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Hussain A, Ray MK. Role of DEAD-box RNA helicases in low-temperature adapted growth of Antarctic Pseudomonas syringae Lz4W. Microbiol Spectr 2024; 12:e0433522. [PMID: 38014988 PMCID: PMC10783127 DOI: 10.1128/spectrum.04335-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 10/16/2023] [Indexed: 11/29/2023] Open
Abstract
IMPORTANCE RNA metabolism is important as RNA acts as a link between genomic information and functional biomolecules, thereby playing a critical role in cellular response to environment. We investigated the role of DEAD-box RNA helicases in low-temperature adapted growth of P. syringae, as this group of enzymes play an essential role in modulation of RNA secondary structures. This is the first report on the assessment of all major DEAD-box RNA helicases in any Antarctic bacterium. Of the five RNA helicases, three (srmB, csdA, and dbpA) are important for the growth of the Antarctic P. syringae at low temperature. However, the requisite role of dbpA and the indispensable requirement of csdA for low-temperature adapted growth are a novel finding of this study. Growth analysis of combinatorial deletion strains was performed to understand the functional interaction among helicase genes. Similarly, genetic complementation of RNA helicase mutants was conducted for identification of gene redundancy in P. syringae.
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Affiliation(s)
- Ashaq Hussain
- Centre for Cellular and Molecular Biology, Hyderabad, Telangana, India
| | - Malay Kumar Ray
- Centre for Cellular and Molecular Biology, Hyderabad, Telangana, India
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Mittal P, Sipani R, Pandiyan A, Sulthana S, Sinha AK, Hussain A, Ray MK, Pavankumar TL. Exoribonuclease RNase R protects Antarctic Pseudomonas syringae Lz4W from DNA damage and oxidative stress. Appl Environ Microbiol 2023; 89:e0116823. [PMID: 37905926 PMCID: PMC10686088 DOI: 10.1128/aem.01168-23] [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: 07/10/2023] [Accepted: 08/30/2023] [Indexed: 11/02/2023] Open
Abstract
IMPORTANCE Bacterial exoribonucleases play a crucial role in RNA maturation, degradation, quality control, and turnover. In this study, we have uncovered a previously unknown role of 3'-5' exoribonuclease RNase R of Pseudomonas syringae Lz4W in DNA damage and oxidative stress response. Here, we show that neither the exoribonuclease function of RNase R nor its association with the RNA degradosome complex is essential for this function. Interestingly, in P. syringae Lz4W, hydrolytic RNase R exhibits physiological roles similar to phosphorolytic 3'-5' exoribonuclease PNPase of E. coli. Our data suggest that during the course of evolution, mesophilic E. coli and psychrotrophic P. syringae have apparently swapped these exoribonucleases to adapt to their respective environmental growth conditions.
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Affiliation(s)
- Pragya Mittal
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Rashmi Sipani
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Apuratha Pandiyan
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Shaheen Sulthana
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Anurag K. Sinha
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Ashaq Hussain
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Malay K. Ray
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
| | - Theetha L. Pavankumar
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Hyderabad, India
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Hussain A, Ray MK. Functional activity of E. coli RNase R in the Antarctic Pseudomonas syringae Lz4W. J Genet Eng Biotechnol 2023; 21:101. [PMID: 37843651 PMCID: PMC10579198 DOI: 10.1186/s43141-023-00553-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 09/20/2023] [Indexed: 10/17/2023]
Abstract
BACKGROUND In Antarctic P. syringae RNase R play an essential role in the processing of 16S and 5S rRNA, thereby playing an important role in cold-adapted growth of the bacterium. This study is focused on deciphering the in vivo functional activity of mesophilic exoribonuclease R and its catalytic domain (RNB) in an evolutionary distant psychrophilic bacterium Pseudomonas syringae Lz4W. RESULTS Our results confirm that E. coli RNase R complemented the physiological functions of the psychrophilic bacterium P. syringae RNase R and rescued the cold-sensitive phenotype of Pseudomonas syringae ∆rnr mutant. More importantly, the catalytic domain (RNB) of the E. coli RNase R is also capable of alleviating the cold-sensitive growth defects of ∆rnr mutant as seen with the catalytic domain (RNB) of the P. syringae enzyme. The Catalytic domain of E. coli RNase R was less efficient than the Catalytic domain of P. syringae RNase R in rescuing the cold-sensitive growth of ∆rnr mutant at 4°C, as the ∆rnr expressing the RNBEc (catalytic domain of E. coli RNase R) displayed longer lag phase than the RNBPs (Catalytic domain of P. syringae RNase R) complemented ∆rnr mutant at 4°C. Altogether it appears that the E. coli RNase R and P. syringae RNase R are functionally exchangeable for the growth requirements of P. syringae at low temperature (4°C). Our results also confirm that in P. syringae the requirement of RNase R for supporting the growth at 4°C is independent of the degradosomal complex. CONCLUSION E. coli RNase R (RNase REc) rescues the cold-sensitive phenotype of the P. syringae Δrnr mutant. Similarly, the catalytic domain of E. coli RNase R (RNBEc) is also capable of supporting the growth of Δrnr mutant at low temperatures. These findings have a vast scope in the design and development of low-temperature-based expression systems.
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Affiliation(s)
- Ashaq Hussain
- Centre for Cellular and Molecular Biology, Hyderabad, India.
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Hussain A, Ray MK. DEAD box RNA helicases protect Antarctic Pseudomonas syringae Lz4W against oxidative stress. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2022; 106:105382. [PMID: 36336276 DOI: 10.1016/j.meegid.2022.105382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 10/28/2022] [Accepted: 11/02/2022] [Indexed: 11/06/2022]
Abstract
DEAD box RNA helicases are involved in important cellular processes like RNA metabolism (Processing and Degradation), ribosome biogenesis and translation. Besides being crucial to the formation of cold adapted degradosomes, RNA helicases have been implicated in structural rearrangement of RNA, implying a role in alleviation of RNA secondary structure stabilization at low temperature. This study depicts the results of experiments on protective role played by DEAD box RNA helicases against nucleic acid damaging agents. RNA helicase mutants ΔrhlE, ΔsrmB, ΔcsdA, ΔdbpA and ΔrhlB cells were exposed to various DNA damaging agents (UV, Paraquat, Mitomycin C, Hydroxyurea and Hydrogen peroxide) and assessed for sensitivity to them. Our results illustrate that ∆csdA displayed sensitivity to paraquat (that causes oxidative damage) and UV radiation induced DNA damage. On the other hand, ∆srmB displays sensitivity to hydroxyurea that causes damage to the replication forks (RFs) by inhibiting ribonucleotide reductase and depleting the dNTP pool of cells. However, all five RNA helicase mutants were resistant to H2O2 mediated oxidative stress and mitomycin C induced DNA cross-links.
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Affiliation(s)
- Ashaq Hussain
- Centre for Cellular and Molecular Biology, Hyderabad, India.
| | - Malay Kumar Ray
- Centre for Cellular and Molecular Biology, Hyderabad, India.
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Silverio MP, Kraychete GB, Rosado AS, Bonelli RR. Pseudomonas fluorescens Complex and Its Intrinsic, Adaptive, and Acquired Antimicrobial Resistance Mechanisms in Pristine and Human-Impacted Sites. Antibiotics (Basel) 2022; 11:antibiotics11080985. [PMID: 35892375 PMCID: PMC9331890 DOI: 10.3390/antibiotics11080985] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 12/16/2022] Open
Abstract
Pseudomonas spp. are ubiquitous microorganisms that exhibit intrinsic and acquired resistance to many antimicrobial agents. Pseudomonas aeruginosa is the most studied species of this genus due to its clinical importance. In contrast, the Pseudomonas fluorescens complex consists of environmental and, in some cases, pathogenic opportunistic microorganisms. The records of antimicrobial-resistant P. fluorescens are quite scattered, which hinders the recognition of patterns. This review compiles published data on antimicrobial resistance in species belonging to the P. fluorescens complex, which were identified through phylogenomic analyses. Additionally, we explored the occurrence of clinically relevant antimicrobial resistance genes in the genomes of the respective species available in the NCBI database. Isolates were organized into two categories: strains isolated from pristine sites and strains isolated from human-impacted or metal-polluted sites. Our review revealed that many reported resistant phenotypes in this complex might be related to intrinsic features, whereas some of them might be ascribed to adaptive mechanisms such as colistin resistance. Moreover, a few studies reported antimicrobial resistance genes (ARGs), mainly β-lactamases. In-silico analysis corroborated the low occurrence of transferable resistance mechanisms in this Pseudomonas complex. Both phenotypic and genotypic assays are necessary to gain insights into the evolutionary aspects of antimicrobial resistance in the P. fluorescens complex and the possible role of these ubiquitous species as reservoirs of clinically important and transmissible ARGs.
