1
|
Yang J, Zhang S, Zhang Y, Zhao D, Liu T, Sun X, Yan L. Phenomic and transcriptomic analyses reveal the sequential synthesis of Fe 3O 4 nanoparticles in Acidithiobacillus ferrooxidans BYM. Microbiol Spectr 2023; 11:e0172923. [PMID: 37800960 PMCID: PMC10714799 DOI: 10.1128/spectrum.01729-23] [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: 04/26/2023] [Accepted: 08/17/2023] [Indexed: 10/07/2023] Open
Abstract
IMPORTANCE As the most important non-magnetotactic magnetosome-producing bacteria, Acidithiobacillus ferrooxidans only requires very mild conditions to produce Fe3O4 nanoparticles, thus conferring greater flexibility and potential application in biomagnetic nanoparticle production. However, the available information cannot explain the mechanism of Fe3O4 nanoparticle formation in A. ferrooxidans. In this study, we applied phenomic and transcriptomic analyses to reveal this mechanism. We found that different treatment condition factors notably affect the phenomic data of Fe3O4 nanoparticle in A. ferrooxidans. Using transcriptomic analyses, the gene network controlling/regulating Fe3O4 nanoparticle biogenesis in A. ferrooxidans was proposed, excavating the candidate hub genes for Fe3O4 nanoparticle formation in A. ferrooxidans. Based on this information, a sequential model for Fe3O4 nanoparticle synthesis in A. ferrooxidans was hypothesized. It lays the groundwork for further clarifying the feature of Fe3O4 nanoparticle synthesis.
Collapse
Affiliation(s)
- Jiani Yang
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, China
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, China
| | - Shuang Zhang
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, China
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, China
| | - Yu Zhang
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, China
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, China
| | - Dan Zhao
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, China
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, China
| | - Tao Liu
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, China
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, China
- Key Laboratory of Low-Carbon Green Agriculture in Northeastern China, Ministry of Agriculture and Rural Affairs, Daqing, Heilongjiang, China
| | - Xindi Sun
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, China
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, China
| | - Lei Yan
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, China
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang, China
- Key Laboratory of Low-Carbon Green Agriculture in Northeastern China, Ministry of Agriculture and Rural Affairs, Daqing, Heilongjiang, China
| |
Collapse
|
2
|
Liu P, Zheng Y, Zhang R, Bai J, Zhu K, Benzerara K, Menguy N, Zhao X, Roberts AP, Pan Y, Li J. Key gene networks that control magnetosome biomineralization in magnetotactic bacteria. Natl Sci Rev 2022; 10:nwac238. [PMID: 36654913 PMCID: PMC9840458 DOI: 10.1093/nsr/nwac238] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 10/17/2022] [Accepted: 10/17/2022] [Indexed: 01/21/2023] Open
Abstract
Magnetotactic bacteria (MTB) are a group of phylogenetically and morphologically diverse prokaryotes that have the capability of sensing Earth's magnetic field via nanocrystals of magnetic iron minerals. These crystals are enclosed within intracellular membranes or organelles known as magnetosomes and enable a sensing function known as magnetotaxis. Although MTB were discovered over half a century ago, the study of the magnetosome biogenesis and organization remains limited to a few cultured MTB strains. Here, we present an integrative genomic and phenomic analysis to investigate the genetic basis of magnetosome biomineralization in both cultured and uncultured strains from phylogenetically diverse MTB groups. The magnetosome gene contents/networks of strains are correlated with magnetic particle morphology and chain configuration. We propose a general model for gene networks that control/regulate magnetosome biogenesis and chain assembly in MTB systems.
Collapse
Affiliation(s)
| | | | - Rongrong Zhang
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing 100029, China,Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266061, China,Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai 519082, China,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jinling Bai
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing 100029, China,Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266061, China,Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai 519082, China,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kelei Zhu
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing 100029, China,Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266061, China,Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai 519082, China,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Karim Benzerara
- Sorbonne Université, UMR CNRS 7590, MNHN, IRD, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, Paris 75005, France
| | - Nicolas Menguy
- Sorbonne Université, UMR CNRS 7590, MNHN, IRD, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, Paris 75005, France
| | - Xiang Zhao
- Research School of Earth Sciences, Australian National University, Canberra ACT 2601, Australia
| | - Andrew P Roberts
- Research School of Earth Sciences, Australian National University, Canberra ACT 2601, Australia
| | - Yongxin Pan
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing 100029, China,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | | |
Collapse
|
3
|
Li J, Liu P, Menguy N, Benzerara K, Bai J, Zhao X, Leroy E, Zhang C, Zhang H, Liu J, Zhang R, Zhu K, Roberts AP, Pan Y. Identification of sulfate-reducing magnetotactic bacteria via a group-specific 16S rDNA primer and correlative fluorescence and electron microscopy: strategy for culture-independent study. Environ Microbiol 2022; 24:5019-5038. [PMID: 35726890 DOI: 10.1111/1462-2920.16109] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/02/2022] [Accepted: 06/18/2022] [Indexed: 11/28/2022]
Abstract
Magnetotactic bacteria (MTB) biomineralize intracellular magnetic nanocrystals and swim along geomagnetic field lines. While few axenic MTB cultures exist, living cells can be separated magnetically from natural environments for analysis. The bacterial universal 27F/1492R primer pair has been used widely to amplify nearly full-length 16S rRNA genes and to provide phylogenetic portraits of MTB communities. However, incomplete coverage and amplification biases inevitably prevent detection of some phylogenetically specific or non-abundant MTB. Here, we propose a new formulation of the upstream 390F primer that we combined with the downstream 1492R primer to specifically amplify 1,100-bp 16S rRNA gene sequences of sulfate-reducing MTB in freshwater sediments from Lake Weiyanghu, Xi'an, northwestern China. With correlative fluorescence in situ hybridization and scanning/transmission electron microscopy, three novel MTB strains (WYHR-2, WYHR-3, and WYHR-4) from the Desulfobacterota phylum were identified phylogenetically and structurally at the single cell level. Strain WYHR-2 produces bullet-shaped magnetosome magnetite, while the other two strains produce both cubic/prismatic greigite and bullet-shaped magnetite. Our results expand knowledge of bacterial diversity and magnetosome biomineralization of sulfate-reducing MTB. We also propose a general strategy for identifying and characterizing uncultured MTB from natural environments. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Jinhua Li
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, China.,Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Peiyu Liu
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, China.,Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China.,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Nicolas Menguy
- Sorbonne Université, UMR CNRS 7590, MNHN, IRD, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, Paris, France
| | - Karim Benzerara
- Sorbonne Université, UMR CNRS 7590, MNHN, IRD, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, Paris, France
| | - Jinling Bai
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, China.,Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China
| | - Xiang Zhao
- Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia
| | - Eric Leroy
- ICMPE, University Paris East, UMR 7182, CNRS, 2-8 rue Henri Dunant, Thiais Cedex, France
| | - Chaoqun Zhang
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, China.,Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China
| | - Heng Zhang
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, China.,Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China
| | - Jiawei Liu
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, China.,Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Rongrong Zhang
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, China.,Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China
| | - Keilei Zhu
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, China.,Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China.,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Andrew P Roberts
- Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia
| | - Yongxin Pan
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, China.,Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
4
|
Magnetotactic bacteria and magnetofossils: ecology, evolution and environmental implications. NPJ Biofilms Microbiomes 2022; 8:43. [PMID: 35650214 PMCID: PMC9160268 DOI: 10.1038/s41522-022-00304-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Accepted: 05/04/2022] [Indexed: 11/08/2022] Open
Abstract
Magnetotactic bacteria (MTB) are a group of phylogenetically diverse and morphologically varied microorganisms with a magnetoresponsive capability called magnetotaxis or microbial magnetoreception. MTB are a distinctive constituent of the microbiome of aquatic ecosystems because they use Earth's magnetic field to align themselves in a north or south facing direction and efficiently navigate to their favored microenvironments. They have been identified worldwide from diverse aquatic and waterlogged microbiomes, including freshwater, saline, brackish and marine ecosystems, and some extreme environments. MTB play important roles in the biogeochemical cycling of iron, sulphur, phosphorus, carbon and nitrogen in nature and have been recognized from in vitro cultures to sequester heavy metals like selenium, cadmium, and tellurium, which makes them prospective candidate organisms for aquatic pollution bioremediation. The role of MTB in environmental systems is not limited to their lifespan; after death, fossil magnetosomal magnetic nanoparticles (known as magnetofossils) are a promising proxy for recording paleoenvironmental change and geomagnetic field history. Here, we summarize the ecology, evolution, and environmental function of MTB and the paleoenvironmental implications of magnetofossils in light of recent discoveries.
