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Uroz S, Geisler O, Fauchery L, Lami R, Rodrigues AMS, Morin E, Leveau JHJ, Oger P. Genomic and transcriptomic characterization of the Collimonas quorum sensing genes and regulon. FEMS Microbiol Ecol 2022; 98:6679101. [PMID: 36040340 DOI: 10.1093/femsec/fiac100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 07/13/2022] [Accepted: 08/26/2022] [Indexed: 01/21/2023] Open
Abstract
Collimonads are well-adapted to nutrient-poor environments. They are known to hydrolyse chitin, produce antifungal metabolites, weather minerals, and are effective biocontrol agents protecting plants from fungal diseases. The production of N-acyl homoserine lactones (AHLs) was suggested to be a conserved trait of collimonads, but little is known about the genes that underlie this production or the genes that are controlled by AHLs. To improve our understanding of the role of AHLs in the ecology of collimonads, we carried out transcriptomic analyses, combined with chemical and functional assays, on strain Collimonas pratensis PMB3(1). The main AHLs produced by this strain were identified as 3-hydroxy-hexa- and octa-noyl-homoserine lactone. Genome analysis permitted to identify putative genes coding for the autoinducer synthase (colI) and cognate transcriptional regulator (colR). The ability to produce AHLs was lost in ΔcolI and ΔcolR mutants. Functional assays revealed that the two mutants metabolized glucose, formate, oxalate, and leucine better than the wild-type (WT) strain. Transcriptome sequencing analyses revealed an up-regulation of different metabolic pathways and of motility in the QS-mutants compared to the WT strain. Overall, our results provide insights into the role of the AHL-dependent regulation system of Collimonas in environment colonization, metabolism readjustment, and microbial interactions.
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Affiliation(s)
- Stephane Uroz
- Université de Lorraine, INRAE, UMR1136 "Interactions Arbres-Microorganismes", F-54280 Champenoux, France.,INRAE, UR1138 "Biogéochimie des écosystèmes forestiers", F-54280 Champenoux, France
| | - Océane Geisler
- Université de Lorraine, INRAE, UMR1136 "Interactions Arbres-Microorganismes", F-54280 Champenoux, France
| | - Laure Fauchery
- Université de Lorraine, INRAE, UMR1136 "Interactions Arbres-Microorganismes", F-54280 Champenoux, France
| | - Raphaël Lami
- Sorbonne Université, CNRS, Laboratoire de Biodiversité et Biotechnologies Microbiennes (LBBM, USR3579), Fédération de Recherche FR3724, Observatoire Océanologique, 66650 Banyuls-sur-Mer, France
| | - Alice M S Rodrigues
- Sorbonne Université, CNRS, Laboratoire de Biodiversité et Biotechnologies Microbiennes (LBBM, USR3579), Fédération de Recherche FR3724, Observatoire Océanologique, 66650 Banyuls-sur-Mer, France
| | - Emmanuelle Morin
- Université de Lorraine, INRAE, UMR1136 "Interactions Arbres-Microorganismes", F-54280 Champenoux, France
| | - Johan H J Leveau
- Department of Plant Pathology, University of California - Davis, Davis, CA 95616, United States
| | - Philippe Oger
- Université Lyon, INSA de Lyon, CNRS UMR 5240, F-69622 Villeurbanne, France
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Wang MF, Wang J, Wang XB, Zhu XC, Wang YP, Wang W. Effect of SPoT-mediated Stringent Response on Biofilm Formation, Stress Resistance and Quorum Sensing in Pseudomonas protegens SN15-2. APPL BIOCHEM MICRO+ 2022. [DOI: 10.1134/s0003683822040172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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3
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Chi X, Wang Y, Miao J, Wang W, Sun Y, Yu Z, Feng Z, Cheng S, Chen L, Ge Y. EppR, a new LysR-family transcription regulator, positively influences phenazine biosynthesis in the plant growth-promoting rhizobacterium Pseudomonas chlororaphis G05. Microbiol Res 2022; 260:127050. [DOI: 10.1016/j.micres.2022.127050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 04/13/2022] [Accepted: 04/19/2022] [Indexed: 10/18/2022]
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Transcription Factor-Based Biosensors for Detecting Pathogens. BIOSENSORS 2022; 12:bios12070470. [PMID: 35884273 PMCID: PMC9312912 DOI: 10.3390/bios12070470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/21/2022] [Accepted: 06/27/2022] [Indexed: 12/23/2022]
Abstract
Microorganisms are omnipresent and inseparable from our life. Many of them are beneficial to humans, while some are not. Importantly, foods and beverages are susceptible to microbial contamination, with their toxins causing illnesses and even death in some cases. Therefore, monitoring and detecting harmful microorganisms are critical to ensuring human health and safety. For several decades, many methods have been developed to detect and monitor microorganisms and their toxicants. Conventionally, nucleic acid analysis and antibody-based analysis were used to detect pathogens. Additionally, diverse chromatographic methods were employed to detect toxins based on their chemical and structural properties. However, conventional techniques have several disadvantages concerning analysis time, sensitivity, and expense. With the advances in biotechnology, new approaches to detect pathogens and toxins have been reported to compensate for the disadvantages of conventional analysis from different research fields, including electrochemistry, nanotechnology, and molecular biology. Among them, we focused on the recent studies of transcription factor (TF)-based biosensors to detect microorganisms and discuss their perspectives and applications. Additionally, the other biosensors for detecting microorganisms reported in recent studies were also introduced in this review.
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Zhang N, Wu J, Zhang S, Yuan M, Xu H, Li J, Zhang P, Wang M, Kempher ML, Tao X, Zhang LQ, Ge H, He YX. Molecular basis for coordinating secondary metabolite production by bacterial and plant signaling molecules. J Biol Chem 2022; 298:102027. [PMID: 35568198 PMCID: PMC9163588 DOI: 10.1016/j.jbc.2022.102027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/03/2022] [Accepted: 05/05/2022] [Indexed: 11/28/2022] Open
Abstract
The production of secondary metabolites is a major mechanism used by beneficial rhizobacteria to antagonize plant pathogens. These bacteria have evolved to coordinate the production of different secondary metabolites due to the heavy metabolic burden imposed by secondary metabolism. However, for most secondary metabolites produced by bacteria, it is not known how their biosynthesis is coordinated. Here, we showed that PhlH from the rhizobacterium Pseudomonas fluorescens is a TetR-family regulator coordinating the expression of enzymes related to the biosynthesis of several secondary metabolites, including 2,4-diacetylphloroglucinol (2,4-DAPG), mupirocin, and pyoverdine. We present structures of PhlH in both its apo form and 2,4-DAPG-bound form and elucidate its ligand-recognizing and allosteric switching mechanisms. Moreover, we found that dissociation of 2,4-DAPG from the ligand-binding domain of PhlH was sufficient to allosterically trigger a pendulum-like movement of the DNA-binding domains within the PhlH dimer, leading to a closed-to-open conformational transition. Finally, molecular dynamics simulations confirmed that two distinct conformational states were stabilized by specific hydrogen bonding interactions and that disruption of these hydrogen bonds had profound effects on the conformational transition. Our findings not only reveal a well-conserved route of allosteric signal transduction in TetR-family regulators but also provide novel mechanistic insights into bacterial metabolic coregulation.
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Affiliation(s)
- Nannan Zhang
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei 230601, Anhui, China.
| | - Jin Wu
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, P.R. China
| | - Siping Zhang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, P.R. China
| | - Maoran Yuan
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, P.R. China
| | - Hang Xu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, P.R. China
| | - Jie Li
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, P.R. China
| | - Pingping Zhang
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei 230601, Anhui, China
| | - Mingzhu Wang
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, P.R. China
| | - Megan L Kempher
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, and School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, Ok, USA
| | - Xuanyu Tao
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, and School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, Ok, USA
| | - Li-Qun Zhang
- College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Honghua Ge
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, P.R. China.
| | - Yong-Xing He
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, P.R. China.
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Ke J, Zhao Z, Coates CR, Hadjithomas M, Kuftin A, Louie K, Weller D, Thomashow L, Mouncey NJ, Northen TR, Yoshikuni Y. Development of platforms for functional characterization and production of phenazines using a multi-chassis approach via CRAGE. Metab Eng 2021; 69:188-197. [PMID: 34890798 DOI: 10.1016/j.ymben.2021.11.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/24/2021] [Accepted: 11/30/2021] [Indexed: 02/08/2023]
Abstract
Phenazines (Phzs), a family of chemicals with a phenazine backbone, are secondary metabolites with diverse properties such as antibacterial, anti-fungal, or anticancer activity. The core derivatives of phenazine, phenazine-1-carboxylic acid (PCA) and phenazine-1,6-dicarboxylic acid (PDC), are themselves precursors for various other derivatives. Recent advances in genome mining tools have enabled researchers to identify many biosynthetic gene clusters (BGCs) that might produce novel Phzs. To characterize the function of these BGCs efficiently, we performed modular construct assembly and subsequent multi-chassis heterologous expression using chassis-independent recombinase-assisted genome engineering (CRAGE). CRAGE allowed rapid integration of a PCA BGC into 23 diverse γ-proteobacteria species and allowed us to identify top PCA producers. We then used the top five chassis hosts to express four partially refactored PDC BGCs. A few of these platforms produced high levels of PDC. Specifically, Xenorhabdus doucetiae and Pseudomonas simiae produced PDC at a titer of 293 mg/L and 373 mg/L, respectively, in minimal media. These titers are significantly higher than those previously reported. Furthermore, selectivity toward PDC production over PCA production was improved by up to 9-fold. The results show that these strains are promising chassis for production of PCA, PDC, and their derivatives, as well as for function characterization of Phz BGCs identified via bioinformatics mining.
