles F. Sio ◽  
Linda G. Otten ◽  
Robbert H. Cool ◽  
Stephen P. Diggle ◽  
Peter G. Braun ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Quorum Quenching ◽  
Homoserine Lactone ◽  
Side Chain ◽  
Signal Molecules ◽  
Acyl Homoserine Lactone ◽  
Beta Lactam ◽  
Signal Molecule ◽  
Pathogenic Potential

ABSTRACT The virulence of the opportunistic human pathogen Pseudomonas aeruginosa PAO1 is controlled by an N-acyl-homoserine lactone (AHL)-dependent quorum-sensing system. During functional analysis of putative acylase genes in the P. aeruginosa PAO1 genome, the PA2385 gene was found to encode an acylase that removes the fatty acid side chain from the homoserine lactone (HSL) nucleus of AHL-dependent quorum-sensing signal molecules. Analysis showed that the posttranslational processing of the acylase and the hydrolysis reaction type are similar to those of the beta-lactam acylases, strongly suggesting that the PA2385 protein is a member of the N-terminal nucleophile hydrolase superfamily. In a bioassay, the purified acylase was shown to degrade AHLs with side chains ranging in length from 11 to 14 carbons at physiologically relevant low concentrations. The substituent at the 3′ position of the side chain did not affect activity, indicating broad-range AHL quorum-quenching activity. Of the two main AHL signal molecules of P. aeruginosa PAO1, N-butanoyl-l-homoserine lactone (C4-HSL) and N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C12-HSL), only 3-oxo-C12-HSL is degraded by the enzyme. Addition of the purified protein to P. aeruginosa PAO1 cultures completely inhibited accumulation of 3-oxo-C12-HSL and production of the signal molecule 2-heptyl-3-hydroxy-4(1H)-quinolone and reduced production of the virulence factors elastase and pyocyanin. Similar results were obtained when the PA2385 gene was overexpressed in P. aeruginosa. These results demonstrate that the protein has in situ quorum-quenching activity. The quorum-quenching AHL acylase may enable P. aeruginosa PAO1 to modulate its own quorum-sensing-dependent pathogenic potential and, moreover, offers possibilities for novel antipseudomonal therapies.

scholarly journals Quenching of acyl-homoserine lactone-dependent quorum sensing by enzymatic disruption of signal molecules.

2009 ◽  
Vol 56 (1) ◽  
Author(s):  
Robert Czajkowski ◽  
Sylwia Jafra
Keyword(s):  
Quorum Sensing ◽  
Pathogenic Bacteria ◽  
Degradation Products ◽  
Antibiotic Production ◽  
Quorum Quenching ◽  
Homoserine Lactone ◽  
Signal Molecules ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Animal Pathogens

Many Gram-positive and Gram-negative bacteria communicate using small diffusible signal molecules called autoinducers. This process, known as quorum sensing (QS), links cell density to the expression of genes as diverse as those associated with virulence factors production of plant and animal pathogens, bioluminescence, antibiotic production, sporulation or biofilm formation. In Gram-negative bacteria, this communication is mainly mediated by N-acyl-homoserine lactones (AHLs). It has been proven that inactivation of the signal molecules attenuates many of the processes controlled by QS. Enzymatic degradation of the signal molecules has been amply described. Two main classes of AHL-inactivating enzymes were identified: AHL lactonases which hydrolyse the lactone ring in AHLs, and AHL acylases (syn. AHL amidases) which liberate a free homoserine lactone and a fatty acid. Recently, AHL oxidoreductase, a novel type of AHL inactivating enzyme, was described. The activity of these enzymes results in silencing the QS-regulated processes, as degradation products cannot act as signal molecules. The ability to inactivate AHL (quorum quenching, QQ) might be useful in controlling virulence of many pathogenic bacteria.