Collapse
|
5
|
Grant CR, Amor M, Trujillo HA, Krishnapura S, Iavarone AT, Komeili A. Distinct gene clusters drive formation of ferrosome organelles in bacteria. Nature 2022; 606:160-164. [PMID: 35585231 PMCID: PMC10906721 DOI: 10.1038/s41586-022-04741-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 04/07/2022] [Indexed: 12/20/2022]
Abstract
Cellular iron homeostasis is vital and maintained through tight regulation of iron import, efflux, storage and detoxification1-3. The most common modes of iron storage use proteinaceous compartments, such as ferritins and related proteins4,5. Although lipid-bounded iron compartments have also been described, the basis for their formation and function remains unknown6,7. Here we focus on one such compartment, herein named the 'ferrosome', that was previously observed in the anaerobic bacterium Desulfovibrio magneticus6. Using a proteomic approach, we identify three ferrosome-associated (Fez) proteins that are responsible for forming ferrosomes in D. magneticus. Fez proteins are encoded in a putative operon and include FezB, a P1B-6-ATPase found in phylogenetically and metabolically diverse species of bacteria and archaea. We show that two other bacterial species, Rhodopseudomonas palustris and Shewanella putrefaciens, make ferrosomes through the action of their six-gene fez operon. Additionally, we find that fez operons are sufficient for ferrosome formation in foreign hosts. Using S. putrefaciens as a model, we show that ferrosomes probably have a role in the anaerobic adaptation to iron starvation. Overall, this work establishes ferrosomes as a new class of iron storage organelles and sets the stage for studying their formation and structure in diverse microorganisms.
Collapse
Affiliation(s)
- Carly R Grant
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Matthieu Amor
- Aix-Marseille Université, CEA, CNRS, BIAM, Saint-Paul-lez-Durance, France
| | - Hector A Trujillo
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Sunaya Krishnapura
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Anthony T Iavarone
- QB3/Chemistry Mass Spectrometry Facility, University of California, Berkeley, Berkeley, CA, USA
| | - Arash Komeili
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, USA.
| |
Collapse
|
6
|
Global Analysis of Biomineralization Genes in Magnetospirillum magneticum AMB-1. mSystems 2022; 7:e0103721. [PMID: 35076272 PMCID: PMC8788322 DOI: 10.1128/msystems.01037-21] [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] [Indexed: 11/20/2022] Open
Abstract
Magnetotactic bacteria (MTB) are a phylogenetically diverse group of bacteria remarkable for their ability to biomineralize magnetite (Fe3O4) or greigite (Fe3S4) in organelles called magnetosomes. The majority of genes required for magnetosome formation are encoded by a magnetosome gene island (MAI). Most previous genetic studies of MTB have focused on the MAI, using screens to identify key MAI genes or targeted genetics to isolate specific genes and their function in one specific growth condition. This is the first study that has taken an unbiased approach to look at many different growth conditions to reveal key genes both inside and outside the MAI. Here, we conducted random barcoded transposon mutagenesis (RB-TnSeq) in Magnetospirillum magneticum AMB-1. We generated a library of 184,710 unique strains in a wild-type background, generating ∼34 mutant strains for each gene. RB-TnSeq also allowed us to determine the essential gene set of AMB-1 under standard laboratory growth conditions. To pinpoint novel genes that are important for magnetosome formation, we subjected the library to magnetic selection screens under varied growth conditions. We compared biomineralization under standard growth conditions to biomineralization under high-iron and anaerobic conditions, respectively. Strains with transposon insertions in the MAI gene mamT had an exacerbated biomineralization defect under both high-iron and anaerobic conditions compared to standard conditions, adding to our knowledge of the role of MamT in magnetosome formation. Mutants in an ex-MAI gene, amb4151, are more magnetic than wild-type cells under anaerobic conditions. All three of these phenotypes were validated by creating a markerless deletion strain of the gene and evaluating with TEM imaging. Overall, our results indicate that growth conditions affect which genes are required for biomineralization and that some MAI genes may have more nuanced functions than was previously understood. IMPORTANCE Magnetotactic bacteria (MTB) are a group of bacteria that can form nano-sized crystals of magnetic minerals. MTB are likely an important part of their ecosystems, because they can account for up to a third of the microbial biomass in an aquatic habitat and consume large amounts of iron, potentially impacting the iron cycle. The ecology of MTB is relatively understudied; however, the cell biology and genetics of MTB have been studied for decades. Here, we leverage genetic studies of MTB to inform environmental studies. We expand the genetic toolset for studying MTB in the lab and identify novel genes, or functions of genes, that have an impact on biomineralization.
Collapse
|
7
|
Pohl A, Young SAE, Schmitz TC, Farhadi D, Zarivach R, Faivre D, Blank KG. Magnetite-binding proteins from the magnetotactic bacterium Desulfamplus magnetovallimortis BW-1. NANOSCALE 2021; 13:20396-20400. [PMID: 34860229 DOI: 10.1039/d1nr04870h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Magnetite-binding proteins are in high demand for the functionalization of magnetic nanoparticles. Binding analysis of six previously uncharacterized proteins from the magnetotactic Deltaproteobacterium Desulfamplus magnetovallimortis BW-1 identified two new magnetite-binding proteins (Mad10, Mad11). These proteins can be utilized as affinity tags for the immobilization of recombinant fusion proteins to magnetite.
Collapse
Affiliation(s)
- Anna Pohl
- Max Planck Institute of Colloids and Interfaces, Mechano(bio)chemistry, Am Mühlenberg 1, 14476 Potsdam, Germany.
- Max Planck Institute of Colloids and Interfaces, Department of Biomaterials, Am Mühlenberg 1, 14476 Potsdam, Germany.
| | - Sarah A E Young
- Max Planck Institute of Colloids and Interfaces, Mechano(bio)chemistry, Am Mühlenberg 1, 14476 Potsdam, Germany.
- Max Planck Institute of Colloids and Interfaces, Department of Biomaterials, Am Mühlenberg 1, 14476 Potsdam, Germany.
| | - Tara C Schmitz
- Max Planck Institute of Colloids and Interfaces, Mechano(bio)chemistry, Am Mühlenberg 1, 14476 Potsdam, Germany.
| | - Daniel Farhadi
- Max Planck Institute of Colloids and Interfaces, Mechano(bio)chemistry, Am Mühlenberg 1, 14476 Potsdam, Germany.
| | - Raz Zarivach
- Department of Life Sciences, The National Institute for Biotechnology in the Negev and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel
| | - Damien Faivre
- Max Planck Institute of Colloids and Interfaces, Department of Biomaterials, Am Mühlenberg 1, 14476 Potsdam, Germany.
