151
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Cáceres C, Spatharis S, Kaiserli E, Smeti E, Flowers H, Bonachela JA. Temporal phosphate gradients reveal diverse acclimation responses in phytoplankton phosphate uptake. ISME JOURNAL 2019; 13:2834-2845. [PMID: 31350454 DOI: 10.1038/s41396-019-0473-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 06/11/2019] [Accepted: 06/28/2019] [Indexed: 11/10/2022]
Abstract
Phytoplankton face environmental nutrient variations that occur in the dynamic upper layers of the ocean. Phytoplankton cells are able to rapidly acclimate to nutrient fluctuations by adjusting their nutrient-uptake system and metabolism. Disentangling these acclimation responses is a critical step in bridging the gap between phytoplankton cellular physiology and community ecology. Here, we analyzed the dynamics of phosphate (P) uptake acclimation responses along different P temporal gradients by using batch cultures of the diatom Phaeodactylum tricornutum. We employed a multidisciplinary approach that combined nutrient-uptake bioassays, transcriptomic analysis, and mathematical models. Our results indicated that cells increase their maximum nutrient-uptake rate (Vmax) both in response to P pulses and strong phosphorus limitation. The upregulation of three genes coding for different P transporters in cells experiencing low intracellular phosphorus levels supported some of the observed Vmax variations. In addition, our mathematical model reproduced the empirical Vmax patterns by including two types of P transporters upregulated at medium-high environmental and low intracellular phosphorus levels, respectively. Our results highlight the existence of a sequence of acclimation stages along the phosphate continuum that can be understood as a succession of acclimation responses. We provide a novel conceptual framework that can contribute to integrating and understanding the dynamics and wide diversity of acclimation responses developed by phytoplankton.
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Affiliation(s)
- Carlos Cáceres
- Department of Mathematics and Statistics, University of Strathclyde, Livingstone Tower, 26 Richmond St., Glasgow, Scotland, G1 1XH, UK. .,Schiermeier Olentangy River Wetland Research Park, School of Environment and Natural Resources, The Ohio State University, Columbus, OH, 43202, USA.
| | - Sofie Spatharis
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, Scotland, G12 8QQ, UK.,School of Life Sciences, University of Glasgow, Glasgow, Scotland, G12 8QQ, UK
| | - Eirini Kaiserli
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Evangelia Smeti
- Hellenic Centre for Marine Research, Institute of Marine Biological Resources and Inland Waters, 46.7 km Athens-Sounio Ave., Anavyssos, 19013, Greece
| | - Hugh Flowers
- Department of Chemistry, University of Glasgow, Glasgow, Scotland, G12 8QQ, UK
| | - Juan A Bonachela
- Department of Mathematics and Statistics, University of Strathclyde, Livingstone Tower, 26 Richmond St., Glasgow, Scotland, G1 1XH, UK. .,Department of Ecology, Evolution, and Natural Resources, Rutgers University, 14 College Farm Road, New Brunswick, NJ, 08901, USA.
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152
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Ahlgren NA, Perelman JN, Yeh YC, Fuhrman JA. Multi-year dynamics of fine-scale marine cyanobacterial populations are more strongly explained by phage interactions than abiotic, bottom-up factors. Environ Microbiol 2019; 21:2948-2963. [PMID: 31106939 DOI: 10.1111/1462-2920.14687] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 03/29/2019] [Accepted: 04/16/2019] [Indexed: 12/01/2022]
Abstract
Currently defined ecotypes in marine cyanobacteria Prochlorococcus and Synechococcus likely contain subpopulations that themselves are ecologically distinct. We developed and applied high-throughput sequencing for the 16S-23S rRNA internally transcribed spacer (ITS) to examine ecotype and fine-scale genotypic community dynamics for monthly surface water samples spanning 5 years at the San Pedro Ocean Time-series site. Ecotype-level structure displayed regular seasonal patterns including succession, consistent with strong forcing by seasonally varying abiotic parameters (e.g. temperature, nutrients, light). We identified tens to thousands of amplicon sequence variants (ASVs) within ecotypes, many of which exhibited distinct patterns over time, suggesting ecologically distinct populations within ecotypes. Community structure within some ecotypes exhibited regular, seasonal patterns, but not for others, indicating other more irregular processes such as phage interactions are important. Network analysis including T4-like phage genotypic data revealed distinct viral variants correlated with different groups of cyanobacterial ASVs including time-lagged predator-prey relationships. Variation partitioning analysis indicated that phage community structure more strongly explains cyanobacterial community structure at the ASV level than the abiotic environmental factors. These results support a hierarchical model whereby abiotic environmental factors more strongly shape niche partitioning at the broader ecotype level while phage interactions are more important in shaping community structure of fine-scale variants within ecotypes.
