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Thöneböhn S, Fischer D, Kreiling V, Kemmler A, Oberheim I, Hager F, Schmid NE, Thormann KM. Identifying components of the Shewanella phage LambdaSo lysis system. J Bacteriol 2024; 206:e0002224. [PMID: 38771038 DOI: 10.1128/jb.00022-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 04/26/2024] [Indexed: 05/22/2024] Open
Abstract
Phage-induced lysis of Gram-negative bacterial hosts usually requires a set of phage lysis proteins, a holin, an endopeptidase, and a spanin system, to disrupt each of the three cell envelope layers. Genome annotations and previous studies identified a gene region in the Shewanella oneidensis prophage LambdaSo, which comprises potential holin- and endolysin-encoding genes but lacks an obvious spanin system. By a combination of candidate approaches, mutant screening, characterization, and microscopy, we found that LambdaSo uses a pinholin/signal-anchor-release (SAR) endolysin system to induce proton leakage and degradation of the cell wall. Between the corresponding genes, we found that two extensively nested open-reading frames encode a two-component spanin module Rz/Rz1. Unexpectedly, we identified another factor strictly required for LambdaSo-induced cell lysis, the phage protein Lcc6. Lcc6 is a transmembrane protein of 65 amino acid residues with hitherto unknown function, which acts at the level of holin in the cytoplasmic membrane to allow endolysin release. Thus, LambdaSo-mediated cell lysis requires at least four protein factors (pinholin, SAR endolysin, spanin, and Lcc6). The findings further extend the known repertoire of phage proteins involved in host lysis and phage egress. IMPORTANCE Lysis of bacteria can have multiple consequences, such as the release of host DNA to foster robust biofilm. Phage-induced lysis of Gram-negative cells requires the disruption of three layers, the outer and inner membranes and the cell wall. In most cases, the lysis systems of phages infecting Gram-negative cells comprise holins to disrupt or depolarize the membrane, thereby releasing or activating endolysins, which then degrade the cell wall. This, in turn, allows the spanins to become active and fuse outer and inner membranes, completing cell envelope disruption and allowing phage egress. Here, we show that the presence of these three components may not be sufficient to allow cell lysis, implicating that also in known phages, further factors may be required.
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Affiliation(s)
- Svenja Thöneböhn
- Institute of Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Dorian Fischer
- Institute of Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Vanessa Kreiling
- Institute of Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Alina Kemmler
- Institute of Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Isabella Oberheim
- Institute of Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Fabian Hager
- Institute of Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Nicole E Schmid
- Institute of Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Kai M Thormann
- Institute of Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Gießen, Germany
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2
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Cho A, Joshi A, Hur HG, Lee JH. Nodulation Experiment by Cross-Inoculation of Nitrogen-Fixing Bacteria Isolated from Root Nodules of Several Leguminous Plants. J Microbiol Biotechnol 2024; 34:570-579. [PMID: 38213271 PMCID: PMC11016771 DOI: 10.4014/jmb.2310.10025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 12/13/2023] [Accepted: 12/21/2023] [Indexed: 01/13/2024]
Abstract
Root-nodule nitrogen-fixing bacteria are known for being specific to particular legumes. This study isolated the endophytic root-nodule bacteria from the nodules of legumes and examined them to determine whether they could be used to promote the formation of nodules in other legumes. Forty-six isolates were collected from five leguminous plants and screened for housekeeping (16S rRNA), nitrogen fixation (nifH), and nodulation (nodC) genes. Based on the 16S rRNA gene sequencing and phylogenetic analysis, the bacterial isolates WC15, WC16, WC24, and GM5 were identified as Rhizobium, Sphingomonas, Methylobacterium, and Bradyrhizobium, respectively. The four isolates were found to have the nifH gene, and the study confirmed that one isolate (GM5) had both the nifH and nodC genes. The Salkowski method was used to measure the isolated bacteria for their capacity to produce phytohormone indole acetic acid (IAA). Additional experiments were performed to examine the effect of the isolated bacteria on root morphology and nodulation. Among the four tested isolates, both WC24 and GM5 induced nodulation in Glycine max. The gene expression studies revealed that GM5 had a higher expression of the nifH gene. The existence and expression of the nitrogen-fixing genes implied that the tested strain had the ability to fix the atmospheric nitrogen. These findings demonstrated that a nitrogen-fixing bacterium, Methylobacterium (WC24), isolated from a Trifolium repens, induced the formation of root nodules in non-host leguminous plants (Glycine max). This suggested the potential application of these rhizobia as biofertilizer. Further studies are required to verify the N2-fixing efficiency of the isolates.