- Aix-Marseille Université, CEA, CNRS, BIAM, 13108 Saint Paul lez Durance, France
| | - Kerstin G Blank
- Max Planck Institute of Colloids and Interfaces, Mechano(bio)chemistry, Am Mühlenberg 1, 14476 Potsdam, Germany.
| |
Collapse
|
8
|
Baaziz W, Ghica C, Cypriano J, Abreu F, Anselme K, Ersen O, Farina M, Werckmann J. New Phenotype and Mineralization of Biogenic Iron Oxide in Magnetotactic Bacteria. NANOMATERIALS 2021; 11:nano11123189. [PMID: 34947538 PMCID: PMC8706698 DOI: 10.3390/nano11123189] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 12/15/2022]
Abstract
Many magnetotactic bacteria (MTB) biomineralize magnetite crystals that nucleate and grow inside intracellular membranous vesicles originating from invaginations of the cytoplasmic membrane. The crystals together with their surrounding membranes are referred to as magnetosomes. Magnetosome magnetite crystals nucleate and grow using iron transported inside the vesicle by specific proteins. Here, we tackle the question of the organization of magnetosomes, which are always described as constituted by linear chains of nanocrystals. In addition, it is commonly accepted that the iron oxide nanocrystals are in the magnetite-based phase. We show, in the case of a wild species of coccus-type bacterium, that there is a double organization of the magnetosomes, relatively perpendicular to each other, and that the nanocrystals are in fact maghemite. These findings were obtained, respectively, by using electron tomography of whole mounts of cells directly from the environment and high-resolution transmission electron microscopy and diffraction. Structure simulations were performed with the MacTempas software. This study opens new perspectives on the diversity of phenotypes within MTBs and allows to envisage other mechanisms of nucleation and formation of biogenic iron oxide crystals.
Collapse
Affiliation(s)
- Walid Baaziz
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), University of Strasbourg, 23 rue du Loess BP 43, CEDEX 2, 67034 Strasbourg, France; (W.B.); (O.E.)
| | - Corneliu Ghica
- National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania
- Correspondence: (C.G.); (J.W.)
| | - Jefferson Cypriano
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho, 373, CCS, UFRJ, Rio de Janeiro 21941-902, Brazil; (J.C.); (F.A.)
| | - Fernanda Abreu
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho, 373, CCS, UFRJ, Rio de Janeiro 21941-902, Brazil; (J.C.); (F.A.)
| | - Karine Anselme
- Institut de Science des Matériaux de Mulhouse, University of Haute Alsace, 68057 Mulhouse, France;
| | - Ovidiu Ersen
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), University of Strasbourg, 23 rue du Loess BP 43, CEDEX 2, 67034 Strasbourg, France; (W.B.); (O.E.)
| | - Marcos Farina
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil;
| | - Jacques Werckmann
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil;
- Centro Brasiliero de Pesquisas Fisicas, LABNANO, Rio de Janeiro 22290-180, Brazil
- Correspondence: (C.G.); (J.W.)
| |
Collapse
|
9
|
Zhang W, Wang Y, Liu L, Pan Y, Lin W. Identification and Genomic Characterization of Two Previously Unknown Magnetotactic Nitrospirae. Front Microbiol 2021; 12:690052. [PMID: 34385986 PMCID: PMC8353452 DOI: 10.3389/fmicb.2021.690052] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 06/29/2021] [Indexed: 11/23/2022] Open
Abstract
Magnetotactic bacteria (MTB) are a group of microbes that biomineralize membrane-bound, nanosized magnetite (Fe3O4), and/or greigite (Fe3S4) crystals in intracellular magnetic organelle magnetosomes. MTB belonging to the Nitrospirae phylum can form up to several hundreds of Fe3O4 magnetosome crystals and dozens of sulfur globules in a single cell. These MTB are widespread in aquatic environments and sometimes account for a significant proportion of microbial biomass near the oxycline, linking these lineages to the key steps of global iron and sulfur cycling. Despite their ecological and biogeochemical importance, our understanding of the diversity and ecophysiology of magnetotactic Nitrospirae is still very limited because this group of MTB remains unculturable. Here, we identify and characterize two previously unknown MTB populations within the Nitrospirae phylum through a combination of 16S rRNA gene-based and genome-resolved metagenomic analyses. These two MTB populations represent distinct morphotypes (rod-shaped and coccoid, designated as XYR, and XYC, respectively), and both form more than 100 bullet-shaped magnetosomal crystals per cell. High-quality draft genomes of XYR and XYC have been reconstructed, and they represent a novel species and a novel genus, respectively, according to their average amino-acid identity values with respect to available genomes. Accordingly, the names Candidatus Magnetobacterium cryptolimnobacter and Candidatus Magnetomicrobium cryptolimnococcus for XYR and XYC, respectively, were proposed. Further comparative genomic analyses of XYR, XYC, and previously reported magnetotactic Nitrospirae reveal the general metabolic potential of this MTB group in distinct microenvironments, including CO2 fixation, dissimilatory sulfate reduction, sulfide oxidation, nitrogen fixation, or denitrification processes. A remarkably conserved magnetosome gene cluster has been identified across Nitrospirae MTB genomes, indicating its putative important adaptive roles in these bacteria. Taken together, the present study provides novel insights into the phylogenomic diversity and ecophysiology of this intriguing, yet poorly understood MTB group.
Collapse
Affiliation(s)
- Wensi Zhang
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
- France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, Beijing, China
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yinzhao Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Li Liu
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
- France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, Beijing, China
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yongxin Pan
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
- France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, Beijing, China
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Wei Lin
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
- France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
10
|
Genome-Wide Identification of Essential and Auxiliary Gene Sets for Magnetosome Biosynthesis in Magnetospirillum gryphiswaldense. mSystems 2020; 5:5/6/e00565-20. [PMID: 33203687 PMCID: PMC7676999 DOI: 10.1128/msystems.00565-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Magnetospirillum gryphiswaldense is one of the few tractable model magnetotactic bacteria (MTB) for studying magnetosome biomineralization. So far, knowledge on the genetic determinants of this complex process has been mainly gathered using reverse genetics and candidate approaches. In contrast, nontargeted forward genetics studies are lacking, since application of such techniques in MTB has been complicated for a number of technical reasons. Here, we report on the first comprehensive transposon mutagenesis study in MTB, aiming at systematic identification of auxiliary genes necessary to support magnetosome formation in addition to key genes harbored in the magnetosome island (MAI). Our work considerably extends the candidate set of novel subsidiary determinants and shows that the full gene complement underlying magnetosome biosynthesis is larger than assumed. In particular, we were able to define certain cellular pathways as specifically important for magnetosome formation that have not been implicated in this process so far. Magnetotactic bacteria (MTB) stand out by their ability to manufacture membrane-enclosed magnetic organelles, so-called magnetosomes. Previously, it has been assumed that a genomic region of approximately 100 kbp, the magnetosome island (MAI), harbors all genetic determinants required for this intricate biosynthesis process. Recent evidence, however, argues for the involvement of additional auxiliary genes that have not been identified yet. In the present study, we set out to delineate the full gene complement required for magnetosome production in the alphaproteobacterium Magnetospirillum gryphiswaldense using a systematic genome-wide transposon mutagenesis approach. By an optimized procedure, a Tn5 insertion library of 80,000 clones was generated and screened, yielding close to 200 insertants with mild to severe impairment of magnetosome biosynthesis. Approximately 50% of all Tn5 insertion sites mapped within the MAI, mostly leading to a nonmagnetic phenotype. In contrast, in the majority of weakly magnetic Tn5 insertion mutants, genes outside the MAI were affected, which typically caused lower numbers of magnetite crystals with partly aberrant morphology, occasionally combined with deviant intracellular localization. While some of the Tn5-struck genes outside the MAI belong to pathways that have been linked to magnetosome formation before (e.g., aerobic and anaerobic respiration), the majority of affected genes are involved in so far unsuspected cellular processes, such as sulfate assimilation, oxidative protein folding, and cytochrome c maturation, or are altogether of unknown function. We also found that signal transduction and redox functions are enriched in the set of Tn5 hits outside the MAI, suggesting that such processes are particularly important in support of magnetosome biosynthesis. IMPORTANCEMagnetospirillum gryphiswaldense is one of the few tractable model magnetotactic bacteria (MTB) for studying magnetosome biomineralization. So far, knowledge on the genetic determinants of this complex process has been mainly gathered using reverse genetics and candidate approaches. In contrast, nontargeted forward genetics studies are lacking, since application of such techniques in MTB has been complicated for a number of technical reasons. Here, we report on the first comprehensive transposon mutagenesis study in MTB, aiming at systematic identification of auxiliary genes necessary to support magnetosome formation in addition to key genes harbored in the magnetosome island (MAI). Our work considerably extends the candidate set of novel subsidiary determinants and shows that the full gene complement underlying magnetosome biosynthesis is larger than assumed. In particular, we were able to define certain cellular pathways as specifically important for magnetosome formation that have not been implicated in this process so far.