Novel approach to quorum quenching: rational design of antibacterials in combination with hexahistidine-tagged organophosphorus hydrolase

2018 ◽  
Vol 399 (8) ◽  
pp. 869-879 ◽  
Author(s):  
Aysel Aslanli ◽  
Ilya Lyagin ◽  
Elena Efremenko
Keyword(s):  
Molecular Docking ◽  
Rational Design ◽  
Pathogenic Bacteria ◽  
Quorum Quenching ◽  
Homoserine Lactone ◽  
Catalytic Action ◽  
Organophosphorus Hydrolase ◽  
Signal Molecules ◽  
Bacterial Strains ◽  
Native Form

Abstract N-acyl homoserine lactones (AHLs) are quorum sensing (QS) signal molecules used by most Gram-negative pathogenic bacteria. In this article the lactonase activity of the preparations based on hexahistidine-tagged organophosphorus hydrolase (His6-OPH) towards AHLs was studied. Initially, three of the most interesting β-lactam antibiotics were selected from seven that were trialed during molecular docking to His6-OPH. Combinations of antibiotics (meropenem, imipenem, ceftriaxone) and His6-OPH taken in the native form or in the form of non-covalent enzyme-polyelectrolyte complexes (EPCs) with poly(glutamic acid) or poly(aspartic acid) were obtained and investigated. The lactonase activity of the preparations was investigated under different physical-chemical conditions in the hydrolysis of AHLs [N-butyryl-D,L-homoserine lactone, N-(3-oxooctanoyl)-D,L-homoserine lactone, N-(3-oxododecanoyl)-L-homoserine lactone]. An increased efficiency of catalytic action and stability of the lactonase activity of His6-OPH was shown for its complexes with antibiotics and was confirmed in trials with bacterial strains. The broadening of the catalytic action of the enzyme against AHLs was revealed in the presence of the meropenem. Results of molecular docking of AHLs to the surface of the His6-OPH dimer in the presence of antibiotics allowed proposing the mechanism of such interference based on a steric repulsion of the carbon chain of hydrolyzed AHLs by the antibiotics bounded to the enzyme surface.

scholarly journals AidH, an Alpha/Beta-Hydrolase Fold Family Member from an Ochrobactrum sp. Strain, Is a Novel N-Acylhomoserine Lactonase

2010 ◽  
Vol 76 (15) ◽  
pp. 4933-4942 ◽  
Author(s):  
Gui-Ying Mei ◽  
Xiao-Xue Yan ◽  
Ali Turak ◽  
Zhao-Qing Luo ◽  
Li-Qun Zhang
Keyword(s):  
Pathogenic Bacteria ◽  
Divalent Cations ◽  
Hydrolytic Enzyme ◽  
Quorum Quenching ◽  
Homoserine Lactone ◽  
Great Promise ◽  
Fold Family ◽  
Hydrolase Fold ◽  
Enzymatic Inactivation ◽  
Alpha Beta

ABSTRACT N-Acylhomoserine lactones (AHLs) are signaling molecules in many quorum-sensing (QS) systems that regulate interactions between various pathogenic bacteria and their hosts. Quorum quenching by the enzymatic inactivation of AHLs holds great promise in preventing and treating infections, and several such enzymes have been reported. In this study, we report the characterization of a novel AHL-degrading protein from the soil bacterium Ochrobactrum sp. strain T63. This protein, termed AidH, shares no similarity with any of the known AHL degradases but is highly homologous with a hydrolytic enzyme from Ochrobactrum anthropi ATCC 49188 that contains the alpha/beta-hydrolase fold. By liquid chromatography-mass spectrometry (MS) analysis, we demonstrate that AidH functions as an AHL-lactonase that hydrolyzes the ester bond of the homoserine lactone ring of AHLs. Mutational analyses indicate that the G-X-Nuc-X-G motif or the histidine residue conserved among alpha/beta-hydrolases is critical for the activity of AidH. Furthermore, the AHL-inactivating activity of AidH requires Mn2+ but not several other tested divalent cations. We also showed that AidH significantly reduces biofilm formation by Pseudomonas fluorescens 2P24 and the pathogenicity of Pectobacterium carotovorum, indicating that this enzyme is able to effectively quench QS-dependent functions in these bacteria by degrading AHLs.