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Affiliation(s)
- Ahyeon Cho
- Department of Agricultural Chemistry, Jeonbuk National University, Jeonju 54896, Republic of Korea
| | - Alpana Joshi
- Department of Bioenvironmental Chemistry, Jeonbuk National University, Jeonju 54896, Republic of Korea
- Department of Agriculture Technology & Agri-Informatics, Shobhit Institute of Engineering & Technology, Meerut 250110, India
| | - Hor-Gil Hur
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Ji-Hoon Lee
- Department of Agricultural Chemistry, Jeonbuk National University, Jeonju 54896, Republic of Korea
- Department of Bioenvironmental Chemistry, Jeonbuk National University, Jeonju 54896, Republic of Korea
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3
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Yu K, Huang Z, Xiao Y, Wang D. Shewanella infection in humans: Epidemiology, clinical features and pathogenicity. Virulence 2022; 13:1515-1532. [PMID: 36065099 PMCID: PMC9481105 DOI: 10.1080/21505594.2022.2117831] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
The genus Shewanella consists of Gram-negative proteobacteria that are ubiquitously distributed in environment. As the members of this genus have rapidly increased within the past decade, several species have become emerging pathogens worldwide, attracting the attention of the medical community. These species are also associated with severe community- and hospital-acquired infections. Patients infected with Shewanella spp. had experiences of occupational or recreational exposure; meanwhile, the process of infection is complex and the pathogenicity is influenced by a variety of factors. Here, an exhaustive internet-based literature search was carried out in PUBMED using terms “Achromobacter putrefaciens,” “Pseudomonas putrefaciens,” “Alteromonas putrefaciens” and “Shewanella” to search literatures published between 1978 and June 2022. We provided a comprehensive review on the epidemiology, clinical features and pathogenicity of Shewanella, which will contribute a better understanding of its clinical aetiology, and facilitate the timely diagnosis and effective treatment of Shewanella infection for clinicians and public health professionals.
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Affiliation(s)
- Keyi Yu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC), Beijing, China.,Center for Human Pathogenic Culture Collection, China CDC, Beijing, China
| | - Zhenzhou Huang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC), Beijing, China.,Center for Human Pathogenic Culture Collection, China CDC, Beijing, China
| | - Yue Xiao
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC), Beijing, China.,Center for Human Pathogenic Culture Collection, China CDC, Beijing, China
| | - Duochun Wang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC), Beijing, China.,Center for Human Pathogenic Culture Collection, China CDC, Beijing, China
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4
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Zhou J, Hong SH. Establishing Efficient Bisphenol A Degradation by Engineering Shewanella oneidensis. Ind Eng Chem Res 2021. [DOI: 10.1021/acs.iecr.1c03324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jiacheng Zhou
- Department of Chemical and Biological Engineering, Illinois Institute of Technology, Chicago, Illinois 60616, United States
| | - Seok Hoon Hong
- Department of Chemical and Biological Engineering, Illinois Institute of Technology, Chicago, Illinois 60616, United States
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5
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Shewanella oneidensis MR-1 as a bacterial platform for electro-biotechnology. Essays Biochem 2021; 65:355-364. [PMID: 33769488 PMCID: PMC8314016 DOI: 10.1042/ebc20200178] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/16/2021] [Accepted: 03/18/2021] [Indexed: 12/18/2022]
Abstract
The genus Shewanella comprises over 70 species of heterotrophic bacteria with versatile respiratory capacities. Some of these bacteria are known to be pathogens of fishes and animals, while many are non-pathogens considered to play important roles in the global carbon cycle. A representative strain is Shewanella oneidensis MR-1 that has been intensively studied for its ability to respire diverse electron acceptors, such as oxygen, nitrate, sulfur compounds, metals, and organics. In addition, studies have been focused on its ability as an electrochemically active bacterium that is capable of discharging electrons to and receiving electrons from electrodes in bioelectrochemical systems (BESs) for balancing intracellular redox states. This ability is expected to be applied to electro-fermentation (EF) for producing value-added chemicals that conventional fermentation technologies are difficult to produce efficiently. Researchers are also attempting to utilize its electrochemical ability for controlling gene expression, for which electro-genetics (EG) has been coined. Here we review fundamental knowledge on this bacterium and discuss future directions of studies on its applications to electro-biotechnology (EB).