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Affiliation(s)
- Nathan A Ahlgren
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Jessica N Perelman
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Yi-Chun Yeh
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Jed A Fuhrman
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
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153
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Feng G, Zhang F, Banakar S, Karlep L, Li Z. Analysis of functional gene transcripts suggests active CO2 assimilation and CO oxidation by diverse bacteria in marine sponges. FEMS Microbiol Ecol 2019; 95:5513993. [DOI: 10.1093/femsec/fiz087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 06/08/2019] [Indexed: 11/13/2022] Open
Affiliation(s)
- Guofang Feng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Dongchuan Road 800, Shanghai 200240, China
| | - Fengli Zhang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Dongchuan Road 800, Shanghai 200240, China
| | - Shivakumar Banakar
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Dongchuan Road 800, Shanghai 200240, China
| | - Liisi Karlep
- Department of Chemistry and Biotechnology, Division of Gene Technology, Tallinn University of Technology, Ehitajate 5, Tallinn 19086, Estonia
| | - Zhiyong Li
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Dongchuan Road 800, Shanghai 200240, China
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154
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Becker JW, Hogle SL, Rosendo K, Chisholm SW. Co-culture and biogeography of Prochlorococcus and SAR11. THE ISME JOURNAL 2019; 13:1506-1519. [PMID: 30742057 PMCID: PMC6775983 DOI: 10.1038/s41396-019-0365-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 01/03/2019] [Accepted: 01/18/2019] [Indexed: 01/07/2023]
Abstract
Prochlorococcus and SAR11 are among the smallest and most abundant organisms on Earth. With a combined global population of about 2.7 × 1028 cells, they numerically dominate bacterioplankton communities in oligotrophic ocean gyres and yet they have never been grown together in vitro. Here we describe co-cultures of Prochlorococcus and SAR11 isolates representing both high- and low-light adapted clades. We examined: (1) the influence of Prochlorococcus on the growth of SAR11 and vice-versa, (2) whether Prochlorococcus can meet specific nutrient requirements of SAR11, and (3) how co-culture dynamics vary when Prochlorococcus is grown with SAR11 compared with sympatric copiotrophic bacteria. SAR11 grew 15-70% faster in co-culture with Prochlorococcus, while the growth of the latter was unaffected. When Prochlorococcus populations entered stationary phase, this commensal relationship rapidly became amensal, as SAR11 abundances decreased dramatically. In parallel experiments with copiotrophic bacteria; however, the heterotrophic partner increased in abundance as Prochlorococcus densities leveled off. The presence of Prochlorococcus was able to meet SAR11's central requirement for organic carbon, but not reduced sulfur. Prochlorococcus strain MIT9313, but not MED4, could meet the unique glycine requirement of SAR11, which could be due to the production and release of glycine betaine by MIT9313, as supported by comparative genomic evidence. Our findings also suggest, but do not confirm, that Prochlorococcus MIT9313 may compete with SAR11 for the uptake of 3-dimethylsulfoniopropionate (DMSP). To give our results an ecological context, we assessed the relative contribution of Prochlorococcus and SAR11 genome equivalents to those of identifiable bacteria and archaea in over 800 marine metagenomes. At many locations, more than half of the identifiable genome equivalents in the euphotic zone belonged to Prochlorococcus and SAR11 - highlighting the biogeochemical potential of these two groups.
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Affiliation(s)
- Jamie W Becker
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Department of Biology, Haverford College, Haverford, PA, USA.
| | - Shane L Hogle
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Kali Rosendo
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Sallie W Chisholm
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
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155
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Rihtman B, Bowman‐Grahl S, Millard A, Corrigan RM, Clokie MRJ, Scanlan DJ. Cyanophage MazG is a pyrophosphohydrolase but unable to hydrolyse magic spot nucleotides. ENVIRONMENTAL MICROBIOLOGY REPORTS 2019; 11:448-455. [PMID: 30809954 PMCID: PMC6850273 DOI: 10.1111/1758-2229.12741] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 02/26/2019] [Accepted: 02/26/2019] [Indexed: 05/28/2023]
Abstract
Bacteriophage possess a variety of auxiliary metabolic genes of bacterial origin. These proteins enable them to maximize infection efficiency, subverting bacterial metabolic processes for the purpose of viral genome replication and synthesis of the next generation of virion progeny. Here, we examined the enzymatic activity of a cyanophage MazG protein - a putative pyrophosphohydrolase previously implicated in regulation of the stringent response via reducing levels of the central alarmone molecule (p)ppGpp. We demonstrate, however, that the purified viral MazG shows no binding or hydrolysis activity against (p)ppGpp. Instead, dGTP and dCTP appear to be the preferred substrates of this protein, consistent with a role preferentially hydrolysing deoxyribonucleotides from the high GC content host Synechococcus genome. This showcases a new example of the fine-tuned nature of viral metabolic processes.
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Affiliation(s)
| | | | - Andrew Millard
- Department of Infection, Immunity and InflammationUniversity of LeicesterLeicesterUK
| | - Rebecca M. Corrigan
- Department of Molecular Biology & BiotechnologyUniversity of SheffieldSheffieldUK
| | - Martha R. J. Clokie
- Department of Infection, Immunity and InflammationUniversity of LeicesterLeicesterUK
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156
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Zheng Q, Chen Q, Cai R, He C, Guo W, Wang Y, Shi Q, Chen C, Jiao N. Molecular characteristics of microbially mediated transformations of Synechococcus-derived dissolved organic matter as revealed by incubation experiments. Environ Microbiol 2019; 21:2533-2543. [PMID: 31044472 DOI: 10.1111/1462-2920.14646] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Revised: 03/24/2019] [Accepted: 04/29/2019] [Indexed: 11/28/2022]
Abstract
In this study, we investigated the microbially mediated transformation of labile Synechococcus-derived DOM to RDOM using a 60-day experimental incubation system. Three phases of TOC degradation activity (I, II and III) were observed following the addition of Synechococcus-derived DOM. The phases were characterized by organic carbon consumption rates of 8.77, 1.26 and 0.16 μmol L-1 day-1 , respectively. Excitation emission matrix analysis revealed the presence of three FDOM components including tyrosine-like, fulvic acid-like, and humic-like molecules. The three components also exhibited differing biological availabilities that could be considered as labile DOM (LDOM), semi-labile DOM (SLDOM) and RDOM, respectively. DOM molecular composition was also evaluated using FT-ICR MS. Based on differing biological turnover rates and normalized intensity values, a total of 1704 formulas were identified as candidate LDOM, SLDOM and RDOM molecules. Microbial transformation of LDOM to RDOM tended to proceed from high to low molecular weight, as well as from molecules with high to low double bond equivalent (DBE) values. Relatively higher aromaticity was observed in the formulas of RDOM molecules relative to those of LDOM molecules. FDOM components provide valuable proxy information to investigate variation in the bioavailability of DOM. These results suggest that coordinating fluorescence spectroscopy and FT-ICR MS of DOM, as conducted here, is an effective strategy to identify and characterize LDOM, SLDOM and RDOM molecules in incubation experiments emulating natural systems. The results described here provide greater insight into the metabolism of phytoplankton photosynthate by heterotrophic bacteria in marine environments.
