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2. Isolation of Novel Bacterial Strains Pseudomonas extremaustralis CSW01 and Stutzerimonas stutzeri CSW02 from Sewage Sludge for Paracetamol Biodegradation.

Author

Vargas-Ordóñez, Antonio, Aguilar-Romero, Inés, Villaverde, Jaime, Madrid, Fernando, and Morillo, Esmeralda

Subjects
SEWAGE sludge, SEWAGE sludge as fertilizer, ACETAMINOPHEN, PSEUDOMONAS stutzeri, SEWAGE disposal plants, SLUDGE management
Abstract

Paracetamol is one of the most used pharmaceuticals worldwide, but due to its widespread use it is detected in various environmental matrices, such as surface and ground waters, sediments, soils or even plants, where it is introduced mainly from the discharge of wastewater and the use of sewage sludge as fertilizer in agriculture. Its accumulation in certain organisms can induce reproductive, neurotoxic or endocrine disorders, being therefore considered an emerging pollutant. This study reports on the isolation, from sewage sludge produced in wastewater treatment plants (WWTPs), of bacterial strains capable of degrading paracetamol. Up to 17 bacterial strains were isolated, but only two of them, identified as Pseudomonas stutzeri CSW02 and Pseudomonas extremaustralis CSW01, were able to degrade very high concentrations of paracetamol in solution as a sole carbon and energy source, and none of them had been previously described as paracetamol degraders. These bacteria showed the ability to degrade up to 500 mg L−1 of paracetamol in only 6 and 4 h, respectively, much quicker than any other paracetamol-degrader strain described in the literature. The two main paracetamol metabolites, 4-aminophenol and hydroquinone, which present high toxicity, were detected during the degradation process, although they disappeared very quickly for paracetamol concentrations up to 500 mg L−1. The IC50 of paracetamol for the growth of these two isolates was also calculated, indicating that P. extremaustralis CSW01 was more tolerant than S. stutzeri CSW02 to high concentrations of paracetamol and/or its metabolites in solution, and this is the reason for the much lower paracetamol degradation by S. stutzeri CSW02 at 2000–3000 mg L−1. These findings indicate that both bacteria are very promising candidates for their use in paracetamol bioremediation in water and sewage sludge. [ABSTRACT FROM AUTHOR]

Published
2023
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3. Draft genome sequence of Pseudomonas extremaustralis strain USBA-GBX 515 isolated from Superparamo soil samples in Colombian Andes.

Author

López, Gina, Diaz-Cárdenas, Carolina, Shapiro, Nicole, Woyke, Tanja, Kyrpides, Nikos C, David Alzate, J, González, Laura N, Restrepo, Silvia, and Baena, Sandra

Subjects
16S rRNA, Gammaproteobacteria, Pseudomonas extremaustralis, Psychrophilic soils, Superparamo ecosystems, Human Genome, Genetics, Biochemistry and Cell Biology
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.

Published
2017

4. Isolation of Novel Bacterial Strains Pseudomonas extremaustralis CSW01 and Stutzerimonas stutzeri CSW02 from Sewage Sludge for Paracetamol Biodegradation

Author

Antonio Vargas-Ordóñez, Inés Aguilar-Romero, Jaime Villaverde, Fernando Madrid, and Esmeralda Morillo

Subjects
biodegradation, paracetamol degrader, sewage sludge, Pseudomonas extremaustralis, Stutzerimonas stutzeri, Biology (General), QH301-705.5
Abstract

Paracetamol is one of the most used pharmaceuticals worldwide, but due to its widespread use it is detected in various environmental matrices, such as surface and ground waters, sediments, soils or even plants, where it is introduced mainly from the discharge of wastewater and the use of sewage sludge as fertilizer in agriculture. Its accumulation in certain organisms can induce reproductive, neurotoxic or endocrine disorders, being therefore considered an emerging pollutant. This study reports on the isolation, from sewage sludge produced in wastewater treatment plants (WWTPs), of bacterial strains capable of degrading paracetamol. Up to 17 bacterial strains were isolated, but only two of them, identified as Pseudomonas stutzeri CSW02 and Pseudomonas extremaustralis CSW01, were able to degrade very high concentrations of paracetamol in solution as a sole carbon and energy source, and none of them had been previously described as paracetamol degraders. These bacteria showed the ability to degrade up to 500 mg L−1 of paracetamol in only 6 and 4 h, respectively, much quicker than any other paracetamol-degrader strain described in the literature. The two main paracetamol metabolites, 4-aminophenol and hydroquinone, which present high toxicity, were detected during the degradation process, although they disappeared very quickly for paracetamol concentrations up to 500 mg L−1. The IC50 of paracetamol for the growth of these two isolates was also calculated, indicating that P. extremaustralis CSW01 was more tolerant than S. stutzeri CSW02 to high concentrations of paracetamol and/or its metabolites in solution, and this is the reason for the much lower paracetamol degradation by S. stutzeri CSW02 at 2000–3000 mg L−1. These findings indicate that both bacteria are very promising candidates for their use in paracetamol bioremediation in water and sewage sludge.

Published
2023
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5. Biodegradation and Bioaccumulation of Decachlorobiphenyl (DCB) by Native Strain Pseudomonas extremaustralis ADA-5.