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Mukherjee M, Zaiden N, Teng A, Hu Y, Cao B. Shewanella biofilm development and engineering for environmental and bioenergy applications. Curr Opin Chem Biol 2020; 59:84-92. [PMID: 32750675 DOI: 10.1016/j.cbpa.2020.05.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/10/2020] [Accepted: 05/12/2020] [Indexed: 12/31/2022]
Abstract
The genus Shewanella comprises about 70 species of Gram-negative, facultative anaerobic bacteria inhabiting various environments, which have shown great potential in various biotechnological applications ranging from environmental bioremediation, metal(loid) recovery and material synthesis to bioenergy generation. Most environmental and energy applications of Shewanella involve the biofilm mode of growth on surfaces of solid minerals or electrodes. In this article, we first provide an overview of Shewanella biofilm biology with the focus on biofilm dynamics, biofilm matrix, and key signalling systems involved in Shewanella biofilm development. Then we review strategies recently exploited to engineer Shewanella biofilms to improve biofilm-mediated bioprocesses.
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Affiliation(s)
- Manisha Mukherjee
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 639798, Singapore
| | - Norazean Zaiden
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551, Singapore; Interdisciplinary Graduate Programme, Graduate College, Nanyang Technological University, 637335, Singapore
| | - Aloysius Teng
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551, Singapore; Interdisciplinary Graduate Programme, Graduate College, Nanyang Technological University, 637335, Singapore
| | - Yidan Hu
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551, Singapore; Interdisciplinary Graduate Programme, Graduate College, Nanyang Technological University, 637335, Singapore
| | - Bin Cao
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 639798, Singapore.
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7
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Koga R, Matsumoto A, Kouzuma A, Watanabe K. Identification of an extracytoplasmic function sigma factor that facilitates
c
‐type cytochrome maturation and current generation under electrolyte‐flow conditions in
Shewanella oneidensis
MR
‐1. Environ Microbiol 2020; 22:3671-3684. [DOI: 10.1111/1462-2920.15131] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 06/11/2020] [Accepted: 06/13/2020] [Indexed: 11/27/2022]
Affiliation(s)
- Ryota Koga
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences 1432‐1 Horinouchi, Hachioji Tokyo 192‐0392 Japan
| | - Akiho Matsumoto
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences 1432‐1 Horinouchi, Hachioji Tokyo 192‐0392 Japan
| | - Atsushi Kouzuma
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences 1432‐1 Horinouchi, Hachioji Tokyo 192‐0392 Japan
| | - Kazuya Watanabe
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences 1432‐1 Horinouchi, Hachioji Tokyo 192‐0392 Japan
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8
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NADH dehydrogenases Nuo and Nqr1 contribute to extracellular electron transfer by Shewanella oneidensis MR-1 in bioelectrochemical systems. Sci Rep 2019; 9:14959. [PMID: 31628378 PMCID: PMC6802487 DOI: 10.1038/s41598-019-51452-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 09/28/2019] [Indexed: 11/22/2022] Open
Abstract
Shewanella oneidensis MR-1 is quickly becoming a synthetic biology workhorse for bioelectrochemical technologies due to a high level of understanding of its interaction with electrodes. Transmembrane electron transfer via the Mtr pathway has been well characterized, however, the role of NADH dehydrogenases in feeding electrons to Mtr has been only minimally studied in S. oneidensis MR-1. Four NADH dehydrogenases are encoded in the genome, suggesting significant metabolic flexibility in oxidizing NADH under a variety of conditions. A strain lacking the two dehydrogenases essential for aerobic growth exhibited a severe growth defect with an anode (+0.4 VSHE) or Fe(III)-NTA as the terminal electron acceptor. Our study reveals that the same NADH dehydrogenase complexes are utilized under oxic conditions or with a high potential anode. Our study also supports the previously indicated importance of pyruvate dehydrogenase activity in producing NADH during anerobic lactate metabolism. Understanding the role of NADH in extracellular electron transfer may help improve biosensors and give insight into other applications for bioelectrochemical systems.
