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Gugger M, Boullié A, Laurent T. Cyanotoxins and Other Bioactive Compounds from the Pasteur Cultures of Cyanobacteria (PCC). Toxins (Basel) 2023; 15:388. [PMID: 37368689 DOI: 10.3390/toxins15060388] [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: 05/12/2023] [Revised: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
In tribute to the bicentenary of the birth of Louis Pasteur, this report focuses on cyanotoxins, other natural products and bioactive compounds of cyanobacteria, a phylum of Gram-negative bacteria capable of carrying out oxygenic photosynthesis. These microbes have contributed to changes in the geochemistry and the biology of Earth as we know it today. Furthermore, some bloom-forming cyanobacterial species are also well known for their capacity to produce cyanotoxins. This phylum is preserved in live cultures of pure, monoclonal strains in the Pasteur Cultures of Cyanobacteria (PCC) collection. The collection has been used to classify organisms within the Cyanobacteria of the bacterial kingdom and to investigate several characteristics of these bacteria, such as their ultrastructure, gas vacuoles and complementary chromatic adaptation. Thanks to the ease of obtaining genetic and further genomic sequences, the diversity of the PCC strains has made it possible to reveal some main cyanotoxins and to highlight several genetic loci dedicated to completely unknown natural products. It is the multidisciplinary collaboration of microbiologists, biochemists and chemists and the use of the pure strains of this collection that has allowed the study of several biosynthetic pathways from genetic origins to the structures of natural products and, eventually, their bioactivity.
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Affiliation(s)
- Muriel Gugger
- Institut Pasteur, Université Paris Cité, Collection of Cyanobacteria, 75015 Paris, France
| | - Anne Boullié
- Institut Pasteur, Université Paris Cité, Collection of Cyanobacteria, 75015 Paris, France
| | - Thierry Laurent
- Institut Pasteur, Université Paris Cité, Collection of Cyanobacteria, 75015 Paris, France
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2
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Díez J, López-Lozano A, Domínguez-Martín MA, Gómez-Baena G, Muñoz-Marín MC, Melero-Rubio Y, García-Fernández JM. Regulatory and metabolic adaptations in the nitrogen assimilation of marine picocyanobacteria. FEMS Microbiol Rev 2023; 47:6794272. [PMID: 36323406 DOI: 10.1093/femsre/fuac043] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 10/25/2022] [Accepted: 10/28/2022] [Indexed: 11/17/2022] Open
Abstract
Prochlorococcus and Synechococcus are the two most abundant photosynthetic organisms on Earth, with a strong influence on the biogeochemical carbon and nitrogen cycles. Early reports demonstrated the streamlining of regulatory mechanisms in nitrogen metabolism and the removal of genes not strictly essential. The availability of a large series of genomes, and the utilization of latest generation molecular techniques have allowed elucidating the main mechanisms developed by marine picocyanobacteria to adapt to the environments where they thrive, with a particular interest in the strains inhabiting oligotrophic oceans. Given that nitrogen is often limited in those environments, a series of studies have explored the strategies utilized by Prochlorococcus and Synechococcus to exploit the low concentrations of nitrogen-containing molecules available in large areas of the oceans. These strategies include the reduction in the GC and the cellular protein contents; the utilization of truncated proteins; a reduced average amount of N in the proteome; the development of metabolic mechanisms to perceive and utilize nanomolar nitrate concentrations; and the reduced responsiveness of key molecular regulatory systems such as NtcA to 2-oxoglutarate. These findings are in sharp contrast with the large body of knowledge obtained in freshwater cyanobacteria. We will outline the main discoveries, stressing their relevance to the ecological success of these important microorganisms.
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Affiliation(s)
- J Díez
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, Córdoba,14001, Spain
| | - A López-Lozano
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, Córdoba,14001, Spain
| | - M A Domínguez-Martín
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, Córdoba,14001, Spain
| | - G Gómez-Baena
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, Córdoba,14001, Spain
| | - M C Muñoz-Marín
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, Córdoba,14001, Spain
| | - Y Melero-Rubio
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, Córdoba,14001, Spain
| | - J M García-Fernández
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario ceiA3, Universidad de Córdoba, Córdoba,14001, Spain
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3
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Ford BA, Sullivan GJ, Moore L, Varkey D, Zhu H, Ostrowski M, Mabbutt BC, Paulsen IT, Shah BS. Functional characterisation of substrate-binding proteins to address nutrient uptake in marine picocyanobacteria. Biochem Soc Trans 2021; 49:2465-2481. [PMID: 34882230 PMCID: PMC8786288 DOI: 10.1042/bst20200244] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 11/03/2021] [Accepted: 11/16/2021] [Indexed: 12/05/2022]
Abstract
Marine cyanobacteria are key primary producers, contributing significantly to the microbial food web and biogeochemical cycles by releasing and importing many essential nutrients cycled through the environment. A subgroup of these, the picocyanobacteria (Synechococcus and Prochlorococcus), have colonised almost all marine ecosystems, covering a range of distinct light and temperature conditions, and nutrient profiles. The intra-clade diversities displayed by this monophyletic branch of cyanobacteria is indicative of their success across a broad range of environments. Part of this diversity is due to nutrient acquisition mechanisms, such as the use of high-affinity ATP-binding cassette (ABC) transporters to competitively acquire nutrients, particularly in oligotrophic (nutrient scarce) marine environments. The specificity of nutrient uptake in ABC transporters is primarily determined by the peripheral substrate-binding protein (SBP), a receptor protein that mediates ligand recognition and initiates translocation into the cell. The recent availability of large numbers of sequenced picocyanobacterial genomes indicates both Synechococcus and Prochlorococcus apportion >50% of their transport capacity to ABC transport systems. However, the low degree of sequence homology among the SBP family limits the reliability of functional assignments using sequence annotation and prediction tools. This review highlights the use of known SBP structural representatives for the uptake of key nutrient classes by cyanobacteria to compare with predicted SBP functionalities within sequenced marine picocyanobacteria genomes. This review shows the broad range of conserved biochemical functions of picocyanobacteria and the range of novel and hypothetical ABC transport systems that require further functional characterisation.