Collapse
|
11
|
Lin W, Zhang W, Paterson GA, Zhu Q, Zhao X, Knight R, Bazylinski DA, Roberts AP, Pan Y. Expanding magnetic organelle biogenesis in the domain Bacteria. MICROBIOME 2020; 8:152. [PMID: 33126926 PMCID: PMC7602337 DOI: 10.1186/s40168-020-00931-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 10/06/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND The discovery of membrane-enclosed, metabolically functional organelles in Bacteria has transformed our understanding of the subcellular complexity of prokaryotic cells. Biomineralization of magnetic nanoparticles within magnetosomes by magnetotactic bacteria (MTB) is a fascinating example of prokaryotic organelles. Magnetosomes, as nano-sized magnetic sensors in MTB, facilitate cell navigation along the local geomagnetic field, a behaviour referred to as magnetotaxis or microbial magnetoreception. Recent discovery of novel MTB outside the traditionally recognized taxonomic lineages suggests that MTB diversity across the domain Bacteria are considerably underestimated, which limits understanding of the taxonomic distribution and evolutionary origin of magnetosome organelle biogenesis. RESULTS Here, we perform the most comprehensive metagenomic analysis available of MTB communities and reconstruct metagenome-assembled MTB genomes from diverse ecosystems. Discovery of MTB in acidic peatland soils suggests widespread MTB occurrence in waterlogged soils in addition to subaqueous sediments and water bodies. A total of 168 MTB draft genomes have been reconstructed, which represent nearly a 3-fold increase over the number currently available and more than double the known MTB species at the genome level. Phylogenomic analysis reveals that these genomes belong to 13 Bacterial phyla, six of which were previously not known to include MTB. These findings indicate a much wider taxonomic distribution of magnetosome organelle biogenesis across the domain Bacteria than previously thought. Comparative genome analysis reveals a vast diversity of magnetosome gene clusters involved in magnetosomal biogenesis in terms of gene content and synteny residing in distinct taxonomic lineages. Phylogenetic analyses of core magnetosome proteins in this largest available and taxonomically diverse dataset support an unexpectedly early evolutionary origin of magnetosome biomineralization, likely ancestral to the origin of the domain Bacteria. CONCLUSIONS These findings expand the taxonomic and phylogenetic diversity of MTB across the domain Bacteria and shed new light on the origin and evolution of microbial magnetoreception. Potential biogenesis of the magnetosome organelle in the close descendants of the last bacterial common ancestor has important implications for our understanding of the evolutionary history of bacterial cellular complexity and emphasizes the biological significance of the magnetosome organelle. Video Abstract.
Collapse
Affiliation(s)
- Wei Lin
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China.
- Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, 100029, China.
- France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, Beijing, 100029, China.
| | - Wensi Zhang
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China
- Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, 100029, China
- France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, Beijing, 100029, China
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Greig A Paterson
- Department of Earth, Ocean and Ecological Sciences, University of Liverpool, L69 7ZE, Liverpool, UK
| | - Qiyun Zhu
- Department of Pediatrics, University of California San Diego, La Jolla, CA, 92037, USA
| | - Xiang Zhao
- Research School of Earth Sciences, Australian National University, ACT, Canberra, 2601, Australia
| | - Rob Knight
- Department of Pediatrics, University of California San Diego, La Jolla, CA, 92037, USA
| | - Dennis A Bazylinski
- School of Life Sciences, University of Nevada at Las Vegas, Las Vegas, NV, 89154-4004, USA
| | - Andrew P Roberts
- Research School of Earth Sciences, Australian National University, ACT, Canberra, 2601, Australia
| | - Yongxin Pan
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China.
- Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing, 100029, China.
- France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, Beijing, 100029, China.
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
| |
Collapse
|
12
|
Greening C, Lithgow T. Formation and function of bacterial organelles. Nat Rev Microbiol 2020; 18:677-689. [PMID: 32710089 DOI: 10.1038/s41579-020-0413-0] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/22/2020] [Indexed: 01/28/2023]
Abstract
Advances in imaging technologies have revealed that many bacteria possess organelles with a proteomically defined lumen and a macromolecular boundary. Some are bound by a lipid bilayer (such as thylakoids, magnetosomes and anammoxosomes), whereas others are defined by a lipid monolayer (such as lipid bodies), a proteinaceous coat (such as carboxysomes) or have a phase-defined boundary (such as nucleolus-like compartments). These diverse organelles have various metabolic and physiological functions, facilitating adaptation to different environments and driving the evolution of cellular complexity. This Review highlights that, despite the diversity of reported organelles, some unifying concepts underlie their formation, structure and function. Bacteria have fundamental mechanisms of organelle formation, through which conserved processes can form distinct organelles in different species depending on the proteins recruited to the luminal space and the boundary of the organelle. These complex subcellular compartments provide evolutionary advantages as well as enabling metabolic specialization, biogeochemical processes and biotechnological advances. Growing evidence suggests that the presence of organelles is the rule, rather than the exception, in bacterial cells.
Collapse
Affiliation(s)
- Chris Greening
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia.
| | - Trevor Lithgow
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia.
| |
Collapse
|
13
|
Davey L, Valdivia RH. Bacterial genetics and molecular pathogenesis in the age of high throughput DNA sequencing. Curr Opin Microbiol 2020; 54:59-66. [PMID: 32044689 PMCID: PMC8765803 DOI: 10.1016/j.mib.2020.01.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 01/12/2020] [Indexed: 12/17/2022]
Abstract
When Stanley Falkow introduced Molecular Koch's Postulates (Falkow, 1988) as a conceptual framework to identify microbial factors that contributed to disease, he reaffirmed the prominent role that the basic principles of genetic analysis should play in defining genotype-phenotype associations in microbial pathogens. In classical bacterial genetics the nature of mutations is inferred through cis-trans complementation and by indirectly mapping their relative position and physical distance through recombination frequencies - all of which were made possible by the genetic tools of the day: natural transformations, conjugation and transduction. Unfortunately, many of these genetic tools are not always available to study pathogenic bacteria. The recombinant DNA revolution in the 1980s launched the field of molecular pathogenesis as genes could be treated as physical units that could be cut, spliced and transplanted from one microbe to another and thus not only 'prove' that an individual gene complemented a virulence defect in a mutant strain but also could impart pathogenic properties to otherwise benign microbes. The recombinant DNA revolution also enabled the generation of newer versions of genetic tools to generate mutations and engineer microbial genomes. The last decade has ushered in next generation sequencing technologies as a new powerful tool for bacterial genetics. The routine and inexpensive sequencing of microbial genomes has increased the number and phylogenetic scope of microbes that are amenable to functional characterization and experimentation. In this review, we highlight some salient advances in this rapidly evolving area.