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9
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Binnenkade L, Kreienbaum M, Thormann KM. Characterization of ExeM, an Extracellular Nuclease of Shewanella oneidensis MR-1. Front Microbiol 2018; 9:1761. [PMID: 30123203 PMCID: PMC6085458 DOI: 10.3389/fmicb.2018.01761] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 07/13/2018] [Indexed: 01/08/2023] Open
Abstract
Bacterial extracellular nucleases have multiple functions in processes as diverse as nutrient acquisition, natural transformation, biofilm formation, or defense against neutrophil extracellular traps (NETs). Here we explored the properties of ExeM in Shewanella oneidensis MR-1, an extracellular nuclease, which is widely conserved among species of Shewanella, Vibrio, Aeromonas, and others. In S. oneidensis, ExeM is crucial for normal biofilm formation. In vitro activity measurements on heterologously produced ExeM revealed that this enzyme is a sugar-unspecific endonuclease, which requires Ca2+ and Mg2+/Mn2+ as co-factors for full activity. ExeM was almost exclusively localized to the cytoplasmic membrane fraction, even when a putative C-terminal membrane anchor was deleted. In contrast, ExeM was not detected in medium supernatants. Based on the results we hypothesize that ExeM predominantly interacts with DNA in close proximity to the cell, e.g., to promote biofilm formation and defense against NETs, or to control uptake of DNA.
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Affiliation(s)
- Lucas Binnenkade
- Institute for Microbiology and Molecular Biology, Justus Liebig University Giessen, Giessen, Germany
| | - Maximilian Kreienbaum
- Institute for Microbiology and Molecular Biology, Justus Liebig University Giessen, Giessen, Germany
| | - Kai M Thormann
- Institute for Microbiology and Molecular Biology, Justus Liebig University Giessen, Giessen, Germany
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10
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Regulation of Gene Expression in Shewanella oneidensis MR-1 during Electron Acceptor Limitation and Bacterial Nanowire Formation. Appl Environ Microbiol 2016; 82:5428-43. [PMID: 27342561 DOI: 10.1128/aem.01615-16] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 06/22/2016] [Indexed: 12/12/2022] Open
Abstract
UNLABELLED In limiting oxygen as an electron acceptor, the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1 rapidly forms nanowires, extensions of its outer membrane containing the cytochromes MtrC and OmcA needed for extracellular electron transfer. RNA sequencing (RNA-Seq) analysis was employed to determine differential gene expression over time from triplicate chemostat cultures that were limited for oxygen. We identified 465 genes with decreased expression and 677 genes with increased expression. The coordinated increased expression of heme biosynthesis, cytochrome maturation, and transport pathways indicates that S. oneidensis MR-1 increases cytochrome production, including the transcription of genes encoding MtrA, MtrC, and OmcA, and transports these decaheme cytochromes across the cytoplasmic membrane during electron acceptor limitation and nanowire formation. In contrast, the expression of the mtrA and mtrC homologs mtrF and mtrD either remains unaffected or decreases under these conditions. The ompW gene, encoding a small outer membrane porin, has 40-fold higher expression during oxygen limitation, and it is proposed that OmpW plays a role in cation transport to maintain electrical neutrality during electron transfer. The genes encoding the anaerobic respiration regulator cyclic AMP receptor protein (CRP) and the extracytoplasmic function sigma factor RpoE are among the transcription factor genes with increased expression. RpoE might function by signaling the initial response to oxygen limitation. Our results show that RpoE activates transcription from promoters upstream of mtrC and omcA The transcriptome and mutant analyses of S. oneidensis MR-1 nanowire production are consistent with independent regulatory mechanisms for extending the outer membrane into tubular structures and for ensuring the electron transfer function of the nanowires. IMPORTANCE Shewanella oneidensis MR-1 has the capacity to transfer electrons to its external surface using extensions of the outer membrane called bacterial nanowires. These bacterial nanowires link the cell's respiratory chain to external surfaces, including oxidized metals important in bioremediation, and explain why S. oneidensis can be utilized as a component of microbial fuel cells, a form of renewable energy. In this work, we use differential gene expression analysis to focus on which genes function to produce the nanowires and promote extracellular electron transfer during oxygen limitation. Among the genes that are expressed at high levels are those encoding cytochrome proteins necessary for electron transfer. Shewanella coordinates the increased expression of regulators, metabolic pathways, and transport pathways to ensure that cytochromes efficiently transfer electrons along the nanowires.