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Affiliation(s)
- Jing Ke
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Zhiying Zhao
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Cameron R Coates
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Michalis Hadjithomas
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Andrea Kuftin
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Katherine Louie
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - David Weller
- USDA Agricultural Research Service, Wheat Health, Genetics and Quality, Washington State University, Pullman, WA, USA; Department of Plant Pathology, Washington State University, Pullman, WA, USA
| | - Linda Thomashow
- USDA Agricultural Research Service, Wheat Health, Genetics and Quality, Washington State University, Pullman, WA, USA; Department of Plant Pathology, Washington State University, Pullman, WA, USA
| | - Nigel J Mouncey
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Trent R Northen
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Yasuo Yoshikuni
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA; Center for Advanced Bioenergy and Bioproducts Innovation, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA; Global Center for Food, Land, and Water Resources, Hokkaido University, Hokkaido, 060-8589, Japan.
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Wang Z, Huang X, Jan M, Kong D, Wang W, Zhang X. Lon protease downregulates phenazine-1-carboxamide biosynthesis by degrading the quorum sensing signal synthase PhzI and exhibits negative feedback regulation of Lon itself in Pseudomonas chlororaphis HT66. Mol Microbiol 2021; 116:690-706. [PMID: 34097792 DOI: 10.1111/mmi.14764] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 06/02/2021] [Accepted: 06/02/2021] [Indexed: 11/28/2022]
Abstract
Pseudomonas chlororaphis HT66 exhibits strong antagonistic activity against various phytopathogenic fungi due to its main antibiotic phenazine-1-carboxamide (PCN). PCN gene cluster consists of phzABCDEFG, phzH, phzI, and phzR operons. phzABCDEFG transcription is activated by the PhzI/R quorum sensing system. Deletion of the lon gene encoding an ATP-dependent protease resulted in significant enhancement of PCN production in strain HT66. However, the regulatory pathway and mechanism of Lon on PCN biosynthesis remain unknown. Here, lon mutation was shown to significantly improve antimicrobial activity of strain HT66. The N-acyl-homoserine lactone synthase PhzI mediates the negative regulation of PCN biosynthesis and phzABCDEFG transcription by Lon. Western blot showed that PhzI protein abundance and stability were significantly enhanced by lon deletion. The in vitro degradation assay suggested that Lon could directly degrade PhzI protein. However, Lon with an amino acid replacement (S674 -A) could not degrade PhzI protein. Lon-recognized region was located within the first 50 amino acids of PhzI. In addition, Lon formed a new autoregulatory feedback circuit to modulate its own degradation by other potential proteases. In summary, we elucidated the Lon-regulated pathway mediated by PhzI during PCN biosynthesis and the molecular mechanism underlying the degradation of PhzI by Lon in P. chlororaphis HT66.
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Affiliation(s)
- Zheng Wang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xianqing Huang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Malik Jan
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Deyu Kong
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Wei Wang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xuehong Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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Functional Analysis of Phenazine Biosynthesis Genes in Burkholderia spp. Appl Environ Microbiol 2021; 87:AEM.02348-20. [PMID: 33741619 DOI: 10.1128/aem.02348-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 03/09/2021] [Indexed: 01/15/2023] Open
Abstract
Burkholderia encompasses a group of ubiquitous Gram-negative bacteria that includes numerous saprophytes as well as species that cause infections in animals, immunocompromised patients, and plants. Some species of Burkholderia produce colored, redox-active secondary metabolites called phenazines. Phenazines contribute to competitiveness, biofilm formation, and virulence in the opportunistic pathogen Pseudomonas aeruginosa, but knowledge of their diversity, biosynthesis, and biological functions in Burkholderia is lacking. In this study, we screened publicly accessible genome sequence databases and identified phenazine biosynthesis genes in multiple strains of the Burkholderia cepacia complex, some isolates of the B. pseudomallei clade, and the plant pathogen B. glumae We then focused on B. lata ATCC 17760 to reveal the organization and function of genes involved in the production of dimethyl 4,9-dihydroxy-1,6-phenazinedicarboxylate. Using a combination of isogenic mutants and plasmids carrying different segments of the phz locus, we characterized three novel genes involved in the modification of the phenazine tricycle. Our functional studies revealed a connection between the presence and amount of phenazines and the dynamics of biofilm growth in flow cell and static experimental systems but at the same time failed to link the production of phenazines with the capacity of Burkholderia to kill fruit flies and rot onions.IMPORTANCE Although the production of phenazines in Burkholderia was first reported almost 70 years ago, the role these metabolites play in the biology of these economically important microorganisms remains poorly understood. Our results revealed that the phenazine biosynthetic pathway in Burkholderia has a complex evolutionary history, which likely involved horizontal gene transfers among several distantly related groups of organisms. The contribution of phenazines to the formation of biofilms suggests that Burkholderia, like fluorescent pseudomonads, may benefit from the unique redox-cycling properties of these versatile secondary metabolites.
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Pang B, Liu T, Zhang W, Ye F, Shang C. Cloning and Characterization of phzR Gene from Pseudomonas aeruginosa. Curr Microbiol 2021; 78:1482-1487. [PMID: 33661422 DOI: 10.1007/s00284-021-02410-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 02/10/2021] [Indexed: 11/29/2022]
Abstract
A gene encoding phzR was isolated from a phenazine-producing bacterium Pseudomonas aeruginosa 2016NX1. This paper provided the full-length cDNA encoding phzR (GenBank Accession no., MW143078). The cDNA of the phzR contained an open reading frame (ORF) of 714 bp. The potential regulatory elements were predicted in the phzR promoter region. The deduced amino acid sequence of P. aeruginosa phzR showed significant homology to the known phzRs from different organisms. Gene overexpression analysis showed that the phenazine content was improved (44.39%) in comparison to wild-type 2016NX1.
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Affiliation(s)
- Bingbing Pang
- College of Life Science, Guangxi Normal University, Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, No. 1, Yanzhong Road, Yanshan District, Guilin, 541006, Guangxi, China
| | - Tingting Liu
- College of Life Science, Guangxi Normal University, Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, No. 1, Yanzhong Road, Yanshan District, Guilin, 541006, Guangxi, China
| | - Wenjia Zhang
- College of Life Science, Guangxi Normal University, Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, No. 1, Yanzhong Road, Yanshan District, Guilin, 541006, Guangxi, China
| | - Fengcai Ye
- College of Life Science, Guangxi Normal University, Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, No. 1, Yanzhong Road, Yanshan District, Guilin, 541006, Guangxi, China
| | - Changhua Shang
- College of Life Science, Guangxi Normal University, Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, No. 1, Yanzhong Road, Yanshan District, Guilin, 541006, Guangxi, China.
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Wu Y, Wang CW, Wang D, Wei N. A Whole-Cell Biosensor for Point-of-Care Detection of Waterborne Bacterial Pathogens. ACS Synth Biol 2021; 10:333-344. [PMID: 33496568 DOI: 10.1021/acssynbio.0c00491] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Water contamination by pathogenic bacteria is a major public health concern globally. Monitoring bacterial contamination in water is critically important to protect human health, but this remains a critical challenge. Engineered whole-cell biosensors created through synthetic biology hold great promise for rapid and cost-effective detection of waterborne pathogens. In this study, we created a novel whole-cell biosensor to detect water contamination by Pseudomonas aeruginosa and Burkholderia pseudomallei, which are two critical bacterial pathogens and are recognized as common causative agents for waterborne diseases. The biosensor detects the target bacterial pathogens by responding to the relevant quorum sensing signal molecules. Particularly, this study constructed and characterized the biosensor on the basis of the QscR quorum sensing signal system for the first time. We first designed and constructed a QscR on the basis of the sensing module in the E. coli host cell and integrated the QscR sensing module with a reporting module that expressed an enhanced green fluorescent protein (EGFP). The results demonstrated that the biosensor had high sensitivity in response to the quorum sensing signals of the target bacterial pathogens. We further engineered a biosensor that expressed a red pigment lycopene in the reporting module to produce a visible signal readout for the pathogen detection. Additionally, we investigated the feasibility of a paper-based assay by immobilizing the lycopene-based whole-cell biosensor on paper with the aim to build a prototype for developing portable detection devices. The biosensor would provide a simple and inexpensive alternative for timely and point-of-care detection of water contamination and protect human health.
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Miller C, Gilmore J. Detection of Quorum-Sensing Molecules for Pathogenic Molecules Using Cell-Based and Cell-Free Biosensors. Antibiotics (Basel) 2020; 9:antibiotics9050259. [PMID: 32429345 PMCID: PMC7277912 DOI: 10.3390/antibiotics9050259] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 05/13/2020] [Accepted: 05/14/2020] [Indexed: 11/18/2022] Open
Abstract
Since the discovery and subsequent use of penicillin, antibiotics have been used to treat most bacterial infections in the U.S. Over time, the repeated prescription of many antibiotics has given rise to many antibiotic-resistant microbes. A bacterial strain becomes resistant by horizontal gene transfer, where surviving microbes acquire genetic material or DNA fragments from adjacent bacteria that encode for resistance. In order to avoid significant bacterial resistance, novel and target therapeutics are needed. Further advancement of diagnostic technologies could be used to develop novel treatment strategies. The use of biosensors to detect quorum-sensing signaling molecules has the potential to provide timely diagnostic information toward mitigating the multidrug-resistant bacteria epidemic. Resistance and pathogenesis are controlled by quorum-sensing (QS) circuits. QS systems secrete or passively release signaling molecules when the bacterial concentration reaches a certain threshold. Signaling molecules give an early indication of virulence. Detection of these compounds in vitro or in vivo can be used to identify the onset of infection. Whole-cell and cell-free biosensors have been developed to detect quorum-sensing signaling molecules. This review will give an overview of quorum networks in the most common pathogens found in chronic and acute infections. Additionally, the current state of research surrounding the detection of quorum-sensing molecules will be reviewed. Followed by a discussion of future works toward the advancement of technologies to quantify quorum signaling molecules in chronic and acute infections.