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Affiliation(s)
- Myllena Pereira Silverio
- Laboratório de Ecologia Molecular Microbiana, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil
- Laboratório de Investigação em Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil
| | - Gabriela Bergiante Kraychete
- Laboratório de Investigação em Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil
| | - Alexandre Soares Rosado
- Laboratório de Ecologia Molecular Microbiana, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil
- Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Raquel Regina Bonelli
- Laboratório de Investigação em Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil
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Ijaq J, Chandra D, Ray MK, Jagannadham MV. Investigating the Functional Role of Hypothetical Proteins From an Antarctic Bacterium Pseudomonas sp. Lz4W: Emphasis on Identifying Proteins Involved in Cold Adaptation. Front Genet 2022; 13:825269. [PMID: 35360867 PMCID: PMC8963723 DOI: 10.3389/fgene.2022.825269] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 02/07/2022] [Indexed: 11/28/2022] Open
Abstract
Exploring the molecular mechanisms behind bacterial adaptation to extreme temperatures has potential biotechnological applications. In the present study, Pseudomonas sp. Lz4W, a Gram-negative psychrophilic bacterium adapted to survive in Antarctica, was selected to decipher the molecular mechanism underlying the cold adaptation. Proteome analysis of the isolates grown at 4°C was performed to identify the proteins and pathways that are responsible for the adaptation. However, many proteins from the expressed proteome were found to be hypothetical proteins (HPs), whose function is unknown. Investigating the functional roles of these proteins may provide additional information in the biological understanding of the bacterial cold adaptation. Thus, our study aimed to assign functions to these HPs and understand their role at the molecular level. We used a structured insilico workflow combining different bioinformatics tools and databases for functional annotation. Pseudomonas sp. Lz4W genome (CP017432, version 1) contains 4493 genes and 4412 coding sequences (CDS), of which 743 CDS were annotated as HPs. Of these, from the proteome analysis, 61 HPs were found to be expressed consistently at the protein level. The amino acid sequences of these 61 HPs were submitted to our workflow and we could successfully assign a function to 18 HPs. Most of these proteins were predicted to be involved in biological mechanisms of cold adaptations such as peptidoglycan metabolism, cell wall organization, ATP hydrolysis, outer membrane fluidity, catalysis, and others. This study provided a better understanding of the functional significance of HPs in cold adaptation of Pseudomonas sp. Lz4W. Our approach emphasizes the importance of addressing the “hypothetical protein problem” for a thorough understanding of mechanisms at the cellular level, as well as, provided the assessment of integrating proteomics methods with various annotation and curation approaches to characterize hypothetical or uncharacterized protein data. The MS proteomics data generated from this study has been deposited to the ProteomeXchange through PRIDE with the dataset identifier–PXD029741.
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Affiliation(s)
- Johny Ijaq
- Metabolomics Facility, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Deepika Chandra
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Malay Kumar Ray
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - M. V. Jagannadham
- Metabolomics Facility, School of Life Sciences, University of Hyderabad, Hyderabad, India
- *Correspondence: M. V. Jagannadham,
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Pavankumar TL, Mittal P, Hallsworth JE. Molecular insights into the ecology of a psychrotolerant
Pseudomonas syringae. Environ Microbiol 2020; 23:3665-3681. [DOI: 10.1111/1462-2920.15304] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/01/2020] [Accepted: 11/03/2020] [Indexed: 02/06/2023]
Affiliation(s)
- Theetha L. Pavankumar
- Department of Microbiology and Molecular Genetics, Briggs Hall, One Shields Avenue University of California Davis CA USA
| | - Pragya Mittal
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine University of Edinburgh Crewe Road South, Edinburgh, EH42XU, Scotland UK
| | - John E. Hallsworth
- Institute for Global Food Security, School of Biological Sciences Queen's University Belfast 19 Chlorine Gardens, Belfast, BT9 5DL Northern Ireland UK
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Torracchi C JE, Morel MA, Tapia-Vázquez I, Castro-Sowinski S, Batista-García RA, Yarzábal R LA. Fighting plant pathogens with cold-active microorganisms: biopesticide development and agriculture intensification in cold climates. Appl Microbiol Biotechnol 2020; 104:8243-8256. [PMID: 32803297 DOI: 10.1007/s00253-020-10812-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/27/2020] [Accepted: 08/02/2020] [Indexed: 01/16/2023]
Abstract
Cold-adapted (CA) microorganisms (= psychrophiles or psychrotolerants) are key players of many ecological interactions in natural ecosystems. Some of them can colonize the rhizosphere of plants and cause damage to their hosts; others, on the contrary, protect plants from their pathogens through direct and indirect mechanisms, thus promoting plant growth and development. These "protective" microbes are known as biocontrol agents (BCA). BCA either limit or inhibit the growth of plant pathogens, owing to the excretion of a panoply of secondary metabolites (including soluble and volatile antibiotics, siderophores, quorum sensing interfering agents). BCA can also control plant pathogens through indirect mechanisms, including competence for nutrients and space, or else by interfering with their chemical communication. That explains why some of these BCA have been included in the formulation of commercial biopesticides, which are environmentally friendly products containing live cells used to control plant diseases and pests. At present, the development of biopesticides from mesophilic microorganisms is an established technology. Unfortunately, these biopesticides are not active at low temperatures. On the other hand, the information concerning the potential use of CA-BCA for the same goal is at its infancy. Here, we review the current knowledge concerning the isolation, identification, and characterization of CA microbes which act as antagonists of plant pathogens, including the mechanisms they deploy to antagonize plant pathogens. We also illustrate their biotechnological potential to develop CA biopesticides and discuss their utility in the context of mountainous agriculture. KEY POINTS: • Many naturally occurring cold-active microbes antagonize plant pathogens. • The mechanisms of biocontrol exerted by these microbes are either direct or indirect. • Cold-active biocontrol agents can be used to develop biopesticides. • Cold-active biopesticides are crucial for sustainably intensifying agriculture in cold climates.
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Affiliation(s)
- José Esteban Torracchi C
- Unidad de Salud y Bienestar, Universidad Católica de Cuenca, Av. Las Américas y Calle Humboldt, Cuenca, Ecuador
- Centro de Investigación, Innovación y Transferencia de Tecnología (CIITT), Universidad Católica de Cuenca, Campus Miracielos, Ricaurte, Ecuador
| | - María A Morel
- Unidad Microbiología Molecular, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Av Italia 3318, 11600, Montevideo, Uruguay
| | - Irán Tapia-Vázquez
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
- Centro de Investigación en Dinámica Celular, Instituto de Investigaciones en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - Susana Castro-Sowinski
- Unidad Microbiología Molecular, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Av Italia 3318, 11600, Montevideo, Uruguay
- Sección Bioquímica y Biología Molecular, Facultad de Ciencias, UdelaR, Iguá 4225, 11400, Montevideo, Uruguay
| | - Ramón Alberto Batista-García
- Centro de Investigación en Dinámica Celular, Instituto de Investigaciones en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
| | - Luis Andrés Yarzábal R
- Unidad de Salud y Bienestar, Universidad Católica de Cuenca, Av. Las Américas y Calle Humboldt, Cuenca, Ecuador.
- Centro de Investigación, Innovación y Transferencia de Tecnología (CIITT), Universidad Católica de Cuenca, Campus Miracielos, Ricaurte, Ecuador.
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Pavlov MS, Lira F, Martinez JL, Olivares-Pacheco J, Marshall SH. Pseudomonas fildesensis sp. nov., a psychrotolerant bacterium isolated from Antarctic soil of King George Island, South Shetland Islands. Int J Syst Evol Microbiol 2020; 70:3255-3263. [PMID: 32375985 DOI: 10.1099/ijsem.0.004165] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The strain KG01T was isolated from a soil sample from King George Island, Antarctica. Cells of KG01T are rod-shaped and motile by means of multiple polar flagella. The absence of arginine dihydrolase activity could be a key feature to readily distinguish KG01T from its closest phylogenetic relative species. The main fatty acids of the strain include summed feature 3 (C16 : 1 ω7c and/or C15 : 0 iso 2-OH), C16 : 0 and C18 : 1 ω7c. Phylogenetic analysis based on the 16S rRNA gene sequence and on a multilocus sequence analysis (MLSA) using housekeeping genes (16S rRNA, rpoB, rpoD, gyrB) were carried out. These analyses allowed us to include the strain within the Pseudomonas fluorescens group, presenting the highest similarity of multilocus sequence with Pseudomonas veronii LMG 17761T (96.67 %). The genome of KG01T was sequenced and in silico compared with genomes of the most closely related species of the P. fluorescens group. The average nucleotide identity (ANIb) and average amino acid identity (AAI) values of the species phylogenetically closest to KG01T were less than 95-96 %, threshold currently accepted to define strain as belonging to a bacterial species, the highest scores being those to Pseudomonas veronii LMG 17761T (87.98 %) and Pseudomonas marginalis ICMP 3553T (91.90 %). Therefore, the phenotypic and genotypic analyses results, allow us to propose that KG01T represents a member of a novel species of the genus Pseudomonas, for which the name Pseudomonas fildesensis is proposed, and KG01T (=CECT 9084T;=DSM 102036T) is established as the type strain .