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11
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Krueger J, Pohl S, Preusse M, Kordes A, Rugen N, Schniederjans M, Pich A, Häussler S. Unravelling post-transcriptional PrmC-dependent regulatory mechanisms in Pseudomonas aeruginosa. Environ Microbiol 2016; 18:3583-3592. [PMID: 27376486 DOI: 10.1111/1462-2920.13435] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 06/28/2016] [Indexed: 02/04/2023]
Abstract
Transcriptional regulation has a central role in cellular adaptation processes and is well investigated. In contrast, the importance of the post-transcriptional regulation on these processes is less well defined. The technological advancements have been critical to precisely quantify protein and mRNA level changes and hold promise to provide more insights into how post-transcriptional regulation determines phenotypes. In Pseudomonas aeruginosa the methyltransferase PrmC methylates peptide chain release factors to facilitate translation termination. Loss of PrmC activity abolishes anaerobic growth and leads to reduced production of quorum sensing-associated virulence factors. Here, by applying SILAC technology in combination with mRNA-sequencing, they provide evidence that the P. aeruginosa phenotype can be attributed to a change in protein to mRNA ratios of selected protein groups. The UAG-dependent translation termination was more dependent on PrmC activity than the UAA- and UGA-dependent translation termination. Additionally, a bias toward UAG stop codons in global transcriptional regulators was found. The finding that this bias in stop codon usage determines the P. aeruginosa phenotype is unexpected and adds complexity to regulatory circuits. Via modulation of PrmC activity the bacterial cell can cross-regulate targets independently of transcriptional signals, a process with an underestimated impact on the bacterial phenotype.
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Affiliation(s)
- Jonas Krueger
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Feodor-Lynen-Str. 7, 30625, Hannover, Germany.,Research Core Unit Proteomics and Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Sarah Pohl
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Feodor-Lynen-Str. 7, 30625, Hannover, Germany.,Department of Molecular Bacteriology, Helmholtz for Centre Infection Research, Braunschweig, Germany
| | - Matthias Preusse
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Feodor-Lynen-Str. 7, 30625, Hannover, Germany.,Department of Molecular Bacteriology, Helmholtz for Centre Infection Research, Braunschweig, Germany
| | - Adrian Kordes
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Feodor-Lynen-Str. 7, 30625, Hannover, Germany
| | - Nils Rugen
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Feodor-Lynen-Str. 7, 30625, Hannover, Germany
| | - Monika Schniederjans
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Feodor-Lynen-Str. 7, 30625, Hannover, Germany.,Department of Molecular Bacteriology, Helmholtz for Centre Infection Research, Braunschweig, Germany
| | - Andreas Pich
- Research Core Unit Proteomics and Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Susanne Häussler
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Feodor-Lynen-Str. 7, 30625, Hannover, Germany. .,Department of Molecular Bacteriology, Helmholtz for Centre Infection Research, Braunschweig, Germany.
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12
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Mitra S, Gachhui R, Mukherjee J. Enhanced biofilm formation and melanin synthesis by the oyster settlement-promoting Shewanella colwelliana is related to hydrophobic surface and simulated intertidal environment. BIOFOULING 2015; 31:283-296. [PMID: 25959367 DOI: 10.1080/08927014.2015.1038705] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A direct relationship between biofilm formation and melanogenesis in Shewanella colwelliana with increased oyster recruitment is already established. Previously, S. colwelliana was grown in a newly patented biofilm-cultivation device, the conico-cylindrical flask (CCF), offering interchangeable hydrophobic/hydrophilic surfaces. Melanization was enhanced when S. colwelliana was cultivated in a hydrophobic vessel compared with a hydrophilic vessel. In the present study, melanogenesis in the CCF was positively correlated with increased architectural parameters of the biofilm (mean thickness and biovolume obtained by confocal laser scanning microscopy) and melanin gene (melA) expression observed by densitometry. Niche intertidal conditions were mimicked in a process operated in an ultra-low-speed rotating disk bioreactor, which demonstrated enhanced biofilm formation, melanogenesis, exopolysaccharide synthesis and melA gene expression compared with a process where 12-h periodic immersion and emersion was prevented. The wettability properties of the settling plane as well as intermittent wetting and drying, which influenced biofilm formation and melA expression, may affect oyster settlement in nature.