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Zhang J, Mavrodi DV, Yang M, Thomashow LS, Mavrodi OV, Kelton J, Weller DM. Pseudomonas synxantha 2-79 Transformed with Pyrrolnitrin Biosynthesis Genes Has Improved Biocontrol Activity Against Soilborne Pathogens of Wheat and Canola. PHYTOPATHOLOGY 2020; 110:1010-1017. [PMID: 32065038 PMCID: PMC7238759 DOI: 10.1094/phyto-09-19-0367-r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A four-gene operon (prnABCD) from Pseudomonas protegens Pf-5 encoding the biosynthesis of the antibiotic pyrronitrin was introduced into P. synxantha (formerly P. fluorescens) 2-79, an aggressive root colonizer of both dryland and irrigated wheat roots that naturally produces the antibiotic phenazine-1-carboxylic acid and suppresses both take-all and Rhizoctonia root rot of wheat. Recombinant strains ZHW15 and ZHW25 produced both antibiotics and maintained population sizes in the rhizosphere of wheat that were comparable to those of strain 2-79. The recombinant strains inhibited in vitro the wheat pathogens Rhizoctonia solani anastomosis group 8 (AG-8) and AG-2-1, Gaeumannomyces graminis var. tritici, Sclerotinia sclerotiorum, Fusarium culmorum, and F. pseudograminearum significantly more than did strain 2-79. Both the wild-type and recombinant strains were equally inhibitory of Pythium ultimum. When applied as a seed treatment, the recombinant strains suppressed take-all, Rhizoctonia root rot of wheat, and Rhizoctonia root and stem rot of canola significantly better than did wild-type strain 2-79.
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Affiliation(s)
- Jibin Zhang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, P. R. China
- Department of Plant Pathology, Washington State University, Pullman 99164-6430, U.S.A
| | - Dmitri V. Mavrodi
- School of Biological, Environmental, and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS 39406, U.S.A
- Department of Plant Pathology, Washington State University, Pullman 99164-6430, U.S.A
| | - Mingming Yang
- Department of Plant Pathology, Washington State University, Pullman 99164-6430, U.S.A
- Department of Agronomy, Northwest A&F University, Yangling, P. R. China
| | - Linda S. Thomashow
- USDA-ARS Wheat Health, Genetics and Quality Research Unit, Pullman, WA 99164-6430, U.S.A
| | - Olga V. Mavrodi
- School of Biological, Environmental, and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS 39406, U.S.A
- Department of Plant Pathology, Washington State University, Pullman 99164-6430, U.S.A
| | - Jason Kelton
- USDA-ARS Wheat Health, Genetics and Quality Research Unit, Pullman, WA 99164-6430, U.S.A
| | - David M. Weller
- USDA-ARS Wheat Health, Genetics and Quality Research Unit, Pullman, WA 99164-6430, U.S.A
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LeTourneau MK, Marshall MJ, Grant M, Freeze PM, Strawn DG, Lai B, Dohnalkova AC, Harsh JB, Weller DM, Thomashow LS. Phenazine-1-Carboxylic Acid-Producing Bacteria Enhance the Reactivity of Iron Minerals in Dryland and Irrigated Wheat Rhizospheres. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:14273-14284. [PMID: 31751506 DOI: 10.1021/acs.est.9b03962] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Phenazine-1-carboxylic acid (PCA) is a broad-spectrum antibiotic produced by rhizobacteria in the dryland wheat fields of the Columbia Plateau. PCA and other phenazines reductively dissolve Fe and Mn oxyhydroxides in bacterial culture systems, but the impact of PCA upon Fe and Mn cycling in the rhizosphere is unknown. Here, concentrations of dithionite-extractable and poorly crystalline Fe were approximately 10% and 30-40% higher, respectively, in dryland and irrigated rhizospheres inoculated with the PCA-producing (PCA+) strain Pseudomonas synxantha 2-79 than in rhizospheres inoculated with a PCA-deficient mutant. However, rhizosphere concentrations of Fe(II) and Mn did not differ significantly, indicating that PCA-mediated redox transformations of Fe and Mn were transient or were masked by competing processes. Total Fe and Mn uptake into wheat biomass also did not differ significantly, but the PCA+ strain significantly altered Fe translocation into shoots. X-ray absorption near edge spectroscopy revealed an abundance of Fe-bearing oxyhydroxides and phyllosilicates in all rhizospheres. These results indicate that the PCA+ strain enhanced the reactivity and mobility of Fe derived from soil minerals without producing parallel changes in plant Fe uptake. This is the first report that directly links significant alterations of Fe-bearing minerals in the rhizosphere to a single bacterial trait.
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Affiliation(s)
- Melissa K LeTourneau
- Department of Crop & Soil Sciences , Washington State University , Pullman , Washington 99164-6420 , United States
- United State Department of Agriculture - Agricultural Research Service , Wheat Health, Genetics and Quality Research Unit , Pullman , Washington 99164-6430 , United States
| | - Matthew J Marshall
- Earth & Biological Sciences Directorate , Pacific Northwest National Laboratory , Richland , Washington 99352 , United States
| | - Michael Grant
- Department of Crop & Soil Sciences , Washington State University , Pullman , Washington 99164-6420 , United States
| | - Patrick M Freeze
- Department of Crop & Soil Sciences , Washington State University , Pullman , Washington 99164-6420 , United States
| | - Daniel G Strawn
- Department of Soil and Water Systems , University of Idaho , Moscow , Idaho 83844-2340 , United States
| | - Barry Lai
- Advanced Photon Source , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - Alice C Dohnalkova
- Environmental Molecular Sciences Laboratory , Pacific Northwest National Laboratory , Richland , Washington 99352 , United States
| | - James B Harsh
- Department of Crop & Soil Sciences , Washington State University , Pullman , Washington 99164-6420 , United States
| | - David M Weller
- United State Department of Agriculture - Agricultural Research Service , Wheat Health, Genetics and Quality Research Unit , Pullman , Washington 99164-6430 , United States
| | - Linda S Thomashow
- United State Department of Agriculture - Agricultural Research Service , Wheat Health, Genetics and Quality Research Unit , Pullman , Washington 99164-6430 , United States
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14
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Mahmoudi TR, Yu JM, Liu S, Pierson LS, Pierson EA. Drought-Stress Tolerance in Wheat Seedlings Conferred by Phenazine-Producing Rhizobacteria. Front Microbiol 2019; 10:1590. [PMID: 31354678 PMCID: PMC6636665 DOI: 10.3389/fmicb.2019.01590] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 06/26/2019] [Indexed: 01/09/2023] Open
Abstract
The specific role of phenazines produced by rhizosphere-colonizing Pseudomonas in mediating wheat seedling drought-stress tolerance and recovery from water deficit was investigated using Pseudomonas chlororaphis 30-84 and isogenic derivatives deficient or enhanced in phenazine production compared to wild type. Following a 7-day water deficit, seedlings that received no-inoculum or were colonized by the phenazine mutant wilted to collapse, whereas seedlings colonized by phenazine producers displayed less severe symptoms. After a 7-day recovery period, survival of seedlings colonized by phenazine-producing strains exceeded 80%, but was less than 60% for no-inoculum controls. A second 7-day water deficit reduced overall survival rates to less than 10% for no-inoculum control seedlings, whereas survival was ∼50% for seedlings colonized by phenazine-producers. The relative water content of seedlings colonized by phenazine-producers was 10-20% greater than for the no-inoculum controls at every stage of water deficit and recovery, resulting in higher recovery indices than observed for the no-inoculum controls. For 10-day water deficits causing the collapse of all seedlings, survival rates remained high for plants colonized by phenazine-producers, especially the enhanced phenazine producer (∼74%), relative to the no-inoculum control (∼25%). These observations indicate that seedlings colonized by the phenazine-producing strains suffered less from dehydration during water deficit and recovered better, potentially contributing to better resilience from a second drought/recovery cycle. Seedlings colonized by phenazine-producing strains invested more in root systems and produced 1.5 to 2 fold more root tips than seedlings colonized by the phenazine mutant or the no-inoculum controls when grown with or without water deficit. The results suggest that the presence of phenazine-producing bacteria in the rhizosphere provides wheat seedlings with a longer adjustment period resulting in greater drought-stress avoidance and resilience.
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Affiliation(s)
- Tessa Rose Mahmoudi
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, United States
| | - Jun Myoung Yu
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, United States
- Department of Applied Biology, Chungnam National University, Daejeon, South Korea
| | - Shuyu Liu
- Texas A&M AgriLife Research and Extension Center, Amarillo, TX, United States
| | - Leland S. Pierson
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, United States
| | - Elizabeth A. Pierson
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, United States
- Department of Horticultural Sciences, Texas A&M University, College Station, TX, United States
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15
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LeTourneau MK, Marshall MJ, Cliff JB, Bonsall RF, Dohnalkova AC, Mavrodi DV, Devi SI, Mavrodi OV, Harsh JB, Weller DM, Thomashow LS. Phenazine‐1‐carboxylic acid and soil moisture influence biofilm development and turnover of rhizobacterial biomass on wheat root surfaces. Environ Microbiol 2018; 20:2178-2194. [DOI: 10.1111/1462-2920.14244] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 04/15/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Melissa K. LeTourneau
- Department of Crop & Soil SciencesWashington State UniversityPullmanWA 99164‐6420 USA
| | - Matthew J. Marshall
- Earth & Biological Sciences DirectoratePacific Northwest National LaboratoryRichlandWA 99352 USA
| | - John B. Cliff
- Environmental Molecular Sciences LaboratoryPacific Northwest National LaboratoryRichlandWA 99352 USA
| | - Robert F. Bonsall
- Department of Plant PathologyWashington State UniversityPullmanWA 99164‐6420 USA
| | - Alice C. Dohnalkova
- Environmental Molecular Sciences LaboratoryPacific Northwest National LaboratoryRichlandWA 99352 USA
| | - Dmitri V. Mavrodi
- Department of Biological SciencesUniversity of Southern MississippiHattiesburgMS 39406‐0001 USA
| | - S. Indira Devi
- Institute of Bioresources and Sustainable DevelopmentTakyelpat ManipurImphal 795001 India
| | - Olga V. Mavrodi
- Department of Biological SciencesUniversity of Southern MississippiHattiesburgMS 39406‐0001 USA
| | - James B. Harsh
- Department of Crop & Soil SciencesWashington State UniversityPullmanWA 99164‐6420 USA
| | - David M. Weller
- United States Department of Agriculture – Agricultural Research ServiceWheat Health, Genetics, and Quality Research UnitPullmanWA 99164‐6430 USA
| | - Linda S. Thomashow
- United States Department of Agriculture – Agricultural Research ServiceWheat Health, Genetics, and Quality Research UnitPullmanWA 99164‐6430 USA
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Zhang B, Wang Y, Miao J, Lu Y, Lu R, Sun X, Luo W, Chi X, Feng Z, Ge Y. Reciprocal enhancement of gene expression between the phz and prn operon in Pseudomonas chlororaphis G05. J Basic Microbiol 2018; 58:793-805. [PMID: 29995319 DOI: 10.1002/jobm.201800206] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/19/2018] [Accepted: 06/24/2018] [Indexed: 11/09/2022]
Abstract
In previous studies with Pseudomonas chlororaphis G05, two operons (phzABCDEFG and prnABCD) were confirmed to respectively encode enzymes for biosynthesis of phenazine-1-carboxylic acid and pyrrolnitrin that mainly contributed to suppression of some fungal phytopathogens. Although some regulators were identified to govern their expression, it is not known how two operons coordinately interact. By constructing the phz- or/and prn- deletion mutants, we found that in comparison with the wild-type strain G05, phenazine-1-carboxylic acid production in the mutant G05Δprn obviously decreased in GA broth in the absence of prn, and pyrrolnitrin production in the mutant G05Δphz remarkably declined in the absence of phz. By generating the phzA and prnA transcriptional and translational fusions with a truncated lacZ on shuttle vector or on the chromosome, we found that expression of the phz or prn operon was correspondingly increased in the presence of the prn or phz operon at the post-transcriptional level, not at the transcriptional level. These results indicated that the presence of one operon would promote the expression of the other one operon between the phz and prn. This reciprocal enhancement would keep the strain G05 producing more different antifungal compounds coordinately and living better with growth suppression of other microorganisms.