Author

López, Miguel Angel Gómez, Zenteno-Rojas, Adalberto, Martinez-Romero, Esperanza, Rincón-Molina, Clara Ivette, Vences-Guzmán, Miguel Angel, Ruíz-Valdiviezo, Víctor Manuel, Rincón-Molina, Francisco Alexander, Manzano-Gomez, Luis Alberto, and Rincón-Rosales, Reiner

Subjects
GAS chromatography/Mass spectrometry (GC-MS), BIOACCUMULATION, CHEMICAL stability, PSEUDOMONAS, POLYCHLORINATED biphenyls, BIODEGRADATION, MEMBRANE lipids
Abstract

Decachlorobiphenyl (DCB) is one of the 209 polychlorinated biphenyls congeners characterized by its high toxicity and chemical stability. It is produced by industrial activities. A possible strategy to eliminate DCB is by bacterial degradation. The main objective of this study was to define the optimal conditions for biodegradation and bioaccumulation of DCB by Pseudomonas extremaustralis ADA-5 isolated from a worm intestine. Bacterial growth kinetics were determined in minimal medium with added biphenyl and DCB. By GC coupled to mass spectrometry, we found that the strain had the ability to degrade 9.75% of available DCB, using it as a carbon source and was able to accumulate 19.98% of this pollutant in biomass. Membrane lipids may be altered by DCB. Phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and cardiolipin (CL) were identified by thin-layer chromatography as the membrane lipids of the cell. At 250 mg L−1 of DCB in the culture medium, membranes showed a 30% decrease in the PE concentration, an 18% increase in the PG, and a 12% increase in CL. ADA-5 was able to catabolize DCB and may be used for bioremediation of highly chlorinated toxic compounds in soil. [ABSTRACT FROM AUTHOR]

Published
2021
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6. 一株樟子松-褐环乳牛肝菌菌根辅助细菌的 筛选和鉴定 .

Author

宋小双, 邓 勋, 遇文婧, 闵 凯, and 周 琦

Abstract

Copyright of Journal of Shenyang Agricultural University is the property of Journal of Shenyang Agricultural University Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2020
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7. Response to lethal UVA radiation in the Antarctic bacterium Pseudomonas extremaustralis: polyhydroxybutyrate and cold adaptation as protective factors.

Author

Tribelli, Paula M., Pezzoni, Magdalena, Brito, María Gabriela, Montesinos, Nahuel V., Costa, Cristina S., and López, Nancy I.

Subjects
*COLD adaptation, *POLYHYDROXYALKANOATES, *POLYHYDROXYBUTYRATE, *PSEUDOMONAS, *RADIATION, *LIGHT scattering, *BACTERIAL cells
Abstract

Pseudomonas extremaustralis is an Antarctic bacterium with high stress resistance, able to grow under cold conditions. It is capable to produce polyhydroxyalkanoates (PHAs) mainly as polyhydroxybutyrate (PHB) and, to a lesser extent, medium-chain length polyhydroxyalkanoates (mclPHAs). In this work, we analyzed the role of PHAs and cold adaptation in the survival of P. extremaustralis after lethal UVA exposure. P. extremaustralis presented higher radiation resistance under polymer accumulation conditions. This result was also observed in the derivative mutant strain PHA−, deficient for mclPHAs production. On the contrary, the PHB− derivative mutant, deficient for PHB production, showed high sensitivity to UVA exposure. Complementation of the PHB− strain restored the wild-type resistance level, indicating that the UVA-sensitive phenotype is due to the lack of PHB. All strains exhibited high sensitivity to radiation when cultured under PHAs non-accumulation conditions. A slight decrease in PHB content was observed after UVA exposure in association with increased survival. The scattering of UVA radiation by intracellular PHAs granules could also result in bacterial cell protection. In addition, cold conditions improved UVA tolerance, probably depending on PHB mobilization. Results showed that PHB accumulation is crucial in the resistance to UVA in P. extremaustralis. Mechanisms involved probably entail depolymerization and light scattering acting as a screen, both conferring protection against oxidative stress. [ABSTRACT FROM AUTHOR]

Published
2020
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8. Draft genome sequence of Pseudomonas extremaustralis strain USBA-GBX 515 isolated from Superparamo soil samples in Colombian Andes

Author

Gina López, Carolina Diaz-Cárdenas, Nicole Shapiro, Tanja Woyke, Nikos C. Kyrpides, J. David Alzate, Laura N. González, Silvia Restrepo, and Sandra Baena

Subjects
Pseudomonas extremaustralis, Gammaproteobacteria, Superparamo ecosystems, Psychrophilic soils, 16S rRNA, Genetics, QH426-470
Abstract

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.

Published
2017
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9. Insights into the bacterial species and communities of a full-scale anaerobic/anoxic/oxic wastewater treatment plant by using third-generation sequencing.