Collapse
Affiliation(s)
- Lauren Davey
- Duke University School of Medicine, Molecular Genetics and Microbiology, 272 Jones Bldg DUMC 3580, Durham, NC 27710, United States
| | - Raphael H Valdivia
- Duke University School of Medicine, Molecular Genetics and Microbiology, 272 Jones Bldg DUMC 3580, Durham, NC 27710, United States.
| |
Collapse
|
14
|
Abstract
Many species of bacteria can manufacture materials on a finer scale than those that are synthetically made. These products are often produced within intracellular compartments that bear many hallmarks of eukaryotic organelles. One unique and elegant group of organisms is at the forefront of studies into the mechanisms of organelle formation and biomineralization. Magnetotactic bacteria (MTB) produce organelles called magnetosomes that contain nanocrystals of magnetic material, and understanding the molecular mechanisms behind magnetosome formation and biomineralization is a rich area of study. In this Review, we focus on the genetics behind the formation of magnetosomes and biomineralization. We cover the history of genetic discoveries in MTB and key insights that have been found in recent years and provide a perspective on the future of genetic studies in MTB.
Collapse
Affiliation(s)
- Hayley C. McCausland
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, United States of America
| | - Arash Komeili
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, United States of America
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, United States of America
| |
Collapse
|
15
|
Anion transport as a target of adaption to perchlorate in sulfate-reducing communities. ISME JOURNAL 2019; 14:450-462. [PMID: 31659234 DOI: 10.1038/s41396-019-0540-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 09/04/2019] [Accepted: 09/12/2019] [Indexed: 11/09/2022]
Abstract
Inhibitors can be used to control the functionality of microbial communities by targeting specific metabolisms. The targeted inhibition of dissimilatory sulfate reduction limits the generation of toxic and corrosive hydrogen sulfide across several industrial systems. Sulfate-reducing microorganisms (SRM) are specifically inhibited by sulfate analogs, such as perchlorate. Previously, we showed pure culture SRM adaptation to perchlorate stress through mutation of the sulfate adenylyltransferase, a central enzyme in the sulfate reduction pathway. Here, we explored adaptation to perchlorate across unconstrained SRM on a community scale. We followed natural and bio-augmented sulfidogenic communities through serial transfers in increasing concentrations of perchlorate. Our results demonstrated that perchlorate stress altered community structure by initially selecting for innately more resistant strains. Isolation, whole-genome sequencing, and molecular biology techniques allowed us to define subsequent genetic mechanisms of adaptation that arose across the dominant adapting SRM. Changes in the regulation of divalent anion:sodium symporter family transporters led to increased intracellular sulfate to perchlorate ratios, allowing SRM to escape the effects of competitive inhibition. Thus, in contrast to pure-culture results, SRM in communities cope with perchlorate stress via changes in anion transport and its regulation. This highlights the value of probing evolutionary questions in an ecological framework, bridging the gap between ecology, evolution, genomics, and physiology.
Collapse
|
16
|
Brumwell SL, MacLeod MR, Huang T, Cochrane RR, Meaney RS, Zamani M, Matysiakiewicz O, Dan KN, Janakirama P, Edgell DR, Charles TC, Finan TM, Karas BJ. Designer Sinorhizobium meliloti strains and multi-functional vectors enable direct inter-kingdom DNA transfer. PLoS One 2019; 14:e0206781. [PMID: 31206509 PMCID: PMC6576745 DOI: 10.1371/journal.pone.0206781] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 05/31/2019] [Indexed: 12/18/2022] Open
Abstract
Storage, manipulation and delivery of DNA fragments is crucial for synthetic biology applications, subsequently allowing organisms of interest to be engineered with genes or pathways to produce desirable phenotypes such as disease or drought resistance in plants, or for synthesis of a specific chemical product. However, DNA with high G+C content can be unstable in many host organisms including Saccharomyces cerevisiae. Here, we report the development of Sinorhizobium meliloti, a nitrogen-fixing plant symbioticα-Proteobacterium, as a novel host that can store DNA, and mobilize DNA to E. coli, S. cerevisiae, and the eukaryotic microalgae Phaeodactylum tricornutum. To achieve this, we deleted the hsdR restriction-system in multiple reduced genome strains of S. meliloti that enable DNA transformation with up to 1.4 x 105 and 2.1 x 103 CFU μg-1 of DNA efficiency using electroporation and a newly developed polyethylene glycol transformation method, respectively. Multi-host and multi-functional shuttle vectors (MHS) were constructed and stably propagated in S. meliloti, E. coli, S. cerevisiae, and P. tricornutum. We also developed protocols and demonstrated direct transfer of these MHS vectors via conjugation from S. meliloti to E. coli, S. cerevisiae, and P. tricornutum. The development of S. meliloti as a new host for inter-kingdom DNA transfer will be invaluable for synthetic biology research and applications, including the installation and study of genes and biosynthetic pathways into organisms of interest in industry and agriculture.
Collapse
Affiliation(s)
- Stephanie L Brumwell
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | | | - Tony Huang
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Ryan R Cochrane
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | | | - Maryam Zamani
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | | | - Kaitlyn N Dan
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | | | - David R Edgell
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Trevor C Charles
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
| | - Turlough M Finan
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | - Bogumil J Karas
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.,Designer Microbes Inc., London, ON, Canada
| |
Collapse
|
17
|
Genome Editing Method for the Anaerobic Magnetotactic Bacterium Desulfovibrio magneticus RS-1. Appl Environ Microbiol 2018; 84:AEM.01724-18. [PMID: 30194101 PMCID: PMC6210102 DOI: 10.1128/aem.01724-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 08/29/2018] [Indexed: 11/20/2022] Open
Abstract
Magnetotactic bacteria (MTB) are a group of organisms that form intracellular nanometer-scale magnetic crystals though a complex process involving lipid and protein scaffolds. These magnetic crystals and their lipid membranes, termed magnetosomes, are model systems for studying bacterial cell biology and biomineralization and are potential platforms for biotechnological applications. Due to a lack of genetic tools and unculturable representatives, the mechanisms of magnetosome formation in phylogenetically deeply branching MTB remain unknown. These MTB contain elongated bullet-/tooth-shaped magnetite and greigite crystals that likely form in a manner distinct from that of the cubooctahedral-shaped magnetite crystals of the genetically tractable MTB within the Alphaproteobacteria. Here, we present a method for genome editing in Desulfovibrio magneticus RS-1, a cultured representative of the deeply branching MTB of the class Deltaproteobacteria. This marks a crucial step in developing D. magneticus as a model for studying diverse mechanisms of magnetic particle formation by MTB. Magnetosomes are complex bacterial organelles that serve as model systems for studying bacterial cell biology, biomineralization, and global iron cycling. Magnetosome biogenesis is primarily studied in two closely related Alphaproteobacteria of the genus Magnetospirillum that form cubooctahedral-shaped magnetite crystals within a lipid membrane. However, chemically and structurally distinct magnetic particles have been found in physiologically and phylogenetically diverse bacteria. Due to a lack of molecular genetic tools, the mechanistic diversity of magnetosome formation remains poorly understood. Desulfovibrio magneticus RS-1 is an anaerobic sulfate-reducing deltaproteobacterium that forms bullet-shaped magnetite crystals. A recent forward genetic screen identified 10 genes in the conserved magnetosome gene island of D. magneticus that are essential for its magnetic phenotype. However, this screen likely missed mutants with defects in crystal size, shape, and arrangement. Reverse genetics to target the remaining putative magnetosome genes using standard genetic methods of suicide vector integration have not been feasible due to the low transconjugation efficiency. Here, we present a reverse genetic method for targeted mutagenesis in D. magneticus using a replicative plasmid. To test this method, we generated a mutant resistant to 5-fluorouracil by making a markerless deletion of the upp gene that encodes uracil phosphoribosyltransferase. We also used this method for targeted marker exchange mutagenesis by replacing kupM, a gene identified in our previous screen as a magnetosome formation factor, with a streptomycin resistance cassette. Overall, our results show that targeted mutagenesis using a replicative plasmid is effective in D. magneticus and may also be applied to other genetically recalcitrant bacteria. IMPORTANCE Magnetotactic bacteria (MTB) are a group of organisms that form intracellular nanometer-scale magnetic crystals though a complex process involving lipid and protein scaffolds. These magnetic crystals and their lipid membranes, termed magnetosomes, are model systems for studying bacterial cell biology and biomineralization and are potential platforms for biotechnological applications. Due to a lack of genetic tools and unculturable representatives, the mechanisms of magnetosome formation in phylogenetically deeply branching MTB remain unknown. These MTB contain elongated bullet-/tooth-shaped magnetite and greigite crystals that likely form in a manner distinct from that of the cubooctahedral-shaped magnetite crystals of the genetically tractable MTB within the Alphaproteobacteria. Here, we present a method for genome editing in Desulfovibrio magneticus RS-1, a cultured representative of the deeply branching MTB of the class Deltaproteobacteria. This marks a crucial step in developing D. magneticus as a model for studying diverse mechanisms of magnetic particle formation by MTB.