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Affiliation(s)
- Baoshen Zhang
- Department of Applied and Environmental Microbiology, School of Life Sciences, Ludong University, Yantai, China
| | - Yanhua Wang
- Department of Applied and Environmental Microbiology, School of Life Sciences, Ludong University, Yantai, China
| | - Jing Miao
- Department of Applied and Environmental Microbiology, School of Life Sciences, Ludong University, Yantai, China
| | - Yang Lu
- Department of Applied and Environmental Microbiology, School of Life Sciences, Ludong University, Yantai, China
| | - Ruiyang Lu
- Department of Applied and Environmental Microbiology, School of Life Sciences, Ludong University, Yantai, China
| | - Xiaoqiang Sun
- Department of Applied and Environmental Microbiology, School of Life Sciences, Ludong University, Yantai, China
| | - Wangtai Luo
- Department of Applied and Environmental Microbiology, School of Life Sciences, Ludong University, Yantai, China
| | - Xiaoyan Chi
- Department of Applied and Environmental Microbiology, School of Life Sciences, Ludong University, Yantai, China
| | - Zhibin Feng
- Department of Applied and Environmental Microbiology, School of Life Sciences, Ludong University, Yantai, China
| | - Yihe Ge
- Department of Applied and Environmental Microbiology, School of Life Sciences, Ludong University, Yantai, China
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Mavrodi DV, Mavrodi OV, Elbourne LDH, Tetu S, Bonsall RF, Parejko J, Yang M, Paulsen IT, Weller DM, Thomashow LS. Long-Term Irrigation Affects the Dynamics and Activity of the Wheat Rhizosphere Microbiome. FRONTIERS IN PLANT SCIENCE 2018; 9:345. [PMID: 29619036 PMCID: PMC5871930 DOI: 10.3389/fpls.2018.00345] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 02/28/2018] [Indexed: 05/24/2023]
Abstract
The Inland Pacific Northwest (IPNW) encompasses 1. 6 million cropland hectares and is a major wheat-producing area in the western United States. The climate throughout the region is semi-arid, making the availability of water a significant challenge for IPNW agriculture. Much attention has been given to uncovering the effects of water stress on the physiology of wheat and the dynamics of its soilborne diseases. In contrast, the impact of soil moisture on the establishment and activity of microbial communities in the rhizosphere of dryland wheat remains poorly understood. We addressed this gap by conducting a three-year field study involving wheat grown in adjacent irrigated and dryland (rainfed) plots established in Lind, Washington State. We used deep amplicon sequencing of the V4 region of the 16S rRNA to characterize the responses of the wheat rhizosphere microbiome to overhead irrigation. We also characterized the population dynamics and activity of indigenous Phz+ rhizobacteria that produce the antibiotic phenazine-1-carboxylic acid (PCA) and contribute to the natural suppression of soilborne pathogens of wheat. Results of the study revealed that irrigation affected the Phz+ rhizobacteria adversely, which was evident from the significantly reduced plant colonization frequency, population size and levels of PCA in the field. The observed differences between irrigated and dryland plots were reproducible and amplified over the course of the study, thus identifying soil moisture as a critical abiotic factor that influences the dynamics, and activity of indigenous Phz+ communities. The three seasons of irrigation had a slight effect on the overall diversity within the rhizosphere microbiome but led to significant differences in the relative abundances of specific OTUs. In particular, irrigation differentially affected multiple groups of Bacteroidetes and Proteobacteria, including taxa with known plant growth-promoting activity. Analysis of environmental variables revealed that the separation between irrigated and dryland treatments was due to changes in the water potential (Ψm) and pH. In contrast, the temporal changes in the composition of the rhizosphere microbiome correlated with temperature and precipitation. In summary, our long-term study provides insights into how the availability of water in a semi-arid agroecosystem shapes the belowground wheat microbiome.
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Affiliation(s)
- Dmitri V. Mavrodi
- Department of Biological Sciences, University of Southern Mississippi, Hattiesburg, MS, United States
| | - Olga V. Mavrodi
- Department of Biological Sciences, University of Southern Mississippi, Hattiesburg, MS, United States
| | - Liam D. H. Elbourne
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Sasha Tetu
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Robert F. Bonsall
- Department of Plant Pathology, Washington State University, Pullman, WA, United States
| | - James Parejko
- Department of Plant Pathology, Washington State University, Pullman, WA, United States
| | - Mingming Yang
- Department of Plant Pathology, Washington State University, Pullman, WA, United States
| | - Ian T. Paulsen
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - David M. Weller
- Wheat Health, Genetics and Quality Research Unit, USDA Agricultural Research Service, Pullman, WA, United States
| | - Linda S. Thomashow
- Wheat Health, Genetics and Quality Research Unit, USDA Agricultural Research Service, Pullman, WA, United States
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18
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Yu JM, Wang D, Ries TR, Pierson LS, Pierson EA. An upstream sequence modulates phenazine production at the level of transcription and translation in the biological control strain Pseudomonas chlororaphis 30-84. PLoS One 2018; 13:e0193063. [PMID: 29451920 PMCID: PMC5815613 DOI: 10.1371/journal.pone.0193063] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 02/02/2018] [Indexed: 12/02/2022] Open
Abstract
Phenazines are bacterial secondary metabolites and play important roles in the antagonistic activity of the biological control strain P. chlororaphis 30-84 against take-all disease of wheat. The expression of the P. chlororaphis 30-84 phenazine biosynthetic operon (phzXYFABCD) is dependent on the PhzR/PhzI quorum sensing system located immediately upstream of the biosynthetic operon as well as other regulatory systems including Gac/Rsm. Bioinformatic analysis of the sequence between the divergently oriented phzR and phzX promoters identified features within the 5'-untranslated region (5'-UTR) of phzX that are conserved only among 2OHPCA producing Pseudomonas. The conserved sequence features are potentially capable of producing secondary structures that negatively modulate one or both promoters. Transcriptional and translational fusion assays revealed that deletion of 90-bp of sequence at the 5'-UTR of phzX led to up to 4-fold greater expression of the reporters with the deletion compared to the controls, which indicated this sequence negatively modulates phenazine gene expression both transcriptionally and translationally. This 90-bp sequence was deleted from the P. chlororaphis 30-84 chromosome, resulting in 30-84Enh, which produces significantly more phenazine than the wild-type while retaining quorum sensing control. The transcriptional expression of phzR/phzI and amount of AHL signal produced by 30-84Enh also were significantly greater than for the wild-type, suggesting this 90-bp sequence also negatively affects expression of the quorum sensing genes. In addition, deletion of the 90-bp partially relieved RsmE-mediated translational repression, indicating a role for Gac/RsmE interaction. Compared to the wild-type, enhanced phenazine production by 30-84Enh resulted in improvement in fungal inhibition, biofilm formation, extracellular DNA release and suppression of take-all disease of wheat in soil without negative consequences on growth or rhizosphere persistence. This work provides greater insight into the regulation of phenazine biosynthesis with potential applications for improved biological control.
