1
|
Wu SC, Hsiao WC, Zhao YC, Wu LF. Hexavalent chromate bioreduction by a magnetotactic bacterium Magnetospirillum gryphiswaldense MSR-1 and the effect of magnetosome synthesis. CHEMOSPHERE 2023; 330:138739. [PMID: 37088211 DOI: 10.1016/j.chemosphere.2023.138739] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 02/17/2023] [Accepted: 04/18/2023] [Indexed: 05/03/2023]
Abstract
Magnetotactic bacteria (MTB) are receiving attention for heavy metal biotreatment due to their potential for biosorption with heavy metals and the capability of the magnetic recovery. In this study, we investigated the characteristics of Cr(VI) bioreduction and biosorption by an MTB isolate, Magnetospirillum gryphiswaldense MSR-1, which has a higher growth rate and wider reflexivity in culture conditions. Our results demonstrated that the MSR-1 strain could remove Cr(VI) up to the concentration of 40 mg L-1 and with an optimal activity at neutral pH conditions. The magnetosome synthesis existed regulatory mechanisms between Cr(VI) reduction and cell division. The addition of 10 mg L-1 Cr(VI) significantly inhibited cell growth, but the magnetosome-deficient strain, B17316, showed an average specific growth rate of 0.062 h-1 at the same dosage. Cr(VI) reduction examined by the heat-inactivated and resting cells demonstrated that the main mechanism for MSR-1 strain to reduce Cr(VI) was chromate reductase and adsorption, and magnetosome synthesis would enhance the chromate reductase activity. Finally, our results elucidated that the chromate reductase distributes diversely in multiple subcellular components of the MSR-1 cells, including extracellular, membrane-associated, and intracellular cytoplasmic activity; and expression of the membrane-associated chromate reductase was increased after the cells were pre-exposed by Cr(VI).
Collapse
Affiliation(s)
- Siang Chen Wu
- Department of Environmental Engineering, National Chung Hsing University, 145 Xingda Road, Taichung, 40227, Taiwan.
| | - Wei-Che Hsiao
- Department of Environmental Engineering, National Chung Hsing University, 145 Xingda Road, Taichung, 40227, Taiwan
| | - Ya-Chun Zhao
- Department of Environmental Engineering, National Chung Hsing University, 145 Xingda Road, Taichung, 40227, Taiwan
| | - Li-Fen Wu
- Department of Environmental Engineering, National Chung Hsing University, 145 Xingda Road, Taichung, 40227, Taiwan
| |
Collapse
|
2
|
Niu W, Zhang Y, Liu J, Wen T, Miao T, Basit A, Jiang W. OxyR controls magnetosome formation by regulating magnetosome island (MAI) genes, iron metabolism, and redox state. Free Radic Biol Med 2020; 161:272-282. [PMID: 33075503 DOI: 10.1016/j.freeradbiomed.2020.10.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/13/2020] [Accepted: 10/14/2020] [Indexed: 12/25/2022]
Abstract
Magnetospirillum gryphiswaldense MSR-1 uses chains of magnetosomes, membrane-enveloped magnetite (Fe(II)Fe(III)2O4) nanocrystals, to align along magnetic field. The process of magnetosome biomineralization requires a precise biological control of redox conditions to maintain a balanced amounts of ferric and ferrous iron. Here, we identified functions of the global regulator OxyR (MGMSRv2_4250, OxyR-4250) in MSR-1 during magnetosome formation. OxyR deletion mutant ΔoxyR-4250 displayed reduced magnetic response, and increased levels of intracellular ROS (reactive oxygen species). OxyR-4250 protein upregulated expression of six antioxidant genes (ahpC1, ahpC2, katE, katG, sodB, trxA), four iron metabolism-related regulator genes (fur, irrA, irrB, irrC), a bacterioferritin gene (bfr), and a DNA protection gene (dps). OxyR-4250 was shown, for the first time, to directly regulate magnetosome island (MAI) genes mamGFDC, mamXY, and feoAB1 operons. Taken together, our findings indicate that OxyR-4250 helps maintain a proper redox environment for magnetosome formation by eliminating excess ROS, regulating iron homeostasis and participating in regulation of Fe2+/Fe3+ ratio within the magnetosome vesicle through regulating MAI genes.