scholarly journals Bioactivity of Selected Phenolic Acids and Hexane Extracts from Bougainvilla spectabilis and Citharexylum spinosum on the Growth of Pectobacterium carotovorum and Dickeya solani Bacteria: An Opportunity to Save the Environment

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 482 ◽  
Author(s):  
Nader A. Ashmawy ◽  
Said I. Behiry ◽  
Asma A. Al-Huqail ◽  
Hayssam M. Ali ◽  
Mohamed Z. M. Salem
Keyword(s):  
Phenolic Acids ◽  
Tannic Acid ◽  
Defense Mechanisms ◽  
Pathogenic Bacteria ◽  
Soft Rot ◽  
Inhibition Zone ◽  
Pectobacterium Carotovorum ◽  
Bacterial Isolates ◽  
Dickeya Solani

Phenolic acids and natural extracts, as ecofriendly environmental agents, can be used as bio bactericides against the growth of plant pathogenic bacteria. In this study, isolation trails from infected potato tubers and stems that showed soft rot symptoms in fields revealed two soft rot bacterial isolates and were initially identified through morphological, physiological, and pathogenicity tests. The molecular characterization of these isolates via PCR, based on the 16S rRNA region, was carried out by an analysis of the DNA sequence via BLAST and Genbank, and showed that the soft rot bacterial isolates belong to Pectobacterium carotovorum subsp. carotovorum (PCC1) and Dickeya solani (Ds1). The in vitro results of the tested phenolic acids against the cultured bacterial isolates proved that concentrations of 800, 1600, and 3200 μg/mL were the most effective. Ferulic acid was the potent suppressive phenolic acid tested against the Ds1 isolate, with an inhibition zone ranging from 6.00 to 25.75 mm at different concentrations (25–3200 μg/mL), but had no effect until reaching a concentration of 100 μg/mL in the PCC1 isolate, followed by tannic acid, which ranged from 7.00 to 25.50 mm. On the other hand, tannic acid resulted in a significant decrease in the growth rate of the PCC1 isolate with a mean of 9.11 mm. Chlorogenic acid was not as effective as the rest of the phenolic acids compared with the control. The n-hexane oily extract (HeOE) from Bougainvillea spectabilis bark showed the highest activity against PCC1 and Ds1, with inhibition zone values of 12 and 12.33 mm, respectively, at a concentration of 4000 μg/mL; while the HeOE from Citharexylum spinosum wood showed less activity. In the GC/MS analysis, nonanal, an oily liquid compound, was found ata percentage of 38.28%, followed by cis-2-nonenal (9.75%), which are the main compounds in B. spectabilis bark HeOE, and 2-undecenal (22.39%), trans-2-decenal (18.74%), and oleic acid (10.85%) were found, which are the main compounds in C. spinosum wood HeOE. In conclusion, the phenolic acids and plant HeOEs seem to raise the resistance of potato plants, improving their defense mechanisms against soft rot bacterial pathogens.

scholarly journals Quorum Quenching Properties and Probiotic Potentials of Intestinal Associated Bacteria in Asian Sea Bass Lates calcarifer

Marine Drugs ◽  
2019 ◽  
Vol 18 (1) ◽  
pp. 23 ◽  
Author(s):  
Reza Ghanei-Motlagh ◽  
Takavar Mohammadian ◽  
Darioush Gharibi ◽  
Simon Menanteau-Ledouble ◽  
Esmaeil Mahmoudi ◽  
...  
Keyword(s):  
High Capacity ◽  
Quorum Quenching ◽  
Homoserine Lactone ◽  
Amino Acid Sequences ◽  
Diffusion Method ◽  
Asian Sea Bass ◽  
Pathogenic Vibrio ◽  
Rdna Sequencing ◽  
Degrading Bacteria