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Affiliation(s)
- Benjamin A. Ford
- Department of Molecular Sciences, Macquarie University, Sydney, Australia
| | | | - Lisa Moore
- Department of Molecular Sciences, Macquarie University, Sydney, Australia
| | - Deepa Varkey
- Department of Molecular Sciences, Macquarie University, Sydney, Australia
| | - Hannah Zhu
- Department of Molecular Sciences, Macquarie University, Sydney, Australia
| | - Martin Ostrowski
- Climate Change Cluster (C3), University of Technology Sydney, Sydney, Australia
| | - Bridget C. Mabbutt
- Department of Molecular Sciences, Macquarie University, Sydney, Australia
| | - Ian T. Paulsen
- Department of Molecular Sciences, Macquarie University, Sydney, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, Australia
| | - Bhumika S. Shah
- Department of Molecular Sciences, Macquarie University, Sydney, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, Australia
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Liu C, Xiao Y, Xiao Y, Li Z. Marine urease with higher thermostability, pH and salinity tolerance from marine sponge-derived Penicillium steckii S4-4. MARINE LIFE SCIENCE & TECHNOLOGY 2021; 3:77-84. [PMID: 37073394 PMCID: PMC10077270 DOI: 10.1007/s42995-020-00076-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 09/16/2020] [Indexed: 05/03/2023]
Abstract
Urease has a broad range of applications, however, the current studies on urease mainly focus on terrestrial plants or microbes. Thus, it is quite necessary to determine if marine-derived ureases have different characteristics from terrestrial origins since the finding of ureases with superior performance is of industrial interest. In this study, the marine urease produced by Penicillium steckii S4-4 derived from marine sponge Siphonochalina sp. was investigated. This marine urease exhibited a maximum specific activity of 1542.2 U mg protein-1. The molecular weight of the enzyme was 183 kDa and a single subunit of 47 kDa was detected, indicating that it was a tetramer. The N-terminal amino acid sequence of the urease was arranged as GPVLKKTKAAAV with greatest similarity to that from marine algae Ectocarpus siliculosus. This urease exhibited a K m of 7.3 mmol L-1 and a V max of 1.8 mmol urea min-1 mg protein-1. The optimum temperature, pH and salinity are 55 ℃, 8.5 and 10%, respectively. This urease was stable and more than 80% of its maximum specific activity was detected after incubating at 25-60 ℃ for 30 min, pH 5.5-10.0 or 0-25% salinity for 6 h. Compared with the terrestrial urease from Jack bean, this marine urease shows higher thermostability, alkaline preference and salinity tolerance, which extends the potential application fields of urease to a great extent.
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Affiliation(s)
- Changrong Liu
- Marine Biotechnology Laboratory, State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Yao Xiao
- Marine Biotechnology Laboratory, State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Yilin Xiao
- Marine Biotechnology Laboratory, State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
| | - Zhiyong Li
- Marine Biotechnology Laboratory, State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240 China
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5
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Zhang X, Zhao S, He Y, Zheng N, Yan X, Wang J. Pipeline for Targeted Meta-Proteomic Analyses to Assess the Diversity of Cattle Rumen Microbial Urease. Front Microbiol 2020; 11:573414. [PMID: 33072036 PMCID: PMC7531017 DOI: 10.3389/fmicb.2020.573414] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/21/2020] [Indexed: 01/01/2023] Open
Abstract
In the rumen of cattle, urease produced by ureolytic bacteria catalyzes the hydrolysis of urea to ammonia, which plays an important role in nitrogen metabolism and animal production. A high diversity of rumen bacterial urease genes was observed in our previous study; however, information on urease protein diversity could not be determined due to technical limitations. Here, we developed a targeted meta-proteomic pipeline to analyze rumen urease protein diversity. Protein extraction (duration of cryomilling in liquid nitrogen), protein digestion state (in-solution or in-gel), and the digestion enzyme used (trypsin or Glu-C/Lys-C) were optimized, and the digested peptides were analyzed by LC-MS/MS. Four minutes was the best duration for cryomilling and yielded the highest urease activity. Trypsin digestion of in-gel proteins outperformed other digestion methods and yielded the greatest number of identifications and superior peptide performance in regards to the digestion efficiency and high-score peptide. The annotation of peptides by PEAKS software revealed diversity among urease proteins, with the predominant proteins being from Prochlorococcus, Helicobacter, and uncultured bacteria. In conclusion, trypsin digestion of in-gel proteins was the optimal method for the meta-proteomic pipeline analyzing rumen microbial ureases. This pipeline provides a guide for targeted meta-proteomic analyses in other ecosystems.
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Affiliation(s)
- Xiaoyin Zhang
- College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shengguo Zhao
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yue He
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Nan Zheng
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xianghua Yan
- College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jiaqi Wang
- College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
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Muñoz-Marín MDC, Gómez-Baena G, Díez J, Beynon RJ, González-Ballester D, Zubkov MV, García-Fernández JM. Glucose Uptake in Prochlorococcus: Diversity of Kinetics and Effects on the Metabolism. Front Microbiol 2017; 8:327. [PMID: 28337178 PMCID: PMC5340979 DOI: 10.3389/fmicb.2017.00327] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 02/16/2017] [Indexed: 12/30/2022] Open
Abstract
We have previously shown that Prochlorococcus sp. SS120 strain takes up glucose by using a multiphasic transporter encoded by the Pro1404 gene. Here, we studied the glucose uptake kinetics in multiple Prochlorococcus strains from different ecotypes, observing diverse values for the Ks constants (15–126.60 nM) and the uptake rates (0.48–6.36 pmol min-1 mg prot-1). Multiphasic kinetics was observed in all studied strains, except for TAK9803-2. Pro1404 gene expression studies during the 21st Atlantic Meridional Transect cruise showed positive correlation with glucose concentrations in the ocean. This suggests that the Pro1404 transporter has been subjected to diversification along the Prochlorococcus evolution, in a process probably driven by the glucose availabilities at the different niches it inhabits. The glucose uptake mechanism seems to be a primary transporter. Glucose addition induced detectable transcriptomic and proteomic changes in Prochlorococcus SS120, but photosynthetic efficiency was unaffected. Our studies indicate that glucose is actively taken up by Prochlorococcus, but its uptake does not significantly alter the trophic ways of this cyanobacterium, which continues performing photosynthesis. Therefore Prochlorococcus seems to remain acting as a fundamentally phototrophic organism, capable of using glucose as an extra resource of carbon and energy when available in the environment.