Collapse
Affiliation(s)
- Wei Niu
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Yunpeng Zhang
- Agricultural Utilization Research Center, Nutrition and Health Research Institute, COFCO Corporation, Beijing, 102209, China
| | - Junquan Liu
- Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Tong Wen
- Department of Biology Science and Technology, Baotou Teacher's College, Baotou, 014030, China
| | - Ting Miao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Abdul Basit
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Wei Jiang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.
| |
Collapse
|
3
|
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
|
4
|
Natural Attenuation of Mn(II) in Metal Refinery Wastewater: Microbial Community Structure Analysis and Isolation of a New Mn(II)-Oxidizing Bacterium Pseudomonas sp. SK3. WATER 2019. [DOI: 10.3390/w11030507] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Natural attenuation of Mn(II) was observed inside the metal refinery wastewater pipeline, accompanying dark brown-colored mineralization (mostly MnIVO2 with some MnIII2O3 and Fe2O3) on the inner pipe surface. The Mn-deposit hosted the bacterial community comprised of Hyphomicrobium sp. (22.1%), Magnetospirillum sp. (3.2%), Geobacter sp. (0.3%), Bacillus sp. (0.18%), Pseudomonas sp. (0.03%), and non-metal-metabolizing bacteria (74.2%). Culture enrichment of the Mn-deposit led to the isolation of a new heterotrophic Mn(II)-oxidizer Pseudomonas sp. SK3, with its closest relative Ps. resinovorans (with 98.4% 16S rRNA gene sequence identity), which was previously unknown as an Mn(II)-oxidizer. Oxidation of up to 100 mg/L Mn(II) was readily initiated and completed by isolate SK3, even in the presence of high contents of MgSO4 (a typical solute in metal refinery wastewaters). Additional Cu(II) facilitated Mn(II) oxidation by isolate SK3 (implying the involvement of multicopper oxidase enzyme), allowing a 2-fold greater Mn removal rate, compared to the well-studied Mn(II)-oxidizer Ps. putida MnB1. Poorly crystalline biogenic birnessite was formed by isolate SK3 via one-electron transfer oxidation, gradually raising the Mn AOS (average oxidation state) to 3.80 in 72 h. Together with its efficient in vitro Mn(II) oxidation behavior, a high Mn AOS level of 3.75 was observed with the pipeline Mn-deposit sample collected in situ. The overall results, including the microbial community structure analysis of the pipeline sample, suggest that the natural Mn(II) attenuation phenomenon was characterized by robust in situ activity of Mn(II) oxidizers (including strain SK3) for continuous generation of Mn(IV). This likely synergistically facilitated chemical Mn(II)/Mn(IV) synproportionation for effective Mn removal in the complex ecosystem established in this artificial pipeline structure. The potential utility of isolate SK3 is illustrated for further industrial application in metal refinery wastewater treatment processes.
Collapse
|
5
|
Wang Q, Wang X, Zhang W, Li X, Zhou Y, Li D, Wang Y, Tian J, Jiang W, Zhang Z, Peng Y, Wang L, Li Y, Li J. Physiological characteristics of Magnetospirillum gryphiswaldense MSR-1 that control cell growth under high-iron and low-oxygen conditions. Sci Rep 2017; 7:2800. [PMID: 28584275 PMCID: PMC5459824 DOI: 10.1038/s41598-017-03012-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 04/21/2017] [Indexed: 11/17/2022] Open
Abstract
Magnetosome formation by Magnetospirillum gryphiswaldense MSR-1 is dependent on iron and oxygen levels. We used transcriptome to evaluate transcriptional profiles of magnetic and non-magnetic MSR-1 cells cultured under high-iron and low-iron conditions. A total of 80 differentially expressed genes (DEGs) were identified, including 53 upregulated and 27 downregulated under high-iron condition. These DEGs belonged to the functional categories of biological regulation, oxidation-reduction process, and ion binding and transport, and were involved in sulfur metabolism and cysteine/methionine metabolism. Comparison with our previous results from transcriptome data under oxygen-controlled conditions indicated that transcription of mam or mms was not regulated by oxygen or iron signals. 17 common DEGs in iron- and oxygen-transcriptomes were involved in energy production, iron transport, and iron metabolism. Some unknown-function DEGs participate in iron transport and metabolism, and some are potential biomarkers for identification of Magnetospirillum strains. IrrA and IrrB regulate iron transport in response to low-oxygen and high-iron signals, respectively. Six transcription factors were predicted to regulate DEGs. Fur and Crp particularly co-regulate DEGs in response to changes in iron or oxygen levels, in a proposed joint regulatory network of DEGs. Our findings provide new insights into biomineralization processes under high- vs. low-iron conditions in magnetotactic bacteria.