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Affiliation(s)
- Sayani Mitra
- a School of Environmental Studies , Jadavpur University , Kolkata , India
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13
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Iron triggers λSo prophage induction and release of extracellular DNA in Shewanella oneidensis MR-1 biofilms. Appl Environ Microbiol 2014; 80:5304-16. [PMID: 24951794 DOI: 10.1128/aem.01480-14] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Prophages are ubiquitous elements within bacterial chromosomes and affect host physiology and ecology in multiple ways. We have previously demonstrated that phage-induced lysis is required for extracellular DNA (eDNA) release and normal biofilm formation in Shewanella oneidensis MR-1. Here, we investigated the regulatory mechanisms of prophage λSo spatiotemporal induction in biofilms. To this end, we used a functional fluorescence fusion to monitor λSo activation in various mutant backgrounds and in response to different physiological conditions. λSo induction occurred mainly in a subpopulation of filamentous cells in a strictly RecA-dependent manner, implicating oxidative stress-induced DNA damage as the major trigger. Accordingly, mutants affected in the oxidative stress response (ΔoxyR) or iron homeostasis (Δfur) displayed drastically increased levels of phage induction and abnormal biofilm formation, while planktonic cells were not or only marginally affected. To further investigate the role of oxidative stress, we performed a mutant screen and identified two independent amino acid substitutions in OxyR (T104N and L197P) that suppress induction of λSo by hydrogen peroxide (H2O2). However, λSo induction was not suppressed in biofilms formed by both mutants, suggesting a minor role of intracellular H2O2 in this process. In contrast, addition of iron to biofilms strongly enhanced λSo induction and eDNA release, while both processes were significantly suppressed at low iron levels, strongly indicating that iron is the limiting factor. We conclude that uptake of iron during biofilm formation triggers λSo-mediated lysis of a subpopulation of cells, likely by an increase in iron-mediated DNA damage sensed by RecA.
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14
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Mbaye S, Séchet P, Pignon F, Martins JMF. Influence of hydrodynamics on the growth kinetics of glass-adhering Pseudomonas putida cells through a parallel plate flow chamber. BIOMICROFLUIDICS 2013; 7:54105. [PMID: 24404068 PMCID: PMC3785520 DOI: 10.1063/1.4821244] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 09/01/2013] [Indexed: 05/28/2023]
Abstract
The objective of this work was to investigate the influence of hydrodynamics on the growth kinetics of surface-adhering Pseudomonas putida cells. The results showed in particular that under non substrate-limiting conditions, the early step of bacterial apparent growth rate is lower than those measured with suspended cells. Contrary to previously cited authors which explain this behavior to the different adhesive properties of the "daughter"-cells (which makes more probable the detachment of these daughter-cells), in our experimental conditions, that explanation does not hold and we show a clear dependence of growth kinetics with flow conditions, due to the formation of boundary layer concentration at low Reynolds number. These results revealed that using Monod law in the modeling of biofilm growth in fixed-biomass processes should be performed with care.
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Affiliation(s)
- S Mbaye
- Laboratoire d'Ecoulements Géophysiques et Industriels, UMR 5519 CNRS, Grenoble INP, Université Joseph Fourier, BP 53 F-38041 Grenoble Cedex 9, France ; Laboratoire Rhéologie et Procédés, UMR 5520 CNRS, Université Joseph Fourier, Grenoble INP, BP 53 F-38041 Grenoble Cedex 9, France
| | - P Séchet
- Laboratoire d'Ecoulements Géophysiques et Industriels, UMR 5519 CNRS, Grenoble INP, Université Joseph Fourier, BP 53 F-38041 Grenoble Cedex 9, France
| | - F Pignon
- Laboratoire Rhéologie et Procédés, UMR 5520 CNRS, Université Joseph Fourier, Grenoble INP, BP 53 F-38041 Grenoble Cedex 9, France
| | - J M F Martins
- Laboratoire d'étude des Transferts en Hydrologie et Environnement, UMR 5519 CNRS-INSU, Grenoble INP, IRD, Université Joseph Fourier Grenoble, BP53 F-38041 Grenoble Cedex 9, France
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