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Affiliation(s)
- Maria S Pavlov
- Laboratorio de Genética e Inmunología Molecular, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Valparaíso, Chile
| | - Felipe Lira
- IRHS, Agrocampus-Ouest, INRA, Université d'Angers, SFR 4207 QuaSaV, 49071, Beaucouzé, France
| | - José Luis Martinez
- Centro Nacional de Biotecnología, CNB, CSIC, Darwin 3, Campus de Cantoblanco, Madrid, Spain
| | - Jorge Olivares-Pacheco
- Millennium Initiative for Collaborative Research on Bacterial Resistance (MICROB-R). Santiago, Chile.,Laboratorio de Genética e Inmunología Molecular, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Valparaíso, Chile
| | - Sergio H Marshall
- Laboratorio de Genética e Inmunología Molecular, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Valparaíso, Chile
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Pavankumar TL, Sinha AK, Ray MK. Biochemical characterization of RecBCD enzyme from an Antarctic Pseudomonas species and identification of its cognate Chi (χ) sequence. PLoS One 2018; 13:e0197476. [PMID: 29775464 PMCID: PMC5959072 DOI: 10.1371/journal.pone.0197476] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 03/13/2018] [Indexed: 11/18/2022] Open
Abstract
Pseudomonas syringae Lz4W RecBCD enzyme, RecBCDPs, is a trimeric protein complex comprised of RecC, RecB, and RecD subunits. RecBCD enzyme is essential for P. syringae growth at low temperature, and it protects cells from low temperature induced replication arrest. In this study, we show that the RecBCDPs enzyme displays distinct biochemical behaviors. Unlike E. coli RecBCD enzyme, the RecD subunit is indispensable for RecBCDPs function. The RecD motor activity is essential for the Chi-like fragments production in P. syringae, highlighting a distinct role for P. syringae RecD subunit in DNA repair and recombination process. Here, we demonstrate that the RecBCDPs enzyme recognizes a unique octameric DNA sequence, 5′-GCTGGCGC-3′ (ChiPs) that attenuates nuclease activity of the enzyme when it enters dsDNA from the 3′-end. We propose that the reduced translocation activities manifested by motor-defective mutants cause cold sensitivity in P. syrinage; emphasizing the importance of DNA processing and recombination functions in rescuing low temperature induced replication fork arrest.
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Affiliation(s)
- Theetha L. Pavankumar
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
- * E-mail: (TLP); (MKR)
| | - Anurag K. Sinha
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Malay K. Ray
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
- * E-mail: (TLP); (MKR)
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López G, Diaz-Cárdenas C, Shapiro N, Woyke T, Kyrpides NC, David Alzate J, González LN, Restrepo S, Baena S. Draft genome sequence of Pseudomonas extremaustralis strain USBA-GBX 515 isolated from Superparamo soil samples in Colombian Andes. Stand Genomic Sci 2017; 12:78. [PMID: 29255573 PMCID: PMC5731063 DOI: 10.1186/s40793-017-0292-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 11/24/2017] [Indexed: 12/22/2022] Open
Abstract
Here we present the physiological features of Pseudomonas extremaustralis strain USBA-GBX-515 (CMPUJU 515), isolated from soils in Superparamo ecosystems, > 4000 m.a.s.l, in the northern Andes of South America, as well as the thorough analysis of the draft genome. Strain USBA-GBX-515 is a Gram-negative rod shaped bacterium of 1.0–3.0 μm × 0.5–1 μm, motile and unable to form spores, it grows aerobically and cells show one single flagellum. Several genetic indices, the phylogenetic analysis of the 16S rRNA gene sequence and the phenotypic characterization confirmed that USBA-GBX-515 is a member of Pseudomonas genus and, the similarity of the 16S rDNA sequence was 100% with P. extremaustralis strain CT14–3T. The draft genome of P. extremaustralis strain USBA-GBX-515 consisted of 6,143,638 Mb with a G + C content of 60.9 mol%. A total of 5665 genes were predicted and of those, 5544 were protein coding genes and 121 were RNA genes. The distribution of genes into COG functional categories showed that most genes were classified in the category of amino acid transport and metabolism (10.5%) followed by transcription (8.4%) and signal transduction mechanisms (7.3%). We performed experimental analyses of the lipolytic activity and results showed activity mainly on short chain fatty acids. The genome analysis demonstrated the existence of two genes, lip515A and est515A, related to a triacylglycerol lipase and carboxylesterase, respectively. Ammonification genes were also observed, mainly nitrate reductase genes. Genes related with synthesis of poly-hydroxyalkanoates (PHAs), especially poly-hydroxybutyrates (PHBs), were detected. The phaABC and phbABC operons also appeared complete in the genome. P. extremaustralis strain USBA-GBX-515 conserves the same gene organization of the type strain CT14–3T. We also thoroughly analyzed the potential for production of secondary metabolites finding close to 400 genes in 32 biosynthetic gene clusters involved in their production.
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Affiliation(s)
- Gina López
- Unidad de Saneamiento y Biotecnología Ambiental (USBA), Departamento de Biología, Pontificia Universidad Javeriana, POB 56710, Bogotá, DC Colombia
| | - Carolina Diaz-Cárdenas
- Unidad de Saneamiento y Biotecnología Ambiental (USBA), Departamento de Biología, Pontificia Universidad Javeriana, POB 56710, Bogotá, DC Colombia
| | - Nicole Shapiro
- Department of Energy Joint Genome Institute, Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Tanja Woyke
- Department of Energy Joint Genome Institute, Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - Nikos C Kyrpides
- Department of Energy Joint Genome Institute, Joint Genome Institute, Walnut Creek, CA 94598 USA
| | - J David Alzate
- Biological Sciences Department, Universidad de los Andes, Cra 1 No. 18A - 12, Bogotá, DC Colombia
| | - Laura N González
- Biological Sciences Department, Universidad de los Andes, Cra 1 No. 18A - 12, Bogotá, DC Colombia
| | - Silvia Restrepo
- Biological Sciences Department, Universidad de los Andes, Cra 1 No. 18A - 12, Bogotá, DC Colombia
| | - Sandra Baena
- Unidad de Saneamiento y Biotecnología Ambiental (USBA), Departamento de Biología, Pontificia Universidad Javeriana, POB 56710, Bogotá, DC Colombia
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Kosina M, Švec P, Černohlávková J, Barták M, Snopková K, De Vos P, Sedláček I. Description of Pseudomonas gregormendelii sp. nov., a Novel Psychrotrophic Bacterium from James Ross Island, Antarctica. Curr Microbiol 2016; 73:84-90. [DOI: 10.1007/s00284-016-1029-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 02/15/2016] [Indexed: 10/22/2022]
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14
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Abstract
A population of cold-tolerant Antarctic bacteria was screened for their ability to tolerate other environmental stress factors. Besides low temperature, they were predominantly found to be tolerant to alkali. Attempt was also made to postulate a genetic basis of their multistress-tolerance. Transposon mutagenesis of an isolate Pseudomonas syringae Lz4W was performed, and mutants with delayed growth at low temperature were further screened for sensitivity to some other stress factors. A number of multistress-sensitive mutants were isolated. The mutated gene in one of the mutants sensitive to low temperature, acid and alkali was found to encode citrate synthase. Possible role of citrate synthase in conferring multistress-tolerance was postulated.
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15
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The proteome of the outer membrane vesicles of an Antarctic bacterium Pseudomonas syringae Lz4W. Data Brief 2015; 4:406-9. [PMID: 26306312 PMCID: PMC4534585 DOI: 10.1016/j.dib.2015.07.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 07/02/2015] [Indexed: 11/22/2022] Open
Abstract
Outer membrane vesicles (OMVs) of gram-negative bacteria are released during all growth phases and play an important role in bacterial physiology. They consist of lipids, proteins, lipopolysaccharides and other molecules. The OMVs of the Antarctic bacterium Pseudomonas syringae Lz 4W were isolated and identified their proteins. The mass spectral data set deposited with PRIDE, accession number PXD 000221 is presented in this report. The proteins identified from the OMVs of P. syringae Lz4W, data of this study were published in the Journal of proteome research [1].
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16
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Moreno R, Rojo F. Features of pseudomonads growing at low temperatures: another facet of their versatility. ENVIRONMENTAL MICROBIOLOGY REPORTS 2014; 6:417-426. [PMID: 25646532 DOI: 10.1111/1758-2229.12150] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Pseudomonads are a diverse and ecologically successful group of γ-proteobacteria present in many environments (terrestrial, freshwater and marine), either free living or associated with plants or animals. Their success is at least partly based on their ability to grow over a wide range of temperatures, their capacity to withstand different kinds of stress and their great metabolic versatility. Although the optimal growth temperature of pseudomonads is usually close to 25–30°C, many strains can also grow between 5°C and 10°C, and some of them even close to 0°C. Such low temperatures strongly affect the physicochemical properties of macromolecules, forcing cells to evolve traits that optimize growth and help them withstand cold-induced stresses such as increased levels of reactive oxygen species, reduced membrane fluidity and enzyme activity, cold-induced protein denaturation and the greater stability of DNA and RNA secondary structures. This review gathers the information available on the strategies used by pseudomonads to adapt to low temperature growth, and briefly describes some of the biotechnological applications that might benefit from cold-adapted bacterial strains and enzymes, e.g., biotransformation or bioremediation processes to be performed at low temperatures.
