scholarly journals Pantoeasp. Isolated from Tropical Fresh Water ExhibitingN-Acyl Homoserine Lactone Production

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Wen-Si Tan ◽  
Nina Yusrina Muhamad Yunos ◽  
Pui-Wan Tan ◽  
Nur Izzati Mohamad ◽  
Tan-Guan-Sheng Adrian ◽  
...  
Keyword(s):  
Gene Sequence ◽  
Sequence Similarity ◽  
Environmental Water ◽  
Homoserine Lactone ◽  
Acyl Homoserine Lactone ◽  
Gram Negative Bacteria ◽  
Water Sampling ◽  
16S Rdna Gene ◽  
Preliminary Screening ◽  
Pantoea Stewartii

N-Acyl homoserine lactone (AHL) serves as signaling molecule for quorum sensing (QS) in Gram-negative bacteria to regulate various physiological activities including pathogenicity. With the aim of isolating freshwater-borne bacteria that can cause outbreak of disease in plants and portrayed QS properties, environmental water sampling was conducted. Here we report the preliminary screening of AHL production usingChromobacterium violaceumCV026 andEscherichia coli[pSB401] as AHL biosensors. The 16S rDNA gene sequence of isolate M009 showed the highest sequence similarity toPantoea stewartiiS9-116, which is a plant pathogen. The isolatedPantoeasp. was confirmed to produceN-3-oxohexanoyl-L-HSL (3-oxo-C6-HSL) through analysis of high resolution mass tandem mass spectrometry.

Variations on a Theme: Diverse N-Acyl Homoserine Lactone-Mediated Quorum Sensing Mechanisms in Gram-Negative Bacteria

2006 ◽  
Vol 89 (3-4) ◽  
pp. 167-211 ◽  
Author(s):  
Debra Smith ◽  
Jin-Hong Wang ◽  
Jane E. Swatton ◽  
Peter Davenport ◽  
Bianca Price ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Homoserine Lactone ◽  
Acyl Homoserine Lactone ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Variations On A Theme

scholarly journals N-Acyl homoserine lactone-mediated quorum sensing in pathogenic Aeromonas veronii biovar sobria strain 159: Identification of LuxIR homologs

2015 ◽  
Author(s):  
Xin Yue Chan ◽  
Kah Yan How ◽  
Wai Fong Yin ◽  
Kok Gan Chan
Keyword(s):  
Quorum Sensing ◽  
Bacterial Population ◽  
Gene Annotation ◽  
Homoserine Lactone ◽  
Genome Comparison ◽  
Acyl Homoserine Lactone ◽  
Gram Negative Bacteria ◽  
Signalling Molecules ◽  
Aeromonas Veronii ◽  
High Degree

Quorum sensing (QS) is a mechanism that plays important roles in gene expression in response to an expanding bacterial population. In many Gram-negative bacteria, N-acyl homoserine lactone is mainly secreted as the diffusible signalling molecules. This QS system has been shown to control diverse array of virulence and secondary metabolism. Recently, whole genome sequencing of Aeromonas veronii biovar sobria strain 159 was performed. Genome comparison with closely-related Aeromonas species showed that A. veronii strain 159 shares a high degree of genome synteny with A. hydrophila ATCC 7966. A detailed genome analysis and gene annotation led us to the findings that A. veronii strain 159 harbors QS system which relies on its signal generator, AveI and the transcriptional regulator, AveR. This Aeromonas strain was found to secrete N-butanoylacyl homoserine lactone (C4-HSL). Its LuxIR homologs are similar to proteins of LuxIR famililies among Aeromonas species. This study aims to gain further insights into AveIR system and to compare with AhyIR from A. hydrophila ATCC 7966 and AsaIR from A. salmonicida.

scholarly journals Chlamydiales – Taxonomy, Pathogenicity, and Zoonotic Potential

2012 ◽  
Vol 56 (3) ◽  
pp. 267-270
Author(s):  
Krzysztof Niemczuk ◽  
Marian Truszczyńsk ◽  
Monika Szymańska-Czerwińska
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rdna ◽  
Gene Sequence ◽  
Sequence Similarity ◽  
Rrna Genes ◽  
23S Rrna ◽  
Zoonotic Potential ◽  
16S Rdna Gene ◽  
The Family ◽  
23S Rrna Genes

Abstract Changes in the taxonomy of the order Chlamydiales, after its separation from the order Rickettsiales, were presented. These changes resulted in the recognition of the following families: Chlamydiaceae, Chlavichlamydiaceae, Criblamydiaceae, Parachlamydiaceae, Piscichlamydiaceae, Rhabdochlamydiaceae, Simkaniaceae, and Waddliaceae. Other described changes concerned particularly the family Chlamydiaceae. Its genus Chlamydia was divided into Chlamydia and Chlamydophila. However, in the following years, a revision to the single original genus was made, based upon phylogenetic analysis of 16S and 23S rRNA genes of the strains belonging to these two taxonomic units. The review also discusses other families outside the family Chlamydiaceae, which contain so-called Chlamydia-related or Chlamydia-like organisms. Members of each family share a 16S rDNA gene sequence similarity >90%. Furthermore, characterisation of the pathogenecity is presented, focusing especially on the representatives of the family Chlamydiaceae, which cause animal infections, and describing their zoonotic potential. Available data on this topic, connected with the representatives of other families, were mentioned.

scholarly journals Probing the Impact of Ligand Binding on the Acyl-Homoserine Lactone-Hindered Transcription Factor EsaR of Pantoea stewartii subsp. stewartii

2011 ◽  
Vol 193 (22) ◽  
pp. 6315-6322 ◽  
Author(s):  
Daniel J. Schu ◽  
Revathy Ramachandran ◽  
Jared S. Geissinger ◽  
Ann M. Stevens
Keyword(s):  
Conformational Changes ◽  
Homoserine Lactone ◽  
Biologically Active ◽  
Acyl Homoserine Lactone ◽  
Content Type ◽  
Pantoea Stewartii ◽  
Cell Densities ◽  
The Impact

The quorum-sensing regulator EsaR fromPantoea stewartiisubsp.stewartiiis a LuxR homologue that is inactivated by acyl-homoserine lactone (AHL). In the corn pathogenP. stewartii, production of exopolysaccharide (EPS) is repressed by EsaR at low cell densities. However, at high cell densities when high concentrations of its cognate AHL signal are present, EsaR is inactivated and derepression of EPS production occurs. Thus, EsaR responds to AHL in a manner opposite to that of most LuxR family members. Depending on the position of its binding site within target promoters, EsaR serves as either a repressor or activator in the absence rather than in the presence of its AHL ligand. The effect of AHL on LuxR homologues has been difficult to studyin vitrobecause AHL is required for purification and stability. EsaR, however, can be purified without AHL enabling anin vitroanalysis of the response of the protein to ligand. Western immunoblots and pulse-chase experiments demonstrated that EsaR is stablein vivoin the absence or presence of AHL. Limitedin vitroproteolytic digestions of a biologically active His-MBP tagged version of EsaR highlighted intradomain and interdomain conformational changes that occur in the protein in response to AHL. Gel filtration chromatography of the full-length fusion protein and cross-linking of the N-terminal domain both suggest that this conformational change does not impact the multimeric state of the protein. These findings provide greater insight into the diverse mechanisms for AHL responsiveness found within the LuxR family.

scholarly journals Inactivation of Baroduric Bacteria Isolated by High Hydrostatic Pressure from Pickled Cowpea

2012 ◽  
Vol 1 (3) ◽  
pp. 101 ◽  
Author(s):  
Xuemei Li ◽  
Dong Zhao ◽  
Anjun Chen ◽  
Tiantian Lin ◽  
Biao Pu
Keyword(s):  
Lactic Acid ◽  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Genomic Dna ◽  
Gene Sequence ◽  
Sequence Similarity ◽  
Holding Time ◽  
Indicator Bacteria ◽  
16S Rdna Gene ◽  
Pressure Resistance

<p>In this study, <em>Pickled Cowpea</em>, a typical lactic acid fermented vegetable in Sichuan, China, was used as samples to study both species and inactivation of baroduric bacteria isolated by HHP treatment under different pressure levels and different pressure holding time. 16S rDNA gene sequence, amplified using genomic DNA of 4 baroduric bacteria from <em>Pickled Cowpea</em> as templates, were sequenced and then were identified based on the sequence similarity and homology analysis, as <em>B. licheniformis</em>, <em>B</em>. <em>subtilis, B</em>. <em>sonorensis and B</em>. <em>pumilus</em>. The pressure resistance of the 4 strains are compared under pressure from 300 to 500 MPa with holding time from 3 to 25 min. <em>B</em>. <em>pumilus </em>which has higher pressure resistance can be selected as indicator bacteria for applying HHP treatment to <em>Pickle </em>production.</p>

scholarly journals Quorum Sensing Activity ofMesorhizobiumsp. F7 Isolated from Potable Water

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Pei-Ling Yong ◽  
Kok-Gan Chan
Keyword(s):  
Mass Spectrometry ◽  
Phylogenetic Analysis ◽  
Potable Water ◽  
Bacterial Isolate ◽  
Homoserine Lactone ◽  
Acyl Homoserine Lactone ◽  
Triple Quadrupole ◽  
Liquid Chromatography Mass Spectrometry ◽  
16S Rdna Gene ◽  
Microbe Interactions

We isolated a bacterial isolate (F7) from potable water. The strain was identified asMesorhizobiumsp. by 16S rDNA gene phylogenetic analysis and screened forN-acyl homoserine lactone (AHL) production by an AHL biosensor. The AHL profile of the isolate was further analyzed using high resolution triple quadrupole liquid chromatography mass spectrometry (LC/MS) which confirmed the production of multiple AHLs, namely,N-3-oxo-octanoyl-L-homoserine lactone (3-oxo-C8-HSL) andN-3-oxo-decanoyl-L-homoserine lactone (3-oxo-C10-HSL). These findings will open the perspective to study the function of these AHLs in plant-microbe interactions.

scholarly journals N-Acyl homoserine lactone-mediated quorum sensing in pathogenic Aeromonas veronii biovar sobria strain 159: Identification of LuxIR homologs

2015 ◽  
Author(s):  
Xin Yue Chan ◽  
Kah Yan How ◽  
Wai Fong Yin ◽  
Kok Gan Chan
Keyword(s):  
Quorum Sensing ◽  
Bacterial Population ◽  
Gene Annotation ◽  
Homoserine Lactone ◽  
Genome Comparison ◽  
Acyl Homoserine Lactone ◽  
Gram Negative Bacteria ◽  
Signalling Molecules ◽  
Aeromonas Veronii ◽  
High Degree

Quorum sensing (QS) is a mechanism that plays important roles in gene expression in response to an expanding bacterial population. In many Gram-negative bacteria, N-acyl homoserine lactone is mainly secreted as the diffusible signalling molecules. This QS system has been shown to control diverse array of virulence and secondary metabolism. Recently, whole genome sequencing of Aeromonas veronii biovar sobria strain 159 was performed. Genome comparison with closely-related Aeromonas species showed that A. veronii strain 159 shares a high degree of genome synteny with A. hydrophila ATCC 7966. A detailed genome analysis and gene annotation led us to the findings that A. veronii strain 159 harbors QS system which relies on its signal generator, AveI and the transcriptional regulator, AveR. This Aeromonas strain was found to secrete N-butanoylacyl homoserine lactone (C4-HSL). Its LuxIR homologs are similar to proteins of LuxIR famililies among Aeromonas species. This study aims to gain further insights into AveIR system and to compare with AhyIR from A. hydrophila ATCC 7966 and AsaIR from A. salmonicida.

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