Collapse
|
18
|
Mitra S, Das A, Sen S, Mahanty B. Potential of metabolic engineering in bacterial nanosilver synthesis. World J Microbiol Biotechnol 2018; 34:138. [DOI: 10.1007/s11274-018-2522-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 08/20/2018] [Indexed: 10/28/2022]
|
19
|
Abstract
Uncovering the mechanisms that underlie the biogenesis and maintenance of eukaryotic organelles is a vibrant and essential area of biological research. In comparison, little attention has been paid to the process of compartmentalization in bacteria and archaea. This lack of attention is in part due to the common misconception that organelles are a unique evolutionary invention of the "complex" eukaryotic cell and are absent from the "primitive" bacterial and archaeal cells. Comparisons across the tree of life are further complicated by the nebulous criteria used to designate subcellular structures as organelles. Here, with the aid of a unified definition of a membrane-bounded organelle, we present some of the recent findings in the study of lipid-bounded organelles in bacteria and archaea.
Collapse
Affiliation(s)
- Carly R Grant
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
| | - Juan Wan
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
| | - Arash Komeili
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
| |
Collapse
|
20
|
Baumgartner J, Menguy N, Gonzalez TP, Morin G, Widdrat M, Faivre D. Elongated magnetite nanoparticle formation from a solid ferrous precursor in a magnetotactic bacterium. J R Soc Interface 2017; 13:rsif.2016.0665. [PMID: 27881802 PMCID: PMC5134017 DOI: 10.1098/rsif.2016.0665] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 10/27/2016] [Indexed: 11/23/2022] Open
Abstract
Magnetotactic bacteria are aquatic microorganisms that intracellularly mineralize ferrimagnetic nanoparticles enabling the cells to align with the geomagnetic field. The bacteria produce a magnetic mineral of species-specific phase (magnetite Fe(II)Fe(III)2O4 or greigite Fe(II)Fe(III)2S4), size, morphology and particle assembly. Several species produce crystals of unusual elongated particle shapes, which break the symmetry of the thermodynamically favoured isometric morphology. Such morphologies are thought to affect domain size and orientation of the internal magnetization. Therefore, they are interesting study objects to develop new synthetic strategies for the morphological control of nanoparticles. We investigate the formation of such irregularly shaped nanomagnets in the species Desulfovibrio magneticus RS-1. In contrast to previously described organisms, this bacterium accumulates iron predominantly as Fe(II) rather than Fe(III) consistent with an alternative oxidative biomineralization route. Further, using high-resolution electron microscopy, we observe an epitaxial relationship between precursor and the final mineral phase supporting the notion of a solid-state transformation pathway. The precursor is likely a green rust previously thought to convert to magnetite only by dissolution and re-precipitation. Our findings represent a novel observation in the interconversion of iron (oxyhydr)oxide materials and suggest that solid-state growth processes could be required to produce irregularly shaped, elongated magnetite nanocrystals.
Collapse
Affiliation(s)
- Jens Baumgartner
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany
| | - Nicolas Menguy
- Institut de Minéralogie et de Physique des Milieux Condensés, Unité Mixte de Recherche 7590 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, Institut de Recherches pour le Développement, Campus Jussieu, 75005 Paris, France
| | - Teresa Perez Gonzalez
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany
| | - Guillaume Morin
- Institut de Minéralogie et de Physique des Milieux Condensés, Unité Mixte de Recherche 7590 Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, Institut de Recherches pour le Développement, Campus Jussieu, 75005 Paris, France
| | - Marc Widdrat
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany
| | - Damien Faivre
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany
| |
Collapse
|
21
|
Werckmann J, Cypriano J, Lefèvre CT, Dembelé K, Ersen O, Bazylinski DA, Lins U, Farina M. Localized iron accumulation precedes nucleation and growth of magnetite crystals in magnetotactic bacteria. Sci Rep 2017; 7:8291. [PMID: 28811607 PMCID: PMC5557804 DOI: 10.1038/s41598-017-08994-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 07/14/2017] [Indexed: 12/16/2022] Open
Abstract
Many magnetotactic bacteria (MTB) biomineralize magnetite crystals that nucleate and grow inside intracellular membranous vesicles that originate from invaginations of the cytoplasmic membrane. The crystals together with their surrounding membranes are referred to magnetosomes. Magnetosome magnetite crystals nucleate and grow using iron transported inside the vesicle by specific proteins. Here we address the question: can iron transported inside MTB for the production of magnetite crystals be spatially mapped using electron microscopy? Cultured and uncultured MTB from brackish and freshwater lagoons were studied using analytical transmission electron microscopy in an attempt to answer this question. Scanning transmission electron microscopy was used at sub-nanometric resolution to determine the distribution of elements by implementing high sensitivity energy dispersive X-ray (EDS) mapping and electron energy loss spectroscopy (EELS). EDS mapping showed that magnetosomes are enmeshed in a magnetosomal matrix in which iron accumulates close to the magnetosome forming a continuous layer visually appearing as a corona. EELS, obtained at high spatial resolution, confirmed that iron was present close to and inside the lipid bilayer magnetosome membrane. This study provides important clues to magnetite formation in MTB through the discovery of a mechanism where iron ions accumulate prior to magnetite biomineralization.
Collapse
Affiliation(s)
- Jacques Werckmann
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil.
| | - Jefferson Cypriano
- Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil
| | - Christopher T Lefèvre
- CNRS/CEA/Aix-Marseille Université, UMR7265 Institut de biosciences et biotechnologies, Laboratoire de Bioénergétique Cellulaire, 13108, Saint Paul lez Durance, France
| | - Kassiogé Dembelé
- Institut de physique et chimie des matériaux de Strasbourg (IPCMS) UMR 7504 CNRS 23 rue du Lœss, BP 43 67034, Strasbourg Cedex 2, France
| | - Ovidiu Ersen
- Institut de physique et chimie des matériaux de Strasbourg (IPCMS) UMR 7504 CNRS 23 rue du Lœss, BP 43 67034, Strasbourg Cedex 2, France
| | - Dennis A Bazylinski
- School of Life Sciences, University of Nevada at Las Vegas, Las Vegas, Nevada, 89154-4004, USA
| | - Ulysses Lins
- Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil
| | - Marcos Farina
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil
| |
Collapse
|
22
|
Lin W, Pan Y, Bazylinski DA. Diversity and ecology of and biomineralization by magnetotactic bacteria. ENVIRONMENTAL MICROBIOLOGY REPORTS 2017; 9:345-356. [PMID: 28557300 DOI: 10.1111/1758-2229.12550] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 05/20/2017] [Accepted: 05/21/2017] [Indexed: 06/07/2023]
Abstract
Magnetotactic bacteria (MTB) biomineralize intracellular, membrane-bounded crystals of magnetite (Fe3 O4 ) and/or greigite (Fe3 S4 ) called magnetosomes. MTB play important roles in the geochemical cycling of iron, sulfur, nitrogen and carbon. Significantly, they also represent an intriguing model system not just for the study of microbial biomineralization but also for magnetoreception, prokaryotic organelle formation and microbial biogeography. Here we review current knowledge on the ecology of and biomineralization by MTB, with an emphasis on more recent reports of unexpected ecological and phylogenetic findings regarding MTB. In this study, we conducted a search of public metagenomic databases and identified six novel magnetosome gene cluster-containing genomic fragments affiliated with the Deltaproteobacteria and Gammaproteobacteria classes of the Proteobacteria phylum, the Nitrospirae phylum and the Planctomycetes phylum from the deep subseafloor, marine oxygen minimum zone, groundwater biofilm and estuary sediment, thereby extending our knowledge on the diversity and distribution of MTB as well deriving important information as to their ecophysiology. We point out that the increasing availability of sequence data will facilitate researchers to systematically explore the ecology and biomineralization of MTB even further.