Collapse
Affiliation(s)
- Qing Wang
- State Key Laboratories for Agro-biotechnology, China Agricultural University, Beijing, 100193, P.R. China.,France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P.R. China
| | - Xu Wang
- State Key Laboratories for Agro-biotechnology, China Agricultural University, Beijing, 100193, P.R. China.,France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P.R. China
| | - Weijia Zhang
- Institute of Deep-sea Science and Engineering, China Academy of Sciences, Sanya, 572000, P.R. China.,France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P.R. China
| | - Xianyu Li
- Beijing Key Laboratory of Traditional Chinese Medicine Basic Research on Prevention and Treatment for Major Diseases, Experimental Research Center, China Academy of Chinese Medical Sciences, Beijing, 100700, P.R. China
| | - Yuan Zhou
- State Key Laboratories for Agro-biotechnology, China Agricultural University, Beijing, 100193, P.R. China
| | - Dan Li
- State Key Laboratories for Agro-biotechnology, China Agricultural University, Beijing, 100193, P.R. China
| | - Yinjia Wang
- Tianjin Biochip Corporation, Tianjin, 300457, P.R. China
| | - Jiesheng Tian
- State Key Laboratories for Agro-biotechnology, China Agricultural University, Beijing, 100193, P.R. China.,France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P.R. China
| | - Wei Jiang
- State Key Laboratories for Agro-biotechnology, China Agricultural University, Beijing, 100193, P.R. China.,France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P.R. China
| | - Ziding Zhang
- State Key Laboratories for Agro-biotechnology, China Agricultural University, Beijing, 100193, P.R. China
| | - Youliang Peng
- State Key Laboratories for Agro-biotechnology, China Agricultural University, Beijing, 100193, P.R. China
| | - Lei Wang
- Tianjin Biochip Corporation, Tianjin, 300457, P.R. China
| | - Ying Li
- State Key Laboratories for Agro-biotechnology, China Agricultural University, Beijing, 100193, P.R. China. .,France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P.R. China.
| | - Jilun Li
- State Key Laboratories for Agro-biotechnology, China Agricultural University, Beijing, 100193, P.R. China.,France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P.R. China
| |
Collapse
|
6
|
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
|
7
|
Zhang Y, Wen T, Guo F, Geng Y, Liu J, Peng T, Guan G, Tian J, Li Y, Li J, Ju J, Jiang W. The Disruption of an OxyR-Like Protein Impairs Intracellular Magnetite Biomineralization in Magnetospirillum gryphiswaldense MSR-1. Front Microbiol 2017; 8:208. [PMID: 28261169 PMCID: PMC5308003 DOI: 10.3389/fmicb.2017.00208] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 01/30/2017] [Indexed: 11/13/2022] Open
Abstract
Magnetotactic bacteria synthesize intracellular membrane-enveloped magnetite bodies known as magnetosomes which have been applied in biotechnology and medicine. A series of proteins involved in ferric ion transport and redox required for magnetite formation have been identified but the knowledge of magnetosome biomineralization remains very limited. Here, we identify a novel OxyR homolog (named OxyR-Like), the disruption of which resulted in low ferromagnetism and disfigured nano-sized iron oxide crystals. High resolution-transmission electron microscopy showed that these nanoparticles are mainly composed of magnetite accompanied with ferric oxide including α-Fe2O3 and 𝜀-Fe2O3. Electrophoretic mobility shift assay and DNase I footprinting showed that OxyR-Like binds the conserved 5'-GATA-N{9}-TATC-3' region within the promoter of pyruvate dehydrogenase (pdh) complex operon. Quantitative real-time reverse transcriptase PCR indicated that not only the expression of pdh operon but also genes related to magnetosomes biosynthesis and tricarboxylic acid cycle decreased dramatically, suggesting a link between carbon metabolism and magnetosome formation. Taken together, our results show that OxyR-Like plays a key role in magnetosomes formation.