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Affiliation(s)
- Qiang Zheng
- State Key Laboratory for Marine Environmental Science, Collage of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, People's Republic of China.,Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, 361102, People's Republic of China
| | - Qi Chen
- State Key Laboratory for Marine Environmental Science, Collage of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, People's Republic of China.,Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, 361102, People's Republic of China
| | - Ruanhong Cai
- State Key Laboratory for Marine Environmental Science, Collage of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, People's Republic of China.,Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, 361102, People's Republic of China
| | - Chen He
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing, 102249, China
| | - Weidong Guo
- State Key Laboratory for Marine Environmental Science, Collage of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, People's Republic of China.,Key Laboratory of Coastal and Wetland Ecosystems, Ministry of Education, Xiamen University, Xiamen, People's Republic of China
| | - Yu Wang
- State Key Laboratory for Marine Environmental Science, Collage of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, People's Republic of China.,Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, 361102, People's Republic of China
| | - Quan Shi
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing, 102249, China
| | - Chang Chen
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, People's Republic of China.,Xisha Deep Sea Marine Environment Observation and Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Sansha, People's Republic of China
| | - Nianzhi Jiao
- State Key Laboratory for Marine Environmental Science, Collage of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, People's Republic of China.,Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, 361102, People's Republic of China
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157
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Li Q, Huisman J, Bibby TS, Jiao N. Biogeography of Cyanobacterial isiA Genes and Their Link to Iron Availability in the Ocean. Front Microbiol 2019; 10:650. [PMID: 31024472 PMCID: PMC6460047 DOI: 10.3389/fmicb.2019.00650] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 03/14/2019] [Indexed: 11/15/2022] Open
Abstract
The cyanobacterial iron-stress-inducible isiA gene encodes a chlorophyll-binding protein that provides flexibility in photosynthetic strategy enabling cells to acclimate to low iron availability. Here, we report on the diversity and abundance of isiA genes from 14 oceanic stations encompassing large natural gradients in iron availability. Synechococcus CRD1 and CRD2-like isiA genes were ubiquitously identified from tropical and subtropical waters of the Pacific, Atlantic, and Indian Oceans. The relative abundance of isiA-containing Synechococcus cells ranged from less than 10% of the total Synechococcus population in regions where iron is replete such as the North Atlantic subtropical gyre, to over 80% in low-iron but high-nitrate regions of the eastern equatorial Pacific. Interestingly, Synechococcus populations in regions with both low iron and low nitrate concentrations such as the subtropical gyres in the North Pacific and South Atlantic had a low relative abundance of the isiA gene. Indeed, fitting our data into a multiple regression model showed that ∼80% of the variation in isiA relative abundances can be explained by nitrate and iron concentrations, whereas no other environmental variables (temperature, salinity, Chl a) had a significant effect. Hence, isiA has a predictable biogeographical distribution, consistent with the perceived biological role of IsiA as an adaptation to low-iron conditions. Understanding such photosynthetic strategies is critical to our ability to accurately estimate primary production and map nutrient limitation on global scales.
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Affiliation(s)
- Qian Li
- State Key Laboratory of Marine Environmental Sciences, Institute of Marine Microbes and Ecosphere, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, Netherlands
- Center for Microbial Oceanography: Research and Education, Department of Oceanography, University of Hawai’i at Mānoa, Honolulu, HI, United States
| | - Jef Huisman
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, Netherlands
| | - Thomas S. Bibby
- School of Ocean and Earth Science, National Oceanography Centre Southampton, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Sciences, Institute of Marine Microbes and Ecosphere, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
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158
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Primer Design for an Accurate View of Picocyanobacterial Community Structure by Using High-Throughput Sequencing. Appl Environ Microbiol 2019; 85:AEM.02659-18. [PMID: 30709827 DOI: 10.1128/aem.02659-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 01/30/2019] [Indexed: 12/26/2022] Open
Abstract
High-throughput sequencing (HTS) of the 16S rRNA gene has been used successfully to describe the structure and dynamics of microbial communities. Picocyanobacteria are important members of bacterioplankton communities, and, so far, they have predominantly been targeted using universal bacterial primers, providing a limited resolution of the picocyanobacterial community structure and dynamics. To increase such resolution, the study of a particular target group is best approached with the use of specific primers. Here, we aimed to design and evaluate specific primers for aquatic picocyanobacterial genera to be used with high-throughput sequencing. Since the various regions of the 16S rRNA gene have different degrees of conservation in different bacterial groups, we therefore first determined which hypervariable region of the 16S rRNA gene provides the highest taxonomic and phylogenetic resolution for the genera Synechococcus, Prochlorococcus, and Cyanobium An in silico analysis showed that the V5, V6, and V7 hypervariable regions appear to be the most informative for this group. We then designed primers flanking these hypervariable regions and tested them in natural marine and freshwater communities. We successfully detected that most (97%) of the obtained reads could be assigned to picocyanobacterial genera. We defined operational taxonomic units as exact sequence variants (zero-radius operational taxonomic units [zOTUs]), which allowed us to detect higher genetic diversity and infer ecologically relevant information about picocyanobacterial community composition and dynamics in different aquatic systems. Our results open the door to future studies investigating picocyanobacterial diversity in aquatic systems.IMPORTANCE The molecular diversity of the aquatic picocyanobacterial community cannot be accurately described using only the available universal 16S rRNA gene primers that target the whole bacterial and archaeal community. We show that the hypervariable regions V5, V6, and V7 of the 16S rRNA gene are better suited to study the diversity, community structure, and dynamics of picocyanobacterial communities at a fine scale using Illumina MiSeq sequencing. Due to its variability, it allows reconstructing phylogenies featuring topologies comparable to those generated when using the complete 16S rRNA gene sequence. Further, we successfully designed a new set of primers flanking the V5 to V7 region whose specificity for picocyanobacterial genera was tested in silico and validated in several freshwater and marine aquatic communities. This work represents a step forward for understanding the diversity and ecology of aquatic picocyanobacteria and sets the path for future studies on picocyanobacterial diversity.