Author

Ji, Bin, Zhang, Xuechun, Zhang, Shufei, Song, Hongjiao, and Kong, Zehua

Subjects
*SEWAGE disposal plants, *BACTERIAL communities, *DENITRIFYING bacteria, *SEQUENCING batch reactor process, *AMMONIA-oxidizing bacteria, *PSEUDOMONAS, *BIOLOGICAL nutrient removal
Abstract

For the first time, full-length 16S rRNA sequencing method was applied to disclose the bacterial species and communities of a full-scale wastewater treatment plant using an anaerobic/anoxic/oxic (A/A/O) process in Wuhan, China. The compositions of the bacteria at phylum and class levels in the activated sludge were similar to which revealed by Illumina Miseq sequencing. At genus and species levels, third-generation sequencing showed great merits and accuracy. Typical functional taxa classified to ammonia-oxidizing bacteria (AOB), nitrite-oxidizing bacteria (NOB), denitrifying bacteria (DB), anaerobic ammonium oxidation bacteria (ANAMMOXB) and polyphosphate-accumulating organisms (PAOs) were presented, which were Nitrosomonas (1.11%), Nitrospira (3.56%), Pseudomonas (3.88%), Planctomycetes (13.80%), Comamonadaceae (1.83%), respectively. Pseudomonas (3.88%) and Nitrospira (3.56%) were the most predominating two genera, mainly containing Pseudomonas extremaustralis (1.69%), Nitrospira defluvii (3.13%), respectively. Bacteria regarding to nitrogen and phosphorus removal at species level were put forward. The predicted functions proved that the A/A/O process was efficient regarding nitrogen and organics removal. [ABSTRACT FROM AUTHOR]

Published
2019
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10. Isolation of Novel Bacterial Strains Pseudomonas extremaustralis CSW01 and Stutzerimonas stutzeri CSW02 from Sewage Sludge for Paracetamol Biodegradation

Author

Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), European Commission, Junta de Andalucía, Vargas-Ordoñez, Antonio [0000-0001-6909-8075], Aguilar Romero, Inés María [0000-0001-7786-8172], Villaverde Capellán, J. [0000-0002-8694-7929], Madrid Díaz, Fernando [0000-0002-2921-3515], Morillo González, Esmeralda [0000-0002-4485-2315], Vargas-Ordóñez, Antonio, Aguilar Romero, Inés María, Villaverde Capellán, J., Madrid Díaz, Fernando, Morillo González, Esmeralda, Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), European Commission, Junta de Andalucía, Vargas-Ordoñez, Antonio [0000-0001-6909-8075], Aguilar Romero, Inés María [0000-0001-7786-8172], Villaverde Capellán, J. [0000-0002-8694-7929], Madrid Díaz, Fernando [0000-0002-2921-3515], Morillo González, Esmeralda [0000-0002-4485-2315], Vargas-Ordóñez, Antonio, Aguilar Romero, Inés María, Villaverde Capellán, J., Madrid Díaz, Fernando, and Morillo González, Esmeralda

Abstract

first_pagesettingsOrder Article Reprints Open AccessArticle Isolation of Novel Bacterial Strains Pseudomonas extremaustralis CSW01 and Stutzerimonas stutzeri CSW02 from Sewage Sludge for Paracetamol Biodegradation by Antonio Vargas-OrdóñezORCID,Inés Aguilar-Romero,Jaime VillaverdeORCID,Fernando MadridORCID andEsmeralda Morillo *ORCID Institute of Natural Resources and Agrobiology of Seville, Spanish National Research Council (IRNAS-CSIC), 41012 Seville, Spain * Author to whom correspondence should be addressed. Microorganisms 2023, 11(1), 196; https://doi.org/10.3390/microorganisms11010196 Received: 23 December 2022 / Revised: 10 January 2023 / Accepted: 11 January 2023 / Published: 12 January 2023 (This article belongs to the Special Issue Feature Collection in Environmental Microbiology Section 2021-2022) Download Browse Figures Versions Notes Abstract Paracetamol is one of the most used pharmaceuticals worldwide, but due to its widespread use it is detected in various environmental matrices, such as surface and ground waters, sediments, soils or even plants, where it is introduced mainly from the discharge of wastewater and the use of sewage sludge as fertilizer in agriculture. Its accumulation in certain organisms can induce reproductive, neurotoxic or endocrine disorders, being therefore considered an emerging pollutant. This study reports on the isolation, from sewage sludge produced in wastewater treatment plants (WWTPs), of bacterial strains capable of degrading paracetamol. Up to 17 bacterial strains were isolated, but only two of them, identified as Pseudomonas stutzeri CSW02 and Pseudomonas extremaustralis CSW01, were able to degrade very high concentrations of paracetamol in solution as a sole carbon and energy source, and none of them had been previously described as paracetamol degraders. These bacteria showed the ability to degrade up to 500 mg L−1 of paracetamol in only 6 and 4 h, respectively, much quicker than any other paracetamol-degrader strain

Published
2023

11. Immobilization of Cells of Hydrocarbon-oxidizing Bacteria for Petroleum Bioremediation Using New Materials

Author

Nadezhda V. Grigor’eva, Irina V. Perminova, Timur Kanapatsky, I. A. Borzenkov, N. G. Loiko, Galina I. El-Registan, Igor Bliznetc, Anna Khreptugova, A.B. Volikov, Yury A. Nikolaev, and E. V. Demkina

Subjects
chemistry.chemical_classification, Pseudomonas extremaustralis, biology, Chemistry, Rhodococcus erythropolis, Biofilm, New materials, biology.organism_classification, Bioremediation, Hydrocarbon, Oxidizing agent, Food science, Bacteria, General Environmental Science
Abstract