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17
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Singh AK, Sad K, Singh SK, Shivaji S. Regulation of gene expression at low temperature: role of cold-inducible promoters. Microbiology (Reading) 2014; 160:1291-1296. [DOI: 10.1099/mic.0.077594-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Psychrophilic micro-organisms are the most dominant flora in cold habitats. Their unique ability to survive and multiply at low temperatures (<5 °C) is based on their ability to modulate the rigidity of the membrane, to transcribe, to translate and to catalyse biochemical reactions at low temperature. A number of genes are known to be upregulated during growth at low temperature and cold-inducible promoters are known to regulate the expression of genes at low temperature. In this review, we attempted to compile promoter sequences of genes that are cold-inducible so as to identify similarities and to compare the distinct features of each type of promoter when microbes are grown in the cold.
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Affiliation(s)
| | - Kirti Sad
- Centre of Biotechnology (University of Allahabad), Allahabad, India
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18
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Kulkarni HM, Swamy CVB, Jagannadham MV. Molecular characterization and functional analysis of outer membrane vesicles from the antarctic bacterium Pseudomonas syringae suggest a possible response to environmental conditions. J Proteome Res 2014; 13:1345-58. [PMID: 24437924 DOI: 10.1021/pr4009223] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Outer membrane vesicles (OMVs) of Gram-negative bacteria form an important aspect of bacterial physiology as they are involved in various functions essential for their survival. The OMVs of the Antarctic bacterium Pseudomonas syringae Lz4W were isolated, and the proteins and lipids they contain were identified. The matrix-assisted laser desorption/ionization time of flight (MALDI-TOF/TOF) analysis revealed that phosphatidylethanolamines and phosphatidylglycerols are the main lipid components. The proteins of these vesicles were identified by separating them by one-dimensional gel electrophoresis and liquid chromatography coupled to electrospray ionization tandem mass spectrometry (ESI-MS/MS). They are composed of outer membrane and periplasmic proteins according to the subcellular localization predictions by Psortb v.3 and Cello V2.5. The functional annotation and gene ontology of these proteins provided hints for various functions attributed to OMVs and suggested a potential mechanism to respond to the extracellular environmental changes. The OMVs were found to protect the producer organism against the membrane active antibiotics colistin and melittin but not from streptomycin. The 1-N-phenylnapthylamine (NPN)-uptake assay revealed that the OMVs protect the bacterium from membrane active antibiotics by scavenging them and also showed that membrane and protein packing of the OMVs was similar to the parent bacterium. The sequestering depends on the composition and organization of lipids and proteins in the OMVs.
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Affiliation(s)
- Heramb M Kulkarni
- CSIR - Centre for Cellular and Molecular Biology , Tarnaka, Hyderabad - 500007, India
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19
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Huang JP, Swain AK, Andersen DT, Bej AK. Bacterial diversity within five unexplored freshwater lakes interconnected by surface channels in East Antarctic Dronning Maud Land (Schirmacher Oasis) using amplicon pyrosequencing. Polar Biol 2014. [DOI: 10.1007/s00300-013-1436-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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20
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Sinha AK, Pavankumar TL, Kamisetty S, Mittal P, Ray MK. Replication arrest is a major threat to growth at low temperature in Antarctic Pseudomonas syringae Lz4W. Mol Microbiol 2013; 89:792-810. [PMID: 23815755 DOI: 10.1111/mmi.12315] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2013] [Indexed: 11/29/2022]
Abstract
Chromosomal damage was detected previously in the recBCD mutants of the Antarctic bacterium Pseudomonas syringae Lz4W, which accumulated linear chromosomal DNA leading to cell death and growth inhibition at 4°C. RecBCD protein generally repairs DNA double-strand breaks by RecA-dependent homologous recombination pathway. Here we show that ΔrecA mutant of P. syringae is not cold-sensitive. Significantly, inactivation of additional DNA repair genes ruvAB rescued the cold-sensitive phenotype of ΔrecBCD mutant. The ΔrecA and ΔruvAB mutants were UV-sensitive as expected. We propose that, at low temperature DNA replication encounters barriers leading to frequent replication fork (RF) arrest and fork reversal. RuvAB binds to the reversed RFs (RRFs) having Holliday junction-like structures and resolves them upon association with RuvC nuclease to cause linearization of the chromosome, a threat to cell survival. RecBCD prevents this by degrading the RRFs, and facilitates replication re-initiation. This model is consistent with our observation that low temperature-induced DNA lesions do not evoke SOS response in P. syringae. Additional studies show that two other repair genes, radA (encoding a RecA paralogue) and recF are not involved in providing cold resistance to the Antarctic bacterium.
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Affiliation(s)
- Anurag K Sinha
- Centre for Cellular and Molecular Biology Council of Scientific and Industrial Research, Uppal Road, Hyderabad, 500007, India
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21
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Draft Genome Sequence of the Antarctic Psychrophilic Bacterium Pseudomonas syringae Strain Lz4W. GENOME ANNOUNCEMENTS 2013; 1:1/3/e00377-13. [PMID: 23788547 PMCID: PMC3707596 DOI: 10.1128/genomea.00377-13] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
The psychrophilic bacterium Pseudomonas syringae strain Lz4W was isolated from soil samples from Antarctica to decipher the mechanisms of low-temperature adaptation. We report here the 4.982-Mb draft genome sequence of P. syringae Lz4W. This sequence will provide insights into the genomic basis of the psychrophilicity of this bacterium.
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22
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Bhave SV, Shanbhag PV, Sonawane SK, Parab RR, Mahajan GB. Isolation and characterization of halotolerant Streptomyces radiopugnans from Antarctica soil. Lett Appl Microbiol 2013; 56:348-55. [PMID: 23384241 DOI: 10.1111/lam.12054] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 01/30/2012] [Accepted: 01/30/2012] [Indexed: 11/30/2022]
Abstract
An actinomycete wild strain PM0626271 (= MTCC 5447), producing novel antibacterial compounds, was isolated from soil collected from Antarctica. The taxonomic status of the isolate was established by polyphasic approach. Scanning electron microscopy observations and the presence of LL-Diaminopimelic acid in the cell wall hydrolysate confirmed the genus Streptomyces. Analysis of 16S rRNA gene sequence showed highest sequence similarity to Streptomyces radiopugnans (99%). The phylogenetic tree constructed using near complete 16S rRNA gene sequences of the isolate and closely related strains revealed that although the isolate fell within the S. radiopugnans gene subclade, it was allocated a different branch in the phylogenetic tree, separating it from the majority of the radiopugnans strains. Similar to type strain, S. radiopugnans R97(T) , the Antarctica isolate displayed thermo tolerance as well as resistance to (60) Co gamma radiation, up to the dose of 15 kGy. However, media and salt tolerance studies revealed that, unlike the type strain, this isolate needed higher salinity for its growth. This is the first report of S. radiopugnans isolated from the Antarctica region. The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of Streptomyces radiopugnans MTCC 5447 is JQ723477.
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Affiliation(s)
- S V Bhave
- Department of Natural Products, Piramal Enterprises Ltd., Mumbai, India.
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23
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Huang JP, Swain AK, Thacker RW, Ravindra R, Andersen DT, Bej AK. Bacterial diversity of the rock-water interface in an East Antarctic freshwater ecosystem, Lake Tawani(P)†. AQUATIC BIOSYSTEMS 2013; 9:4. [PMID: 23369372 PMCID: PMC3740781 DOI: 10.1186/2046-9063-9-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 01/25/2013] [Indexed: 05/31/2023]
Abstract
Schirmacher Oasis is one of the few ice-free plateaus in East Antarctica that maintains a unique distribution of over 120 microbial-rich, dynamic freshwater lakes, most of which are unexplored. In this study, we describe the bacterial diversity of the rock-water interface in Lake Tawani(P) using culture-independent Bacterial Tag Encoded FLX Amplicon Pyrosequencing (bTEFAP), clone library construction, and culture-based analysis targeting the eubacterial 16S rRNA gene. Lake Tawani(P)was formed in a fossil valley by the accumulation of snow and glacial melt through surface channels into a low-catchment depression. Overall this lake exhibited thirteen bacterial phyla and one-hundred and twelve genera. The Qiime bioinformatics analysis on the bTEFAP alone exhibited higher coverage of the bacterial composition in Lake Tawani(P) than the clone library construction or culture-based methodology. Particularly due to the higher sensitivity of the bTEFAP approach, we detected and differentiated members of the phyla: Chloroflexi, Gemmatimonadetes, Planctomycetes, Nitrospira, and Candidate Division TM7 that other methods were unable to reveal. Nevertheless we found that the use of multiple approaches identified a more complete bacterial community than by using any single approach. Investigating the bacterial diversity of the Schirmacher Oasis lakes, especially those connected through surface channels and encompassed by valleys, will help unravel the dynamic nature of these unique seasonal, freshwater lakes, which potentially harbors highly adapted bacterial taxa with defined ecological functions.