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159
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Teira E, Logares R, Gutiérrez‐Barral A, Ferrera I, Varela MM, Morán XAG, Gasol JM. Impact of grazing, resource availability and light on prokaryotic growth and diversity in the oligotrophic surface global ocean. Environ Microbiol 2019; 21:1482-1496. [DOI: 10.1111/1462-2920.14581] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 02/26/2019] [Accepted: 03/02/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Eva Teira
- Departamento de Ecoloxía e Bioloxía AnimalUniversidade de Vigo Vigo Spain
| | - Ramiro Logares
- Departamento de Biologia Marina i OceanografiaInstitut de Ciències del Mar, CSIC Barcelona Catalonia Spain
| | | | - Isabel Ferrera
- Departamento de Biologia Marina i OceanografiaInstitut de Ciències del Mar, CSIC Barcelona Catalonia Spain
- Instituto Español de OceanografíaCentro Oceanográfico de Málaga Fuengirola Spain
| | - Marta M. Varela
- Instituto Español de OceanografíaCentro Oceanográfico de A Coruña A Coruña Spain
| | - Xosé Anxelu G. Morán
- Red Sea Research Center, Division of Biological and Environmental Sciences and EngineeringKing Abdullah University of Science and Technology Thuwal Saudi Arabia
| | - Josep M. Gasol
- Departamento de Biologia Marina i OceanografiaInstitut de Ciències del Mar, CSIC Barcelona Catalonia Spain
- Centre for Marine Ecosystems ResearchEdith Cowan University Joondalup Western Australia Australia
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160
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Lee MD, Ahlgren NA, Kling JD, Walworth NG, Rocap G, Saito MA, Hutchins DA, Webb EA. Marine
Synechococcus
isolates representing globally abundant genomic lineages demonstrate a unique evolutionary path of genome reduction without a decrease in GC content. Environ Microbiol 2019; 21:1677-1686. [DOI: 10.1111/1462-2920.14552] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 01/10/2019] [Accepted: 01/29/2019] [Indexed: 11/29/2022]
Affiliation(s)
- Michael D. Lee
- Department of Biological Sciences University of Southern California Los Angeles CA USA
- Exobiology, Ames Research Center Moffett Field CA USA
| | | | - Joshua D. Kling
- Department of Biological Sciences University of Southern California Los Angeles CA USA
| | - Nathan G. Walworth
- Department of Biological Sciences University of Southern California Los Angeles CA USA
| | - Gabrielle Rocap
- School of Oceanography University of Washington Seattle WA USA
| | - Mak A. Saito
- Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institute Woods Hole MA USA
| | - David A. Hutchins
- Department of Biological Sciences University of Southern California Los Angeles CA USA
| | - Eric A. Webb
- Department of Biological Sciences University of Southern California Los Angeles CA USA
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161
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The mesopelagic anoxic Black Sea as an unexpected habitat for Synechococcus challenges our understanding of global "deep red fluorescence". ISME JOURNAL 2019; 13:1676-1687. [PMID: 30820035 PMCID: PMC6776005 DOI: 10.1038/s41396-019-0378-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 01/28/2019] [Accepted: 01/31/2019] [Indexed: 11/23/2022]
Abstract
The Black Sea is the largest meromictic sea with a reservoir of anoxic water extending from 100 to 1000 m depth. These deeper layers are characterised by a poorly understood fluorescence signal called “deep red fluorescence”, a chlorophyll a- (Chl a) like signal found in deep dark oceanic waters. In two cruises, we repeatedly found up to 103 cells ml−1 of picocyanobacteria at 750 m depth in these waters and isolated two phycoerythrin-rich Synechococcus sp. strains (BS55D and BS56D). Tests on BS56D revealed its high adaptability, involving the accumulation of Chl a in anoxic/dark conditions and its capacity to photosynthesise when re-exposed to light. Whole-genome sequencing of the two strains showed the presence of genes that confirms the putative ability of our strains to survive in harsh mesopelagic environments. This discovery provides new evidence to support early speculations associating the “deep red fluorescence” signal to viable picocyanobacteria populations in the deep oxygen-depleted oceans, suggesting a reconsideration of the ecological role of a viable stock of Synechococcus in dark deep waters.
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162
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Costa M, Sampaio-Dias IE, Castelo-Branco R, Scharfenstein H, Rezende de Castro R, Silva A, Schneider MPC, Araújo MJ, Martins R, Domingues VF, Nogueira F, Camões V, Vasconcelos VM, Leão PN. Structure of Hierridin C, Synthesis of Hierridins B and C, and Evidence for Prevalent Alkylresorcinol Biosynthesis in Picocyanobacteria. JOURNAL OF NATURAL PRODUCTS 2019; 82:393-402. [PMID: 30715888 DOI: 10.1021/acs.jnatprod.8b01038] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Small, single-celled planktonic cyanobacteria are ubiquitous in the world's oceans yet tend not to be perceived as secondary metabolite-rich organisms. Here we report the isolation and structure elucidation of hierridin C, a minor metabolite obtained from the cultured picocyanobacterium Cyanobium sp. LEGE 06113. We describe a simple, straightforward synthetic route to the scarcely produced hierridins that relies on a key regioselective halogenation step. In addition, we show that these compounds originate from a type III PKS pathway and that similar biosynthetic gene clusters are found in a variety of bacterial genomes, most notably those of the globally distributed picocyanobacteria genera Prochlorococcus, Cyanobium and Synechococcus.