While liquid biopreparations for water and soil bioremediation are convenient and economically attractive, microbial survival under standard environmental conditions is poor. Microbial immobilization is a common and efficient method to preserve high viable cell titers. We tested the effect of three new materials on the survival of various hydrocarbon oxidizers during long-term storage. The suspended (planktonic) cultures stored under the same conditions served as a control when assessing the viability of immobilized cultures after long-term storage. The cells of Acinetobacter seifertii, Pseudomonas extremaustralis, P. aeruginosa, Rhodococcus erythropolis, and Dietzia maris grown with microcapsules (MCs) of chitosan-modified polyurea (represented by crumpled spheres, 40–200 µm in diameter) attached abundantly to the MC surface. After several months of storage with MCs, CFU titers were two to five times higher than in the control. Cultivation of P. aeruginosa and R. erythropolis with polylactide (PLA) MCs (represented by slightly crumpled thin-walled spheres 25–100 µm in size) resulted in the formation of thick biofilms on MC surface. After 30-day storage with these MCs, CFU titers of R. erytropolis were up to one thousand times higher than in the control. In the presence of PLA MCs, the respiration rates of both cultures were five to eight times higher than in the control without MCs. The reasons of the better survival of immobilized cells are being discussed. After storage for up to 12 months, CFU titers of bacteria (R. erythropolis, A. seifertii, P. aeruginosa, P. extremaustralis) and yeasts (Yarrovia lipolytica) immobilized in the gel based on silanol derivatives of humic substances were ten to one hundred times higher than in the control. After 4-month storage, hydrocarbon degradation by the stabilized cultures began earlier and was faster and more complete than in the control. The tested materials may be used to extend the storage time for the preparations of biotechnologically important bacteria and for application for petroleum bioremediation.

Published
2021

12. Microaerophilic alkane degradation in Pseudomonas extremaustralis: a transcriptomic and physiological approach.

Author

Tribelli, Paula M., Rossi, Leticia, Ricardi, Martiniano M., Gomez-Lozano, Maria, Molin, Søren, Raiger Iustman, Laura J., and Lopez, Nancy I.

Subjects
*DIESEL fuels, *HYDROCARBONS, *ALKANES, *AROMATIC compounds, *PSEUDOMONAS
Abstract

Diesel fuel is one of the most important sources of hydrocarbon contamination worldwide. Its composition consists of a complex mixture of n-alkanes, branched alkanes and aromatic compounds. Hydrocarbon degradation in Pseudomonas species has been mostly studied under aerobic conditions; however, a dynamic spectrum of oxygen availability can be found in the environment. Pseudomonas extremaustralis, an Antarctic bacterium isolated from a pristine environment, is able to degrade diesel fuel and presents a wide microaerophilic metabolism. In this work RNA-deep sequence experiments were analyzed comparing the expression profile in aerobic and microaerophilic cultures. Interestingly, genes involved in alkane degradation, including alkB, were over-expressed in micro-aerobiosis in absence of hydrocarbon compounds. In minimal media supplemented with diesel fuel, n-alkanes degradation (C13-C19) after 7 days was observed under low oxygen conditions but not in aerobiosis. In-silico analysis of the alkB promoter zone showed a putative binding sequence for the anaerobic global regulator, Anr. Our results indicate that some diesel fuel components can be utilized as sole carbon source under microaerophilic conditions for cell maintenance or slow growth in a Pseudomonas species and this metabolism could represent an adaptive advantage in polluted environments. [ABSTRACT FROM AUTHOR]

Published
2018
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14. Microaerophilic alkane degradation in Pseudomonas extremaustralis: a transcriptomic and physiological approach

Author

Nancy I. López, Laura J. Raiger Iustman, Martiniano M. Ricardi, María Gómez-Lozano, Paula M. Tribelli, Leticia Rossi, and Søren Molin

Subjects
0301 basic medicine, 030106 microbiology, Biotecnología del Medio Ambiente, AlkB, chemistry.chemical_element, Bioengineering, INGENIERÍAS Y TECNOLOGÍAS, Applied Microbiology and Biotechnology, Oxygen, PSEUDOMONAS EXTREMAUSTRALIS, 03 medical and health sciences, Diesel fuel, Pseudomonas, Alkanes, MICRO-AEROBIOSIS, Microaerophile, ALKANE DEGRADATION, RNA-SEQ, Bioremediación, Diagnóstico Biotecnológico en Gestión Medioambiental, chemistry.chemical_classification, biology, Metabolism, biology.organism_classification, Aerobiosis, 030104 developmental biology, Hydrocarbon, Biodegradation, Environmental, Biochemistry, chemistry, biology.protein, Degradation (geology), Cytochrome P-450 CYP4A, ALKB, Transcriptome, Bacteria, Gasoline, Biotechnology
Abstract

Diesel fuel is one of the most important sources of hydrocarbon contamination worldwide. Its composition consists of a complex mixture of n-alkanes, branched alkanes and aromatic compounds. Hydrocarbon degradation in Pseudomonas species has been mostly studied under aerobic conditions; however, a dynamic spectrum of oxygen availability can be found in the environment. Pseudomonas extremaustralis, an Antarctic bacterium isolated from a pristine environment, is able to degrade diesel fuel and presents a wide microaerophilic metabolism. In this work RNA-deep sequence experiments were analyzed comparing the expression profile in aerobic and microaerophilic cultures. Interestingly, genes involved in alkane degradation, including alkB, were over-expressed in micro-aerobiosis in absence of hydrocarbon compounds. In minimal media supplemented with diesel fuel, n-alkanes degradation (C13–C19) after 7 days was observed under low oxygen conditions but not in aerobiosis. In-silico analysis of the alkB promoter zone showed a putative binding sequence for the anaerobic global regulator, Anr. Our results indicate that some diesel fuel components can be utilized as sole carbon source under microaerophilic conditions for cell maintenance or slow growth in a Pseudomonas species and this metabolism could represent an adaptive advantage in polluted environments. Fil: Tribelli, Paula Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina Fil: Rossi, Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina Fil: Ricardi, Martiniano María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina Fil: Gomez Lozano, Maria. Technical University of Denmark; Dinamarca Fil: Molin, Søren. Technical University of Denmark; Dinamarca Fil: Raiger Iustman, Laura Judith. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina Fil: López, Nancy Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina

Published
2018

15. Draft genome sequence of Pseudomonas extremaustralis strain USBA-GBX 515 isolated from Superparamo soil samples in Colombian Andes

Author

Tanja Woyke, J. David Alzate, Nicole Shapiro, Nikos C. Kyrpides, Carolina Díaz-Cárdenas, Gina López, Laura N. González, Sandra Baena, and Silvia Restrepo

Subjects
0301 basic medicine, Whole genome sequencing, Genetics, Phylogenetic tree, lcsh:QH426-470, Operon, 030106 microbiology, Pseudomonas, Pseudomonas extremaustralis, RNA, Superparamo ecosystems, Biology, biology.organism_classification, 16S ribosomal RNA, Genome, Psychrophilic soils, 03 medical and health sciences, lcsh:Genetics, 16S rRNA, Extended Genome Report, Gene, Gammaproteobacteria
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.

Published
2017

16. Découverte de nouveaux chalcophores de type méthanobactine chez les non-méthanotrophes : construction d’un système d’expression hétérologue

Author

Sayous, Victor and UB -, BU Carreire

Subjects
[SDV.SP] Life Sciences [q-bio]/Pharmaceutical sciences, Recombinaison homologue, Sacharomyces cerevisiae, Pseudomonas extremaustralis, Maladie de Wilson, Méthanobactines, Chalcophore, Escherichia coli, Expression hétérologue
Abstract

Transition metals such as copper and iron are essentials for bacterial survival in their ecological niches. The methanobactins produced by the methanotroph bacteria are the only example of chalcophores that specifically chelate copper with high affinity. They play an important role in the physiology and the ecology of the methanotrophs which have a strong need for copper in order to realize the oxidation of methane. Genome analyses revealed that the related chalcophores exist in some non-methanotroph bacteria such as Pseudomonas extrmaustralis. In order to understand the chemo-diversity of these peptides, this internship aimed to develop a system of heterologous expression in Escherichia coli for the gene cluster of the methanobactine-like peptide originating from P. extremaustralis. We have established a cloning protocol based on the homologous recombination in Sacharomyces cerevisiae and have applied this method to insert the whole gene cluster into an expression vector. The obtained results open the perspective to discover and characterize the related methanobactin-like peptide., Les métaux de transition comme le cuivre et le fer sont essentiels pour la survie des bactéries dans les niches écologiques. Les méthanobactines produites par des bactéries méthanoptrophes sont le seul exemple de peptide chalkophore complexant spécifiquement le cuivre avec une haute affinité. Elles jouent un rôle majeur dans la physiologie et l’écologie des méthanotrophes, qui ont un fort besoin en cuivre pour réaliser l’oxydation du méthane. Toutefois, l’analyse génomique a révélé que des chalkophores apparentés existeraient chez certaines bactéries non-méthanotrophes comme chez Pseudomonas extremaustralis. Afin de comprendre le chimio-diversité de ces peptides, ce stage est pour but de construire un système d’expression hétérologue chez Escherichia coli pour le cluster des gènes impliqué dans la biosynthèse d’un peptide apparenté à la méthanobactine d’origine de P. extremaustralis. Le stage a mis en place d’un protocole de clonage par recombinaison homologue chez la Sacharomyces cerevisiae et a appliqué cette méthode pour insérer le cluster entier dans le vecteur d’expression. Les résultats obtenus ouvrirent les perspectives pour découvrir et caractériser la méthanobactine-like.

Published
2016

17. Novel essential role of ethanol oxidation genes at low temperature revealed by transcriptome analysis in the antarctic bacterium pseudomonas extremaustralis

Author

Esmeralda C. Solar Venero, Laura J. Raiger Iustman, Paula M. Tribelli, María Gómez-Lozano, Martiniano M. Ricardi, Søren Molin, and Nancy I. López

Subjects
Otras Ciencias Biológicas, Pseudomonas extremaustralis, Antarctic Regions, Aldehyde dehydrogenase, lcsh:Medicine, Bacterial growth, Microbiology, purl.org/becyt/ford/1 [https], Ciencias Biológicas, Open Reading Frames, chemistry.chemical_compound, Biosynthesis, Pyrroloquinoline quinone, Pseudomonas, Ethanol metabolism, purl.org/becyt/ford/1.6 [https], Psychrophile, lcsh:Science, Multidisciplinary, biology, Ethanol, Gene Expression Profiling, lcsh:R, Alcohol Dehydrogenase, Gene Expression Regulation, Bacterial, biology.organism_classification, Pseudomonas putida, Up-Regulation, Cold Temperature, Citric acid cycle, chemistry, Biochemistry, Genes, Bacterial, biology.protein, lcsh:Q, Essencial, Oxidation-Reduction, Software, CIENCIAS NATURALES Y EXACTAS, Research Article, Cold
Abstract

Temperature is one of the most important factors for bacterial growth and development. Cold environments are widely distributed on earth, and psychrotolerant and psychrophilic microorganisms have developed different adaptation strategies to cope with the stress derived from low temperatures. Pseudomonas extremaustralis is an Antarctic bacterium able to grow under low temperatures and to produce high amounts of polyhydroxyalkanoates (PHAs). In this work, we analyzed the genome-wide transcriptome by RNA deepsequencing technology of early exponential cultures of P. extremaustralis growing in LB (Luria Broth) supplemented with sodium octanoate to favor PHA accumulation at 8°C and 30°C. We found that genes involved in primary metabolism, including tricarboxylic acid cycle (TCA) related genes, as well as cytochromes and amino acid metabolism coding genes, were repressed at low temperature. Among up-regulated genes, those coding for transcriptional regulatory and signal transduction proteins were over-represented at cold conditions. Remarkably, we found that genes involved in ethanol oxidation, exaA, exaB and exaC, encoding a pyrroloquinoline quinone (PQQ)-dependent ethanol dehydrogenase, the cytochrome c550 and an aldehyde dehydrogenase respectively, were up-regulated. Along with RNA-seq experiments, analysis of mutant strains for pqqB (PQQ biosynthesis protein B) and exaA were carried out. We found that the exaA and pqqB genes are essential for growth under low temperature in LB supplemented with sodium octanoate. Additionally, prosaniline assay measurements showed the presence of alcohol dehydrogenase activity at both 8°C and 30°C, while the activity was abolished in a pqqB mutant strain. These results together with the detection of ethanol by gas chromatography in P. extremaustralis cultures grown at 8°C support the conclusion that this pathway is important under cold conditions. The obtained results have led to the identification of novel components involved in cold adaptation mechanisms in this bacterium, suggesting for the first time a role of the ethanol oxidation pathway for bacterial growth at low temperatures. Fil: Tribelli, Paula Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina Fil: Solar Venero, Esmeralda Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina Fil: Ricardi, Martiniano María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina Fil: Gómez Lozano, Maria. Technical University of Denmark; Dinamarca Fil: Raiger Iustman, Laura Judith. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina Fil: Molin, Søren. Technical University of Denmark; Dinamarca Fil: López, Nancy Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina

Published
2015

18. Novel role of the LPS core glycosyltransferase WapH for cold adaptation in the Antarctic bacterium Pseudomonas extremaustralis

Author

Florencia Carla Benforte, Nancy I. López, Martiniano M. Ricardi, Esmeralda C. Solar Venero, Paula M. Tribelli, María Antonela Colonnella, and Leonardo Lizarraga

Subjects
Lipopolysaccharides, 0301 basic medicine, Pseudomonas extremaustralis, Confocal Microscopy, lcsh:Medicine, Biochemistry, purl.org/becyt/ford/1 [https], lcsh:Science, Microscopy, Multidisciplinary, biology, Atomic force microscopy, Chemistry, Light Microscopy, Adaptation, Physiological, Atomic Force Microscopy, Enzymes, Cold Temperature, Mutant Strains, Laboratory Equipment, Core (optical fiber), Physical Sciences, Engineering and Technology, AFM, CIENCIAS NATURALES Y EXACTAS, Research Article, Materials Science, Material Properties, 030106 microbiology, Antarctic Regions, Equipment, Real-Time Polymerase Chain Reaction, Research and Analysis Methods, Permeability, Microbiology, Ciencias Biológicas, 03 medical and health sciences, Biología Celular, Microbiología, Transferases, Pseudomonas, Glycosyltransferase, Genetics, COLD, purl.org/becyt/ford/1.6 [https], Bacteria, Scanning Probe Microscopy, LIPOPOLYSACCHARIDES, lcsh:R, Organisms, Glycosyltransferases, Biology and Life Sciences, Proteins, Laboratory Glassware, biology.organism_classification, 030104 developmental biology, Genes, Bacterial, NANOMECHANIC, Mutation, Cold adaptation, Enzymology, biology.protein, lcsh:Q
Abstract

Psychrotroph microorganisms have developed cellular mechanisms to cope with cold stress. Cell envelopes are key components for bacterial survival. Outer membrane is a constituent of Gram negative bacterial envelopes, consisting of several components, such as lipopolysaccharides (LPS). In this work we investigated the relevance of envelope characteristics for cold adaptation in the Antarctic bacterium Pseudomonas extremaustralis by analyzing a mini Tn5 wapH mutant strain, encoding a core LPS glycosyltransferase. Our results showed that wapH strain is impaired to grow under low temperature but not for cold survival. The mutation in wapH, provoked a strong aggregative phenotype and modifications of envelope nanomechanical properties such as lower flexibility and higher turgor pressure, cell permeability and surface area to volume ratio (S/V). Changes in these characteristics were also observed in the wild type strain grown at different temperatures, showing higher cell flexibility but lower turgor pressure under cold conditions. Cold shock experiments indicated that an acclimation period in the wild type is necessary for cell flexibility and S/V ratio adjustments. Alteration in cell-cell interaction capabilities was observed in wapH strain. Mixed cells of wild type and wapH strains, as well as those of the wild type strain grown at different temperatures, showed a mosaic pattern of aggregation. These results indicate that wapH mutation provoked marked envelope alterations showing that LPS core conservation appears as a novel essential feature for active growth under cold conditions. Fil: Benforte, Florencia Carla. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentina Fil: Colonnella, Maria Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Bionanociencias "Elizabeth Jares Erijman"; Argentina Fil: Ricardi, Martiniano María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina Fil: Solar Venero, Esmeralda Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina Fil: Lizarraga, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Bionanociencias "Elizabeth Jares Erijman"; Argentina Fil: López, Nancy Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina Fil: Tribelli, Paula Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina

Published
2018

19. Oxygen-Sensitive Global Regulator, Anr, Is Involved in the Biosynthesis of Poly(3-Hydroxybutyrate) in Pseudomonas extremaustralis

Author

Nancy I. López, Beatriz S. Méndez, and Paula M. Tribelli

Subjects
Pseudomonas extremaustralis, Physiology, Pseudomonas, technology, industry, and agriculture, Poly-3-hydroxybutyrate, Regulator, chemistry.chemical_element, macromolecular substances, Cell Biology, Biology, biology.organism_classification, Applied Microbiology and Biotechnology, Biochemistry, Microbiology, Oxygen, Redox, chemistry.chemical_compound, Biosynthesis, chemistry, lipids (amino acids, peptides, and proteins), Biotechnology
Abstract

We analyzed the influence of the redox global regulator Anr on the accumulation of poly(3-hydroxybutyrate) (PHB) in Pseudomonas extremaustralis. Anr regulates a set of genes in the aerobic-anaerobic transition including genes involved in nitrate reduction and arginine fermentation. An anr mutant was constructed using PCR-based strategies. The wild-type strain was able to grow in both microaerobic and anaerobic conditions using nitrate as the terminal electron acceptor while the mutant strain was unable to grow under anaerobic conditions. In bioreactor cultures, PHB content in the wild-type strain was higher in microaerobic and anaerobic cultures compared with highly aerated cultures. The mutant strain showed decreased PHB levels in both aerobic and microaerobic conditions compared with the wild-type strain. Inactivation of anr led to decreased expression of phaC and phaR genes as demonstrated in real-time RT-PCR experiments. Associated with the PHB gene region, two putative binding sites for Anr were found that, in line with the phenotype observed in bioreactor cultures, suggest a role of this regulator in PHB biosynthesis.

Published
2010

20. High polyhydroxybutyrate production in Pseudomonas extremaustralis is associated with differential expression of horizontally acquired and core genome polyhydroxyalkanoate synthase genes

Author

Jimena A. Ruiz, Mariela V. Catone, Daniel Segura, Guadalupe Espín, Mildred Castellanos, and Nancy I. López

Subjects
POLYHYDROXYALKANOATE SYNTHASE, Proteomics, Applied Microbiology, lcsh:Medicine, POLYHYDROXYALKANOATES, Gene Expression, Hydroxybutyrates, PHAL PROTEIN, BACTERIAL METABOLISM, GENE INSERTION, UNCLASSIFIED DRUG, Genome, Biochemistry, BACTERIAL GROWTH, PSEUDOMONAS EXTREMAUSTRALIS, Polyhydroxybutyrate, purl.org/becyt/ford/1 [https], Genomic island, BACTERIAL GENOME, POLYHYDROXYBUTYRATE, Bacterial Physiology, lcsh:Science, Genetics, Multidisciplinary, GENE CLUSTER, Spectrometric Identification of Proteins, BACTERIAL GENE, BURKHOLDERIALES, Pseudomonas, Genomics, Pseudomonas putida, Functional Genomics, Bacterial Biochemistry, Complementation, GENETIC CODE, GENOME ANALYSIS, OPEN READING FRAME, PSEUDOMONAS, Sequence Analysis, CIENCIAS NATURALES Y EXACTAS, Research Article, Biotechnology, GENE EXPRESSION, Gene Transfer, Horizontal, Otras Ciencias Biológicas, Gene prediction, GENETIC COMPLEMENTATION, Biology, PHBC GENE, Microbiology, Ciencias Biológicas, Molecular Genetics, Industrial Microbiology, PHBP PROTEIN, Genomic Medicine, Bacterial Proteins, GENETIC SIMILARITY, NONHUMAN, PHAC1 GENE, purl.org/becyt/ford/1.6 [https], Molecular Biology Techniques, Sequencing Techniques, Gene, Molecular Biology, lcsh:R, GENETIC ORGANIZATION, POLY(3 HYDROXYBUTYRIC ACID), Biology and Life Sciences, Computational Biology, Bacteriology, biology.organism_classification, Genome Analysis, BACTERIAL PROTEIN, PHAC2 GENE, Genes, Bacterial, lcsh:Q, Gene Function, Acyltransferases
Abstract

Pseudomonas extremaustralis produces mainly polyhydroxybutyrate (PHB), a short chain length polyhydroxyalkanoate (sclPHA) infrequently found in Pseudomonas species. Previous studies with this strain demonstrated that PHB genes are located in a genomic island. In this work, the analysis of the genome of P. extremaustralis revealed the presence of another PHB cluster phbFPX, with high similarity to genes belonging to Burkholderiales, and also a cluster, phaC1ZC2D, coding for medium chain length PHA production (mclPHA). All mclPHA genes showed high similarity to genes from Pseudomonas species and interestingly, this cluster also showed a natural insertion of seven ORFs not related to mclPHA metabolism. Besides PHB, P. extremaustralis is able to produce mclPHA although in minor amounts. Complementation analysis demonstrated that both mclPHA synthases, PhaC1 and PhaC2, were functional. RT-qPCR analysis showed different levels of expression for the PHB synthase, phbC, and the mclPHA synthases. The expression level of phbC, was significantly higher than the obtained for phaC1 and phaC2, in late exponential phase cultures. The analysis of the proteins bound to the PHA granules showed the presence of PhbC and PhaC1, whilst PhaC2 could not be detected. In addition, two phasin like proteins (PhbP and PhaI) associated with the production of scl and mcl PHAs, respectively, were detected. The results of this work show the high efficiency of a foreign gene (phbC) in comparison with the mclPHA core genome genes (phaC1 and phaC2) indicating that the ability of P. extremaustralis to produce high amounts of PHB could be explained by the different expression levels of the genes encoding the scl and mcl PHA synthases. Fil: Catone, Mariela Verónica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Ruiz, Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; Argentina Fil: Castellanos, Mildred. Universidad Nacional Autónoma de México; México Fil: Segura, Daniel Genaro. Universidad Nacional Autónoma de México; México Fil: Espín, Elda Guadalupe. Universidad Nacional Autónoma de México; México Fil: López, Nancy Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina

Published
2014

21. Anr, the anaerobic global regulator, modulates the redox state and oxidative stress resistance in Pseudomonas extremaustralis

Author

Paula M. Tribelli, Oscar J. Oppezzo, Pablo I. Nikel, and Nancy I. López

Subjects
DNA, Bacterial, Molecular Sequence Data, chemistry.chemical_element, medicine.disease_cause, Microbiology, Redox, Oxygen, PSEUDOMONAS EXTREMAUSTRALIS, REDOX HOMEOSTASIS, Ciencias Biológicas, chemistry.chemical_compound, Biología Celular, Microbiología, Bacterial Proteins, Stress, Physiological, Pseudomonas, medicine, Sulfhydryl Compounds, OXIDATIVE STRESS, Hydrogen peroxide, chemistry.chemical_classification, GLOBAL REGULATORY NETWORKS, Reactive oxygen species, biology, Gene Expression Regulation, Bacterial, Hydrogen Peroxide, Sequence Analysis, DNA, Bioquímica y Biología Molecular, Glutathione synthase, Oxidative Stress, chemistry, Biochemistry, Catalase, biology.protein, Anr, Oxidation-Reduction, CIENCIAS NATURALES Y EXACTAS, Oxidative stress, Gene Deletion, Genome, Bacterial, Peroxidase, Transcription Factors
Abstract

The role of Anr in oxidative stress resistance was investigated in Pseudomonas extremaustralis, a polyhydroxybutyrate-producing Antarctic bacterium. The absence of Anr caused increased sensitivity to hydrogen peroxide under low oxygen tension. This phenomenon was associated with a decrease in the redox ratio, higher oxygen consumption and higher reactive oxygen species production. Physiological responses of the mutant to the oxidized state included an increase in NADP(H) content, catalase activity and exopolysaccharide production. The wild-type strain showed a sharp decrease in the reduced thiol pool when exposed to hydrogen peroxide, not observed in the mutant strain. In silico analysis of the genome sequence of P. extremaustralis revealed putative Anr binding sites upstream from genes related to oxidative stress. Genes encoding several chaperones and cold shock proteins, a glutathione synthase, a sulfate transporter and a thiol peroxidase were identified as potential targets for Anr regulation. Our results suggest a novel role for Anr in oxidative stress resistance and in redox balance maintenance under conditions of restricted oxygen supply. Fil: Tribelli, Paula Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina Fil: Nikel, Pablo Ivan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina Fil: Oppezzo, Oscar J.. Comisión Nacional de Energía Atómica. Gerencia de Area de Aplicaciones de la Tecnología Nuclear. Departamento de Radiobiología; Argentina Fil: López, Nancy I.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentina

Published
2012

22. Genome Sequence of the Polyhydroxybutyrate Producer Pseudomonas extremaustralis, a Highly Stress-Resistant Antarctic Bacterium

Author

Mariela V. Catone, Santiago Revale, Carla Di Martino, Laura J. Raiger Iustman, Beatriz S. Méndez, Paula M. Tribelli, and Nancy I. López

Subjects
DNA, Bacterial, Genetics, Whole genome sequencing, Pseudomonas extremaustralis, Molecular Sequence Data, Pseudomonas, Antarctic Regions, Hydroxybutyrates, Gene Expression Regulation, Bacterial, Chromosomes, Bacterial, Biology, biology.organism_classification, Microbiology, Polyhydroxyalkanoates, Genome Announcements, Polyhydroxybutyrate, Stress, Physiological, Molecular Biology, Gene, Genome, Bacterial, Bacteria
Abstract

Pseudomonas extremaustralis 14-3b presents genes involved in the synthesis of different polyhydroxyalkanoates, in tolerance and degradation of pollutants, and in microaerobic metabolism. Several genomic islands were detected. Genetic machinery could contribute to the adaptability to stressful conditions. This is the first genome sequence reported from a Pseudomonas isolated from cold environments.

Published
2012

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