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Affiliation(s)
- María Del Carmen Muñoz-Marín
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario, Universidad de Córdoba Córdoba, Spain
| | - Guadalupe Gómez-Baena
- Centre for Proteome Research, Institute of Integrative Biology, University of Liverpool Liverpool, UK
| | - Jesús Díez
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario, Universidad de Córdoba Córdoba, Spain
| | - Robert J Beynon
- Centre for Proteome Research, Institute of Integrative Biology, University of Liverpool Liverpool, UK
| | - David González-Ballester
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario, Universidad de Córdoba Córdoba, Spain
| | | | - José M García-Fernández
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario, Universidad de Córdoba Córdoba, Spain
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7
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Konieczna I, Zarnowiec P, Kwinkowski M, Kolesinska B, Fraczyk J, Kaminski Z, Kaca W. Bacterial urease and its role in long-lasting human diseases. Curr Protein Pept Sci 2013; 13:789-806. [PMID: 23305365 PMCID: PMC3816311 DOI: 10.2174/138920312804871094] [Citation(s) in RCA: 144] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 07/15/2012] [Accepted: 09/03/2012] [Indexed: 02/07/2023]
Abstract
Urease is a virulence factor found in various pathogenic bacteria. It is essential in colonization of a host organism and in maintenance of bacterial cells in tissues. Due to its enzymatic activity, urease has a toxic effect on human cells. The presence of ureolytic activity is an important marker of a number of bacterial infections. Urease is also an immunogenic protein and is recognized by antibodies present in human sera. The presence of such antibodies is connected with progress of several long-lasting diseases, like rheumatoid arthritis, atherosclerosis or urinary tract infections. In bacterial ureases, motives with a sequence and/or structure similar to human proteins may occur. This phenomenon, known as molecular mimicry, leads to the appearance of autoantibodies, which take part in host molecules destruction. Detection of antibodies-binding motives (epitopes) in bacterial proteins is a complex process. However, organic chemistry tools, such as synthetic peptide libraries, are helpful in both, epitope mapping as well as in serologic investigations. In this review, we present a synthetic report on a molecular organization of bacterial ureases - genetic as well as structural. We characterize methods used in detecting urease and ureolytic activity, including techniques applied in disease diagnostic processes and in chemical synthesis of urease epitopes. The review also provides a summary of knowledge about a toxic effect of bacterial ureases on human body and about occurrence of anti-urease antibodies in long-lasting diseases.
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Affiliation(s)
- Iwona Konieczna
- Department of Microbiology, Institute of Biology, The Jan Kochanowski University, ul. Swietokrzyska 15, 25-406 Kielce, Poland.
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8
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Mackey KRM, Buck KN, Casey JR, Cid A, Lomas MW, Sohrin Y, Paytan A. Phytoplankton responses to atmospheric metal deposition in the coastal and open-ocean Sargasso Sea. Front Microbiol 2012; 3:359. [PMID: 23181057 PMCID: PMC3470407 DOI: 10.3389/fmicb.2012.00359] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 09/20/2012] [Indexed: 11/22/2022] Open
Abstract
This study investigated the impact of atmospheric metal deposition on natural phytoplankton communities at open-ocean and coastal sites in the Sargasso Sea during the spring bloom. Locally collected aerosols with different metal contents were added to natural phytoplankton assemblages from each site, and changes in nitrate, dissolved metal concentration, and phytoplankton abundance and carbon content were monitored. Addition of aerosol doubled the concentrations of cadmium (Cd), cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), and nickel (Ni) in the incubation water. Over the 3-day experiments, greater drawdown of dissolved metals occurred in the open ocean water, whereas little metal drawdown occurred in the coastal water. Two populations of picoeukaryotic algae and Synechococcus grew in response to aerosol additions in both experiments. Particulate organic carbon increased and was most sensitive to changes in picoeukaryote abundance. Phytoplankton community composition differed depending on the chemistry of the aerosol added. Enrichment with aerosol that had higher metal content led to a 10-fold increase in Synechococcus abundance in the oceanic experiment but not in the coastal experiment. Enrichment of aerosol-derived Co, Mn, and Ni were particularly enhanced in the oceanic experiment, suggesting the Synechococcus population may have been fertilized by these aerosol metals. Cu-binding ligand concentrations were in excess of dissolved Cu in both experiments, and increased with aerosol additions. Bioavailable free hydrated Cu(2+) concentrations were below toxicity thresholds throughout both experiments. These experiments show (1) atmospheric deposition contributes biologically important metals to seawater, (2) these metals are consumed over time scales commensurate with cell growth, and (3) growth responses can differ between distinct Synechococcus or eukaryotic algal populations despite their relatively close geographic proximity and taxonomic similarity.
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Affiliation(s)
- Katherine R. M. Mackey
- Institute for Marine Science, University of California at Santa CruzSanta Cruz, CA, USA
- Woods Hole Oceanographic InstitutionWoods Hole, MA, USA
- Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological LaboratoryWoods Hole, MA, USA
| | | | - John R. Casey
- Bermuda Institute of Ocean Sciences, St George’sBermuda
- University of Hawaii at ManoaHonolulu, HI, USA
| | - Abigail Cid
- Institute for Chemical Research, Kyoto University, UjiKyoto, Japan
| | | | - Yoshiki Sohrin
- Institute for Chemical Research, Kyoto University, UjiKyoto, Japan
| | - Adina Paytan
- Institute for Marine Science, University of California at Santa CruzSanta Cruz, CA, USA
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Scanlan DJ, West NJ. Molecular ecology of the marine cyanobacterial genera Prochlorococcus and Synechococcus. FEMS Microbiol Ecol 2012; 40:1-12. [PMID: 19709205 DOI: 10.1111/j.1574-6941.2002.tb00930.x] [Citation(s) in RCA: 170] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Oxygenic photoautotrophs of the genera Synechococcus and Prochlorococcus contribute significantly to primary production and are now widely accepted as the most abundant members of the picophytoplankton in the world's oceans. Since they represent one of the few cultured and representative groups of marine microorganisms, study of their physiology and biochemistry has progressed rapidly since their discovery. The recent and on-going sequencing of the complete genomes of representative strains will further hasten our understanding, and allow a complete interrogation, of the metabolism of these organisms. Moreover, since they inhabit a relatively simple environment they provide an excellent model system to begin to identify the underlying molecular mechanisms which allow their success in water columns with large vertical gradients of light and nutrients. Such work should provide novel insights into the genetic adaptations of these important marine microbes to their environment. We review here molecular ecological methods that are already available or which are currently being developed for these organisms. Such methods allow community structure, growth rate and nutrient status analysis, potentially at the single cell level, and can be used to define the niches, or identify the biotic or abiotic factors, which might control the productivity of specific genotypes. These techniques will undoubtedly provide the tools for answering more discerning questions concerning their ecology. How the complete genome sequence information is providing insights, and can further facilitate our understanding, of the ecology of these organisms is also discussed.