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Affiliation(s)
- Margarida Costa
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR) , University of Porto , Avenida General Norton de Matos, s/n , 4450-208 Matosinhos , Portugal
| | - Ivo E Sampaio-Dias
- LAQV-REQUIMTE, Department of Chemistry and Biochemistry, Faculty of Sciences , University of Porto , Rua do Campo Alegre 687 , 4169-007 Porto , Portugal
| | - Raquel Castelo-Branco
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR) , University of Porto , Avenida General Norton de Matos, s/n , 4450-208 Matosinhos , Portugal
| | - Hugo Scharfenstein
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR) , University of Porto , Avenida General Norton de Matos, s/n , 4450-208 Matosinhos , Portugal
| | - Roberta Rezende de Castro
- Institute of Biological Sciences, Center of Genomic and System Biology , Federal University of Pará (UFPA) , Beleḿ , PA66075-110, Brazil
| | - Artur Silva
- Institute of Biological Sciences, Center of Genomic and System Biology , Federal University of Pará (UFPA) , Beleḿ , PA66075-110, Brazil
| | - Maria Paula C Schneider
- Institute of Biological Sciences, Center of Genomic and System Biology , Federal University of Pará (UFPA) , Beleḿ , PA66075-110, Brazil
| | - Maria João Araújo
- Institute of Biological Sciences, Center of Genomic and System Biology , Federal University of Pará (UFPA) , Beleḿ , PA66075-110, Brazil
| | - Rosário Martins
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR) , University of Porto , Avenida General Norton de Matos, s/n , 4450-208 Matosinhos , Portugal
- Health and Environment Research Centre (CISA), School of Health , Polytechnic Institute of Porto , Rua Dr. António Bernardino de Almeida, 400 , 4200-072 , Porto , Portugal
| | - Valentina F Domingues
- REQUIMTE/LAQV, Instituto Superior de Engenharia , Instituto Politécnico do Porto , Rua Dr. António Bernardino de Almeida, 431 , 4200-072 Porto , Portugal
| | - Fátima Nogueira
- Global Health and Tropical Medicine, GHTM, Unidade de Ensino e Investigação de Parasitologia Médica , Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa , UNL, Rua da Junqueira no. 100 , 1349-008 Lisboa , Portugal
| | - Vera Camões
- Global Health and Tropical Medicine, GHTM, Unidade de Ensino e Investigação de Parasitologia Médica , Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa , UNL, Rua da Junqueira no. 100 , 1349-008 Lisboa , Portugal
| | - Vitor M Vasconcelos
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR) , University of Porto , Avenida General Norton de Matos, s/n , 4450-208 Matosinhos , Portugal
- Department of Biology, Sciences Faculty , University of Porto , Rua do Campo Alegre , 4169-007 Porto , Portugal
| | - Pedro N Leão
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR) , University of Porto , Avenida General Norton de Matos, s/n , 4450-208 Matosinhos , Portugal
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163
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Berube PM, Rasmussen A, Braakman R, Stepanauskas R, Chisholm SW. Emergence of trait variability through the lens of nitrogen assimilation in Prochlorococcus. eLife 2019; 8:41043. [PMID: 30706847 PMCID: PMC6370341 DOI: 10.7554/elife.41043] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 01/31/2019] [Indexed: 12/12/2022] Open
Abstract
Intraspecific trait variability has important consequences for the function and stability of marine ecosystems. Here we examine variation in the ability to use nitrate across hundreds of Prochlorococcus genomes to better understand the modes of evolution influencing intraspecific allocation of ecologically important functions. Nitrate assimilation genes are absent in basal lineages but occur at an intermediate frequency that is randomly distributed within recently emerged clades. The distribution of nitrate assimilation genes within clades appears largely governed by vertical inheritance, gene loss, and homologous recombination. By mapping this process onto a model of Prochlorococcus’ macroevolution, we propose that niche-constructing adaptive radiations and subsequent niche partitioning set the stage for loss of nitrate assimilation genes from basal lineages as they specialized to lower light levels. Retention of these genes in recently emerged lineages has likely been facilitated by selection as they sequentially partitioned into niches where nitrate assimilation conferred a fitness benefit.
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Affiliation(s)
- Paul M Berube
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, United States
| | - Anna Rasmussen
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, United States
| | - Rogier Braakman
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, United States
| | | | - Sallie W Chisholm
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
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164
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Sánchez-Baracaldo P, Bianchini G, Di Cesare A, Callieri C, Chrismas NAM. Insights Into the Evolution of Picocyanobacteria and Phycoerythrin Genes ( mpeBA and cpeBA). Front Microbiol 2019; 10:45. [PMID: 30761097 PMCID: PMC6363710 DOI: 10.3389/fmicb.2019.00045] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 01/11/2019] [Indexed: 11/13/2022] Open
Abstract
Marine picocyanobacteria, Prochlorococcus and Synechococcus, substantially contribute to marine primary production and have been the subject of extensive ecological and genomic studies. Little is known about their close relatives from freshwater and non-marine environments. Phylogenomic analyses (using 136 proteins) provide strong support for the monophyly of a clade of non-marine picocyanobacteria consisting of Cyanobium, Synechococcus and marine Sub-cluster 5.2; this clade itself is sister to marine Synechococcus and Prochlorococcus. The most basal lineage within the Syn/Pro clade, Sub-Cluster 5.3, includes marine and freshwater strains. Relaxed molecular clock (SSU, LSU) analyses show that while ancestors of the Syn/Pro clade date as far back as the end of the Pre-Cambrian, modern crown groups evolved during the Carboniferous and Triassic. Comparative genomic analyses reveal novel gene cluster arrangements involved in phycobilisome (PBS) metabolism in freshwater strains. Whilst PBS genes in marine Synechococcus are mostly found in one type of phycoerythrin (PE) rich gene cluster (Type III), strains from non-marine habitats, so far, appear to be more diverse both in terms of pigment content and gene arrangement, likely reflecting a wider range of habitats. Our phylogenetic analyses show that the PE genes (mpeBA) evolved via a duplication of the cpeBA genes in an ancestor of the marine and non-marine picocyanobacteria and of the symbiotic strains Synechococcus spongiarum. A 'primitive' Type III-like ancestor containing cpeBA and mpeBA had thus evolved prior to the divergence of the Syn/Pro clade and S. spongiarum. During the diversification of Synechococcus lineages, losses of mpeBA genes may explain the emergence of pigment cluster Types I, II, IIB, and III in both marine and non-marine habitats, with few lateral gene transfer events in specific taxa.
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Affiliation(s)
| | - Giorgio Bianchini
- School of Geographical Sciences, University of Bristol, Bristol, United Kingdom
| | - Andrea Di Cesare
- Institute of Ecosystem Study–Consiglio Nazionale delle Ricerche, Verbania, Italy
- Department of Earth, Environment and Life Sciences, University of Genoa, Genoa, Italy
| | - Cristiana Callieri
- Institute of Ecosystem Study–Consiglio Nazionale delle Ricerche, Verbania, Italy
| | - Nathan A. M. Chrismas
- School of Geographical Sciences, University of Bristol, Bristol, United Kingdom
- The Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, United Kingdom
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165
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Fang X, Liu Y, Zhao Y, Chen Y, Liu R, Qin QL, Li G, Zhang YZ, Chan W, Hess WR, Zeng Q. Transcriptomic responses of the marine cyanobacterium Prochlorococcus to viral lysis products. Environ Microbiol 2019; 21:2015-2028. [PMID: 30585375 DOI: 10.1111/1462-2920.14513] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 12/19/2018] [Indexed: 01/27/2023]
Abstract
Viral infection of marine phytoplankton releases a variety of dissolved organic matter (DOM). The impact of viral DOM (vDOM) on the uninfected co-occurring phytoplankton remains largely unknown. Here, we conducted transcriptomic analyses to study the effects of vDOM on the cyanobacterium Prochlorococcus, which is the most abundant photosynthetic organism on Earth. Using Prochlorococcus MIT9313, we showed that its growth was not affected by vDOM, but many tRNAs increased in abundance. We tested tRNA-gly and found that its abundance increased upon addition of glycine. The decreased transcript abundances of N metabolism genes also suggested that Prochlorococcus responded to organic N compounds in vDOM. Addition of vDOM to Prochlorococcus reduced the maximum photochemical efficiency of photosystem II and CO2 fixation while increasing its respiration rate, consistent with differentially abundant transcripts related to photosynthesis and respiration. One of the highest positive fold-changes was observed for the 6S RNA, a noncoding RNA functioning as a global transcriptional regulator in bacteria. The high level of 6S RNA might be responsible for some of the observed transcriptional responses. Taken together, our results revealed the transcriptional regulation of Prochlorococcus in response to viral lysis products and suggested its metabolic potential to utilize organic N compounds.