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Affiliation(s)
- Jonathan P Huang
- Department of Biology, University of Alabama at Birmingham, 1300 University Blvd., CH464, Birmingham, AL 35294-1170, USA
| | - Ashit K Swain
- Geological Survey of India, Antarctic Division, NH-5P, NIT, Faridabad 121001, India
| | - Robert W Thacker
- Department of Biology, University of Alabama at Birmingham, 1300 University Blvd., CH464, Birmingham, AL 35294-1170, USA
| | - Rasik Ravindra
- National Centre for Antarctic & Ocean Research, Head Land Sada, Vasco-da-Gama, Goa, India
- Current address: Panikkar Professor and Chairman, INSA-SCAR National Committee, Earth System Science Organization (MoES)Lodi Road, New Delhi 110 003, India
| | - Dale T Andersen
- Carl Sagan Center for the Study of Life in the Universe, Mountain View, CA 94043, USA
| | - Asim K Bej
- Department of Biology, University of Alabama at Birmingham, 1300 University Blvd., CH464, Birmingham, AL 35294-1170, USA
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24
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Goh YS, Tan IKP. Polyhydroxyalkanoate production by antarctic soil bacteria isolated from Casey Station and Signy Island. Microbiol Res 2012; 167:211-9. [DOI: 10.1016/j.micres.2011.08.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 08/12/2011] [Accepted: 08/22/2011] [Indexed: 10/17/2022]
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25
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Jagannadham MV, Chowdhury C. Differential expression of membrane proteins helps Antarctic Pseudomonas syringae to acclimatize upon temperature variations. J Proteomics 2012; 75:2488-99. [PMID: 22418587 DOI: 10.1016/j.jprot.2012.02.033] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Revised: 02/15/2012] [Accepted: 02/25/2012] [Indexed: 01/16/2023]
Abstract
Antarctic bacteria are adapted to the extremely low temperature. The transcriptional and translational machineries of these bacteria are adapted to the sub-zero degrees of temperature. Studies directed towards identifying the changes in the protein profiles during changes in the growth temperatures of an Antarctic bacterium Pseudomonas syringae Lz4W may help in understanding the molecular basis of cold adaptation. In this study, subcellular fractionation methods of proteins were used for the enrichment and identification of proteins including low abundance proteins. The membrane proteins of the bacterium P. syringae Lz4W were prepared employing sucrose density gradient method. The proteins were separated through 2D gel-electrophoresis with the pH ranges 3-10, 4-7 and 5-8 using the detergent, amidosulfobetaine (ASB-14). The proteins separated on the 1D SDS PAGE and 2D gels were identified with the help of LC-ESI MS/MS and MALDI TOF TOF using bioinformatic programs MASCOT and SEQUEST. Since the genome sequence of P. syringae Lz4W is not available, the proteins are identified by using the genome database of the Pseudomonas sp. available at NCBI. The present studies focus on identifying temperature dependent expression of proteins by employing LC-MS/MS method and the functional significance of these proteins is discussed.
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26
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rnr gene from the antarctic bacterium Pseudomonas syringae Lz4W, encoding a psychrophilic RNase R. Appl Environ Microbiol 2011; 77:7896-904. [PMID: 21926201 DOI: 10.1128/aem.05683-11] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
RNase R is a highly processive, hydrolytic 3'-5' exoribonuclease belonging to the RNB/RNR superfamily which plays significant roles in RNA metabolism in bacteria. The enzyme was observed to be essential for growth of the psychrophilic Antarctic bacterium Pseudomonas syringae Lz4W at a low temperature. We present results here pertaining to the biochemical properties of RNase R and the RNase R-encoding gene (rnr) locus from this bacterium. By cloning and expressing a His₆-tagged form of the P. syringae RNase R (RNase R(Ps)), we show that the enzyme is active at 0 to 4°C but exhibits optimum activity at ∼25°C. The enzyme is heat labile in nature, losing activity upon incubation at 37°C and above, a hallmark of many psychrophilic enzymes. The enzyme requires divalent cations (Mg²⁺ and Mn²⁺) for activity, and the activity is higher in 50 to 150 mM KCl when it largely remains as a monomer. On synthetic substrates, RNase R(Ps) exhibited maximum activity on poly(A) and poly(U) in preference over poly(G) and poly(C). The enzyme also degraded structured malE-malF RNA substrates. Analysis of the cleavage products shows that the enzyme, apart from releasing 5'-nucleotide monophosphates by the processive exoribonuclease activity, produces four-nucleotide end products, as opposed to two-nucleotide products, of RNA chain by Escherichia coli RNase R. Interestingly, three ribonucleotides (ATP, GTP, and CTP) inhibited the activity of RNase R(Ps) in vitro. The ability of the nonhydrolyzable ATP-γS to inhibit RNase R(Ps) activity suggests that nucleotide hydrolysis is not required for inhibition. This is the first report on the biochemical property of a psychrophilic RNase R from any bacterium.
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Comparison of bacterial diversity in proglacial soil from Kafni Glacier, Himalayan Mountain ranges, India, with the bacterial diversity of other glaciers in the world. Extremophiles 2011; 15:673-90. [PMID: 21918795 DOI: 10.1007/s00792-011-0398-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 08/26/2011] [Indexed: 10/17/2022]
Abstract
Two 16S rRNA gene clone libraries (KF and KS) were constructed using two soil samples (K7s and K8s) collected near Kafni Glacier, Himalayas. The two libraries yielded a total of 648 clones. Phyla Actinobacteria, Bacteroidetes, Chloroflexi Firmicutes, Proteobacteria, Spirochaetae, Tenericutes and Verrucomicrobia were common to the two libraries. Phyla Acidobacteria, Chlamydiae and Nitrospirae were present only in KF library, whereas Lentisphaerae and TM7 were detected only in KS. In the two libraries, clones belonging to phyla Bacteroidetes and Proteobacteria were the most predominant. Principal component analysis (PCA) revealed that KF and KS were different and arsenic content influenced the differences in the percentage of OTUs. PCA indicated that high water content in the K8s sample results in high total bacterial count. PCA also indicated that bacterial diversity of KF and KS was similar to soils from the Pindari Glacier, Himalayas; Samoylov Island, Siberia; Schrimacher Oasis, Antarctica and Siberian tundra. The eleven bacterial strains isolated from the above two soil samples were phylogenetically related to six different genera. All the isolates were psychro-, halo- and alkalitolerant. Amylase, lipase and urease activities were detected in the majority of the strains. Long chain, saturated, unsaturated and branched fatty acids were predominant in the psychrotolerant bacteria.
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28
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Hart KM, Szpak MT, Mahaney WC, Dohm JM, Jordan SF, Frazer AR, Allen CCR, Kelleher BP. A bacterial enrichment study and overview of the extractable lipids from paleosols in the Dry Valleys, Antarctica: implications for future Mars reconnaissance. ASTROBIOLOGY 2011; 11:303-321. [PMID: 21545270 DOI: 10.1089/ast.2010.0583] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The Dry Valleys of Antarctica are one of the coldest and driest environments on Earth with paleosols in selected areas that date to the emplacement of tills by warm-based ice during the Early Miocene. Cited as an analogue to the martian surface, the ability of the Antarctic environment to support microbial life-forms is a matter of special interest, particularly with the upcoming NASA/ESA 2018 ExoMars mission. Lipid biomarkers were extracted and analyzed by gas chromatography--mass spectrometry to assess sources of organic carbon and evaluate the contribution of microbial species to the organic matter of the paleosols. Paleosol samples from the ice-free Dry Valleys were also subsampled and cultivated in a growth medium from which DNA was extracted with the explicit purpose of the positive identification of bacteria. Several species of bacteria were grown in solution and the genus identified. A similar match of the data to sequenced DNA showed that Alphaproteobacteria, Gammaproteobacteria, Bacteriodetes, and Actinobacteridae species were cultivated. The results confirm the presence of bacteria within some paleosols, but no assumptions have been made with regard to in situ activity at present. These results underscore the need not only to further investigate Dry Valley cryosols but also to develop reconnaissance strategies to determine whether such likely Earth-like environments on the Red Planet also contain life.
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Affiliation(s)
- Kris M Hart
- School of Chemical Sciences, Dublin City University, Dublin, Ireland.
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29
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Bacterial diversity of soil in the vicinity of Pindari glacier, Himalayan mountain ranges, India, using culturable bacteria and soil 16S rRNA gene clones. Extremophiles 2011; 15:1-22. [PMID: 21061031 DOI: 10.1007/s00792-010-0333-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 10/22/2010] [Indexed: 10/18/2022]
Abstract
Three 16S rRNA gene clone libraries (P1L, P4L and P8L) were constructed using three soil samples (P1S, P4S and P8S) collected near Pindari glacier, Himalayas. The three libraries yielded a total of 703 clones. Actinobacteria, Firmicutes and Proteobacteria were common to the three libraries. In addition to the above P1L and P8L shared the phyla Acidobacteria, Bacteroidetes, Gemmatimonadetes and Planctomycetes. Phyla Chlamydiae, Chlorobi, Chloroflexi, Dictyoglomi, Fibrobacteres, Nitrospirae, Verrucomicrobia, candidate division SPAM and candidate TM7s TM7a phylum were present only in P1L. Rarefaction analysis indicated that the bacterial diversity in P4S and P8S soil samples was representative of the sample. Principal component analysis (PCA) revealed that P1S and P8S were different from P4S soil sample. PCA also indicated that arsenic content, pH, Cr and altitude influence the observed differences in the percentage of specific OTUs in the three 16S rRNA gene clone libraries. The observed bacterial diversity was similar to that observed for other Himalayan and non-polar cold habitats. A total of 40 strains of bacteria were isolated from the above three soil samples and based on the morphology 20 bacterial strains were selected for further characterization. The 20 bacteria belonged to 12 different genera. All the isolates were psychro-, halo- and alkalitolerant. Amylase and urease activities were detected in majority of the strains but lipase and protease activities were not detected. Long chain, saturated, unsaturated and branched fatty acids were predominant in the psychrotolerant bacteria.