Collapse
Affiliation(s)
- Wei Lin
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China
- France-China Bio-Mineralization and Nano-Structures Laboratory, Chinese Academy of Sciences, Beijing, 100029, China
| | - Yongxin Pan
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China
- France-China Bio-Mineralization and Nano-Structures Laboratory, Chinese Academy of Sciences, Beijing, 100029, China
- College of Earth Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Dennis A Bazylinski
- School of Life Sciences, University of Nevada at Las Vegas, Las Vegas, NV, 89154-4004, USA
| |
Collapse
|
23
|
Talib A, Khan Z, Bokhari H, Hidayathula S, Jilani G, Khan AA. Respiring cellular nano-magnets. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2017; 80:526-531. [PMID: 28866196 DOI: 10.1016/j.msec.2017.07.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 05/30/2017] [Accepted: 07/03/2017] [Indexed: 12/29/2022]
Abstract
Magnetotactic bacteria provide an interesting example for the biosynthesis of magnetic (Fe3O4 or Fe3S4) nanoparticles, synthesized through a process known as biologically controlled mineralization, resulting in complex monodispersed, and nanostructures with unique magnetic properties. In this work, we report a novel aerobic bacterial strain isolated from sludge of an oil refinery. Microscopic and staining analysis revealed that it was a gram positive rod with the capability to thrive in a medium (9K) supplemented, with Fe2+ ions at an acidic pH (~3.2). The magnetic behaviour of these cells was tested by their alignment towards a permanent magnet, and later on confirmed by magnetometry analysis. The X-ray diffraction studies proved the cellular biosynthesis of magnetite nanoparticles inside the bacteria. This novel, bio-nano-magnet, could pave the way for green synthesis of magnetic nanoparticles to be used in industrial and medical applications such as MRI, magnetic hyperthermia and ferrofluids.
Collapse
Affiliation(s)
- Ayesha Talib
- Department of Biosciences, COMSATS Institute of Information Technology, Park Road, Tarlai Kalan, 45550 Islamabad, Pakistan
| | - Zanib Khan
- Department of Microbiology, Government Post Graduate College No. 2, Mandian, Abbottabad, Pakistan
| | - Habib Bokhari
- Department of Biosciences, COMSATS Institute of Information Technology, Park Road, Tarlai Kalan, 45550 Islamabad, Pakistan
| | - Syed Hidayathula
- College of Pharmacy, King Saud University, 11362 Riyadh, Saudi Arabia
| | - Ghulam Jilani
- Department of Soil Sciences, Pir Mehr Ali Shah ARID Agriculture University, Shamsabad, Murree Road, Rawalpindi, Pakistan
| | - Abid Ali Khan
- Department of Biosciences, COMSATS Institute of Information Technology, Park Road, Tarlai Kalan, 45550 Islamabad, Pakistan.
| |
Collapse
|
24
|
Abstract
Magnetotactic bacteria derive their magnetic orientation from magnetosomes, which are unique organelles that contain nanometre-sized crystals of magnetic iron minerals. Although these organelles have evident potential for exciting biotechnological applications, a lack of genetically tractable magnetotactic bacteria had hampered the development of such tools; however, in the past decade, genetic studies using two model Magnetospirillum species have revealed much about the mechanisms of magnetosome biogenesis. In this Review, we highlight these new insights and place the molecular mechanisms of magnetosome biogenesis in the context of the complex cell biology of Magnetospirillum spp. Furthermore, we discuss the diverse properties of magnetosome biogenesis in other species of magnetotactic bacteria and consider the value of genetically 'magnetizing' non-magnetotactic bacteria. Finally, we discuss future prospects for this highly interdisciplinary and rapidly advancing field.
Collapse
|
25
|
Leão P, Chen YR, Abreu F, Wang M, Zhang WJ, Zhou K, Xiao T, Wu LF, Lins U. Ultrastructure of ellipsoidal magnetotactic multicellular prokaryotes depicts their complex assemblage and cellular polarity in the context of magnetotaxis. Environ Microbiol 2017; 19:2151-2163. [PMID: 28120460 DOI: 10.1111/1462-2920.13677] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 01/11/2017] [Accepted: 01/18/2017] [Indexed: 11/28/2022]
Abstract
Magnetotactic multicellular prokaryotes (MMPs) consist of unique microorganisms formed by genetically identical Gram-negative bacterial that live as a single individual capable of producing magnetic nano-particles called magnetosomes. Two distinct morphotypes of MMPs are known: spherical MMPs (sMMPs) and ellipsoidal MMPs (eMMPs). sMMPs have been extensively characterized, but less information exists for eMMPs. Here, we report the ultrastructure and organization as well as gene clusters responsible for magnetosome and flagella biosynthesis in the magnetite magnetosome producer eMMP Candidatus Magnetananas rongchenensis. Transmission electron microscopy and focused ion beam scanning electron microscopy (FIB-SEM) 3D reconstruction reveal that cells with a conspicuous core-periphery polarity were organized around a central space. Magnetosomes were organized in multiple chains aligned along the periphery of each cell. In the partially sequenced genome, magnetite-related mamAB gene and mad gene clusters were identified. Two cell morphologies were detected: irregular elliptical conical 'frustum-like' (IECF) cells and H-shaped cells. IECF cells merge to form H-shaped cells indicating a more complex structure and possibly a distinct evolutionary position of eMMPs when compared with sMMPs considering multicellularity.
Collapse
Affiliation(s)
- Pedro Leão
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil
| | - Yi-Ran Chen
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,CNRS, Laboratoire International Associé de la Bio-Minéralisation et Nano-Structures (LIA-BioMNSL), Marseille, France
| | - Fernanda Abreu
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil
| | - Mingling Wang
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Wei-Jia Zhang
- CNRS, Laboratoire International Associé de la Bio-Minéralisation et Nano-Structures (LIA-BioMNSL), Marseille, France.,Laboratory of Deep Sea Microbial Cell Biology, Institute of Deep Sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China
| | - Ke Zhou
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Tian Xiao
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,CNRS, Laboratoire International Associé de la Bio-Minéralisation et Nano-Structures (LIA-BioMNSL), Marseille, France
| | - Long-Fei Wu
- CNRS, Laboratoire International Associé de la Bio-Minéralisation et Nano-Structures (LIA-BioMNSL), Marseille, France.,Aix Marseille Univ, CNRS, LCB, Marseille, France
| | - Ulysses Lins
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil
| |
Collapse
|
26
|
Genomic sequencing-based mutational enrichment analysis identifies motility genes in a genetically intractable gut microbe. Proc Natl Acad Sci U S A 2016; 113:14127-14132. [PMID: 27911803 DOI: 10.1073/pnas.1612753113] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
A major roadblock to understanding how microbes in the gastrointestinal tract colonize and influence the physiology of their hosts is our inability to genetically manipulate new bacterial species and experimentally assess the function of their genes. We describe the application of population-based genomic sequencing after chemical mutagenesis to map bacterial genes responsible for motility in Exiguobacterium acetylicum, a representative intestinal Firmicutes bacterium that is intractable to molecular genetic manipulation. We derived strong associations between mutations in 57 E. acetylicum genes and impaired motility. Surprisingly, less than half of these genes were annotated as motility-related based on sequence homologies. We confirmed the genetic link between individual mutations and loss of motility for several of these genes by performing a large-scale analysis of spontaneous suppressor mutations. In the process, we reannotated genes belonging to a broad family of diguanylate cyclases and phosphodiesterases to highlight their specific role in motility and assigned functions to uncharacterized genes. Furthermore, we generated isogenic strains that allowed us to establish that Exiguobacterium motility is important for the colonization of its vertebrate host. These results indicate that genetic dissection of a complex trait, functional annotation of new genes, and the generation of mutant strains to define the role of genes in complex environments can be accomplished in bacteria without the development of species-specific molecular genetic tools.