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Affiliation(s)
- Jun Myoung Yu
- Department of Horticultural Sciences, Texas A&M University, College Station, TX, United States of America
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, United States of America
| | - Dongping Wang
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, United States of America
| | - Tessa R. Ries
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, United States of America
| | - Leland S. Pierson
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, United States of America
| | - Elizabeth A. Pierson
- Department of Horticultural Sciences, Texas A&M University, College Station, TX, United States of America
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, United States of America
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Yao R, Pan K, Peng H, Feng L, Hu H, Zhang X. Engineering and systems-level analysis of Pseudomonas chlororaphis for production of phenazine-1-carboxamide using glycerol as the cost-effective carbon source. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:130. [PMID: 29755589 PMCID: PMC5934903 DOI: 10.1186/s13068-018-1123-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 04/19/2018] [Indexed: 05/21/2023]
Abstract
BACKGROUND Glycerol, an inevitable byproduct of biodiesel, has become an attractive feedstock for the production of value-added chemicals due to its availability and low price. Pseudomonas chlororaphis HT66 can use glycerol to synthesize phenazine-1-carboxamide (PCN), a phenazine derivative, which is strongly antagonistic to fungal phytopathogens. A systematic understanding of underlying mechanisms for the PCN overproduction will be important for the further improvement and industrialization. RESULTS We constructed a PCN-overproducing strain (HT66LSP) through knocking out three negative regulatory genes, lon, parS, and prsA in HT66. The strain HT66LSP produced 4.10 g/L of PCN with a yield of 0.23 (g/g) from glycerol, which was of the highest titer and the yield obtained among PCN-producing strains. We studied gene expression, metabolomics, and dynamic 13C tracer in HT66 and HT66LSP. In response to the phenotype changes, the transcript levels of phz biosynthetic genes, which are responsible for PCN biosynthesis, were all upregulated in HT66LSP. Central carbon was rerouted to the shikimate pathway, which was shown by the modulation of specific genes involved in the lower glycolysis, the TCA cycle, and the shikimate pathway, as well as changes in abundances of intracellular metabolites and flux distribution to increase the precursor availability for PCN biosynthesis. Moreover, dynamic 13C-labeling experiments revealed that the presence of metabolite channeling of 3-phosphoglyceric acid to phosphoenolpyruvate and shikimate to trans-2,3-dihydro-3-hydroxyanthranilic acid in HT66LSP could enable high-yielding synthesis of PCN. CONCLUSIONS The integrated analysis of gene expression, metabolomics, and dynamic 13C tracer enabled us to gain a more in-depth insight into complex mechanisms for the PCN overproduction. This study provides important basis for further engineering P. chlororaphis for high PCN production and efficient glycerol conversion.
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Affiliation(s)
- Ruilian Yao
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240 China
| | - Keli Pan
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240 China
| | - Huasong Peng
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240 China
| | - Lei Feng
- Instrumental Analysis Center, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240 China
| | - Hongbo Hu
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240 China
| | - Xuehong Zhang
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240 China
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20
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Fluorescent pseudomonads pursue media-dependent strategies to inhibit growth of pathogenic Verticillium fungi. Appl Microbiol Biotechnol 2017; 102:817-831. [PMID: 29151161 DOI: 10.1007/s00253-017-8618-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/30/2017] [Accepted: 10/30/2017] [Indexed: 10/24/2022]
Abstract
Verticillium species represent economically important phytopathogenic fungi with bacteria as natural rhizosphere antagonists. Growth inhibition patterns of Verticillium in different media were compared to saprophytic Aspergillus strains and were significantly more pronounced in various co-cultivations with different Pseudomonas strains. The Brassica napus rhizosphere bacterium Pseudomonas fluorescens DSM8569 is able to inhibit growth of rapeseed (Verticillium longisporum) or tomato (Verticillium dahliae) pathogens without the potential for phenazine or 2,4-diacetylphloroglucinol (DAPG) mycotoxin biosynthesis. Bacterial inhibition of Verticillium growth remained even after the removal of pseudomonads from co-cultures. Fungal growth response in the presence of the bacterium is independent of the fungal control genes of secondary metabolism LAE1 and CSN5. The phenazine producer P. fluorescens 2-79 (P_phen) inhibits Verticillium growth especially on high glucose solid agar surfaces. Additional phenazine-independent mechanisms in the same strain are able to reduce fungal surface growth in the presence of pectin and amino acids. The DAPG-producing Pseudomonas protegens CHA0 (P_DAPG), which can also produce hydrogen cyanide or pyoluteorin, has an additional inhibitory potential on fungal growth, which is independent of these antifungal compounds, but which requires the bacterial GacA/GacS control system. This translational two-component system is present in many Gram-negative bacteria and coordinates the production of multiple secondary metabolites. Our data suggest that pseudomonads pursue different media-dependent strategies that inhibit fungal growth. Metabolites such as phenazines are able to completely inhibit fungal surface growth in the presence of glucose, whereas GacA/GacS controlled inhibitors provide the same fungal growth effect on pectin/amino acid agar.
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21
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Gallique M, Decoin V, Barbey C, Rosay T, Feuilloley MGJ, Orange N, Merieau A. Contribution of the Pseudomonas fluorescens MFE01 Type VI Secretion System to Biofilm Formation. PLoS One 2017; 12:e0170770. [PMID: 28114423 PMCID: PMC5256989 DOI: 10.1371/journal.pone.0170770] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 01/10/2017] [Indexed: 12/16/2022] Open
Abstract
Type VI secretion systems (T6SSs) are widespread in Gram-negative bacteria, including Pseudomonas. These macromolecular machineries inject toxins directly into prokaryotic or eukaryotic prey cells. Hcp proteins are structural components of the extracellular part of this machinery. We recently reported that MFE01, an avirulent strain of Pseudomonas fluorescens, possesses at least two hcp genes, hcp1 and hcp2, encoding proteins playing important roles in interbacterial interactions. Indeed, P. fluorescens MFE01 can immobilise and kill diverse bacteria of various origins through the action of the Hcp1 or Hcp2 proteins of the T6SS. We show here that another Hcp protein, Hcp3, is involved in killing prey cells during co-culture on solid medium. Even after the mutation of hcp1, hcp2, or hcp3, MFE01 impaired biofilm formation by MFP05, a P. fluorescens strain isolated from human skin. These mutations did not reduce P. fluorescens MFE01 biofilm formation, but the three Hcp proteins were required for the completion of biofilm maturation. Moreover, a mutant with a disruption of one of the unique core component genes, MFE01ΔtssC, was unable to produce its own biofilm or inhibit MFP05 biofilm formation. Finally, MFE01 did not produce detectable N-acyl-homoserine lactones for quorum sensing, a phenomenon reported for many other P. fluorescens strains. Our results suggest a role for the T6SS in communication between bacterial cells, in this strain, under biofilm conditions.
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Affiliation(s)
- Mathias Gallique
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, IUT d'Evreux, Université de Rouen, Normandy University, Evreux, France
| | - Victorien Decoin
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, IUT d'Evreux, Université de Rouen, Normandy University, Evreux, France
| | - Corinne Barbey
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, IUT d'Evreux, Université de Rouen, Normandy University, Evreux, France
- Seeds Innovation Protection Research and Environment (SIPRE), Achicourt, France
| | - Thibaut Rosay
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, IUT d'Evreux, Université de Rouen, Normandy University, Evreux, France
| | - Marc G. J. Feuilloley
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, IUT d'Evreux, Université de Rouen, Normandy University, Evreux, France
| | - Nicole Orange
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, IUT d'Evreux, Université de Rouen, Normandy University, Evreux, France
| | - Annabelle Merieau
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, IUT d'Evreux, Université de Rouen, Normandy University, Evreux, France
- * E-mail:
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22
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Bauer JS, Hauck N, Christof L, Mehnaz S, Gust B, Gross H. The Systematic Investigation of the Quorum Sensing System of the Biocontrol Strain Pseudomonas chlororaphis subsp. aurantiaca PB-St2 Unveils aurI to Be a Biosynthetic Origin for 3-Oxo-Homoserine Lactones. PLoS One 2016; 11:e0167002. [PMID: 27861617 PMCID: PMC5115851 DOI: 10.1371/journal.pone.0167002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 11/07/2016] [Indexed: 11/30/2022] Open
Abstract
The shoot endophytic biocontrol strain Pseudomonas chlororaphis subsp. aurantiaca PB-St2 produces a wide range of exoproducts, including enzymes and antibiotics. The production of exoproducts is commonly tightly regulated. In order to get a deeper insight into the regulatory network of PB-St2, the strain was systematically investigated regarding its quorum sensing systems, both on the genetic and metabolic level. The genome analysis of PB-St2 revealed the presence of four putative acyl homoserine lactone (AHL) biosynthesis genes: phzI, csaI, aurI, and hdtS. LC-MS/MS analyses of the crude supernatant extracts demonstrated that PB-St2 produces eight AHLs. In addition, the concentration of all AHL derivatives was quantified time-resolved in parallel over a period of 42 h during the growth of P. aurantiaca PB-St2, resulting in production curves, which showed differences regarding the maximum levels of the AHLs (14.6 nM– 1.75 μM) and the production period. Cloning and heterologous overexpression of all identified AHL synthase genes in Escherichia coli proved the functionality of the resulting synthases PhzI, CsaI, and AurI. A clear AHL production pattern was assigned to each of these three AHL synthases, while the HdtS synthase did not lead to any AHL production. Furthermore, the heterologous expression study demonstrated unequivocally and for the first time that AurI directs the synthesis of two 3-oxo-AHLs.
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Affiliation(s)
- Judith S. Bauer
- Department of Pharmaceutical Biology, Pharmaceutical Institute, University of Tuebingen, Tuebingen, Germany
- German Centre for Infection Research (DZIF), Partner site Tuebingen, Tuebingen, Germany
| | - Nils Hauck
- Department of Pharmaceutical Biology, Pharmaceutical Institute, University of Tuebingen, Tuebingen, Germany
- German Centre for Infection Research (DZIF), Partner site Tuebingen, Tuebingen, Germany
| | - Lisa Christof
- Department of Pharmaceutical Biology, Pharmaceutical Institute, University of Tuebingen, Tuebingen, Germany
- German Centre for Infection Research (DZIF), Partner site Tuebingen, Tuebingen, Germany
| | - Samina Mehnaz
- Department of Biological Sciences, Forman Christian College (A Chartered University), Lahore, Pakistan
| | - Bertolt Gust
- Department of Pharmaceutical Biology, Pharmaceutical Institute, University of Tuebingen, Tuebingen, Germany
- German Centre for Infection Research (DZIF), Partner site Tuebingen, Tuebingen, Germany
| | - Harald Gross
- Department of Pharmaceutical Biology, Pharmaceutical Institute, University of Tuebingen, Tuebingen, Germany
- German Centre for Infection Research (DZIF), Partner site Tuebingen, Tuebingen, Germany
- * E-mail:
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Martins ML, Pinto UM, Riedel K, Vanetti MCD, Mantovani HC, de Araújo EF. Lack of AHL-based quorum sensing in Pseudomonas fluorescens isolated from milk. Braz J Microbiol 2014; 45:1039-46. [PMID: 25477941 PMCID: PMC4204945 DOI: 10.1590/s1517-83822014000300037] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 12/13/2013] [Indexed: 11/22/2022] Open
Abstract
Numerous bacteria coordinate gene expression in response to small signalling molecules in many cases known as acylhomoserine lactones (AHLs), which accumulate as a function of cell density in a process known as quorum sensing. This work aimed to determine if phenotypes that are important to define microbial activity in foods such as biofilm formation, swarming motility and proteolytic activity of two Pseudomonas fluorescens strains, isolated from refrigerated raw milk, are influenced by AHL molecules. The tested P. fluorescens strains did not produce AHL molecules in none of the evaluated media. We found that biofilm formation was dependent on the culture media, but it was not influenced by AHLs. Our results indicate that biofilm formation, swarming motility and proteolytic activity of the tested P. fluorescens strains are not regulated by acyl-homoserine lactones. It is likely that AHL-dependent quorum sensing system is absent from these strains.
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Affiliation(s)
- Maurilio L Martins
- Instituto Federal de Educação Ciência e Tecnologia do Sudeste de Minas Gerais Campus Rio Pomba Belo HorizonteMG Brazil Instituto Federal de Educação, Ciência e Tecnologia do Sudeste de Minas Gerais, Campus Rio Pomba, Belo Horizonte, MG, Brazil
| | - Uelinton M Pinto
- Departamento de Alimentos Universidade Federal de Ouro Preto Ouro PretoMG Brazil Departamento de Alimentos, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil
| | - Kathrin Riedel
- Institute of Microbiology Ernst-Moritz-Arndt University of Greifswald Germany Institute of Microbiology Ernst-Moritz-Arndt University of Greifswald, Germany
| | - Maria C D Vanetti
- Departamento de Microbiologia Universidade Federal de Viçosa ViçosaMG Brazil Departamento de Microbiologia, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Hilário C Mantovani
- Departamento de Microbiologia Universidade Federal de Viçosa ViçosaMG Brazil Departamento de Microbiologia, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Elza F de Araújo
- Departamento de Microbiologia Universidade Federal de Viçosa ViçosaMG Brazil Departamento de Microbiologia, Universidade Federal de Viçosa, Viçosa, MG, Brazil
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N-acyl homoserine lactone-mediated quorum sensing with special reference to use of quorum quenching bacteria in membrane biofouling control. BIOMED RESEARCH INTERNATIONAL 2014; 2014:162584. [PMID: 25147787 PMCID: PMC4131561 DOI: 10.1155/2014/162584] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 07/04/2014] [Accepted: 07/06/2014] [Indexed: 11/17/2022]
Abstract
Membrane biofouling remains a severe problem to be addressed in wastewater treatment systems affecting reactor performance and economy. The finding that many wastewater bacteria rely on N-acyl homoserine lactone-mediated quorum sensing to synchronize their activities essential for biofilm formations; the quenching bacterial quorum sensing suggests a promising approach for control of membrane biofouling. A variety of quorum quenching compounds of both synthetic and natural origin have been identified and found effective in inhibition of membrane biofouling with much less environmental impact than traditional antimicrobials. Work over the past few years has demonstrated that enzymatic quorum quenching mechanisms are widely conserved in several prokaryotic organisms and can be utilized as a potent tool for inhibition of membrane biofouling. Such naturally occurring bacterial quorum quenching mechanisms also play important roles in microbe-microbe interactions and have been used to develop sustainable nonantibiotic antifouling strategies. Advances in membrane fabrication and bacteria entrapment techniques have allowed the implication of such quorum quenching bacteria for better design of membrane bioreactor with improved antibiofouling efficacies. In view of this, the present paper is designed to review and discuss the recent developments in control of membrane biofouling with special emphasis on quorum quenching bacteria that are applied in membrane bioreactors.
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25
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Banderas A, Guiliani N. Bioinformatic prediction of gene functions regulated by quorum sensing in the bioleaching bacterium Acidithiobacillus ferrooxidans. Int J Mol Sci 2013; 14:16901-16. [PMID: 23959118 PMCID: PMC3759942 DOI: 10.3390/ijms140816901] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 07/18/2013] [Accepted: 07/22/2013] [Indexed: 12/14/2022] Open
Abstract
The biomining bacterium Acidithiobacillus ferrooxidans oxidizes sulfide ores and promotes metal solubilization. The efficiency of this process depends on the attachment of cells to surfaces, a process regulated by quorum sensing (QS) cell-to-cell signalling in many Gram-negative bacteria. At. ferrooxidans has a functional QS system and the presence of AHLs enhances its attachment to pyrite. However, direct targets of the QS transcription factor AfeR remain unknown. In this study, a bioinformatic approach was used to infer possible AfeR direct targets based on the particular palindromic features of the AfeR binding site. A set of Hidden Markov Models designed to maintain palindromic regions and vary non-palindromic regions was used to screen for putative binding sites. By annotating the context of each predicted binding site (PBS), we classified them according to their positional coherence relative to other putative genomic structures such as start codons, RNA polymerase promoter elements and intergenic regions. We further used the Multiple EM for Motif Elicitation algorithm (MEME) to further filter out low homology PBSs. In summary, 75 target-genes were identified, 34 of which have a higher confidence level. Among the identified genes, we found afeR itself, zwf, genes encoding glycosyltransferase activities, metallo-beta lactamases, and active transport-related proteins. Glycosyltransferases and Zwf (Glucose 6-phosphate-1-dehydrogenase) might be directly involved in polysaccharide biosynthesis and attachment to minerals by At. ferrooxidans cells during the bioleaching process.
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Affiliation(s)
- Alvaro Banderas
- Authors to whom correspondence should be addressed; E-Mails: (A.B.); (N.G.); Tel.: +49-06221-546846 (A.B.); +56-2-2978-7241 (N.G.)
| | - Nicolas Guiliani
- Laboratory of Bacterial Communication, Department of Biology, Faculty of Sciences, University of Chile, Santiago 780-0024, Chile
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26
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Fighting Plant Diseases Through the Application of Bacillus and Pseudomonas Strains. SOIL BIOLOGY 2013. [DOI: 10.1007/978-3-642-39317-4_9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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27
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Mavrodi DV, Parejko JA, Mavrodi OV, Kwak YS, Weller DM, Blankenfeldt W, Thomashow LS. Recent insights into the diversity, frequency and ecological roles of phenazines in fluorescent Pseudomonas spp. Environ Microbiol 2012; 15:675-86. [PMID: 22882648 DOI: 10.1111/j.1462-2920.2012.02846.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Phenazine compounds represent a large class of bacterial metabolites that are produced by some fluorescent Pseudomonas spp. and a few other bacterial genera. Phenazines were first noted in the scientific literature over 100 years ago, but for a long time were considered to be pigments of uncertain function. Following evidence that phenazines act as virulence factors in the opportunistic human and animal pathogen Pseudomonas aeruginosa and are actively involved in the suppression of plant pathogens, interest in these compounds has broadened to include investigations of their genetics, biosynthesis, activity as electron shuttles, and contribution to the ecology and physiology of the cells that produce them. This minireview highlights some recent and exciting insights into the diversity, frequency and ecological roles of phenazines produced by fluorescent Pseudomonas spp.
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Affiliation(s)
- Dmitri V Mavrodi
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA.
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Parejko JA, Mavrodi DV, Mavrodi OV, Weller DM, Thomashow LS. Population structure and diversity of phenazine-1-carboxylic acid producing fluorescent Pseudomonas spp. from dryland cereal fields of central Washington State (USA). MICROBIAL ECOLOGY 2012; 64:226-241. [PMID: 22383119 DOI: 10.1007/s00248-012-0015-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Accepted: 01/20/2012] [Indexed: 05/28/2023]
Abstract
Certain strains of the rhizosphere bacterium Pseudomonas fluorescens contain the phenazine biosynthesis operon (phzABCDEFG) and produce redox-active phenazine antibiotics that suppress a wide variety of soilborne plant pathogens. In 2007 and 2008, we isolated 412 phenazine-producing (Phz(+)) fluorescent Pseudomonas strains from roots of dryland wheat and barley grown in the low-precipitation region (<350 mm annual precipitation) of central Washington State. Based on results of BOX-PCR genomic fingerprinting analysis, these isolates, as well as the model biocontrol Phz(+) strain P. fluorescens 2-79, were assigned to 31 distinct genotypes separated into four clusters. All of the isolates exhibited high 16S rDNA sequence similarity to members of the P. fluorescens species complex including Pseudomonas orientalis, Pseudomonas gessardii, Pseudomonas libanensis, and Pseudomonas synxantha. Further recA-based sequence analyses revealed that the majority of new Phz(+) isolates (386 of 413) form a clade distinctly separated from P. fluorescens 2-79. Analysis of phzF alleles, however, revealed that the majority of those isolates (280 of 386) carried phenazine biosynthesis genes similar to those of P. fluorescens 2-79. phzF-based analyses also revealed that phenazine genes were under purifying selection and showed evidence of intracluster recombination. Phenotypic analyses using Biolog substrate utilization and observations of phenazine-1-carboxylic acid production showed considerable variability amongst members of all four clusters. Biodiversity indices indicated significant differences in diversity and evenness between the sampled sites. In summary, this study revealed a genotypically and phenotypically diverse group of phenazine producers with a population structure not seen before in indigenous rhizosphere-inhabiting Phz(+) Pseudomonas spp.
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Affiliation(s)
- James A Parejko
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164-4234, USA
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Bandara HMHN, Lam OLT, Jin LJ, Samaranayake L. Microbial chemical signaling: a current perspective. Crit Rev Microbiol 2012; 38:217-49. [PMID: 22300377 DOI: 10.3109/1040841x.2011.652065] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Communication among microorganisms is mediated through quorum sensing. The latter is defined as cell-density linked, coordinated gene expression in microbial populations as a response to threshold signal concentrations followed by induction of a synchronized population response. This phenomenon is used by a variety of microbes to optimize their survival in a constantly challenging, dynamic milieu, by correlating individual cellular functions to community-based requirements. The synthesis, secretion, and perception of quorum-sensing molecules and their target response play a pivotal role in quorum sensing and are tightly controlled by complex, multilayered and interconnected signal transduction pathways that regulate diverse cellular functions. Quorum sensing exemplifies interactive social behavior innate to the microbial world that controls features such as, virulence, biofilm maturation, antibiotic resistance, swarming motility, and conjugal plasmid transfer. Over the past two decades, studies have been performed to rationalize bacterial cell-to-cell communication mediated by structurally and functionally diverse small molecules. This review describes the theoretical aspects of cellular and quorum-sensing mechanisms that affect microbial physiology and pathobiology.
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Affiliation(s)
- H M H N Bandara
- Oral Biosciences, Prince Philip Dental Hospital, 34, Hospital Road, Sai Ying Pun, Hong Kong
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Selin C, Fernando WGD, de Kievit T. The PhzI/PhzR quorum-sensing system is required for pyrrolnitrin and phenazine production, and exhibits cross-regulation with RpoS in Pseudomonas chlororaphis PA23. MICROBIOLOGY-SGM 2012; 158:896-907. [PMID: 22262095 DOI: 10.1099/mic.0.054254-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The aim of the current study was to determine how quorum sensing (QS) affects the production of secondary metabolites in Pseudomonas chlororaphis strain PA23. A phzR mutant (PA23phzR) and an N-acylhomoserine lactone (AHL)-deficient strain (PA23-6863) were generated that no longer inhibited the fungal pathogen Sclerotinia sclerotiorum in vitro. Both strains exhibited reduced pyrrolnitrin (PRN), phenazine (PHZ) and protease production. Moreover, phzA-lacZ and prnA-lacZ transcription was significantly reduced in PA23phzR and PA23-6863. As the majority of secondary metabolites are produced at the onset of stationary phase, we investigated whether cross-regulation occurs between QS and RpoS. Analysis of transcriptional fusions revealed that RpoS has a positive and negative effect on phzI and phzR, respectively. In a reciprocal manner, RpoS is positively regulated by QS. Characterization of a phzRrpoS double mutant showed reduced antifungal activity as well as PRN and PHZ production, similar to the QS-deficient strains. Furthermore, phzR but not rpoS was able to complement the phzRrpoS double mutant for the aforementioned traits, indicating that the Phz QS system is a central regulator of PA23-mediated antagonism. Finally, we discovered that QS and RpoS have opposing effects on PA23 biofilm formation. While both QS-deficient strains produced little biofilm, the rpoS mutant showed enhanced biofilm production compared with PA23. Collectively, our findings indicate that QS controls diverse aspects of PA23 physiology, including secondary metabolism, RpoS and biofilm formation. As such, QS is expected to play a crucial role in PA23 biocontrol and persistence in the environment.
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Affiliation(s)
- Carrie Selin
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | | | - Teresa de Kievit
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
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31
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Ha C, Park SJ, Im SJ, Park SJ, Lee JH. Interspecies signaling through QscR, a quorum receptor of Pseudomonas aeruginosa. Mol Cells 2012; 33:53-9. [PMID: 22228182 PMCID: PMC3887745 DOI: 10.1007/s10059-012-2208-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 10/21/2011] [Accepted: 10/24/2011] [Indexed: 10/14/2022] Open
Abstract
The QS machinery of Pseudomonas aeruginosa, an opportunistic human pathogen, consists of three acyl-homoserine lactone (acyl-HSL) signaling systems, LasR-I, RhlR-I, and QscR. QscR, known as an orphan receptor and a repressor of other QS systems, operates its own regulon using N-3-oxododecanoyl HSL (3OC12), which is synthesized by LasI, as its signal. In this study, we addressed the role of QscR in interspecies communication. We found that QscR auto-activates its own transcription in the presence of 3OC12. In a single population of P. aeruginosa, where 3OC12 is the sole signal available for QscR, the QscR regulon is activated by 3OC12 produced by the LasI-R system. However, the broad signal specificity of QscR allowed it to respond to a non-P. aeruginosa signal, such as N-decanoyl HSL (C10) and N-3-hydroxydecanoyl HSL (3OHC10), which preferentially activated QscR to LasR. The signal extracts from Pseudomonas fluorescens and Burkholeria vietnamiensis also preferentially activated QscR. These non-P. aeruginosa signals activated QscR more strongly than 3OC12, the authentic P. aeruginosa signal. Since a variety of acyl-HSLs are produced in the multi-species habitat of nature, our study provides a clue for the particular situation that allows QscR to secede from the conventional QS cascade in mixed microbial community.
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Affiliation(s)
| | | | - Su-Jin Im
- Department of Pharmacy, College of Pharmacy, Pusan National University, Busan 609-735,
Korea
| | - Su-Jin Park
- Department of Pharmacy, College of Pharmacy, Pusan National University, Busan 609-735,
Korea
| | - Joon-Hee Lee
- Department of Pharmacy, College of Pharmacy, Pusan National University, Busan 609-735,
Korea
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32
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Yong YC, Zhong JJ. Impacts of quorum sensing on microbial metabolism and human health. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2012; 131:25-61. [PMID: 22767136 DOI: 10.1007/10_2012_138] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Bacteria were considered to be lonely 'mutes' for hundreds of years. However, recently it was found that bacteria usually coordinate their behaviors at the population level by producing (speaking), sensing (listening), and responding to small signal molecules. This so-called quorum sensing (QS) regulation enables bacteria to live in a 'society' with cell-cell communication and controls many important bacterial behaviors. In this chapter, QS systems and their signal molecules for Gram-negative and Gram-positive bacteria are introduced. Most interestingly, QS regulates the important bacterial behaviors such as metabolism and pathogenesis. QS-regulated microbial metabolism includes antibiotic synthesis, pollutant biodegradation, and bioenergy production, which are very relevant to human health. QS is also well-known for its involvement in bacterial pathogenesis, such as iin nfections by Pseudomonas aeruginosa and Staphylococcus aureus. Novel disease diagnosis strategies and antimicrobial agents have also been developed based on QS regulation on bacterial infections. In addition, to meet the requirements for the detection/quantification of QS signaling molecules for research and application, different biosensors have been constructed, which will also be reviewed here. QS regulation is essential to bacterial survival and important to human health. A better understanding of QS could lead better control/manipulation of bacteria, thus making them more helpful to people.
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Affiliation(s)
- Yang-Chun Yong
- Biofuels Institute, School of the Environment, Jiangsu University, 301 Xuefu Road, 212013, Zhenjiang, Jiangsu Province, China
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33
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De Maeyer K, D'aes J, Hua GKH, Perneel M, Vanhaecke L, Noppe H, Höfte M. N-Acylhomoserine lactone quorum-sensing signalling in antagonistic phenazine-producing Pseudomonas isolates from the red cocoyam rhizosphere. Microbiology (Reading) 2011; 157:459-472. [DOI: 10.1099/mic.0.043125-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Forty fluorescent Pseudomonas strains isolated from white and red cocoyam roots were tested for their ability to synthesize N-acyl-l-homoserine lactones (acyl-HSLs). Remarkably, only isolates from the red cocoyam rhizosphere that were antagonistic against the cocoyam root rot pathogen Pythium myriotylum and synthesized phenazine antibiotics produced acyl-HSLs. This supports the assumption that acyl-HSL production is related to the antagonistic activity of the strains. After detection, the signal molecules were identified through TLC-overlay and liquid chromatography-multiple MS (LC-MS/MS) analysis. In our representative strain, Pseudomonas CMR12a, production of the signal molecules could be assigned to two quorum-sensing (QS) systems. The first one is the QS system for phenazine production, PhzI/PhzR, which seemed to be well conserved, since it was genetically organized in the same way as in the well-described phenazine-producing Pseudomonas strains Pseudomonas fluorescens 2-79, Pseudomonas chlororaphis PCL1391 and Pseudomonas aureofaciens 30-84. The newly characterized genes cmrI and cmrR make up the second QS system of CMR12a, under the control of the uncommon N-3-hydroxy-dodecanoyl-homoserine lactone (3-OH-C12-HSL) and with low similarity to other Pseudomonas QS systems. No clear function could yet be assigned to the CmrI/CmrR system, although it contributes to the biocontrol capability of CMR12a. Both the PhzI/PhzR and CmrI/CmrR systems are controlled by the GacS/GacA two-component regulatory system.
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Affiliation(s)
- K. De Maeyer
- Laboratory of Phytopathology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
| | - J. D'aes
- Laboratory of Phytopathology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
| | - G. K. H. Hua
- Laboratory of Phytopathology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
| | - M. Perneel
- Laboratory of Phytopathology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
| | - L. Vanhaecke
- Laboratory of Chemical Analysis, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
- Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
| | - H. Noppe
- Laboratory of Chemical Analysis, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - M. Höfte
- Laboratory of Phytopathology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium
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Affiliation(s)
- Mair E A Churchill
- Department of Pharmacology and Program in Structural Biology and Biophysics, The University of Colorado School of Medicine, Aurora, Colorado 80045, USA.
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35
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Wang J, Quan C, Wang X, Zhao P, Fan S. Extraction, purification and identification of bacterial signal molecules based on N-acyl homoserine lactones. Microb Biotechnol 2010; 4:479-90. [PMID: 21375695 PMCID: PMC3815260 DOI: 10.1111/j.1751-7915.2010.00197.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Bacteria possess an extraordinary repertoire for intercellular communication and social behaviour. This repertoire for bacterial communication, termed as quorum sensing (QS), depends on specific diffusible signal molecules. There are many different kinds of signal molecules in the bacterial community. Among those signal molecules, N‐acyl homoserine lactones (HSLs, in other publications also referred to as AHLs, acy‐HSLs etc.) are often employed as QS signal molecules for many Gram‐negative bacteria. Due to the specific structure and tiny amount of those HSL signal molecules, the characterization of HSLs has been the subject of extensive investigations in the last decades and has become a paradigm for bacteria intercellular signalling. In this article, different methods, including extraction, purification and characterization of HSLs, are reviewed. The review provides an insight into identification and characterization of new HSLs and other signal molecules for bacterial intercellular communication.
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Affiliation(s)
- Jianhua Wang
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, China
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36
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AidH, an alpha/beta-hydrolase fold family member from an Ochrobactrum sp. strain, is a novel N-acylhomoserine lactonase. Appl Environ Microbiol 2010; 76:4933-42. [PMID: 20525860 DOI: 10.1128/aem.00477-10] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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 Mn(2+) 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.
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Fekete A, Kuttler C, Rothballer M, Hense BA, Fischer D, Buddrus-Schiemann K, Lucio M, Müller J, Schmitt-Kopplin P, Hartmann A. Dynamic regulation ofN-acyl-homoserine lactone production and degradation inPseudomonas putidaIsoF. FEMS Microbiol Ecol 2010; 72:22-34. [DOI: 10.1111/j.1574-6941.2009.00828.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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39
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Pinto UM, Costa ED, Mantovani HC, Vanetti MCD. The proteolytic activity of Pseudomonas Fluorescens 07A isolated from milk is not regulated by quorum sensing signals. Braz J Microbiol 2010; 41:91-6. [PMID: 24031468 PMCID: PMC3768619 DOI: 10.1590/s1517-838220100001000015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2008] [Revised: 03/30/2009] [Accepted: 08/22/2009] [Indexed: 11/24/2022] Open
Abstract
The proteolytic activity of Pseudomonas fluorescens 07A was investigated, and was optimal on tryptone-calcium medium. N-acyl-homoserine lactones (AHLs) were not detected on supernatants of late-exponential and stationary-phase culture broths. Synthetic AHLs or bacterial cell extracts added to the medium did not influence growth or proteolytic activity suggesting that quorum sensing might not regulate protease production in this strain.
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Affiliation(s)
- Uelinton M Pinto
- 363 Wing Hall, Department of Microbiology, Cornell University , Ithaca NY , U.S.A
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40
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Mutational analysis of Burkholderia thailandensis quorum sensing and self-aggregation. J Bacteriol 2009; 191:5901-9. [PMID: 19648250 DOI: 10.1128/jb.00591-09] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acyl-homoserine lactone (acyl-HSL) quorum-sensing signaling is common to many Proteobacteria. Acyl-HSLs are synthesized by the LuxI family of synthases, and the signal response is mediated by members of the LuxR family of transcriptional regulators. Burkholderia thailandensis is a member of a closely related cluster of three species, including the animal pathogens Burkholderia mallei and Burkholderia pseudomallei. Members of this group have similar luxI and luxR homologs, and these genes contribute to B. pseudomallei and B. mallei virulence. B. thailandensis possesses three pairs of luxI-luxR homologs. One of these pairs, BtaI2-BtaR2, has been shown to produce and respond to 3OHC(10)-HSL and to control the synthesis of an antibiotic. By using a markerless-exhange method, we constructed an assortment of B. thailandensis quorum-sensing mutants, and we used these mutants to show that BtaI1 is responsible for C(8)-HSL production and BtaI3 is responsible for 3OHC(8)-HSL production. We also show that a strain incapable of acyl-HSL production is capable of growth on the same assortment of carbon and nitrogen sources as the wild type. Furthermore, this mutant shows no loss of virulence compared to the wild type in mice. However, the wild type self-aggregates in minimal medium, whereas the quorum-sensing mutant does not. The wild-type aggregation phenotype is recovered by addition of the BtaI1-R1 HSL signal C(8)-HSL. We propose that the key function of the BtaR1-BtaI1 quorum-sensing system is to cause cells to gather into aggregates once a sufficient population has been established.
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Schmidt S, Blom JF, Pernthaler J, Berg G, Baldwin A, Mahenthiralingam E, Eberl L. Production of the antifungal compound pyrrolnitrin is quorum sensing-regulated in members of theBurkholderia cepaciacomplex. Environ Microbiol 2009; 11:1422-37. [DOI: 10.1111/j.1462-2920.2009.01870.x] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Mazurier S, Corberand T, Lemanceau P, Raaijmakers JM. Phenazine antibiotics produced by fluorescent pseudomonads contribute to natural soil suppressiveness to Fusarium wilt. ISME JOURNAL 2009; 3:977-91. [PMID: 19369971 DOI: 10.1038/ismej.2009.33] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Natural disease-suppressive soils provide an untapped resource for the discovery of novel beneficial microorganisms and traits. For most suppressive soils, however, the consortia of microorganisms and mechanisms involved in pathogen control are unknown. To date, soil suppressiveness to Fusarium wilt disease has been ascribed to carbon and iron competition between pathogenic Fusarium oxysporum and resident non-pathogenic F. oxysporum and fluorescent pseudomonads. In this study, the role of bacterial antibiosis in Fusarium wilt suppressiveness was assessed by comparing the densities, diversity and activity of fluorescent Pseudomonas species producing 2,4-diacetylphloroglucinol (DAPG) (phlD+) or phenazine (phzC+) antibiotics. The frequencies of phlD+ populations were similar in the suppressive and conducive soils but their genotypic diversity differed significantly. However, phlD genotypes from the two soils were equally effective in suppressing Fusarium wilt, either alone or in combination with non-pathogenic F. oxysporum strain Fo47. A mutant deficient in DAPG production provided a similar level of control as its parental strain, suggesting that this antibiotic does not play a major role. In contrast, phzC+ pseudomonads were only detected in the suppressive soil. Representative phzC+ isolates of five distinct genotypes did not suppress Fusarium wilt on their own, but acted synergistically in combination with strain Fo47. This increased level of disease suppression was ascribed to phenazine production as the phenazine-deficient mutant was not effective. These results suggest, for the first time, that redox-active phenazines produced by fluorescent pseudomonads contribute to the natural soil suppressiveness to Fusarium wilt disease and may act in synergy with carbon competition by resident non-pathogenic F. oxysporum.
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Affiliation(s)
- Sylvie Mazurier
- INRA, Université de Bourgogne, UMR 1229 Microbiologie des Sols et de l'Environnement, Dijon cedex, France
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Venturi V, Subramoni S. Future research trends in the major chemical language of bacteria. HFSP JOURNAL 2009; 3:105-16. [PMID: 19794815 DOI: 10.2976/1.3065673] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Accepted: 12/16/2008] [Indexed: 01/22/2023]
Abstract
Microbiology was revolutionized in the 1990's by the discovery that many different bacterial species coordinate their behavior when they form a group. In fact, bacteria are now considered multicellular organisms capable of communicating and changing behavior in relation to their cell-density; since 1994 this has been called quorum sensing. This group behavior ensures survival and propagation of the community in many natural environments. Bacterial intercellular communication is mediated by different chemical signals that are synthesized by bacteria which are then either secreted or diffused in the external environment. Bacteria are then able to detect the type and concentration of the signal resulting in regulation of gene expression and, consequently, a synchronized response by the community. The predominant signalling molecules produced by Gram-negative bacteria are N-acyl derivatives of homoserine lactone (AHLs) which have been shown to be produced by over seventy bacterial species. In this essay we discuss the importance of quorum sensing via AHLs and highlight current and future trends in this important field of research.
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Affiliation(s)
- Vittorio Venturi
- Bacteriology Group, International Centre for Genetic Engineering and Biotechnology, 34012 Trieste, Italy
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Abstract
This review describes secondary metabolites that have been shown to be synthesized by symbiotic bacteria, or for which this possibility has been discussed. It includes 365 references.
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Affiliation(s)
- Jörn Piel
- Kekulé-Institute of Organic Chemistry and Biochemistry, University of Bonn, Gerhard-Domagk-Str. 1, 53121 Bonn, Germany.
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Ammor MS, Michaelidis C, Nychas GJE. Insights into the role of quorum sensing in food spoilage. J Food Prot 2008; 71:1510-25. [PMID: 18680957 DOI: 10.4315/0362-028x-71.7.1510] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Food spoilage is a consequence of the degrading enzymatic activity of some food-associated bacteria. Several proteolytic, lipolytic, chitinolytic, and pectinolytic activities associated with the deterioration of goods are regulated by quorum sensing, suggesting a potential role of such cell-to-cell communication in food spoilage. Here we review quorum sensing signaling molecules and methods of their detection and quantification, and we provide insights into the role of quorum sensing in food spoilage and address potential quorum sensing inhibitors that might be used as biopreservatives.
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Affiliation(s)
- Mohammed Salim Ammor
- Laboratory of Microbiology and Biotechnology of Foods, Department of Food Science & Technology, Agricultural University of Athens, 75 lera Odos, 11855 Athens, Greece.
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The Burkholderia mallei BmaR3-BmaI3 quorum-sensing system produces and responds to N-3-hydroxy-octanoyl homoserine lactone. J Bacteriol 2008; 190:5137-41. [PMID: 18487338 DOI: 10.1128/jb.00246-08] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Burkholderia mallei has two acyl-homoserine lactone (acyl-HSL) signal generator-receptor pairs and two additional signal receptors, all of which contribute to virulence. We show that B. mallei produces N-3-hydroxy-octanoyl HSL (3OHC8-HSL) but a bmaI3 mutant does not. Recombinant Escherichia coli expressing BmaI3 produces hydroxylated acyl-HSLs, with 3OHC8-HSL being the most abundant compound. In recombinant E. coli, BmaR3 responds to 3OHC8-HSL but not to other acyl-HSLs. These data indicate that the signal for BmaR3-BmaI3 quorum sensing is 3OHC8-HSL.
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Las-like quorum-sensing system negatively regulates both pyoluteorin and phenazine-1-carboxylic acid production in Pseudomonas sp. M18. ACTA ACUST UNITED AC 2008; 51:174-81. [DOI: 10.1007/s11427-008-0026-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2007] [Accepted: 10/16/2007] [Indexed: 11/26/2022]
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