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Affiliation(s)
- Xiaoting Fang
- Department of Ocean Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Yaxin Liu
- Department of Ocean Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Yao Zhao
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Yue Chen
- Department of Ocean Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Riyue Liu
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Qi-Long Qin
- State Key Lab of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan, China
| | - Gang Li
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology (CAS), Guangzhou, China
| | - Yu-Zhong Zhang
- State Key Lab of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan, China.,College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Wan Chan
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Wolfgang R Hess
- Genetics & Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Germany
| | - Qinglu Zeng
- Department of Ocean Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.,Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.,HKUST Shenzhen Research Institute, Shenzhen, China
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166
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Lambrecht SJ, Wahlig JML, Steglich C. The GntR family transcriptional regulator PMM1637 regulates the highly conserved cyanobacterial sRNA Yfr2 in marine picocyanobacteria. DNA Res 2019; 25:489-497. [PMID: 29901694 PMCID: PMC6191309 DOI: 10.1093/dnares/dsy019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 05/14/2018] [Indexed: 11/21/2022] Open
Abstract
Prochlorococcus is a marine picocyanobacterium with a streamlined genome that is adapted to different ecological niches in the oligotrophic oceans. There are currently >20 regulatory small RNAs (sRNAs) that have been identified in the model strain Prochlorococcus MED4. While most of these sRNAs are ecotype-specific, sRNA homologs of Yfr1 and of the Yfr2 family are widely found throughout the cyanobacterial phylum. Although they were identified 13 yrs ago, the functions of Yfr1 and Yfr2 have remained unknown. We observed a strong induction of two Yfr2 sRNA homologs of Prochlorococcus MED4 during high light stress and nitrogen starvation. Several Prochlorococcus and marine Synechococcus yfr2 promoter regions contain a conserved motif we named CGRE1 (cyanobacterial GntR family transcriptional regulator responsive element 1). Using the conserved promoter region as bait in a DNA affinity pull-down assay we identified the GntR family transcriptional regulator PMM1637 as a binding partner. Similar to Yfr2, homologs of PMM1637 are universally and exclusively found in cyanobacteria. We suggest that PMM1637 governs the induction of gene expression of Yfr2 homologs containing CGRE1 in their promoters under nitrogen-depleted and high-light stress conditions.
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Affiliation(s)
- S Joke Lambrecht
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Freiburg, Germany
| | - J Mascha L Wahlig
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Freiburg, Germany
| | - Claudia Steglich
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Freiburg, Germany
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167
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Moreno-Cabezuelo JÁ, López-Lozano A, Díez J, García-Fernández JM. Differential expression of the glucose transporter gene glcH in response to glucose and light in marine picocyanobacteria. PeerJ 2019; 6:e6248. [PMID: 30648008 PMCID: PMC6330958 DOI: 10.7717/peerj.6248] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 12/09/2018] [Indexed: 11/20/2022] Open
Abstract
Background Our team discovered that Prochlorococcus can take up glucose, in a process that changes the transcriptional pattern of several genes involved in glucose metabolization. We have also shown that glcH encodes a very high affinity glucose transporter, and that glucose is taken up by natural Prochlorococcus populations. We demonstrated that the kinetic parameters of glucose uptake show significant diversity in different Prochlorococcus and Synechococcus strains. Here, we tested whether the transcriptional response of glcH to several glucose concentrations and light conditions was also different depending on the studied strain. Methods Cultures were grown in the light, supplemented with five different glucose concentrations or subjected to darkness, and cells harvested after 24 h of treatment. qRT-PCR was used to determine glcH expression in four Prochlorococcus and two Synechococcus strains. Results In all studied strains glcH was expressed in the absence of glucose, and it increased upon glucose addition to cultures. The changes differed depending on the strain, both in the magnitude and in the way cells responded to the tested glucose concentrations. Unlike the other strains, Synechococcus BL107 showed the maximum glucose uptake at 5 nM glucose. Darkness induced a strong decrease in glcH expression, especially remarkable in Prochlorococcus MIT9313. Discussion Our results suggest that marine picocyanobacteria are actively monitoring the availability of glucose, to upregulate glcH expression in order to exploit the presence of sugars in the environment. The diverse responses observed in different strains suggest that the transcriptional regulation of glucose uptake has been adjusted by evolutive selection. Darkness promotes a strong decrease in glcH expression in all studied strains, which fits with previous results on glucose uptake in Prochlorococcus. Overall, this work reinforces the importance of mixotrophy for marine picocyanobacteria.