Collapse
Affiliation(s)
- Yunpeng Zhang
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural UniversityBeijing, China; France-China Bio-Mineralization and Nano-Structures LaboratoryBeijing, China
| | - Tong Wen
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural UniversityBeijing, China; France-China Bio-Mineralization and Nano-Structures LaboratoryBeijing, China
| | - Fangfang Guo
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural UniversityBeijing, China; Beijing Key Laboratory for Prevention and Control of Infectious Diseases in Livestock and Poultry, Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry SciencesBeijing, China
| | - Yuanyuan Geng
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural UniversityBeijing, China; France-China Bio-Mineralization and Nano-Structures LaboratoryBeijing, China
| | - Junquan Liu
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural UniversityBeijing, China; France-China Bio-Mineralization and Nano-Structures LaboratoryBeijing, China
| | - Tao Peng
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University Beijing, China
| | - Guohua Guan
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural UniversityBeijing, China; France-China Bio-Mineralization and Nano-Structures LaboratoryBeijing, China
| | - Jiesheng Tian
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural UniversityBeijing, China; France-China Bio-Mineralization and Nano-Structures LaboratoryBeijing, China
| | - Ying Li
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural UniversityBeijing, China; France-China Bio-Mineralization and Nano-Structures LaboratoryBeijing, China
| | - Jilun Li
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural UniversityBeijing, China; France-China Bio-Mineralization and Nano-Structures LaboratoryBeijing, China
| | - Jing Ju
- College of Chemistry and Molecular Engineering, Peking University Beijing, China
| | - Wei Jiang
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural UniversityBeijing, China; France-China Bio-Mineralization and Nano-Structures LaboratoryBeijing, China
| |
Collapse
|
8
|
Marcano L, García-Prieto A, Muñoz D, Fernández Barquín L, Orue I, Alonso J, Muela A, Fdez-Gubieda ML. Influence of the bacterial growth phase on the magnetic properties of magnetosomes synthesized by Magnetospirillum gryphiswaldense. Biochim Biophys Acta Gen Subj 2017; 1861:1507-1514. [PMID: 28093197 DOI: 10.1016/j.bbagen.2017.01.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 12/23/2016] [Accepted: 01/10/2017] [Indexed: 01/17/2023]
Abstract
BACKGROUND The magnetosome biosynthesis is a genetically controlled process but the physical properties of the magnetosomes can be slightly tuned by modifying the bacterial growth conditions. METHODS We designed two time-resolved experiments in which iron-starved bacteria at the mid-logarithmic phase are transferred to Fe-supplemented medium to induce the magnetosomes biogenesis along the exponential growth or at the stationary phase. We used flow cytometry to determine the cell concentration, transmission electron microscopy to image the magnetosomes, DC and AC magnetometry methods for the magnetic characterization, and X-ray absorption spectroscopy to analyze the magnetosome structure. RESULTS When the magnetosomes synthesis occurs during the exponential growth phase, they reach larger sizes and higher monodispersity, displaying a stoichiometric magnetite structure, as fingerprinted by the well defined Verwey temperature. On the contrary, the magnetosomes synthesized at the stationary phase reach smaller sizes and display a smeared Verwey transition, that suggests that these magnetosomes may deviate slightly from the perfect stoichiometry. CONCLUSIONS Magnetosomes magnetically closer to stoichiometric magnetite are obtained when bacteria start synthesizing them at the exponential growth phase rather than at the stationary phase. GENERAL SIGNIFICANCE The growth conditions influence the final properties of the biosynthesized magnetosomes. This article is part of a Special Issue entitled "Recent Advances in Bionanomaterials" Guest Editors: Dr. Marie-Louise Saboungi and Dr. Samuel D. Bader.