Collapse
|
27
|
|
28
|
Hershey DM, Browne PJ, Iavarone AT, Teyra J, Lee EH, Sidhu SS, Komeili A. Magnetite Biomineralization in Magnetospirillum magneticum Is Regulated by a Switch-like Behavior in the HtrA Protease MamE. J Biol Chem 2016; 291:17941-52. [PMID: 27302060 DOI: 10.1074/jbc.m116.731000] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Indexed: 11/06/2022] Open
Abstract
Magnetotactic bacteria are aquatic organisms that produce subcellular magnetic particles in order to orient in the earth's geomagnetic field. MamE, a predicted HtrA protease required to produce magnetite crystals in the magnetotactic bacterium Magnetospirillum magneticum AMB-1, was recently shown to promote the proteolytic processing of itself and two other biomineralization factors in vivo Here, we have analyzed the in vivo processing patterns of three proteolytic targets and used this information to reconstitute proteolysis with a purified form of MamE. MamE cleaves a custom peptide substrate with positive cooperativity, and its autoproteolysis can be stimulated with exogenous substrates or peptides that bind to either of its PDZ domains. A misregulated form of the protease that circumvents specific genetic requirements for proteolysis causes biomineralization defects, showing that proper regulation of its activity is required during magnetite biosynthesis in vivo Our results represent the first reconstitution of the proteolytic activity of MamE and show that its behavior is consistent with the previously proposed checkpoint model for biomineralization.
Collapse
Affiliation(s)
| | | | - Anthony T Iavarone
- the California Institute for Quantitative Biosciences, and the QB3/Chemistry Mass Spectrometry Facility, and the University of California, Berkeley, California 94720 and
| | - Joan Teyra
- the Department of Molecular Genetics, Terrance Donnelly Centre for Cellular and Biomedical Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | | | - Sachdev S Sidhu
- the Department of Molecular Genetics, Terrance Donnelly Centre for Cellular and Biomedical Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Arash Komeili
- From the Departments of Plant and Microbial Biology and the California Institute for Quantitative Biosciences, and Molecular and Cell Biology,
| |
Collapse
|
29
|
Abstract
Magnetotactic bacteria produce chains of membrane-bound organelles that direct the biomineralization of magnetic nanoparticles. These magnetosome compartments are a model for studying the biogenesis and subcellular organization of bacterial organelles. Previous studies have suggested that discrete gene products build and assemble magnetosomes in a stepwise fashion. Here, using an inducible system, we show that the stages of magnetosome formation are highly dynamic and interconnected. During de novo formation, magnetosomes first organize into discontinuous chain fragments that are subsequently connected by the bacterial actin-like protein MamK. We also find that magnetosome membranes are not uniform in size and can grow in a biomineralization-dependent manner. In the absence of biomineralization, magnetosome membranes stall at a diameter of ~50 nm. Those that have initiated biomineralization then expand to significantly larger sizes and accommodate mature magnetic particles. We speculate that such a biomineralization-dependent checkpoint for membrane growth establishes the appropriate conditions within the magnetosome to ensure successful nucleation and growth of magnetic particles. Magnetotactic bacteria make magnetic nanoparticles inside membrane-bound organelles called magnetosomes; however, it is unclear how the magnetosome membrane controls the biomineralization that occurs within this bacterial organelle. We placed magnetosome formation under inducible control in Magnetospirillum magneticum AMB-1 and used electron cryo-tomography to capture magnetosomes in their near-native state as they form de novo. An inducible system provided the key evidence that magnetosome membranes grow continuously unless they have not properly initiated biomineralization. Our finding that the size of a bacterial organelle impacts its biochemical function is a fundamental advance that impacts our perception of organelle formation and can inform future attempts aimed at creating designer magnetic particles.
Collapse
|
30
|
Arai K, Belthangady C, Zhang H, Bar-Gill N, DeVience SJ, Cappellaro P, Yacoby A, Walsworth RL. Fourier magnetic imaging with nanoscale resolution and compressed sensing speed-up using electronic spins in diamond. NATURE NANOTECHNOLOGY 2015; 10:859-864. [PMID: 26258549 DOI: 10.1038/nnano.2015.171] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 07/03/2015] [Indexed: 06/04/2023]
Abstract
Optically detected magnetic resonance using nitrogen-vacancy (NV) colour centres in diamond is a leading modality for nanoscale magnetic field imaging, as it provides single electron spin sensitivity, three-dimensional resolution better than 1 nm (ref. 5) and applicability to a wide range of physical and biological samples under ambient conditions. To date, however, NV-diamond magnetic imaging has been performed using 'real-space' techniques, which are either limited by optical diffraction to ∼250 nm resolution or require slow, point-by-point scanning for nanoscale resolution, for example, using an atomic force microscope, magnetic tip, or super-resolution optical imaging. Here, we introduce an alternative technique of Fourier magnetic imaging using NV-diamond. In analogy with conventional magnetic resonance imaging (MRI), we employ pulsed magnetic field gradients to phase-encode spatial information on NV electronic spins in wavenumber or 'k-space' followed by a fast Fourier transform to yield real-space images with nanoscale resolution, wide field of view and compressed sensing speed-up.
Collapse
Affiliation(s)
- K Arai
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - C Belthangady
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - H Zhang
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - N Bar-Gill
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - S J DeVience
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - P Cappellaro
- Nuclear Science and Engineering Department, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Yacoby
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - R L Walsworth
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Center for Brain Science, Harvard University, Cambridge, Massachusetts 02138, USA
| |
Collapse
|
31
|
Gray AN, Koo BM, Shiver AL, Peters JM, Osadnik H, Gross CA. High-throughput bacterial functional genomics in the sequencing era. Curr Opin Microbiol 2015; 27:86-95. [PMID: 26336012 DOI: 10.1016/j.mib.2015.07.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 07/23/2015] [Indexed: 01/17/2023]
Abstract
High-throughput functional genomic technologies are accelerating progress in understanding the diversity of bacterial life and in developing a systems-level understanding of model bacterial organisms. Here we highlight progress in deep-sequencing-based functional genomics, show how whole genome sequencing is enabling phenotyping in organisms recalcitrant to genetic approaches, recount the rapid proliferation of functional genomic approaches to non-growth phenotypes, and discuss how advances are enabling genome-scale resource libraries for many different bacteria.
Collapse
Affiliation(s)
- Andrew N Gray
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94158, USA
| | - Byoung-Mo Koo
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94158, USA
| | - Anthony L Shiver
- Graduate Group in Biophysics, University of California, San Francisco, CA 94158, USA
| | - Jason M Peters
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94158, USA
| | - Hendrik Osadnik
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94158, USA
| | - Carol A Gross
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94158, USA; Department of Cell and Tissue Biology, University of California, San Francisco, CA 94158, USA.
| |
Collapse
|
32
|
Faivre D, Baumgartner J. The combination of random mutagenesis and sequencing highlight the role of unexpected genes in an intractable organism. PLoS Genet 2015; 11:e1004895. [PMID: 25569789 PMCID: PMC4287431 DOI: 10.1371/journal.pgen.1004895] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Damien Faivre
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, Potsdam, Germany
- * E-mail:
| | - Jens Baumgartner
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, Potsdam, Germany
| |
Collapse
|