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Affiliation(s)
- José Ángel Moreno-Cabezuelo
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain
| | - Antonio López-Lozano
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain
| | - Jesús Díez
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain
| | - José Manuel García-Fernández
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain
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168
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Tang J, Du LM, Liang YM, Daroch M. Complete Genome Sequence and Comparative Analysis of Synechococcus sp. CS-601 (SynAce01), a Cold-Adapted Cyanobacterium from an Oligotrophic Antarctic Habitat. Int J Mol Sci 2019; 20:E152. [PMID: 30609821 PMCID: PMC6337551 DOI: 10.3390/ijms20010152] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/19/2018] [Accepted: 12/20/2018] [Indexed: 12/24/2022] Open
Abstract
Marine picocyanobacteria belonging to Synechococcus are major contributors to the global carbon cycle, however the genomic information of its cold-adapted members has been lacking to date. To fill this void the genome of a cold-adapted planktonic cyanobacterium Synechococcus sp. CS-601 (SynAce01) has been sequenced. The genome of the strain contains a single chromosome of approximately 2.75 MBp and GC content of 63.92%. Gene prediction yielded 2984 protein coding sequences and 44 tRNA genes. The genome contained evidence of horizontal gene transfer events during its evolution. CS-601 appears as a transport generalist with some specific adaptation to an oligotrophic marine environment. It has a broad repertoire of transporters of both inorganic and organic nutrients to survive in inhospitable environments. The cold adaptation of the strain exhibited characteristics of a psychrotroph rather than psychrophile. Its salt adaptation strategy is likely to rely on the uptake and synthesis of osmolytes, like glycerol or glycine betaine. Overall, the genome reveals two distinct patterns of adaptation to the inhospitable environment of Antarctica. Adaptation to an oligotrophic marine environment is likely due to an abundance of genes, probably acquired horizontally, that are associated with increased transport of nutrients, osmolytes, and light harvesting. On the other hand, adaptations to low temperatures are likely due to prolonged evolutionary changes.
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Affiliation(s)
- Jie Tang
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, School of Pharmacy and Biological Engineering, Chengdu University, Chengdu 610106, China.
- Shenzhen Aone Medical Laboratory Co Ltd, Shenzhen 518107, China.
| | - Lian-Ming Du
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, School of Pharmacy and Biological Engineering, Chengdu University, Chengdu 610106, China.
| | - Yuan-Mei Liang
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
| | - Maurycy Daroch
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
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169
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Zhang CC, Zhou CZ, Burnap RL, Peng L. Carbon/Nitrogen Metabolic Balance: Lessons from Cyanobacteria. TRENDS IN PLANT SCIENCE 2018; 23:1116-1130. [PMID: 30292707 DOI: 10.1016/j.tplants.2018.09.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 09/07/2018] [Accepted: 09/11/2018] [Indexed: 05/20/2023]
Abstract
Carbon and nitrogen are the two most abundant nutrient elements for all living organisms, and their metabolism is tightly coupled. What are the signaling mechanisms that cells use to sense and control the carbon/nitrogen (C/N) metabolic balance following environmental changes? Based on studies in cyanobacteria, it was found that 2-phosphoglycolate derived from the oxygenase activity of Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase) and 2-oxoglutarate from the Krebs cycle act as the carbon- and nitrogen-starvation signals, respectively, and their concentration ratio likely reflects the status of the C/N metabolic balance. We will present and discuss the regulatory principles underlying the signaling mechanisms, which are likely to be conserved in other photosynthetic organisms. These concepts may also contribute to developments in the field of biofuel engineering or improvements in crop productivity.
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Affiliation(s)
- Cheng-Cai Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan, Hubei 430072, People's Republic of China; Aix-Marseille Université, CNRS, LCB, France.
| | - Cong-Zhao Zhou
- School of Life Sciences and Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230027, People's Republic of China
| | - Robert L Burnap
- Department of Microbiology and Molecular Genetics, Henry Bellmon Research Center, Oklahoma State University, Stillwater, OK 74078, USA
| | - Ling Peng
- Aix-Marseille Université, CNRS, Centre Interdisciplinaire de Nanoscience de Marseille, Equipe Labellisée Ligue Contre le Cancer, CINaM UMR 7325, 13288 Marseille, France
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170
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Shibl AA, Ngugi DK, Talarmin A, Thompson LR, Blom J, Stingl U. The genome of a novel isolate of Prochlorococcus from the Red Sea contains transcribed genes for compatible solute biosynthesis. FEMS Microbiol Ecol 2018; 94:5090968. [PMID: 30188995 DOI: 10.1093/femsec/fiy182] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 09/04/2018] [Indexed: 11/14/2022] Open
Abstract
Marine microbes possess genomic and physiological adaptations to cope with varying environmental conditions. So far, the effects of high salinity on the most abundant marine photoautotrophic organism, Prochlorococcus, in marine oligotrophic environments, are mostly unknown. Here, we report the isolation of a new Prochlorococcus strain (RSP50) belonging to high-light (HL) clade II from the Red Sea, one of the warmest and most saline bodies of water in the global oceans. A comparative genomic analysis identified a set of 59 genes that were exclusive to RSP50 relative to currently available Prochlorococcus genomes, the majority of which (70%) encode for hypothetical proteins of unknown function. However, three of the unique genes encode for a complete pathway for the biosynthesis of the compatible solute glucosylglycerol, and are homologous to enzymes found in the sister lineage Synechococcus. Metatranscriptomic analyses of this metabolic pathway in the water column of the Red Sea revealed that the corresponding genes were constitutively transcribed, independent of depth and light, suggesting that osmoregulation using glucosylglycerol is a general feature of HL II Prochlorococcus in the Red Sea.
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Affiliation(s)
- Ahmed A Shibl
- Marine Microbial Ecology Lab, Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.,Biology Department, New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, UAE
| | - David K Ngugi
- Marine Microbial Ecology Lab, Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.,Department of Microorganisms, Leibniz Insitute DSMZ, Inhoffenstrasse 7B, 38124 Braunschweig, Germany
| | - Agathe Talarmin
- Marine Microbial Ecology Lab, Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.,Petroleum Geosciences Department, Petroleum Institute, P.O. Box 2533 Abu Dhabi, UAE
| | - Luke R Thompson
- Marine Microbial Ecology Lab, Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.,Department of Biological Sciences and Northern Gulf Institute, University of Southern Mississippi, Hattiesburg, Mississippi, USA.,Ocean Chemistry and Ecosystems Division, Atlantic Oceanographic and Meteorological Laboratory, National Oceanic and Atmospheric Administration, stationed at Southwest Fisheries Science Center, La Jolla, California, USA
| | - Jochen Blom
- Bioinformatics and Systems Biology, Justus Liebig University, D-35392 Giessen, Germany
| | - Ulrich Stingl
- Marine Microbial Ecology Lab, Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.,University of Florida, UF/IFAS, Department for Microbiology & Cell Science, Fort Lauderdale Research and Education Center, Davie, FL 33314, USA
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171
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Liang Y, Kaczmarek MB, Kasprzak AK, Tang J, Shah MMR, Jin P, Klepacz-Smółka A, Cheng JJ, Ledakowicz S, Daroch M. Thermosynechococcaceae as a source of thermostable C-phycocyanins: properties and molecular insights. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.08.037] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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172
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Bolay P, Muro-Pastor MI, Florencio FJ, Klähn S. The Distinctive Regulation of Cyanobacterial Glutamine Synthetase. Life (Basel) 2018; 8:E52. [PMID: 30373240 PMCID: PMC6316151 DOI: 10.3390/life8040052] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 10/23/2018] [Accepted: 10/25/2018] [Indexed: 12/02/2022] Open
Abstract
Glutamine synthetase (GS) features prominently in bacterial nitrogen assimilation as it catalyzes the entry of bioavailable nitrogen in form of ammonium into cellular metabolism. The classic example, the comprehensively characterized GS of enterobacteria, is subject to exquisite regulation at multiple levels, among them gene expression regulation to control GS abundance, as well as feedback inhibition and covalent modifications to control enzyme activity. Intriguingly, the GS of the ecologically important clade of cyanobacteria features fundamentally different regulatory systems to those of most prokaryotes. These include the interaction with small proteins, the so-called inactivating factors (IFs) that inhibit GS linearly with their abundance. In addition to this protein interaction-based regulation of GS activity, cyanobacteria use alternative elements to control the synthesis of GS and IFs at the transcriptional level. Moreover, cyanobacteria evolved unique RNA-based regulatory mechanisms such as glutamine riboswitches to tightly tune IF abundance. In this review, we aim to outline the current knowledge on the distinctive features of the cyanobacterial GS encompassing the overall control of its activity, sensing the nitrogen status, transcriptional and post-transcriptional regulation, as well as strain-specific differences.
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Affiliation(s)
- Paul Bolay
- Helmholtz Centre for Environmental Research, Department of Solar Materials, Permoserstrasse 15, D-04318 Leipzig, Germany.
| | - M Isabel Muro-Pastor
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, Américo Vespucio 49, E-41092 Seville, Spain.
| | - Francisco J Florencio
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, Américo Vespucio 49, E-41092 Seville, Spain.
| | - Stephan Klähn
- Helmholtz Centre for Environmental Research, Department of Solar Materials, Permoserstrasse 15, D-04318 Leipzig, Germany.
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173
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Parallel phylogeography of Prochlorococcus and Synechococcus. ISME JOURNAL 2018; 13:430-441. [PMID: 30283146 DOI: 10.1038/s41396-018-0287-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 09/11/2018] [Accepted: 09/14/2018] [Indexed: 11/08/2022]
Abstract
The globally abundant marine Cyanobacteria Prochlorococcus and Synechococcus share many physiological traits but presumably have different evolutionary histories and associated phylogeography. In Prochlorococcus, there is a clear phylogenetic hierarchy of ecotypes, whereas multiple Synechococcus clades have overlapping physiologies and environmental distributions. However, microbial traits are associated with different phylogenetic depths. Using this principle, we reclassified diversity at different phylogenetic levels and compared the phylogeography. We sequenced the genetic diversity of Prochlorococcus and Synechococcus from 339 samples across the tropical Pacific Ocean and North Atlantic Ocean using a highly variable phylogenetic marker gene (rpoC1). We observed clear parallel niche distributions of ecotypes leading to high Pianka's Index values driven by distinct shifts at two transition points. The first transition point at 6°N distinguished ecotypes adapted to warm waters but separated by macronutrient content. At 39°N, ecotypes adapted to warm, low macronutrient vs. colder, high macronutrient waters shifted. Finally, we detected parallel vertical and regional single-nucleotide polymorphism microdiversity within clades from both Prochlorococcus and Synechococcus, suggesting uniquely adapted populations at very specific depths, as well as between the Atlantic and Pacific Oceans. Overall, this study demonstrates that Prochlorococcus and Synechococcus have shared phylogenetic organization of traits and associated phylogeography.
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174
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Cabello-Yeves PJ, Picazo A, Camacho A, Callieri C, Rosselli R, Roda-Garcia JJ, Coutinho FH, Rodriguez-Valera F. Ecological and genomic features of two widespread freshwater picocyanobacteria. Environ Microbiol 2018; 20:3757-3771. [PMID: 30117250 DOI: 10.1111/1462-2920.14377] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 08/08/2018] [Indexed: 12/15/2022]
Abstract
We present two genomes of widespread freshwater picocyanobacteria isolated by extinction dilution from a Spanish oligotrophic reservoir. Based on microscopy and genomic properties, both picocyanobacteria were tentatively designated Synechococcus lacustris Tous, formerly described as a metagenome assembled genome (MAG) from the same habitat, and Cyanobium usitatum Tous, described here for the first time. Both strains were purified in unicyanobacterial cultures, and their genomes were sequenced. They are broadly distributed in freshwater systems; the first seems to be a specialist on temperate reservoirs (Tous, Amadorio, Dexter, Lake Lanier, Sparkling), and the second appears to also be abundant in cold environments including ice-covered lakes such as Lake Baikal, Lake Erie or the brackish Baltic Sea. Having complete genomes provided access to the flexible genome that does not assemble in MAGs. We found several genomic islands in both genomes, within which there were genes for nitrogen acquisition, transporters for a wide set of compounds and biosynthesis of phycobilisomes in both strains. Some of these regions of low coverage in metagenomes also included antimicrobial compounds, transposases and phage defence systems, including a novel type III CRISPR-Cas phage defence system that was only detected in Synechococcus lacustris Tous.
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Affiliation(s)
- Pedro J Cabello-Yeves
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, Alicante, Spain
| | - Antonio Picazo
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Valencia, Spain
| | - Antonio Camacho
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Valencia, Spain
| | | | - Riccardo Rosselli
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, Alicante, Spain
| | - Juan J Roda-Garcia
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, Alicante, Spain
| | - Felipe H Coutinho
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, Alicante, Spain
| | - Francisco Rodriguez-Valera
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, Alicante, Spain
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175
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Partensky F, Mella-Flores D, Six C, Garczarek L, