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LaSarre B, Kysela DT, Stein BD, Ducret A, Brun YV, McKinlay JB. Restricted Localization of Photosynthetic Intracytoplasmic Membranes (ICMs) in Multiple Genera of Purple Nonsulfur Bacteria. mBio 2018; 9:e00780-18. [PMID: 29970460 PMCID: PMC6030561 DOI: 10.1128/mbio.00780-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 06/06/2018] [Indexed: 01/18/2023] Open
Abstract
In bacteria and eukaryotes alike, proper cellular physiology relies on robust subcellular organization. For the phototrophic purple nonsulfur bacteria (PNSB), this organization entails the use of a light-harvesting, membrane-bound compartment known as the intracytoplasmic membrane (ICM). Here we show that ICMs are spatially and temporally localized in diverse patterns among PNSB. We visualized ICMs in live cells of 14 PNSB species across nine genera by exploiting the natural autofluorescence of the photosynthetic pigment bacteriochlorophyll (BChl). We then quantitatively characterized ICM localization using automated computational analysis of BChl fluorescence patterns within single cells across the population. We revealed that while many PNSB elaborate ICMs along the entirety of the cell, species across as least two genera restrict ICMs to discrete, nonrandom sites near cell poles in a manner coordinated with cell growth and division. Phylogenetic and phenotypic comparisons established that ICM localization and ICM architecture are not strictly interdependent and that neither trait fully correlates with the evolutionary relatedness of the species. The natural diversity of ICM localization revealed herein has implications for both the evolution of phototrophic organisms and their light-harvesting compartments and the mechanisms underpinning spatial organization of bacterial compartments.IMPORTANCE Many bacteria organize their cellular space by constructing subcellular compartments that are arranged in specific, physiologically relevant patterns. The purple nonsulfur bacteria (PNSB) utilize a membrane-bound compartment known as the intracytoplasmic membrane (ICM) to harvest light for photosynthesis. It was previously unknown whether ICM localization within cells is systematic or irregular and if ICM localization is conserved among PNSB. Here we surveyed ICM localization in diverse PNSB and show that ICMs are spatially organized in species-specific patterns. Most strikingly, several PNSB resolutely restrict ICMs to regions near the cell poles, leaving much of the cell devoid of light-harvesting machinery. Our results demonstrate that bacteria of a common lifestyle utilize unequal portions of their intracellular space to harvest light, despite light harvesting being a process that is intuitively influenced by surface area. Our findings therefore raise fundamental questions about ICM biology and evolution.
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Affiliation(s)
- Breah LaSarre
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - David T Kysela
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Barry D Stein
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Adrien Ducret
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Yves V Brun
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - James B McKinlay
- Department of Biology, Indiana University, Bloomington, Indiana, USA
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Roychowdhury S, Dong Q, Bauer CE. DNA-binding properties of a cGMP-binding CRP homologue that controls development of metabolically dormant cysts of Rhodospirillum centenum. MICROBIOLOGY-SGM 2015; 161:2256-64. [PMID: 26362215 DOI: 10.1099/mic.0.000172] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Rhodospirillum centenum utilizes 3',5'-cyclic guanosine monophosphate (cGMP) as a messenger to regulate development of desiccation-resistant cysts. In this study, we demonstrated that gcyA, gcyB and gcyC, coding for putative subunits of a guanylyl cyclase, increase expression from 8- to 500-fold when cells transition from vegetative to cyst phases of growth. This induction did not occur in a strain that is defective in cGMP synthesis or in a strain that contains a deletion of cgrA that codes for a cGMP-binding homologue of Escherichia coli catabolite repressor protein (CRP). We also demonstrated that cgrA auto-induces its own expression in the presence of cGMP, indicating that a feed-forward loop is used to ramp up cGMP production as cells undergo encystment. Inspection of an intragenic region upstream of gcyB revealed a sequence that is identical to the CRP consensus sequence from E. coli. DNase I and fluorescence anisotropy analyses demonstrated that CgrA bound to this target sequence at a protein : cGMP ratio of 1 : 2 with Kd ∼61 nM. This was in contrast to CgrA in the presence of cAMP, which exhibited Kd ∼1795 nM. CgrA thus constitutes a novel variant of CRP that utilizes cGMP to regulate production of cGMP synthase for the control of cyst development.
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Affiliation(s)
- Sugata Roychowdhury
- Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, IN 47405, USA
| | - Qian Dong
- Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, IN 47405, USA
| | - Carl E Bauer
- Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, IN 47405, USA
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He K, Dragnea V, Bauer CE. Adenylate Charge Regulates Sensor Kinase CheS3 To Control Cyst Formation in Rhodospirillum centenum. mBio 2015; 6:e00546-15. [PMID: 25944862 PMCID: PMC4436063 DOI: 10.1128/mbio.00546-15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 04/06/2015] [Indexed: 12/02/2022] Open
Abstract
UNLABELLED Rhodospirillum centenum forms metabolically dormant cysts under unfavorable growth conditions such as desiccation or nutrient starvation. The development of cysts is tightly regulated and involves a cyst-repressing chemotaxis-like signal transduction pathway called the Che3 signaling cascade. The Che3 cascade is comprised of a methyl chemoreceptor (MCP3), receptor-methylating/demethylating proteins CheB3 and CheR3, two CheW3 linker proteins, a CheA3-CheY hybrid histidine kinase, and a single-domain response regulator, CheY3. In addition to Che-like components, the Che3 cascade also contains a second hybrid histidine kinase, CheS3. Recent biochemical and genetic studies show that CheA3 does not serve as a phosphor donor for CheY3; instead, CheA3 inhibits a CheS3→CheY3 two-component system by phosphorylating an inhibitory receiver domain of CheS3. In this study, we show that in addition to phosphorylation by CheA3, the phosphorylation state of CheS3 is also regulated by the cellular energy level as quantified by the molar ratio of ATP/(ATP + ADP). A 35% decrease in cellular energy is shown to occur in vivo upon a nutrient downshift that gives rise to cyst formation. When this energy decline is replicated in vitro, the phosphorylation level of CheS3 is reduced by ~75%. Finally, we also show that ADP-mediated reduction of CheS3 phosphorylation is a consequence of ADP enhancing autodephosphorylation of CheS3. IMPORTANCE Upon starvation, Rhodospirillum centenum undergoes a developmental process that forms metabolically dormant cysts, which withstand desiccation and nutritional limitation. This study explores the role of the cellular energy state as measured by the ratio of ATP to ADP as an important regulator of cyst formation in Rhodospirillum centenum. We show that R. centenum cells experience a significant reduction in ATP during cyst formation using ATP/(ATP + ADP) as a measurement. When this in vivo level of energy starvation is simulated in vitro, CheS3 phosphorylation is reduced by 75%. This profound reduction in CheS3 autophosphorylation is contrasted with a much lower 25% decrease in CheA3 phosphorylation in response to a similar downward shift in ATP/(ATP + ADP). We argue that even though adenylate energy affects all ATP-dependent enzymes to an extent, the enhanced inhibition of CheS3 activity in response to a reduction in the ATP/(ATP + ADP) ratio likely functions as an important input signal to regulate cyst development.
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Affiliation(s)
- Kuang He
- Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, Indiana, USA
| | - Vladimira Dragnea
- Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, Indiana, USA
| | - Carl E Bauer
- Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, Indiana, USA
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Heat treatment induced bacterial changes in irrigation water and their implications for plant disease management. World J Microbiol Biotechnol 2013; 30:1591-601. [PMID: 24343781 DOI: 10.1007/s11274-013-1583-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 12/12/2013] [Indexed: 10/25/2022]
Abstract
A new heat treatment for recycled irrigation water using 48 °C for 24 h to inactivate Phytophthora and bacterial plant pathogens is estimated to reduce fuel cost and environmental footprint by more than 50 % compared to current protocol (95 °C for 30 s). The objective of this study was to determine the impact of this new heat treatment temperature regime on bacterial community structure in water and its practical implications. Bacterial communities in irrigation water were analyzed before and after heat treatment using both culture-dependent and -independent strategies based on the 16S ribosomal DNA. A significant shift was observed in the bacterial community after heat treatment. Most importantly, bacteria with biological control potential--Bacillus and Paenibacillus, and Pseudomonas species became more abundant at both 48 and 42 °C. These findings imply that the new heat treatment procedure not only controls existing plant pathogens but also may make the heat-treated irrigation water a more antagonistic environment against plant pathogens, promoting sustainable disease management.
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Bird TH, MacKrell A. A CtrA homolog affects swarming motility and encystment in Rhodospirillum centenum. Arch Microbiol 2011; 193:451-9. [PMID: 21243338 DOI: 10.1007/s00203-011-0676-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Revised: 12/19/2010] [Accepted: 12/23/2010] [Indexed: 11/29/2022]
Abstract
The α-proteobacterium, Rhodospirillum centenum, has a complex life cycle that allows adaptation to different environments. Transitions between vegetative swim cell and swarmer cell types depend on whether the organism is growing in liquid surroundings or on a solid substrate. Moreover, starvation can induce vegetative cells to differentiate into quiescent cysts. This paper describes the results of our investigation into the role of a putative DNA-binding response regulator that is homologous to CtrA, the cell cycle regulator from Caulobacter crescentus. Deletion of ctrA from the R. centenum genome resulted in a viable strain with impaired swarming motility coupled with an increased tendency to form cysts. Conversely, overexpression of wild type CtrA or a phosphomimetic allele, CtrAD51E, suppressed cyst cell formation, whereas overexpression of a CtrAD51A allele failed to suppress encystment but did prevent swarming motility. Thus, we propose that CtrA participates within a two-component signal transduction pathway that promotes swarming motility while contributing to the suppression of cyst cell formation.
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Affiliation(s)
- Terry H Bird
- Biology Department, University of San Diego, San Diego, CA 92110, USA.
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A CheR/CheB fusion protein is involved in cyst cell development and chemotaxis in Azospirillum brasilense Sp7. Microbiol Res 2011; 166:606-17. [PMID: 21232929 DOI: 10.1016/j.micres.2010.12.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 12/06/2010] [Accepted: 12/12/2010] [Indexed: 01/28/2023]
Abstract
We here report the sequence and functional analysis of cstB of Azospirillum brasilense Sp7. The predicted cstB contains C-terminal two PAS domains and N-terminal part which has similarity with CheB-CheR fusion protein. cstB mutants had reduced swarming ability compared to that of A. brasilense wild-type strain, implying that cstB was involved in chemotaxis in A. brasilense. A microscopic analysis revealed that cstB mutants developed mature cyst cells more quickly than wild type, indicating that cstB is involved in cyst formation. cstB mutants were affected in colony morphology and the production of exopolysaccharides (EPS) which are essential for A. brasilense cells to differentiate into cyst-like forms. These observations suggested that cstB was a multi-effector involved in cyst development and chemotaxis in A. brasilense.
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Marden JN, Dong Q, Roychowdhury S, Berleman JE, Bauer CE. Cyclic GMP controls Rhodospirillum centenum cyst development. Mol Microbiol 2011; 79:600-15. [PMID: 21214648 DOI: 10.1111/j.1365-2958.2010.07513.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Adenylyl cyclases are widely distributed across all kingdoms whereas guanylyl cyclases are generally thought to be restricted to eukaryotes. Here we report that the α-proteobacterium Rhodospirillum centenum secretes cGMP when developing cysts and that a guanylyl cyclase deletion strain fails to synthesize cGMP and is defective in cyst formation. The R. centenum cyclase was purified and shown to effectively synthesize cGMP from GTP in vitro, demonstrating that it is a functional guanylyl cyclase. A homologue of the Escherichia coli cAMP receptor protein (CRP) is linked to the guanylyl cyclase and when deleted is deficient in cyst development. Isothermal calorimetry (ITC) and differential scanning fluorimetry (DSF) analyses demonstrate that the recombinant CRP homologue preferentially binds to, and is stabilized by cGMP, but not cAMP. This study thus provides evidence that cGMP has a crucial role in regulating prokaryotic development. The involvement of cGMP in regulating bacterial development has broader implications as several plant-interacting bacteria contain a similar cyclase coupled by the observation that Azospirillum brasilense also synthesizes cGMP when inducing cysts.
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Affiliation(s)
- Jeremiah N Marden
- Indiana University, Bloomington, IN 47405, USA University of California at Berkeley, Berkeley, CA 94720, USA
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Din N, Shoemaker CJ, Akin KL, Frederick C, Bird TH. Two putative histidine kinases are required for cyst formation in Rhodospirillum Centenum. Arch Microbiol 2010; 193:209-22. [PMID: 21184217 DOI: 10.1007/s00203-010-0664-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 11/17/2010] [Accepted: 11/22/2010] [Indexed: 10/18/2022]
Abstract
The photosynthetic bacterium, Rhodospirillum centenum, has a flexible life cycle that permits it to survive starvation as dormant cyst cells. Previous studies have identified some of the key regulators for encystment and demonstrated that the control of development is intricate. This complexity may arise from the need to integrate several environmental signals to mediate a switch from one mode of energy metabolism to another and to ensure that a transition to dormancy is initiated only when necessary. We searched for additional regulators of development by screening for encystment deficient strains after subjecting wild type R. centenum to mini-Tn5 mutagenesis. Analysis of "hypo-cyst" strains led to the identification of two genes that encode putative hybrid histidine kinases (cyd1 and cyd2). Cells with deletions of either gene fail to form cysts under conditions that normally induce development. Furthermore, the deletion strains exhibit altered swarming behavior suggesting that Cyd1 and Cyd2 affect behaviors utilized when the organism is attached to a substrate.
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Affiliation(s)
- Neena Din
- Biology Department, University of San Diego, 5998 Alcalá Park, San Diego, CA 92110, USA
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Lu YK, Marden J, Han M, Swingley WD, Mastrian SD, Chowdhury SR, Hao J, Helmy T, Kim S, Kurdoglu AA, Matthies HJ, Rollo D, Stothard P, Blankenship RE, Bauer CE, Touchman JW. Metabolic flexibility revealed in the genome of the cyst-forming alpha-1 proteobacterium Rhodospirillum centenum. BMC Genomics 2010; 11:325. [PMID: 20500872 PMCID: PMC2890560 DOI: 10.1186/1471-2164-11-325] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Accepted: 05/25/2010] [Indexed: 11/23/2022] Open
Abstract
Background Rhodospirillum centenum is a photosynthetic non-sulfur purple bacterium that favors growth in an anoxygenic, photosynthetic N2-fixing environment. It is emerging as a genetically amenable model organism for molecular genetic analysis of cyst formation, photosynthesis, phototaxis, and cellular development. Here, we present an analysis of the genome of this bacterium. Results R. centenum contains a singular circular chromosome of 4,355,548 base pairs in size harboring 4,105 genes. It has an intact Calvin cycle with two forms of Rubisco, as well as a gene encoding phosphoenolpyruvate carboxylase (PEPC) for mixotrophic CO2 fixation. This dual carbon-fixation system may be required for regulating internal carbon flux to facilitate bacterial nitrogen assimilation. Enzymatic reactions associated with arsenate and mercuric detoxification are rare or unique compared to other purple bacteria. Among numerous newly identified signal transduction proteins, of particular interest is a putative bacteriophytochrome that is phylogenetically distinct from a previously characterized R. centenum phytochrome, Ppr. Genes encoding proteins involved in chemotaxis as well as a sophisticated dual flagellar system have also been mapped. Conclusions Remarkable metabolic versatility and a superior capability for photoautotrophic carbon assimilation is evident in R. centenum.
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Affiliation(s)
- Yih-Kuang Lu
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
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Masuda S, Berleman J, Hasselbring BM, Bauer CE. Regulation of aerobic photosystem synthesis in the purple bacterium Rhodospirillum centenum by CrtJ and AerR. Photochem Photobiol Sci 2008; 7:1267-72. [PMID: 18846293 DOI: 10.1039/b802365b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Genes coding for putative CrtJ and AerR homologs were identified and characterized in the purple photosynthetic bacterium Rhodospirillum centenum (also known as Rhodocista centenaria), an organism that synthesizes photopigments even under highly aerated conditions. Mutational analysis indicated that in Rsp. centenum, gene crtJ codes for a repressor for photosynthesis gene expression as in Rhodobacter capsulatus, which exhibits a high level of oxygen repression of photosystem synthesis. In contrast to Rba. capsulatus, AerR in Rsp. centenum appears to be an aerobic activator; an aerR mutation resulted in significantly reduced levels of photopigment synthesis. Both aerR and crtJ mutants retained essentially normal levels of photosystem synthesis under anaerobic conditions, indicating that their activities are specific for aerobic photosystem synthesis. The readthrough transcript from crtE promoter, which is regulated by AerR and CrtJ, seems to be significant in maintaining the expression levels of the light harvesting I (puf) genes in Rsp. centenum. We suggest that AerR and CrtJ regulate aerobic photosystem synthesis primarily through controlling activity of the transcriptional readthrough.
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Affiliation(s)
- Shinji Masuda
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, 226-8501, Japan.
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Csotonyi JT, Swiderski J, Stackebrandt E, Yurkov VV. Novel halophilic aerobic anoxygenic phototrophs from a Canadian hypersaline spring system. Extremophiles 2008; 12:529-39. [PMID: 18385928 DOI: 10.1007/s00792-008-0156-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Accepted: 02/27/2008] [Indexed: 11/26/2022]
Abstract
The first enumeration of cultivable obligately aerobic phototrophic bacteria from a terrestrial saline spring was accomplished in the East German Creek system (salinity approximately 6%), near Lake Winnipegosis, Manitoba, Canada. Occurring at densities up to 3.3x10(7) CFU/ml of sample, aerobic phototrophs comprised 15-36% of the total cultivable bacterial population in the diatom- and chlorophyte-dominated aerobic microbial mats. Many of the representative strains isolated for phenotypic characterization and phylogenetic analysis possessed <96% 16S rDNA sequence overlap with published species, including an obligately aerobic phototrophic gammaproteobacterium displaying only 92.9% 16S rDNA sequence similarity to Congregibacter litoralis. The springs yielded the most highly halotolerant aerobic anoxygenic phototroph yet recorded, strain EG11, which grew with 26% NaCl.
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Affiliation(s)
- Julius T Csotonyi
- Department of Microbiology, University of Manitoba, 418 Buller Building, R3T 2N2, Winnipeg, MB, Canada
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Berleman JE, Bauer CE. A che-like signal transduction cascade involved in controlling flagella biosynthesis in Rhodospirillum centenum. Mol Microbiol 2005; 55:1390-402. [PMID: 15720548 DOI: 10.1111/j.1365-2958.2005.04489.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Rhodospirillum centenum is a photosynthetic bacterium capable of undergoing swim cell to swarm cell differentiation that allows this species to be motile on both liquid and solid media. Previous experiments have demonstrated that the che1 operon is required for the control of chemotactic and phototactic behaviour of both swim and swarm cells. In this report, we analyse the function of a second che-like gene cluster in R. centenum, the che2 gene cluster. In-frame deletion mutants of cheW2, cheB2, cheR2, cheY2, and of the entire che2 operon, exhibit defects in swim and swarm cell motility. Analysis of these strains demonstrates that they are non-motile, and that the non-motile phenotype is resulting from reduced polar and lateral flagella synthesis. Additionally, mutations in mcp2, ORF204, cheA2 and ORF74 remain chemotacticly and phototacticly competent at both high and low growth temperatures. Mutations in these che2 genes result in elevated levels of flagellin proteins giving rise to a hyperflagellate phenotype. We propose a model in which R. centenum utilizes a che-like signal transduction pathway (che2) for regulating flagellum synthesis in order to optimize swim cell-swarm cell differentiation in response to changing environmental conditions.
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Affiliation(s)
- James E Berleman
- School of Biology, Georgia Institute of Technology, Atlanta, GA 30332, USA
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Berleman JE, Bauer CE. Involvement of a Che-like signal transduction cascade in regulating cyst cell development inRhodospirillum centenum. Mol Microbiol 2005; 56:1457-66. [PMID: 15916598 DOI: 10.1111/j.1365-2958.2005.04646.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Homologues of the E. coli chemotaxis (Che) signal transduction pathway are present in nearly all motile bacteria. Although E. coli contains only one Che cascade, many other bacteria are known to possess multiple sets of che genes. The role of multiple che-like gene clusters could potentially code for parallel Che-like signal transduction pathways that have distinctly different input and output functions. In this study, we describe a che-like gene cluster in Rhodospirillum centenum that controls a developmental cycle. In-frame deletion mutants of homologues of CheW (DeltacheW(3a)and DeltacheW(3b)), CheR (DeltacheR(3)), CheA (DeltacheA(3)) and a methyl-accepting chemotaxis protein (Deltamcp(3)) are defective in starvation-induced formation of heat and desiccation resistant cyst cells. In contrast, mutants of homologues of CheY (DeltacheY(3)), CheB (DeltacheB(3)), and a second input kinase designated as CheS (DeltacheS(3)) result in cells that are derepressed in the formation of cysts. A model of signal transduction is presented in which there are three distinct Che-like signal transduction cascades; one that is involved in chemotaxis, one that is involved in flagella biosynthesis and the third that is involved in cyst development.
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Affiliation(s)
- James E Berleman
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
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Berleman JE, Hasselbring BM, Bauer CE. Hypercyst mutants in Rhodospirillum centenum identify regulatory loci involved in cyst cell differentiation. J Bacteriol 2004; 186:5834-41. [PMID: 15317789 PMCID: PMC516826 DOI: 10.1128/jb.186.17.5834-5841.2004] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rhodospirillum centenum is a purple photosynthetic bacterium that forms resting cyst cells when starved for nutrients. In this study, we demonstrate that chalcone synthase gene (chsA) expression is developmentally regulated, with expression of chsA increasing up to 86-fold upon induction of the cyst developmental cycle. Screening for mini-Tn5-induced mutants that exhibit elevated chsA::lacZ expression has led to the isolation of a set of R. centenum mutants that display increased chsA gene expression concomitant with constitutive induction of the cyst developmental cycle. These "hypercyst" mutants have lost the ability to regulate cyst cell formation in response to nutrient availability. Sequence analysis indicates that the mini-Tn5-disrupted genes code for a variety of factors, including metabolic enzymes and a large set of potential regulatory factors, including four gene products with homology to histidine sensor kinases and three with homology to response regulators. Several of the disrupted genes also have sequence similarity to che-like signal transduction components.
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Affiliation(s)
- James E Berleman
- Department of Biology, Indiana University, Myers Hall, 915 E. Third St., Bloomington, IN 47405, USA
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15
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Berleman JE, Bauer CE. Characterization of cyst cell formation in the purple photosynthetic bacterium Rhodospirillum centenum. MICROBIOLOGY-SGM 2004; 150:383-390. [PMID: 14766916 DOI: 10.1099/mic.0.26846-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Rhodospirillum centenum is an anoxygenic photosynthetic bacterium that is capable of differentiating into several cell types. When grown phototrophically in liquid, cells exhibit a vibrioid shape and have a single polar flagellum. When grown on a solid surface, R. centenum will differentiate into rod-shaped swarm cells that display numerous lateral flagella. Upon starvation for nutrients, R. centenum also forms desiccation-resistant cysts. In this study, it was determined that R. centenum has heat- and desiccation-resistance properties similar to other cyst-forming species. In addition, microscopic analyses of the morphological changes that occur during cyst cell development were performed. It was observed that R. centenum typically forms multi-celled clusters of cysts that contain from four to more than 10 cells per cluster. It was also determined that cell density has a minor effect on the percentage of cyst cells formed, with cell densities of 10(5)-10(7) cells per 5 micro l spot yielding the highest percentage of cyst cells. The striking similarities between the life cycle of R. centenum and the life cycle exhibited by Azospirillum spp. are discussed.
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Affiliation(s)
- James E Berleman
- Department of Biology, Indiana University, Jordan Hall, Bloomington, IN 47405, USA
| | - Carl E Bauer
- Department of Biology, Indiana University, Jordan Hall, Bloomington, IN 47405, USA
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Zhang D, Yang H, Zhang W, Huang Z, Liu SJ. Rhodocista pekingensis sp. nov., a cyst-forming phototrophic bacterium from a municipal wastewater treatment plant. Int J Syst Evol Microbiol 2003; 53:1111-1114. [PMID: 12892135 DOI: 10.1099/ijs.0.02500-0] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A novel bacterial species, Rhodocista pekingensis sp. nov., was isolated from a municipal wastewater treatment plant and characterized by polyphasic taxonomy. Cells of R. pekingensis were gram-negative, motile by a single polar flagellum, vibrioid to spiral, 0.6-0.8 microm in width and 0.8-1.5 microm in length. R-bodies were not observed. Phototrophically grown cells contained lamellar photosynthetic membranes and bacteriochlorophyll a. Cell growth was anaerobically phototrophic or aerobically chemoheterotrophic. Anaerobically grown cultures were pink-reddish. Thiamin and vitamin B12, but not biotin, were required for growth and 0.05% yeast extract stimulated growth. Acetate, lactate, pyruvate and succinate supported growth. Cysts were formed when butyrate was used as the sole carbon source. Molecular hydrogen (H2), but not sulfide or thiosulfate, was used as an electron donor. The major cellular quinone was Q-9. The DNA G + C content of cells was 68.8 mol%. The type strain of Rhodocista pekingensis is 3-pT (=AS 1.2194T=JCM 11689T).
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Affiliation(s)
- Demin Zhang
- Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, P. R. China
| | - Huifang Yang
- Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, P. R. China
| | - Wei Zhang
- Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, P. R. China
| | - Zhiyong Huang
- Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, P. R. China
| | - Shuang-Jiang Liu
- Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, P. R. China
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17
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Samyn B, Fitch J, Meyer TE, Cusanovich MA, Van Beeumen JJ. Purification and primary structure analysis of two cytochrome c2 isozymes from the purple phototrophic bacterium Rhodospirillum centenum. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1384:345-55. [PMID: 9659396 DOI: 10.1016/s0167-4838(98)00030-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The isolation and amino acid sequences of two cytochromes c-552 from the thermotolerant bacterium Rhodospirillum (R.) centenum have been determined. They are very similar to one another with 85% identity. They are homologous to the cytochromes c2 from purple bacteria with approximately 67% identity to that from Rhodopseudomonas (Rps.) palustris compared to only 42% identity with others of the c2 subclass. In addition, they share an unusual six-residue insertion with Rps. palustris cytochrome c2 not found in any other cytochrome. The relationship with Rps. palustris is thus highly significant. The redox potentials of the R. centenum isozymes are 293 and 316 mV. Although the proteins have strongly different iso-electric points, both have three conserved lysine residues at the proposed site of electron transfer. These results suggest that they may be functionally interchangeable.
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Affiliation(s)
- B Samyn
- Department of Biochemistry, Physiology and Microbiology, University of Gent, Belgium
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18
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Jiang ZY, Rushing BG, Bai Y, Gest H, Bauer CE. Isolation of Rhodospirillum centenum mutants defective in phototactic colony motility by transposon mutagenesis. J Bacteriol 1998; 180:1248-55. [PMID: 9495765 PMCID: PMC107014 DOI: 10.1128/jb.180.5.1248-1255.1998] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The purple photosynthetic bacterium Rhodospirillum centenum is capable of forming swarm colonies that rapidly migrate toward or away from light, depending on the wavelength of excitation. To identify components specific for photoperception, we conducted mini-Tn5-mediated mutagenesis and screened approximately 23,000 transposition events for mutants that failed to respond to either continuous illumination or to a step down in light intensity. A majority of the ca. 250 mutants identified lost the ability to form motile swarm cells on an agar surface. These cells appeared to contain defects in the synthesis or assembly of surface-induced lateral flagella. Another large fraction of mutants that were unresponsive to light were shown to be defective in the formation of a functional photosynthetic apparatus. Several photosensory mutants also were obtained with defects in the perception and transmission of light signals. Twelve mutants in this class were shown to contain disruptions in a chemotaxis operon, and five mutants contained disruptions of components unique to photoperception. It was shown that screening for photosensory defective R. centenum swarm colonies is an effective method for genetic dissection of the mechanism of light sensing in eubacteria.
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Affiliation(s)
- Z Y Jiang
- Department of Biology, Indiana University, Bloomington 47405, USA
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19
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20
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Ragatz L, Jiang ZY, Bauer CE, Gest H. Macroscopic phototactic behavior of the purple photosynthetic bacterium Rhodospirillum centenum. Arch Microbiol 1995; 163:1-6. [PMID: 7710317 DOI: 10.1007/bf00262196] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Most photosynthetic microorganisms have the capability of photosensing light quality and intensity. Movement of motile photosynthetic microorganisms to locales that offer optimal physical and chemical conditions for light-dependent growth provides obvious selective advantages. Among phototrophs, many cyanobacteria and algae migrate towards or away from the direction of light, a process termed phototaxis. In contrast, anoxygenic photosynthetic bacteria are believed to respond to changes in light intensity in a manner that is not related to the direction of light, a process that is often described by the term "photophobic". We recently reported that "swarm colonies" of the purple photosynthetic bacterium Rhodospirillum centenum are capable of macroscopically visible phototactic behavior. In the present study we further characterize the phototactic behavior of R. centenum swarm colonies and provide an action spectrum that delineates regions of the spectrum that elicit positive and negative phototaxis.
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Affiliation(s)
- L Ragatz
- Department of Biology, Indiana University, Bloomington 47405
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21
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Gest H. A serendipic legacy: Erwin Esmarch's isolation of the first photosynthetic bacterium in pure culture. PHOTOSYNTHESIS RESEARCH 1995; 46:473-478. [PMID: 24301642 DOI: 10.1007/bf00032302] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/1995] [Accepted: 10/10/1995] [Indexed: 06/02/2023]
Abstract
During the 1880's, Erwin von Esmarch was a junior associate ('Assistent') of Robert Koch studying bacteria of medical significance. In 1887, he isolated the first example of spiral-shaped bacteria in pure culture, from the dry residue of a dead mouse that he had suspended sometime earlier in Berlin tap-water. Under certain conditions, colonies of the organism were the color of red wine, and this led Esmarch to name the bacterium Spirillum rubrum. Twenty years later, Hans Molisch demonstrated that S. rubrum, an apparent heterotroph, was in fact a non-oxygenic purple photosynthetic bacterium, and it was renamed Rhodospirillum rubrum. Esmarch was a careful investigator and his classic paper of 1887 details the serendipitous isolation and general characteristics of the first pure culture of an anoxyphototroph, which later played a prominent role as an experimental system for study of basic aspects of bacterial photosynthesis. This report includes an English translation of his original paper (in German), a commentary on the historical significance of 'Esmarch's spirillum', and a summary of Esmarch's career.
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Affiliation(s)
- H Gest
- Photosynthetic Bacteria Group, Department of Biology, Indiana University, 47405, Bloomington, IN, USA
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22
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Sasikala C, Ramana CV. Biotechnological potentials of anoxygenic phototrophic bacteria. I. Production of single-cell protein, vitamins, ubiquinones, hormones, and enzymes and use in waste treatment. ADVANCES IN APPLIED MICROBIOLOGY 1995; 41:173-226. [PMID: 7572333 DOI: 10.1016/s0065-2164(08)70310-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- C Sasikala
- Department of Botany, Osmania University, Hyderabad, India
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23
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Anoxygenic Phototrophic Bacteria: Physiology and Advances in Hydrogen Production Technology. ADVANCES IN APPLIED MICROBIOLOGY 1993. [DOI: 10.1016/s0065-2164(08)70217-x] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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24
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Yildiz FH, Gest H, Bauer CE. Attenuated effect of oxygen on photopigment synthesis in Rhodospirillum centenum. J Bacteriol 1991; 173:5502-6. [PMID: 1885527 PMCID: PMC208263 DOI: 10.1128/jb.173.17.5502-5506.1991] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Rhodospirillum centenum resembles typical nonsulfur photosynthetic bacteria in a number of respects, including its ability to grow either anaerobically as a phototroph or aerobically as a heterotroph. We demonstrate, however, that R. centenum is unusual in its ability to synthesize a functional photosynthetic apparatus regardless of the presence of molecular oxygen. Aerobically expressed photopigments were shown to be functionally active, as demonstrated by the ability of heterotrophically grown cells to grow photosynthetically, without a lag, when suddenly placed under anaerobic conditions. An R. centenum mutant that has acquired the ability to repress synthesis of photopigments in the presence of oxygen was also characterized. Both the wild type and the oxygen-repressed mutant of R. centenum were found to exhibit high light intensity repression of photopigment biosynthesis. The latter result suggests that R. centenum contains separate regulatory circuits for controlling synthesis of its photochemical apparatus by light intensity and oxygen.
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Affiliation(s)
- F H Yildiz
- Department of Biology, Indiana University, Bloomington 47405
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25
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Abstract
A genetic system has been developed for studying bacterial photosynthesis in the recently described nonsulfur purple photosynthetic bacterium Rhodospirillum centenum. Nonphotosynthetic mutants of R. centenum were obtained by enrichment for spontaneous mutations, by ethyl methanesulfonate mutagenesis coupled to penicillin selection on solid medium, and by Tn5 transposition mutagenesis with an IncP plasmid vector containing a temperature-sensitive origin of replication. In vivo and in vitro characterization of individual strains demonstrated that 38 strains contained mutations that blocked bacteriochlorophyll a biosynthesis at defined steps of the biosynthetic pathway. Collectively, these mutations were shown to block seven of eight steps of the pathway leading from protoporphyrin IX to bacteriochlorophyll a. Three mutants were isolated in which carotenoid biosynthesis was blocked early in the biosynthetic pathway; the mutants also exhibited pleiotropic effects on stability or assembly of the photosynthetic apparatus. Five mutants failed to assemble a functional reaction center complex, and seven mutants contained defects in electron transport as shown by an alteration in cytochromes. In addition, several regulatory mutants were isolated that acquired enhanced repression of bacteriochlorophyll in response to the presence of molecular oxygen. The phenotypes of these mutants are discussed in relation to those of similar mutants of Rhodobacter and other Rhodospirillum species of purple photosynthetic bacteria.
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Affiliation(s)
- F H Yildiz
- Department of Biology, Indiana University, Bloomington 47405
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26
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Stadtwald-Demchick R, Rudolf Turner F, Gest H. Rhodopseudomonas cryptolactis, sp. nov., a new thermotolerant species of budding phototrophic purple bacteria. FEMS Microbiol Lett 1990. [DOI: 10.1111/j.1574-6968.1990.tb03808.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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