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30
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Jagannadham MV, Abou-Eladab EF, Kulkarni HM. Identification of outer membrane proteins from an Antarctic bacterium Pseudomonas syringae Lz4W. Mol Cell Proteomics 2011; 10:M110.004549. [PMID: 21447709 DOI: 10.1074/mcp.m110.004549] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Subcellular fractionation of proteins is a preferred method of choice for detection and identification of proteins from complex mixtures such as bacterial cells. To characterize the membrane proteins of the Antarctic bacterium Pseudomonas syringae Lz4W, the membrane fractions were prepared using three different methods, namely Triton X-100 solubilization, sucrose density gradient, and carbonate extraction methods. The proteins were separated on one-dimensional polyacrylamide gels and analyzed using a combination of liquid chromatography-coupled electrospray ionization-MS. The membrane proteins that were prepared by carbonate extraction were separated on two-dimensional PAGE in different pI ranges using the detergent 2% amidosulfobetaine (ASB). The proteins were then subjected to matrix-assisted laser desorption ionization-time-of-flight/time-of-flight for analysis and identification. Because the genome sequence of P. syringae Lz4W is not known, the proteins were identified by using the relevant sequence databases of the Pseudomonas sp available at National Centre for Biotechnology Information (NCBI). The sequence identification of some tryptic peptides were validated by de novo sequencing and others by chemical modification and mass spectrometry. The peptide sequences of P. syringae Lz4W were then matched with the sequences of the peptides from different Pseudomonas sp. by similarity search of the proteins from different species using clustal W2 program. Thus by using a combination of the methods, we have been able to identify large number of proteins of this bacterial strain, which include most of the outer membrane proteins.
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Affiliation(s)
- M V Jagannadham
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Hyderabad, India.
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31
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Shivaji S, Kumari K, Kishore KH, Pindi PK, Rao PS, Radha Srinivas TN, Asthana R, Ravindra R. Vertical distribution of bacteria in a lake sediment from Antarctica by culture-independent and culture-dependent approaches. Res Microbiol 2010; 162:191-203. [PMID: 21126578 DOI: 10.1016/j.resmic.2010.09.020] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Accepted: 09/21/2010] [Indexed: 11/29/2022]
Abstract
Bacterial diversity of the subsurface (18-22 cm), middle (60-64 cm) and bottom (100-104 cm) of a 136-cm-long sediment core sampled from a freshwater lake in Antarctica was determined by the culturable approach, T-RFLP and 16S rRNA gene clone libraries. Using the culturable approach, 41 strains were isolated and, based on phylogenetic analysis, they could be categorized into 14 groups. Representatives of the 14 groups varied in their growth temperature range (4-30 °C), in their tolerance to NaCl (0-2 M NaCl) and in the growth pH range (5-11). Eleven of fourteen representative strains exhibited either amylase, lipase, protease and (or) urease activities at 4 °C. Bacterial diversity at the phyla level using T-RFLP and 16S rRNA clone libraries was similar and clones were affiliated with Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes. TRFs affiliated with Spirochaetes were detected only by the T-RFLP approach and clones affiliated with Caldiserica only in the clone libraries. Stratification of bacteria along the depth of the sediment was observed both with the T-RFLP and the 16S rRNA gene clone library methods, and results indicated that stratification was dependent on the nature of the organism, aerobic or anaerobic. For instance, aerobic Janthinobacterium and Polaromonas were confined to the surface of the sediment, whereas anaerobic Caldisericum was present only in the bottom portion of the core. It may be concluded that the bacterial diversity of an Antarctic lake sediment core sample varies throughout the length of the core depending on the oxic-anoxic conditions of the sediment. Furthermore, these psychrophilic bacteria, due to their ability to produce extracellular cold active enzymes, might play a key role in the transformation of complex organic compounds.
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Affiliation(s)
- Sisinthy Shivaji
- Center for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India.
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32
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Carrión O, Miñana-Galbis D, Montes MJ, Mercadé E. Pseudomonas deceptionensis sp. nov., a psychrotolerant bacterium from the Antarctic. Int J Syst Evol Microbiol 2010; 61:2401-2405. [PMID: 21062736 DOI: 10.1099/ijs.0.024919-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
During the taxonomic investigation of cold-adapted bacteria from samples collected in the Antarctic area of the South Shetland Islands, one Gram-reaction-negative, psychrotolerant, aerobic bacterium, designated strain M1(T), was isolated from marine sediment collected on Deception Island. The organism was rod-shaped, catalase- and oxidase-positive and motile by means of a polar flagellum. This psychrotolerant strain grew at temperatures ranging from -4 °C to 34 °C. Phylogenetic studies based on 16S rRNA gene sequences confirmed that Antarctic isolate M1(T) was a member of the genus Pseudomonas and was located in the Pseudomonas fragi cluster. 16S rRNA gene sequence similarity values were >98 % between 13 type strains belonging to the Pseudomonas fluorescens lineage. However, phylogenetic analysis of rpoD gene sequences showed that strain M1(T) exhibited high sequence similarity only with respect to Pseudomonas psycrophila (97.42 %) and P. fragi (96.40 %) and DNA-DNA hybridization experiments between the Antarctic isolate M1(T) and the type strains of these two closely related species revealed relatedness values of 58 and 57 %, respectively. Several phenotypic characteristics, together with the results of polar lipid and cellular fatty acid analyses, were used to differentiate strain M1(T) from related pseudomonads. Based on the evidence of this polyphasic taxonomic study, strain M1(T) represents a novel species, for which the name Pseudomonas deceptionensis sp. nov. is proposed. The type strain is M1(T) ( = LMG 25555(T) = CECT 7677(T)).
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Affiliation(s)
- Ornella Carrión
- Laboratori de Microbiologia, Facultat de Farmacia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain
| | - David Miñana-Galbis
- Laboratori de Microbiologia, Facultat de Farmacia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain
| | - Ma Jesús Montes
- Laboratori de Microbiologia, Facultat de Farmacia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain
| | - Elena Mercadé
- Laboratori de Microbiologia, Facultat de Farmacia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain
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Chattopadhyay MK, Raghu G, Sharma YVRK, Biju AR, Rajasekharan MV, Shivaji S. Increase in oxidative stress at low temperature in an antarctic bacterium. Curr Microbiol 2010; 62:544-6. [PMID: 20730433 DOI: 10.1007/s00284-010-9742-y] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 08/05/2010] [Indexed: 10/19/2022]
Abstract
Association between cold stress and oxidative stress was demonstrated by measuring the activity of two antioxidant enzymes and the level of free radicals generated in two batches of cells of an Antarctic bacterium Pseudomonas fluorescens MTCC 667, grown at 22 and 4°C. Increase in oxidative stress in cells grown at low temperature was evidenced by increase in the activity of an enzyme and also in the amount of free radicals generated, in the cold-grown cells. The association between cold stress and oxidative stress demonstrated in this investigation bolsters the concept of interlinked stress response in bacteria.
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Affiliation(s)
- M K Chattopadhyay
- Centre for Cellular and Molecular Biology (CSIR), Hyderabad, 500 007, India,
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Characterization of the RNA degradosome of Pseudoalteromonas haloplanktis: conservation of the RNase E-RhlB interaction in the gammaproteobacteria. J Bacteriol 2010; 192:5413-23. [PMID: 20729366 DOI: 10.1128/jb.00592-10] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The degradosome is a multienzyme complex involved in mRNA degradation in Escherichia coli. The essential endoribonuclease RNase E contains a large noncatalytic region necessary for protein-protein interactions with other components of the RNA degradosome. Interacting proteins include the DEAD-box RNA helicase RhlB, the glycolytic enzyme enolase, and the exoribonuclease PNPase. Pseudoalteromonas haloplanktis, a psychrotolerant gammaproteobacterium distantly related to E. coli, encodes homologs of each component of the RNA degradosome. In P. haloplanktis, RNase E associates with RhlB and PNPase but not enolase. Plasmids expressing P. haloplanktis RNase E (Ph-RNase E) can complement E. coli strains lacking E. coli RNase E (Ec-RNase E). Ph-RNase E, however, does not confer a growth advantage to E. coli at low temperature. Ph-RNase E has a heterologous protein-protein interaction with Ec-RhlB but not with Ec-enolase or Ec-PNPase. The Ph-RNase E binding sites for RhlB and PNPase were mapped by deletion analysis. The PNPase binding site is located at the C-terminal end of Ph-RNase E at the same position as that in Ec-RNase E, but the sequence of the site is not conserved. The sequence of the RhlB binding site in Ph-RNase E is related to the sequence in Ec-RNase E. Together with the heterologous interaction between Ph-RNase E and Ec-RhlB, our results suggest that the underlying structural motif for the RNase E-RhlB interaction is conserved. Since the activity of Ec-RhlB requires its physical interaction with Ec-RNase E, conservation of the underlying structural motif over a large evolutionary distance could be due to constraints involved in the control of RhlB activity.