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Affiliation(s)
- David J Scanlan
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.
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10
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López-Lozano A, Diez J, Alaoui S, Moreno-Vivián C, García-Fernández JM. Nitrate is reduced by heterotrophic bacteria but not transferred to Prochlorococcus in non-axenic cultures. FEMS Microbiol Ecol 2012; 41:151-60. [PMID: 19709249 DOI: 10.1111/j.1574-6941.2002.tb00976.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Abstract The ability to assimilate nitrate in non-axenic isolates of Prochlorococcus spp. was addressed in this work, particularly in three low-irradiance adapted strains originating from ocean depths with measurable nitrate concentrations. None of the studied strains was able to use nitrate as the sole nitrogen source. Nitrate reductase (NR; EC 1.6.6.2) activity was, however, detected using the methyl viologen/dithionite assay in crude extracts from all studied Prochlorococcus strains. Characterization of this activity unambiguously demonstrated its enzymatic origin. We observed that NR activity did not decrease in vivo under darkness. Attempts to detect the narB gene (coding for NR in other cyanobacteria) by PCR with primers designed on the basis of the specific codon usage in Prochlorococcus were unsuccessful. However, when primers were designed considering the codon frequencies typical of other bacteria, we could amplify different fragments of nas genes, coding for bacterial assimilatory NRs. Similar amplification products were obtained using colonies of contaminant bacteria from Prochlorococcus cultures as PCR template. Furthermore, NR activity was found in cultures of these contaminants, demonstrating the non-cyanobacterial origin of the enzyme. These results strongly suggest that the studied strains of Prochlorococcus lack NR, in spite of inhabiting environments with nitrate as the main nitrogen source. In addition, they indicate that the nitrite produced by heterotrophic bacteria is not transferred to Prochlorococcus for growth, thus discarding a trophic nitrogen chain between heterotrophic bacteria and Prochlorococcus in the studied cultures.
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Affiliation(s)
- Antonio López-Lozano
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, 1 planta, Campus de Rabanales, Universidad de Córdoba, E-14071 Córdoba, Spain
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11
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Collier JL, Baker KM, Bell SL. Diversity of urea-degrading microorganisms in open-ocean and estuarine planktonic communities. Environ Microbiol 2009; 11:3118-31. [PMID: 19659552 DOI: 10.1111/j.1462-2920.2009.02016.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Urea is an important and dynamic natural component of marine nitrogen cycling and also a major contributor to anthropogenic eutrophication of coastal ecosystems, yet little is known about the identities or diversity of ureolytic marine microorganisms. Primers targeting the gene encoding urease were used to PCR-amplify, clone and sequence 709 urease gene fragments from 31 plankton samples collected at both estuarine and open-ocean locations. Two hundred and eighty-six amplicons belonged to 22 distinct sequence types that were closely enough related to named organisms to be identified, and included urease sequences both from typical marine planktonic organisms and from bacteria usually associated with terrestrial habitats. The remaining 423 amplicons were not closely enough related to named organisms to be identified, and belonged to 96 distinct sequence types of which 43 types were found in two or more different samples. The distributions of unidentified urease sequence types suggested that some represented truly marine microorganisms while others reflected terrestrial inputs to low-salinity estuarine areas. The urease primers revealed this great diversity of ureolytic organisms because they were able to amplify many previously unknown, environmentally relevant urease genes, and they will support new approaches for exploring the role of urea in marine ecosystems.
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Affiliation(s)
- Jackie L Collier
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000, USA.
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12
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Scanlan DJ, Ostrowski M, Mazard S, Dufresne A, Garczarek L, Hess WR, Post AF, Hagemann M, Paulsen I, Partensky F. Ecological genomics of marine picocyanobacteria. Microbiol Mol Biol Rev 2009; 73:249-99. [PMID: 19487728 PMCID: PMC2698417 DOI: 10.1128/mmbr.00035-08] [Citation(s) in RCA: 446] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Marine picocyanobacteria of the genera Prochlorococcus and Synechococcus numerically dominate the picophytoplankton of the world ocean, making a key contribution to global primary production. Prochlorococcus was isolated around 20 years ago and is probably the most abundant photosynthetic organism on Earth. The genus comprises specific ecotypes which are phylogenetically distinct and differ markedly in their photophysiology, allowing growth over a broad range of light and nutrient conditions within the 45 degrees N to 40 degrees S latitudinal belt that they occupy. Synechococcus and Prochlorococcus are closely related, together forming a discrete picophytoplankton clade, but are distinguishable by their possession of dissimilar light-harvesting apparatuses and differences in cell size and elemental composition. Synechococcus strains have a ubiquitous oceanic distribution compared to that of Prochlorococcus strains and are characterized by phylogenetically discrete lineages with a wide range of pigmentation. In this review, we put our current knowledge of marine picocyanobacterial genomics into an environmental context and present previously unpublished genomic information arising from extensive genomic comparisons in order to provide insights into the adaptations of these marine microbes to their environment and how they are reflected at the genomic level.
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Affiliation(s)
- D J Scanlan
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom.
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13
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Glass JB, Wolfe-Simon F, Anbar AD. Coevolution of metal availability and nitrogen assimilation in cyanobacteria and algae. GEOBIOLOGY 2009; 7:100-23. [PMID: 19320747 DOI: 10.1111/j.1472-4669.2009.00190.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Marine primary producers adapted over eons to the changing chemistry of the oceans. Because a number of metalloenzymes are necessary for N assimilation, changes in the availability of transition metals posed a particular challenge to the supply of this critical nutrient that regulates marine biomass and productivity. Integrating recently developed geochemical, biochemical, and genetic evidence, we infer that the use of metals in N assimilation - particularly Fe and Mo - can be understood in terms of the history of metal availability through time. Anoxic, Fe-rich Archean oceans were conducive to the evolution of Fe-using enzymes that assimilate abiogenic NH(4)(+) and NO(2)(-). The N demands of an expanding biosphere were satisfied by the evolution of biological N(2) fixation, possibly utilizing only Fe. Trace O(2) in late Archean environments, and the eventual 'Great Oxidation Event' c. 2.3 Ga, mobilized metals such as Mo, enabling the evolution of Mo (or V)-based N(2) fixation and the Mo-dependent enzymes for NO(3)(-) assimilation and denitrification by prokaryotes. However, the subsequent onset of deep-sea euxinia, an increasingly-accepted idea, may have kept ocean Mo inventories low and depressed Fe, limiting the rate of N(2) fixation and the supply of fixed N. Eukaryotic ecosystems may have been particularly disadvantaged by N scarcity and the high Mo requirement of eukaryotic NO(3)(-) assimilation. Thorough ocean oxygenation in the Neoproterozoic led to Mo-rich oceans, possibly contributing to the proliferation of eukaryotes and thus the Cambrian explosion of metazoan life. These ideas can be tested by more intensive study of the metal requirements in N assimilation and the biological strategies for metal uptake, regulation, and storage.
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Affiliation(s)
- J B Glass
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, USA.
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14
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Glibert PM, Azanza R, Burford M, Furuya K, Abal E, Al-Azri A, Al-Yamani F, Andersen P, Beardall J, Berg GM, Brand L, Bronk D, Brookes J, Burkholder JM, Cembella A, Cochlan WP, Collier J, Collos Y, Diaz R, Doblin M, Drennen T, Dyhrman S, Fukuyo Y, Furnas M, Galloway J, Granéli E, Ha DV, Hallegraeff G, Harrison J, Harrison PJ, Heil CA, Heimann K, Howarth R, Jauzein C, Kana AA, Kana TM, Kim H, Kudela R, Legrand C, Mallin M, Mulholland M, Murray S, O’Neil J, Pitcher G, Qi Y, Rabalais N, Raine R, Seitzinger S, Solomon C, Stoecker DK, Usup G, Wilson J, Yin K, Zhou M, Zhu M. Ocean urea fertilization for carbon credits poses high ecological risks. MARINE POLLUTION BULLETIN 2008; 56:1049-56. [PMID: 18439628 PMCID: PMC5373553 DOI: 10.1016/j.marpolbul.2008.03.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Accepted: 03/02/2008] [Indexed: 05/12/2023]
Abstract
The proposed plan for enrichment of the Sulu Sea, Philippines, a region of rich marine biodiversity, with thousands of tonnes of urea in order to stimulate algal blooms and sequester carbon is flawed for multiple reasons. Urea is preferentially used as a nitrogen source by some cyanobacteria and dinoflagellates, many of which are neutrally or positively buoyant. Biological pumps to the deep sea are classically leaky, and the inefficient burial of new biomass makes the estimation of a net loss of carbon from the atmosphere questionable at best. The potential for growth of toxic dinoflagellates is also high, as many grow well on urea and some even increase their toxicity when grown on urea. Many toxic dinoflagellates form cysts which can settle to the sediment and germinate in subsequent years, forming new blooms even without further fertilization. If large-scale blooms do occur, it is likely that they will contribute to hypoxia in the bottom waters upon decomposition. Lastly, urea production requires fossil fuel usage, further limiting the potential for net carbon sequestration. The environmental and economic impacts are potentially great and need to be rigorously assessed.
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Affiliation(s)
- Patricia M. Glibert
- University of Maryland Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge MD 21613, USA; ; ; ;
- Corresponding author:; 410-221-8422 (office); 410-221-8490 (fax)
| | - Rhodora Azanza
- The Marine Science Institute, Velasquez, University of the Philippines, Diliman, Quezon City, Philippines;
| | - Michele Burford
- Griffith University, Australian Rivers Institute, Kessel Rd., Nathan Queensland 4111, Australia; ;
| | - Ken Furuya
- Department of Aquatic Bioscience, the University of Tokyo, Yayoi, Bunkyo, Tokyo 113-8657, Japan;
| | - Eva Abal
- South East Queensland Healthy Waterways Partnership, 239 George Street, GPO Box 1434, Brisbane Queensland 4001, Australia;
| | - Adnan Al-Azri
- Dept. of Marine Sciences and Fisheries, Sultan Qaboos University, P.O.Box 34, Al-Khodh, PC123 Muscat, Oman;
| | - Faiza Al-Yamani
- Kuwait Institute for Scientific Research, P.O Box 24885 Safat 13109, Kuwait;
| | - Per Andersen
- Orbicon A/S, Jens Juuls Vej 18, 8260, Viby J., Denmark;
| | - John Beardall
- School of Biological Sciences, Monash University, Clayton Victoria 3800, Australia;
| | - G. Mine Berg
- Department of Geophysics, Stanford University, Stanford, CA 94305, USA;
| | - Larry Brand
- Division of Marine Biology and Fisheries, Rosentiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA;
| | - Deborah Bronk
- Virginia Institute of Marine Science, P.O. Box 1346, Gloucester Point, VA 23062 USA; ;
| | - Justin Brookes
- Water Research Cluster, The University of Adelaide, Adelaide South Australia 5005, Australia;
| | - JoAnn M. Burkholder
- Center for Applied Aquatic Ecology, North Carolina State University, Raleigh, NC 27695 USA;
| | - Allan Cembella
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany;
| | - William P. Cochlan
- Romberg Tiburon Center for Environmental Studies, San Francisco State University, San Francisco, CA 94920, USA;
| | - Jackie Collier
- Marine Sciences Research Center, SUNY Stony Brook, Stony Brook, NY 11794, USA;
| | - Yves Collos
- Université Montpellier 2, CNRS, Ifremer, Laboratoire Ecosystèmes Lagunaires (UMR 5119) CC093, 34095 Montpellier Cedex 5, France; ;
| | - Robert Diaz
- Virginia Institute of Marine Science, P.O. Box 1346, Gloucester Point, VA 23062 USA; ;
| | - Martina Doblin
- Department of Environmental Sciences, University of Technology Sydney, P.O. Box 123, Broadway NSW 2007, Australia;
| | - Thomas Drennen
- Departments of Economics and Environmental Studies, Hobart and William Smith Colleges, Geneva NY 14456, USA; ;
| | - Sonya Dyhrman
- Biology Department MS#33, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA;
| | - Yasuwo Fukuyo
- Asian Natural Environmental Science Center, the University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan;
| | - Miles Furnas
- Water Quality and Ecosystem Health Team, Australian Institute of Marine Science PMB No. 3, Townsville MC, Queensland 4810, Australia;
| | - James Galloway
- Environmental Sciences Department, Clark Hall, University of Virginia, Charlottesville, 22903 VA, USA;
| | - Edna Granéli
- Department of Marine Sciences, University of Kalmar, 39182 Kalmar, Sweden; ;
| | - Dao Viet Ha
- Institute of Oceanography, Cauda 01, Vinh Nguyen, Nhatrang City, Vietnam;
| | - Gustaaf Hallegraeff
- School of Plant Science,University of Tasmania, Private Bag 55, Hobart Tasmania 7001, Australia;
| | - John Harrison
- School of Earth and Environmental Sciences, Washington State University, Vancouver Campus, 14204 NE Salmon Creek Avenue, Vancouver, WA 98686, USA;
| | - Paul J. Harrison
- Atmospheric, Marine and Coastal Environment Program, Hong Kong University of Science and Technology, Kowloon, Hong Kong, China;
| | - Cynthia A. Heil
- Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, 100 Eighth Ave., S., St. Petersburg, FL 33701 USA;
| | - Kirsten Heimann
- School of Marine and Tropical Biology, James Cook University, Townsville Queensland 4811, Australia;
| | - Robert Howarth
- Department of Ecology and Evolutionary Biology, Cornell University, E311 Corson Hall, Ithaca NY 14853, USA;
| | - Cécile Jauzein
- Université Montpellier 2, CNRS, Ifremer, Laboratoire Ecosystèmes Lagunaires (UMR 5119) CC093, 34095 Montpellier Cedex 5, France; ;
| | - Austin A. Kana
- Departments of Economics and Environmental Studies, Hobart and William Smith Colleges, Geneva NY 14456, USA; ;
| | - Todd M. Kana
- University of Maryland Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge MD 21613, USA; ; ; ;
| | - Hakgyoon Kim
- Pukyong National University, Department of Ocean Science, 599-1 Daeyon-Dong, Nam-gu, Busan, Korea;
| | - Raphael Kudela
- Ocean Sciences and Institute for Marine Sciences, University of California Santa Cruz, 1156 High St., Santa Cruz, CA 95064, USA;
| | - Catherine Legrand
- Department of Marine Sciences, University of Kalmar, 39182 Kalmar, Sweden; ;
| | - Michael Mallin
- Center for Marine Science, University of North Carolina Wilmington, 5600 Marvin K. Moss Lane, Wilmington, N.C. 28409;
| | - Margaret Mulholland
- Department of Ocean, Earth and Atmospheric Sciences, Old Dominion University, 4600 Elkhorn Avenue, Norfolk, VA 23529, USA;
| | - Shauna Murray
- School of Biological Sciences A08, University of Sydney, Sydney NSW 2006, Australia;
| | - Judith O’Neil
- University of Maryland Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge MD 21613, USA; ; ; ;
| | - Grant Pitcher
- Marine and Coastal Management, Private Bag X2, Rogge Bay 8012, Cape Town, South Africa;
| | - Yuzao Qi
- Jinan University, Research Center for Harmful Algae and Aquatic Environment, 510632, Guanzhou, P.R. China;
| | - Nancy Rabalais
- Louisiana Universities Marine Consortium, Chauvin, LA 70344, USA;
| | - Robin Raine
- Martin Ryan Institute, National University of Ireland, Galway, Ireland;
| | - Sybil Seitzinger
- Institute of Marine and Coastal Sciences, Rutgers, The State University of New Jersey, Rutgers/NOAA CMER, 71 Dudley Road, New Brunswick, NJ 08901, USA;
| | - Caroline Solomon
- Department of Biology, Gallaudet University, 800 Florida Ave, NE, Washington D.C. 20002, USA;
| | - Diane K. Stoecker
- University of Maryland Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge MD 21613, USA; ; ; ;
| | - Gires Usup
- Faculty of Science and Technology, Universitii Kebagsaan Malaysia, Bangi, Selangor, Malaysia;
| | - Joanne Wilson
- Coral Triangle Centre, The Nature Conservancy, Jl Pengembak 2, Sanur, 80228, Bali, Indonesia;
| | - Kedong Yin
- Griffith University, Australian Rivers Institute, Kessel Rd., Nathan Queensland 4111, Australia; ;
| | - Mingjiang Zhou
- Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, P.R. China;
| | - Mingyuan Zhu
- First Institute of Oceanography, 6 Xianxialing Road, High-tech Industrial Park, 266061 Qingdao, P.R. China;
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15
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Tolonen AC, Aach J, Lindell D, Johnson ZI, Rector T, Steen R, Church GM, Chisholm SW. Global gene expression of Prochlorococcus ecotypes in response to changes in nitrogen availability. Mol Syst Biol 2006; 2:53. [PMID: 17016519 PMCID: PMC1682016 DOI: 10.1038/msb4100087] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2006] [Accepted: 07/03/2006] [Indexed: 11/08/2022] Open
Abstract
Nitrogen (N) often limits biological productivity in the oceanic gyres where Prochlorococcus is the most abundant photosynthetic organism. The Prochlorococcus community is composed of strains, such as MED4 and MIT9313, that have different N utilization capabilities and that belong to ecotypes with different depth distributions. An interstrain comparison of how Prochlorococcus responds to changes in ambient nitrogen is thus central to understanding its ecology. We quantified changes in MED4 and MIT9313 global mRNA expression, chlorophyll fluorescence, and photosystem II photochemical efficiency (Fv/Fm) along a time series of increasing N starvation. In addition, the global expression of both strains growing in ammonium-replete medium was compared to expression during growth on alternative N sources. There were interstrain similarities in N regulation such as the activation of a putative NtcA regulon during N stress. There were also important differences between the strains such as in the expression patterns of carbon metabolism genes, suggesting that the two strains integrate N and C metabolism in fundamentally different ways.
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Affiliation(s)
- Andrew C Tolonen
- Department of Biology, MIT/WHOI Joint Program in Oceanography, Cambridge, MA, USA
| | - John Aach
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Debbie Lindell
- Department of Civil and Environmental Engineering, MIT, Cambridge, MA, USA
| | | | - Trent Rector
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Robert Steen
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - George M Church
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Sallie W Chisholm
- Department of Civil and Environmental Engineering, MIT, Cambridge, MA, USA
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16
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. NSG. Purification and Characterization of Intracellular Urease Enzyme Isolated from Rhizopus oryzae. ACTA ACUST UNITED AC 2006. [DOI: 10.3923/biotech.2006.358.364] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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17
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Osanai T, Sato S, Tabata S, Tanaka K. Identification of PamA as a PII-binding membrane protein important in nitrogen-related and sugar-catabolic gene expression in Synechocystis sp. PCC 6803. J Biol Chem 2005; 280:34684-90. [PMID: 16109709 DOI: 10.1074/jbc.m507489200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The PII signaling protein plays a pivotal role in the coordination of carbon and nitrogen metabolism in a wide variety of bacteria, Archaea, and plant chloroplasts. By using a yeast two-hybrid screening system, we identified a transmembrane protein, designated PamA (encoded by sll0985), as a PII-binding protein in Synechocystis sp. PCC 6803. The interaction between PII and PamA was confirmed in vitro, and the interaction was inhibited in the presence of ATP and 2-oxoglutarate, whereas the interaction was not influenced by the phosphorylation status of PII. Northern blot analyses revealed that the transcripts of a set of nitrogen-related genes, including nblA, nrtABCD, and ureG, were decreased in a pamA deletion mutant. The mRNA and protein levels of a group 2 sigma factor SigE were also reduced by the pamA mutation, and transcripts for sugar catabolic genes, such as gap1, zwf, and gnd that are under the control of SigE, were consequently decreased in the pamA mutant. In addition, the pamA mutant was found to be unable to grow in glucose-containing media. These results indicate that PamA has a role in the transcript control of genes for nitrogen and sugar metabolism in Synechocystis sp. PCC 6803.
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Affiliation(s)
- Takashi Osanai
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
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18
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García-Fernández JM, de Marsac NT, Diez J. Streamlined regulation and gene loss as adaptive mechanisms in Prochlorococcus for optimized nitrogen utilization in oligotrophic environments. Microbiol Mol Biol Rev 2005; 68:630-8. [PMID: 15590777 PMCID: PMC539009 DOI: 10.1128/mmbr.68.4.630-638.2004] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Prochlorococcus is one of the dominant cyanobacteria and a key primary producer in oligotrophic intertropical oceans. Here we present an overview of the pathways of nitrogen assimilation in Prochlorococcus, which have been significantly modified in these microorganisms for adaptation to the natural limitations of their habitats, leading to the appearance of different ecotypes lacking key enzymes, such as nitrate reductase, nitrite reductase, or urease, and to the simplification of the metabolic regulation systems. The only nitrogen source utilizable by all studied isolates is ammonia, which is incorporated into glutamate by glutamine synthetase. However, this enzyme shows unusual regulatory features, although its structural and kinetic features are unchanged. Similarly, urease activities remain fairly constant under different conditions. The signal transduction protein P(II) is apparently not phosphorylated in Prochlorococcus, despite its conserved amino acid sequence. The genes amt1 and ntcA (coding for an ammonium transporter and a global nitrogen regulator, respectively) show noncorrelated expression in Prochlorococcus under nitrogen stress; furthermore, high rates of organic nitrogen uptake have been observed. All of these unusual features could provide a physiological basis for the predominance of Prochlorococcus over Synechococcus in oligotrophic oceans.
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Affiliation(s)
- Jose Manuel García-Fernández
- Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba, Edificio Severo Ochoa, Planta 1, Campus de Rabanales, 14071-Córdoba, Spain.
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19
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El Alaoui S, Diez J, Toribio F, Gómez-Baena G, Dufresne A, García-Fernández JM. Glutamine synthetase from the marine cyanobacteria Prochlorococcus spp: characterization, phylogeny and response to nutrient limitation. Environ Microbiol 2003; 5:412-23. [PMID: 12713467 DOI: 10.1046/j.1462-2920.2003.00433.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The regulation of glutamine synthetase (EC 6.3.1.2) from Prochlorococcus was previously shown to exhibit unusual features: it is not upregulated by nitrogen starvation and it is not inactivated by darkness (El Alaoui et al. (2001) Appl Environ Microbiol 67: 2202-2207). These are probably caused by adaptations to oligotrophic environments, as confirmed in this work by the marked decrease in the enzymatic activity when cultures were subjected to iron or phosphorus starvation. In order to further understand the adaptive features of ammonium assimilation in this cyanobacterium, glutamine synthetase was purified from two Prochlorococcus strains: PCC 9511 (high-light adapted) and SS120 (low-light adapted). We obtained approximately 100-fold purified samples of glutamine synthetase electrophoretically homogeneous, with a yield of approximately 30%. The estimated molecular mass of the subunits was roughly the same for both strains: 48.3 kDa. The apparent Km constants for the biosynthetic activity were 0.30 mM for ammonium, 1.29 mM for glutamate and 1.35 mM for ATP; the optimum pH was 8.0. Optimal temperature was surprisingly high (55 degrees C). Phylogenetic analysis of glnA from three Prochlorococcus strains (MED4, MIT9313 and SS120) showed they group closely with marine Synechococcus isolates, in good agreement with other studies based on 16 S RNA sequences. All of our results suggest that the structure and kinetics of glutamine synthetase in Prochlorococcus have not been significantly modified during the evolution within the cyanobacterial radiation, in sharp contrast with its regulatory properties.
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Affiliation(s)
- Sabah El Alaoui
- Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba, Edificio Severo Ochoa, planta 1, Campus de Rabanales, 14071-Córdoba, Spain
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20
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Palinska KA, Laloui W, Bédu S, Loiseaux-de Goer S, Castets AM, Rippka R, Tandeau de Marsac N. The signal transducer P(II) and bicarbonate acquisition in Prochlorococcus marinus PCC 9511, a marine cyanobacterium naturally deficient in nitrate and nitrite assimilation. MICROBIOLOGY (READING, ENGLAND) 2002; 148:2405-2412. [PMID: 12177334 DOI: 10.1099/00221287-148-8-2405] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The amino acid sequence of the signal transducer P(II) (GlnB) of the oceanic photosynthetic prokaryote Prochlorococcus marinus strain PCC 9511 displays a typical cyanobacterial signature and is phylogenetically related to all known cyanobacterial glnB genes, but forms a distinct subclade with two other marine cyanobacteria. P(II) of P. marinus was not phosphorylated under the conditions tested, despite its highly conserved primary amino acid sequence, including the seryl residue at position 49, the site for the phosphorylation of the protein in the cyanobacterium Synechococcus PCC 7942. Moreover, P. marinus lacks nitrate and nitrite reductase activities and does not take up nitrate and nitrite. This strain, however, expresses a low- and a high-affinity transport system for inorganic carbon (C(i); K(m,app) 240 and 4 micro M, respectively), a result consistent with the unphosphorylated form of P(II) acting as a sensor for the control of C(i) acquisition, as proposed for the cyanobacterium Synechocystis PCC 6803. The present data are discussed in relation to the genetic information provided by the P. marinus MED4 genome sequence.
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Affiliation(s)
- Katarzyna A Palinska
- Unité; des Cyanobacté;ries, CNRS URA 2172, Département de Microbiologie Fondamentale et Mé;dicale, Institut Pasteur, 28 Rue du Docteur Roux, 75724 Paris Cedex 15, France1
| | - Wassila Laloui
- Unité; des Cyanobacté;ries, CNRS URA 2172, Département de Microbiologie Fondamentale et Mé;dicale, Institut Pasteur, 28 Rue du Docteur Roux, 75724 Paris Cedex 15, France1
| | - Sylvie Bédu
- Laboratoire de Chimie Bacté;rienne, CNRS, 31 chemin Joseph Aiguier, BP71 13277, Marseille Cedex 9, France2
| | | | - Anne Marie Castets
- Unité; des Cyanobacté;ries, CNRS URA 2172, Département de Microbiologie Fondamentale et Mé;dicale, Institut Pasteur, 28 Rue du Docteur Roux, 75724 Paris Cedex 15, France1
| | - Rosmarie Rippka
- Unité; des Cyanobacté;ries, CNRS URA 2172, Département de Microbiologie Fondamentale et Mé;dicale, Institut Pasteur, 28 Rue du Docteur Roux, 75724 Paris Cedex 15, France1
| | - Nicole Tandeau de Marsac
- Unité; des Cyanobacté;ries, CNRS URA 2172, Département de Microbiologie Fondamentale et Mé;dicale, Institut Pasteur, 28 Rue du Docteur Roux, 75724 Paris Cedex 15, France1
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21
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Valladares A, Montesinos ML, Herrero A, Flores E. An ABC-type, high-affinity urea permease identified in cyanobacteria. Mol Microbiol 2002; 43:703-15. [PMID: 11929526 DOI: 10.1046/j.1365-2958.2002.02778.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Urea is an important nitrogen source for many microorganisms, but urea active transporters have not been characterized at a molecular level in any bacterium. Cells of Synechocystis sp. PCC 6803 and Anabaena sp. PCC 7120 exhibited the capacity to take up [14C]-urea from low-concentration (<1 microM) urea solutions. The Ks of Anabaena cells for urea was about 0.11 microM, and the observed uptake activity involved the transport and metabolism of urea. In contrast to urease, which was constitutively ex-pressed, expression of the high-affinity urea uptake activity was subjected to nitrogen control. In an Anabaena ureG (urease-) mutant, a concentrative, active transport of urea could be demonstrated. We found that a mutant of open reading frame (ORF) sll0374 from the Synechocystis genomic sequence lacked urea transport activity. This ORF encoded a conserved component of an ABC-type transporter, but it is not clustered together with any other possible transporter-encoding gene. An Anabaena homologue of sll0374, urtE, was isolated and found to be part of a cluster of genes, urtABCDE, putatively encoding all the elements of an ABC-type permease. Although the longest transcript that we could detect only covered urtABC, the impairment of urea transport by inactivation of urtA, urtB or urtE suggested that the whole gene cluster is expressed producing the urea permease. Expression was induced under nitrogen-limiting conditions, and a complex promoter regulated by the cyanobacterial global nitrogen control transcription factor NtcA was found upstream from urtA. Our work adds urea to the known substrates of the versatile class of ABC-type transporters and suggests the involvement of a transporter of this superfamily in urea scavenging by some bacteria in natural environments.
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Affiliation(s)
- Ana Valladares
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas, Universidad de Sevilla, Avda Américo Vespucio s/n, E-41092 Sevilla, Spain
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22
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Berg GM, Repeta DJ, Laroche J. Dissolved organic nitrogen hydrolysis rates in axenic cultures of Aureococcus anophagefferens (Pelagophyceae): comparison with heterotrophic bacteria. Appl Environ Microbiol 2002; 68:401-4. [PMID: 11772651 PMCID: PMC126575 DOI: 10.1128/aem.68.1.401-404.2002] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2001] [Accepted: 10/15/2001] [Indexed: 11/20/2022] Open
Abstract
The marine autotroph Aureococcus anophagefferens (Pelagophyceae) was rendered axenic in order to investigate hydrolysis rates of peptides, chitobiose, acetamide, and urea as indicators of the ability to support growth on dissolved organic nitrogen. Specific rates of hydrolysis varied between 8 and 700% of rates observed in associated heterotrophic marine bacteria.
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Affiliation(s)
- Gry Mine Berg
- Department of Marine Biogeochemistry, Institut für Meereskunde an der Universität Kiel, Kiel, Germany.
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23
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Gómez-Baena G, Diez J, García-Fernández JM, El Alaoui S, Humanes L. Regulation of glutamine synthetase by metal-catalyzed oxidative modification in the marine oxyphotobacterium Prochlorococcus. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1568:237-44. [PMID: 11786230 DOI: 10.1016/s0304-4165(01)00226-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The inactivation of glutamine synthetase (GS; EC 6.3.1.2) by metal-catalyzed oxidation (MCO) systems was studied in several Prochlorococcus strains, including the axenic PCC 9511. GS was inactivated in the presence of various oxidative systems, either enzymatic (as NAD(P)H+NAD(P)H-oxidase+Fe(3+)+O(2)) or non-enzymatic (as ascorbate+Fe(3+)+O(2)). This process required the presence of oxygen and a metal cation, and is prevented under anaerobic conditions. Catalase and peroxidase, but not superoxide dismutase, effectively protected the enzyme against inactivation, suggesting that hydrogen peroxide mediates this mechanism, although it is not directly responsible for the reaction. Addition of azide (an inhibitor of both catalase and peroxidase) to the MCO systems enhanced the inactivation. Different thiols induced the inactivation of the enzyme, even in the absence of added metals. However, this inactivation could not be reverted by addition of strong oxidants, as hydrogen peroxide or oxidized glutathione. After studying the effect of addition of the physiological substrates and products of GS on the inactivation mechanism, we could detect a protective effect in the case of inorganic phosphate and glutamine. Immunochemical determinations showed that the concentration of GS protein significantly decreased by effect of the MCO systems, indicating that inactivation precedes the degradation of the enzyme.
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Affiliation(s)
- G Gómez-Baena
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, 1a planta, Campus de Rabanales, Universidad de Córdoba, E-14071 Córdoba, Spain
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