Quorum quenching (QQ), the enzymatic degradation of N-acyl homoserine lactones (AHLs), has been suggested as a promising strategy to control bacterial diseases. In this study, 10 AHL-degrading bacteria isolated from the intestine of barramundi were identified by 16S rDNA sequencing. They were able to degrade both short and long-chain AHLs associated with several pathogenic Vibrio species (spp.) in fish, including N-[(RS)-3-Hydroxybutyryl]-l-homoserine lactone (3-oh-C4-HSL), N-Hexanoyl-l-homoserine lactone (C6-HSL), N-(β-Ketocaproyl)-l-homoserine lactone (3-oxo-C6-HSL), N-(3-Oxodecanoyl)-l-homoserine lactone (3-oxo-C10-HSL), N-(3-Oxotetradecanoyl)-l-homoserine lactone (3-oxo-C14-HSL). Five QQ isolates (QQIs) belonging to the Bacillus and Shewanella genera, showed high capacity to degrade both synthetic AHLs as well as natural AHLs produced by Vibrio harveyi and Vibrio alginolyticus using the well-diffusion method and thin-layer chromatography (TLC). The genes responsible for QQ activity, including aiiA, ytnP, and aaC were also detected. Analysis of the amino acid sequences from the predicted lactonases revealed the presence of the conserved motif HxHxDH. The selected isolates were further characterized in terms of their probiotic potentials in vitro. Based on our scoring system, Bacillus thuringiensis QQ1 and Bacillus cereus QQ2 exhibited suitable probiotic characteristics, including the production of spore and exoenzymes, resistance to bile salts and pH, high potential to adhere on mucus, appropriate growth abilities, safety to barramundi, and sensitivity to antibiotics. These isolates, therefore, constitute new QQ probiotics that could be used to control vibriosis in Lates calcalifer.

scholarly journals Novel Reporter for Identification of Interference with Acyl Homoserine Lactone and Autoinducer-2 Quorum Sensing

2014 ◽  
Vol 81 (4) ◽  
pp. 1477-1489 ◽  
Author(s):  
Nancy Weiland-Bräuer ◽  
Nicole Pinnow ◽  
Ruth A. Schmitz
Keyword(s):  
Quorum Sensing ◽  
Vibrio Fischeri ◽  
Quorum Quenching ◽  
Homoserine Lactone ◽  
Signal Molecules ◽  
Lethal Gene ◽  
Reporter Strain ◽  
Content Type ◽  
E Coli ◽  
Autoinducer 2

ABSTRACTTwo reporter strains were established to identify novel biomolecules interfering with bacterial communication (quorum sensing [QS]). The basic design of theseEscherichia coli-based systems comprises a gene encoding a lethal protein fused to promoters induced in the presence of QS signal molecules. Consequently, theseE. colistrains are unable to grow in the presence of the respective QS signal molecules unless a nontoxic QS-interfering compound is present. The first reporter strain designed to detect autoinducer-2 (AI-2)-interfering activities (AI2-QQ.1) contained theE. coliccdBlethal gene under the control of theE. colilsrApromoter. The second reporter strain (AI1-QQ.1) contained theVibrio fischeriluxIpromoter fused to theccdBgene to detect interference with acyl-homoserine lactones. Bacteria isolated from the surfaces of several marine eukarya were screened for quorum-quenching (QQ) activities using the established reporter systems AI1-QQ.1 and AI2-QQ.1. Out of 34 isolates, two interfered with acylated homoserine lactone (AHL) signaling, five interfered with AI-2 QS signaling, and 10 were demonstrated to interfere with both signal molecules. Open reading frames (ORFs) conferring QQ activity were identified for three selected isolates (Photobacteriumsp.,Pseudoalteromonassp., andVibrio parahaemolyticus). Evaluation of the respective heterologously expressed and purified QQ proteins confirmed their ability to interfere with the AHL and AI-2 signaling processes.

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