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Sundareswaran VR, Singh AK, Dube S, Shivaji S. Aspartate aminotransferase is involved in cold adaptation in psychrophilic Pseudomonas syringae. Arch Microbiol 2010; 192:663-72. [DOI: 10.1007/s00203-010-0591-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Revised: 05/19/2010] [Accepted: 05/21/2010] [Indexed: 11/28/2022]
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Pavankumar TL, Sinha AK, Ray MK. All three subunits of RecBCD enzyme are essential for DNA repair and low-temperature growth in the Antarctic Pseudomonas syringae Lz4W. PLoS One 2010; 5:e9412. [PMID: 20195537 PMCID: PMC2828478 DOI: 10.1371/journal.pone.0009412] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Accepted: 01/29/2010] [Indexed: 01/13/2023] Open
Abstract
Background The recD mutants of the Antarctic Pseudomonas syringae Lz4W are sensitive to DNA-damaging agents and fail to grow at 4°C. Generally, RecD associates with two other proteins (RecB and RecC) to produce RecBCD enzyme, which is involved in homologous recombination and DNA repair in many bacteria, including Escherichia coli. However, RecD is not essential for DNA repair, nor does its deletion cause any growth defects in E. coli. Hence, the assessment of the P. syringae RecBCD pathway was imperative. Methodology/Principal Findings Mutational analysis and genetic complementation studies were used to establish that the individual null-mutations of all three genes, recC, recB, and recD, or the deletion of whole recCBD operon of P. syringae, lead to growth inhibition at low temperature, and sensitivity to UV and mitomycin C. Viability of the mutant cells dropped drastically at 4°C, and the mutants accumulated linear chromosomal DNA and shorter DNA fragments in higher amounts compared to 22°C. Additional genetic data using the mutant RecBCD enzymes that were inactivated either in the ATPase active site of RecB (RecBK29Q) or RecD (RecDK229Q), or in the nuclease center of RecB (RecBD1118A and RecBΔnuc) suggested that, while the nuclease activity of RecB is not so critical in vivo, the ATP-dependent functions of both RecB and RecD are essential. Surprisingly, E. coli recBCD or recBC alone on plasmid could complement the defects of the ΔrecCBD strain of P. syringae. Conclusions/Significance All three subunits of the RecBCDPs enzyme are essential for DNA repair and growth of P. syringae at low temperatures (4°C). The RecD requirement is only a function of the RecBCD complex in the bacterium. The RecBCD pathway protects the Antarctic bacterium from cold-induced DNA damages, and is critically dependent on the helicase activities of both RecB and RecD subunits, but not on the nuclease of RecBCDPs enzyme.
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Affiliation(s)
- Theetha L. Pavankumar
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Hyderabad, India
| | - Anurag K. Sinha
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Hyderabad, India
| | - Malay K. Ray
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Hyderabad, India
- * E-mail:
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Kulkarni HM, Ramesh V, Srinivas R, Jagannadham M. Acetylating Tryptic Peptides Enhances b Ion Intensity in MALDI TOF/TOF: Implications in Peptide Sequencing and Identification of Proteins in an Antarctic Bacterium Pseudomonas Syringae. PROTEOMICS INSIGHTS 2010. [DOI: 10.4137/pri.s3676] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Several approaches have been described to identify proteins from MALDI MS/MS mass spectra. The sequence of tryptic peptides is determined by database searching or by de novo sequencing. Different algorithms are available to determine peptide sequence using mass spectra. False discovery of peptides is an associated problem with it. A combination of chemical modifications followed by mass spectral analysis helps in overcoming this problem. Acetylating the tryptic peptides of β-galactosidase in methanol is found to increase the b-ion signal intensity in MALDI TOF mass spectrometry. The method of acetylation is extended to the tryptic peptides of the proteins of an Antarctic bacterium Pseudomonas syringae, whose genome sequence is not known. These proteins are identified by searching the available database of the Pseudomonas spp at NCBI using the MS/MS spectra. The sequences of the peptides are validated using the CID mass spectra of the acetylated tryptic peptides.
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Affiliation(s)
- Heramb M. Kulkarni
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Uppal Road, Hyderabad-500 007, India
| | - V. Ramesh
- Indian Institute of Chemical Technology, Hyderabad-500 007, India
| | - R. Srinivas
- Indian Institute of Chemical Technology, Hyderabad-500 007, India
| | - M.V. Jagannadham
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Uppal Road, Hyderabad-500 007, India
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Singh AK, Shivaji S. A cold-active heat-labile t-RNA modification GTPase from a psychrophilic bacterium Pseudomonas syringae (Lz4W). Res Microbiol 2009; 161:46-50. [PMID: 19944148 DOI: 10.1016/j.resmic.2009.11.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Revised: 10/22/2009] [Accepted: 11/02/2009] [Indexed: 10/20/2022]
Abstract
A cold-active heat-labile t-RNA modification GTPase (TrmE) from psychrophilic bacterium Pseudomonas syringae (Lz4W) has been purified and characterized. The purified TrmE is a 53 kDa protein, has GTPase activity and hydrolyses only the oxy and deoxy forms of GTP but not the other nucleotide triphosphates. The enzyme exhibits optimal activity at 12-18 degrees C and retains 65% of its optimal activity at 4 degrees C, indicating that it is a cold-active enzyme. The enzyme is also heat-labile and loses 60% of its activity at 30 degrees C. This is the first report on the purification and characterization of a TrmE from a psychrophilic bacterium.
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Affiliation(s)
- Ashish Kumar Singh
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
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Jagannadham MV. Article Commentary: Identifying the Sequence and Distinguishing the Oxidized—Methionine from Phenylalanine Peptides by MALDI TOF/TOF Mass Spectrometry in an Antarctic Bacterium Pseudomonas Syringae. PROTEOMICS INSIGHTS 2009. [DOI: 10.4137/pri.s3158] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
This short note highlights a procedure to distinguish the residues having similar masses, oxidized methionine and phenylalanine containing peptides using MALDI TOF/TOF. The isotope intensities give a preliminary recognition of peptides containing oxidized methionine. In the peptides with partial oxidation of methionine a mass difference of 16 Da can be observed in the mass finger print of the peptide. Neutral loss of methane sulphenate (CH3 SOH) in the MS/MS spectra is the most abundant ion in the peptide containing oxidized methionine, whereas this fragment ion is not produced from phenylalanine containing peptide. The mass spectra of methionine, oxidized methionine and phenylalanine containing peptides were examined from the proteins of Pseudomonas syringae Lz4W, whose genome sequence is not known.
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Affiliation(s)
- M. V. Jagannadham
- Centre for Cellular and Molecular Biology (CSIR), Hydearabd-500 007, India
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40
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Pseudomonas extremaustralis sp. nov., a Poly(3-hydroxybutyrate) Producer Isolated from an Antarctic Environment. Curr Microbiol 2009; 59:514-9. [DOI: 10.1007/s00284-009-9469-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Revised: 07/08/2009] [Accepted: 07/20/2009] [Indexed: 10/20/2022]
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41
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Isolation and characterization of an arsenic-resistant bacterium from a bore-well in West Bengal, India. ANN MICROBIOL 2009. [DOI: 10.1007/bf03178325] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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42
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Wu Z, Qin L, Walker VK. Characterization and recombinant expression of a divergent ice nucleation protein from 'Pseudomonas borealis'. MICROBIOLOGY-SGM 2009; 155:1164-1169. [PMID: 19332818 DOI: 10.1099/mic.0.025114-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Isolates of 'Pseudomonas borealis' were recovered after ice-affinity selection of summer-collected soils. 'P. borealis' DL7 was further characterized and shown to have ice nucleation activity (INA), a property that allows the crystallization of ice at temperatures close to the melting point, effectively preventing the supercooling of water. INA was optimally detected after culturing at temperatures consistent with psychrophilic growth. The sequence encoding the 'P. borealis' ice nucleation protein (INP) was obtained using both PCR and chromosome walking. When expressed in Escherichia coli, the resulting inaPb recombinants had INA. The 'P. borealis' sequence, dubbed inaPb, is clearly related to previously cloned INP genes, but it shows greater divergence. Sequence analysis suggests that there are two opposite flat surfaces, one relatively hydrophobic that likely serves as an ice template, and the other that could function as a complementary face to facilitate interprotein interaction for ice-step formation.
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Affiliation(s)
- Zhongqin Wu
- Department of Biology, Kingston, ON K7L 3N6, Canada
| | - Lei Qin
- Department of Biology, Kingston, ON K7L 3N6, Canada
| | - Virginia K Walker
- Department of Microbiology and Immunology, Kingston, ON K7L 3N6, Canada.,Department of Biology, Kingston, ON K7L 3N6, Canada
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43
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Importance of trmE for growth of the psychrophile Pseudomonas syringae at low temperatures. Appl Environ Microbiol 2009; 75:4419-26. [PMID: 19429554 DOI: 10.1128/aem.01523-08] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transposon mutagenesis of Pseudomonas syringae Lz4W, a psychrophilic bacterium capable of growing at temperatures between 2 and 30 degrees C, yielded 30 cold-sensitive mutants, and CSM1, one of these cold-sensitive mutants, was characterized. Growth of CSM1 was retarded when it was cultured at 4 degrees C but not when it was cultured at 22 degrees C and 28 degrees C compared to the growth of wild-type cells, indicating that CSM1 is a cold-sensitive mutant of P. syringae Lz4W. The mutated gene in CSM1 was identified as trmE (coding for tRNA modification GTPase), and evidence is provided that this gene is induced at low temperatures. Further, the cold-inducible nature of the trmE promoter was demonstrated. In addition, the transcription start site and the various regulatory elements of the trmE promoter, such as the -10 region, -35 region, UP element, cold box, and DEAD box, were identified, and the importance of these regulatory elements in promoter activity were confirmed. The importance of trmE in rapid adaptation to growth at low temperatures was further highlighted by plasmid-mediated complementation that alleviated the cold-sensitive phenotype of CSM1.
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44
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Jagannadham MV. Identification of proteins from membrane preparations by a combination of MALDI TOF-TOF and LC-coupled linear ion trap MS analysis of an Antarctic bacteriumPseudomonas syringaeLz4W, a strain with unsequenced genome. Electrophoresis 2008; 29:4341-50. [DOI: 10.1002/elps.200700750] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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45
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Sahu B, Ray MK. Auxotrophy in natural isolate: minimal requirements for growth of the Antarctic psychrotrophic bacteriumPseudomonas syringae Lz4W. J Basic Microbiol 2008; 48:38-47. [DOI: 10.1002/jobm.200700185] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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46
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Bozal N, Montes MJ, Mercadé E. Pseudomonas guineae sp. nov., a novel psychrotolerant bacterium from an Antarctic environment. Int J Syst Evol Microbiol 2008; 57:2609-2612. [PMID: 17978227 DOI: 10.1099/ijs.0.65141-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two Gram-negative, cold-adapted, aerobic bacteria, designated strains M8T and M6, were isolated from soil collected from the South Shetland Islands. The organisms were rod-shaped, catalase- and oxidase-positive and motile by means of polar flagella. These two psychrotolerant strains grew between -4 and 30 degrees C. 16S rRNA gene sequence analysis placed strains M8T and M6 within the genus Pseudomonas. DNA-DNA hybridization experiments between the Antarctic isolate M8T and type strains of phylogenetically related species, namely Pseudomonas peli and Pseudomonas anguilliseptica, revealed levels of relatedness of 33 and 37%, respectively. Strain M6 showed 99% DNA similarity to strain M8T. Several phenotypic characteristics, together with data on cellular fatty acid composition, served to differentiate strains M8T and M6 from related pseudomonads. On the basis of the polyphasic taxonomic evidence presented in this study, it can be concluded that strains M8T and M6 belong to the same genospecies, representing a novel species of the genus Pseudomonas, for which the name Pseudomonas guineae sp. nov. is proposed. The type strain is M8T (=LMG 24016T=CECT 7231T).
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Affiliation(s)
- Núria Bozal
- Laboratori de Microbiologia, Facultat de Farmacia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain
| | - M Jesús Montes
- Laboratori de Microbiologia, Facultat de Farmacia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain
| | - Elena Mercadé
- Laboratori de Microbiologia, Facultat de Farmacia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain
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Romanenko LA, Tanaka N, Uchino M, Kalinovskaya NI, Mikhailov VV. Diversity and Antagonistic Activity of Sea Ice Bacteria Isolated from the Sea of Japan. Microbes Environ 2008; 23:209-14. [DOI: 10.1264/jsme2.23.209] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Lyudmila A. Romanenko
- Pacific Institute of Bioorganic Chemistry, Far-Eastern Branch, Russian Academy of Sciences
| | - Naoto Tanaka
- NODAI Culture Collection Center, Tokyo University of Agriculture
| | - Masataka Uchino
- Laboratory of Food Science and Technology, Department of Applied Biology and Chemistry, Tokyo University of Agriculture
| | | | - Valery V. Mikhailov
- Pacific Institute of Bioorganic Chemistry, Far-Eastern Branch, Russian Academy of Sciences
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48
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Taxonomic heterogeneity, as shown by siderotyping, of strains primarily identified as Pseudomonas putida. Int J Syst Evol Microbiol 2007; 57:2543-2556. [DOI: 10.1099/ijs.0.65233-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
One hundred and forty-four fluorescent pseudomonad strains isolated from various environments (soil, water, plant rhizosphere, hospital) and received as Pseudomonas putida (83 strains), P. putida biovar A (49 strains), P. putida biovar B (10 strains) and P. putida biovar C (2 strains), were analysed by the pyoverdine-isoelectrofocusing and pyoverdine-mediated iron uptake methods of siderotyping. Both methods demonstrated a great diversity among these strains, which could be subdivided into 35 siderovars. Some siderovars specifically included strains that have subsequently been transferred to well-defined Pseudomonas species, e.g. Pseudomonas monteilii or Pseudomonas mosselii, or which could be related by their siderotype to Pseudomonas jessenii or Pseudomonas mandelii. Other siderovars included strains sharing a high level of DNA-DNA relatedness (>70 %), thus demonstrating that siderotyping could easily circumscribe strains at the species level. However, a group of seven strains, including the type strain, P. putida ATCC 12633T, were allocated into four siderovars, despite sharing DNA–DNA relatedness values of higher than 70 %. Interestingly, the strong genomic relationships between these seven strains were supported by the structural relationships among their pyoverdines, thus reflecting their phylogenetic affinities. These results strongly support the view that pyoverdine-based siderotyping could be used as a powerful tool in Pseudomonas taxonomy.
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49
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Pandey A, Trivedi P, Kumar B, Palni LMS. Characterization of a Phosphate Solubilizing and Antagonistic Strain of Pseudomonas putida (B0) Isolated from a Sub-Alpine Location in the Indian Central Himalaya. Curr Microbiol 2006; 53:102-7. [PMID: 16832725 DOI: 10.1007/s00284-006-4590-5] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2005] [Accepted: 01/05/2006] [Indexed: 10/24/2022]
Abstract
The morphological, biochemical, and physiological characteristics of a phosphate solubilizing and antagonistic bacterial strain, designated as B0, isolated from a sub-alpine Himalayan forest site have been described. The isolate is gram negative, rod shaped, 0.8 x 1.6 microm in size, and psychrotrophic in nature that could grow from 0 to 35 degrees C (optimum temp. 25 degrees C). It exhibited tolerance to a wide pH range (3-12; optimum 8.0) and salt concentration up to 4% (w/v). Although it was sensitive to kanamycin, gentamicin, and streptomycin (<10 microg mL(-1)), it showed resistance to higher concentrations of ampicillin, penicillin, and carbenicillin (>1000 microg mL(-1)). The isolate showed maximum similarity with Pseudomonas putida based on 16S rRNA analysis. It solubilized tricalcium phosphate under in vitro conditions. The phosphate solubilization was estimated along a temperature range (4-28 degrees C), and maximum activity (247 microg mL(-1)) was recorded at 21 degrees C after 15 days of incubation. The phosphate solubilizing activity coincided with a concomitant decrease in pH of the medium. The isolate also exhibited antifungal activity against phytopathogenic fungi in Petri dish assays and produced chitinase, ss-l,3-glucanase, salicylic acid, siderophore, and hydrogen cyanide. The plant growth promotion and antifungal properties were demonstrated through a maize-based bioassay under greenhouse conditions. Although the bacterial inoculation was found to result in significant increment in plant biomass, it stimulated bacterial and suppressed fungal counts in the rhizosphere. The present study is important with respect to enumerating microbial diversity of the colder regions as well as understanding the potential biotechnological applications of native microbes.
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Affiliation(s)
- Anita Pandey
- Environmental Physiology and Biotechnology, GB Pant Institute of Himalayan Environment and Development, Kosi-Katarmal, 263 643, Almora, Uttaranchal, India.
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Shivaji S, Chaturvedi P, Reddy GSN, Suresh K. Pedobacter himalayensis sp. nov., from the Hamta glacier located in the Himalayan mountain ranges of India. Int J Syst Evol Microbiol 2005; 55:1083-1088. [PMID: 15879237 DOI: 10.1099/ijs.0.63532-0] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Strain HHS 22(T) was isolated from a glacial water sample from the snout of the Hamta glacier located in the Himalayan mountain ranges of India. Phenotypic, chemotaxonomic and phylogenetic analyses established the affiliation of the isolate to the genus Pedobacter. HHS 22(T) exhibits high 16S rRNA gene sequence similarity with Pedobacter cryoconitis (98 %). However, the level of DNA-DNA relatedness between HHS 22(T) and P. cryoconitis is only 42 %. Furthermore, HHS 22(T) differs from P. cryoconitis and the four other recognized species of Pedobacter in a number of phenotypic characteristics. These data suggest that HHS 22(T) represents a novel species of the genus Pedobacter, for which the name Pedobacter himalayensis sp. nov. is proposed. The type strain is HHS 22(T) (= JCM 12171(T) = MTCC 6384(T)).
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Affiliation(s)
- S Shivaji
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | - P Chaturvedi
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | - G S N Reddy
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | - K Suresh
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
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