Collapse
Affiliation(s)
- L Marcano
- Dpto. de Electricidad y Electrónica, Universidad del País Vasco - UPV/EHU, Leioa 48940, Spain
| | - A García-Prieto
- Dpto. de Física Aplicada I, Universidad del País Vasco - UPV/EHU, Bilbao 48013, Spain; BCMaterials, Parque tecnológico de Zamudio, Derio 48160, Spain
| | - D Muñoz
- Dpto. de Electricidad y Electrónica, Universidad del País Vasco - UPV/EHU, Leioa 48940, Spain; Dpto. de Inmunología, Microbiología y Parasitología, Universidad del País Vasco - UPV/EHU, Leioa 48940, Spain
| | | | - I Orue
- SGIker, Universidad del País Vasco - UPV/EHU, Leioa 48940, Spain
| | - J Alonso
- BCMaterials, Parque tecnológico de Zamudio, Derio 48160, Spain
| | - A Muela
- BCMaterials, Parque tecnológico de Zamudio, Derio 48160, Spain; Dpto. de Inmunología, Microbiología y Parasitología, Universidad del País Vasco - UPV/EHU, Leioa 48940, Spain
| | - M L Fdez-Gubieda
- Dpto. de Electricidad y Electrónica, Universidad del País Vasco - UPV/EHU, Leioa 48940, Spain; BCMaterials, Parque tecnológico de Zamudio, Derio 48160, Spain
| |
Collapse
|
9
|
Wang X, Wang Q, Zhang Y, Wang Y, Zhou Y, Zhang W, Wen T, Li L, Zuo M, Zhang Z, Tian J, Jiang W, Li Y, Wang L, Li J. Transcriptome analysis reveals physiological characteristics required for magnetosome formation in Magnetospirillum gryphiswaldense MSR-1. ENVIRONMENTAL MICROBIOLOGY REPORTS 2016; 8:371-381. [PMID: 27043321 DOI: 10.1111/1758-2229.12395] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 02/21/2016] [Indexed: 06/05/2023]
Abstract
Magnetosome synthesis ability of Magnetospirillum gryphiswaldense MSR-1 in an autofermentor can be precisely controlled through strict control of dissolved oxygen concentration. In this study, using transcriptome data we discovered gene transcriptional differences and compared physiological characteristics of MSR-1 cells cultured under aerobic (high-oxygen) and micro-aerobic (low-oxygen) conditions. The results showed that 77 genes were up-regulated and 95 genes were down-regulated significantly under micro-aerobic situation. These genes were involved primarily in the categories of cell metabolism, transport, regulation and unknown-function proteins. The nutrient transport and physiological metabolism were slowed down under micro-aerobic condition, whereas dissimilatory denitrification pathways were activated and it may supplemental energy was made available for magnetosome synthesis. The result suggested that the genes of magnetosome membrane proteins (Mam and Mms) are not directly regulated by oxygen level, or are constitutively expressed. A proposed regulatory network of differentially expressed genes reflects the complexity of physiological metabolism in MSR-1, and suggests that some yet-unknown functional proteins play important roles such as ferric iron uptake and transport during magnetosome synthesis. The transcriptome data provides a holistic view of the responses of MSR-1 cells to differing oxygen levels. This approach will give new insights into general principles of magnetosome formation.
Collapse
Affiliation(s)
- Xu Wang
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, P. R. China
- France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P. R. China
| | - Qing Wang
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, P. R. China
- France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P. R. China
| | - Yang Zhang
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, P. R. China
- France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P. R. China
| | - Yinjia Wang
- Tianjin Biochip Corporation, Tianjin, 300457, P. R. China
| | - Yuan Zhou
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, P. R. China
| | - Weijia Zhang
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, P. R. China
- France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P. R. China
| | - Tong Wen
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, P. R. China
- France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P. R. China
| | - Li Li
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, P. R. China
- France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P. R. China
| | - Meiqing Zuo
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, P. R. China
- France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P. R. China
| | - Ziding Zhang
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, P. R. China
| | - Jiesheng Tian
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, P. R. China
- France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P. R. China
| | - Wei Jiang
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, P. R. China
- France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P. R. China
| | - Ying Li
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, P. R. China
- France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P. R. China
| | - Lei Wang
- Tianjin Biochip Corporation, Tianjin, 300457, P. R. China
| | - Jilun Li
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, P. R. China
- France-China Bio-mineralization and Nano-structure Laboratory, Beijing, 100193, P. R. China
| |
Collapse
|
10
|
A novel role for Crp in controlling magnetosome biosynthesis in Magnetospirillum gryphiswaldense MSR-1. Sci Rep 2016; 6:21156. [PMID: 26879571 PMCID: PMC4754748 DOI: 10.1038/srep21156] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 01/18/2016] [Indexed: 01/10/2023] Open
Abstract
Magnetotactic bacteria (MTB) are specialized microorganisms that synthesize intracellular magnetite particles called magnetosomes. Although many studies have focused on the mechanism of magnetosome synthesis, it remains unclear how these structures are formed. Recent reports have suggested that magnetosome formation is energy dependent. To investigate the relationship between magnetosome formation and energy metabolism, a global regulator, named Crp, which mainly controls energy and carbon metabolism in most microorganisms, was genetically disrupted in Magnetospirillum gryphiswaldense MSR-1. Compared with the wild-type or complemented strains, the growth, ferromagnetism and intracellular iron content of crp-deficient mutant cells were dramatically decreased. Transmission electron microscopy (TEM) showed that magnetosome synthesis was strongly impaired by the disruption of crp. Further gene expression profile analysis showed that the disruption of crp not only influenced genes related to energy and carbon metabolism, but a series of crucial magnetosome island (MAI) genes were also down regulated. These results indicate that Crp is essential for magnetosome formation in MSR-1. This is the first time to demonstrate that Crp plays an important role in controlling magnetosome biomineralization and provides reliable expression profile data that elucidate the mechanism of Crp regulation of magnetosome formation in MSR-1.
Collapse
|
11
|
Identification of Multiple Soluble Fe(III) Reductases in Gram-Positive Thermophilic Bacterium Thermoanaerobacter indiensis BSB-33. Int J Genomics 2014; 2014:850607. [PMID: 25180173 PMCID: PMC4142287 DOI: 10.1155/2014/850607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Revised: 07/03/2014] [Accepted: 07/06/2014] [Indexed: 11/18/2022] Open
Abstract
Thermoanaerobacter indiensis BSB-33 has been earlier shown to reduce Fe(III) and Cr(VI) anaerobically at 60°C optimally. Further, the Gram-positive thermophilic bacterium contains Cr(VI) reduction activity in both the membrane and cytoplasm. The soluble fraction prepared from T. indiensis cells grown at 60°C was found to contain the majority of Fe(III) reduction activity of the microorganism and produced four distinct bands in nondenaturing Fe(III) reductase activity gel. Proteins from each of these bands were partially purified by chromatography and identified by mass spectrometry (MS) with the help of T. indiensis proteome sequences. Two paralogous dihydrolipoamide dehydrogenases (LPDs), thioredoxin reductase (Trx), NADP(H)-nitrite reductase (Ntr), and thioredoxin disulfide reductase (Tdr) were determined to be responsible for Fe(III) reductase activity. Amino acid sequence and three-dimensional (3D) structural similarity analyses of the T. indiensis Fe(III) reductases were carried out with Cr(VI) reducing proteins from other bacteria. The two LPDs and Tdr showed very significant sequence and structural identity, respectively, with Cr(VI) reducing dihydrolipoamide dehydrogenase from Thermus scotoductus and thioredoxin disulfide reductase from Desulfovibrio desulfuricans. It appears that in addition to their iron reducing activity T. indiensis LPDs and Tdr are possibly involved in Cr(VI) reduction as well.
Collapse
|
12
|
Arnoux P, Siponen MI, Lefèvre CT, Ginet N, Pignol D. Structure and evolution of the magnetochrome domains: no longer alone. Front Microbiol 2014; 5:117. [PMID: 24723915 PMCID: PMC3971196 DOI: 10.3389/fmicb.2014.00117] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 03/08/2014] [Indexed: 11/13/2022] Open
Abstract
Magnetotactic bacteria (MTB) can swim along Earth's magnetic field lines, thanks to the alignment of dedicated cytoplasmic organelles. These organelles, termed magnetosomes, are proteolipidic vesicles filled by a 35–120 nm crystal of either magnetite or greigite. The formation and alignment of magnetosomes are mediated by a group of specific genes, the mam genes, encoding the magnetosome-associated proteins. The whole process of magnetosome biogenesis can be divided into four sequential steps; (i) cytoplasmic membrane invagination, (ii) magnetosomes alignment, (iii) iron crystal nucleation and (iv) species-dependent mineral size and shape control. Since both magnetite and greigite are a mix of iron (III) and iron (II), iron redox state management within the magnetosome vesicle is a key issue. Recently, studies have started pointing out the importance of a MTB-specific c-type cytochrome domain found in several magnetosome-associated proteins (MamE, P, T, and X). This magnetochrome (MCR) domain is almost always found in tandem, and this tandem is either found alone (MamT), in combination with a PDZ domain (MamP), a domain of unknown function (MamX) or with a trypsin combined to one or two PDZ domains (MamE). By taking advantage of new genomic data available on MTB and a recent structural study of MamP, which helped define the MCR domain boundaries, we attempt to retrace the evolutionary history within and between the different MCR-containing proteins. We propose that the observed tandem repeat of MCR is the result of a convergent evolution and attempt to explain why this domain is rarely found alone.
Collapse
Affiliation(s)
- Pascal Arnoux
- Commissariat à l'énergie Atomique, DSV, IBEB, Lab Bioenerget Cellulaire Saint-Paul-lez-Durance, France ; Centre National de la Recherche Scientifique, UMR Biol Veget and Microbiol Environ Saint-Paul-lez-Durance, France ; Aix-Marseille Université Saint-Paul-lez-Durance, France
| | - Marina I Siponen
- Commissariat à l'énergie Atomique, DSV, IBEB, Lab Bioenerget Cellulaire Saint-Paul-lez-Durance, France ; Centre National de la Recherche Scientifique, UMR Biol Veget and Microbiol Environ Saint-Paul-lez-Durance, France ; Aix-Marseille Université Saint-Paul-lez-Durance, France
| | - Christopher T Lefèvre
- Commissariat à l'énergie Atomique, DSV, IBEB, Lab Bioenerget Cellulaire Saint-Paul-lez-Durance, France ; Centre National de la Recherche Scientifique, UMR Biol Veget and Microbiol Environ Saint-Paul-lez-Durance, France ; Aix-Marseille Université Saint-Paul-lez-Durance, France
| | - Nicolas Ginet
- Commissariat à l'énergie Atomique, DSV, IBEB, Lab Bioenerget Cellulaire Saint-Paul-lez-Durance, France ; Centre National de la Recherche Scientifique, UMR Biol Veget and Microbiol Environ Saint-Paul-lez-Durance, France ; Aix-Marseille Université Saint-Paul-lez-Durance, France
| | - David Pignol
- Commissariat à l'énergie Atomique, DSV, IBEB, Lab Bioenerget Cellulaire Saint-Paul-lez-Durance, France ; Centre National de la Recherche Scientifique, UMR Biol Veget and Microbiol Environ Saint-Paul-lez-Durance, France ; Aix-Marseille Université Saint-Paul-lez-Durance, France
| |
Collapse
|
13
|
Structural insight into magnetochrome-mediated magnetite biomineralization. Nature 2013; 502:681-4. [DOI: 10.1038/nature12573] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 08/13/2013] [Indexed: 01/04/2023]
|
14
|
Wang Q, Liu JX, Zhang WJ, Zhang TW, Yang J, Li Y. Expression patterns of key iron and oxygen metabolism genes during magnetosome formation in Magnetospirillum gryphiswaldense MSR-1. FEMS Microbiol Lett 2013; 347:163-72. [PMID: 23937222 DOI: 10.1111/1574-6968.12234] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 08/06/2013] [Accepted: 08/07/2013] [Indexed: 11/28/2022] Open
Abstract
To evaluate the expression patterns of genes involved in iron and oxygen metabolism during magnetosome formation, the profiles of 13 key genes in Magnetospirillum gryphiswaldense MSR-1 cells cultured under high-iron vs. low-iron conditions were examined. Cell growth rates did not differ between the two conditions. Only the high-iron cells produced magnetosomes. Transmission electron microscopy observations revealed that magnetosome formation began at 6 h and crystal maturation occurred from 10 to 18 h. Real-time polymerase chain reaction analysis showed that expression of these genes increased during cell growth and magnetosome synthesis, particularly for ferric reductase gene (fer6) and ferrous transport system-related genes feoAB1, feoAB2, sodB, and katG. The low-iron cells showed increased expression of feoAB1 and feoB2 from 12 to 18 h but no clear expression changes for the other genes. Expression patterns of the genes were divided by hierarchical clustering into four clusters for the high-iron cells and three clusters for the low-iron cells. Each cluster included both iron and oxygen metabolism genes showing similar expression patterns. The findings indicate the coordination and co-dependence of iron and oxygen metabolism gene activity to achieve a balance during the biomineralization process. Future transcriptome analysis will help elucidate the mechanism of biomineralization in MSR-1 magnetosome formation.
Collapse
Affiliation(s)
- Qing Wang
- State Key Laboratories for Agro-biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China; France-China Bio-mineralization and Nano-structure Laboratory, Beijing, China
| | | | | | | | | | | |
Collapse
|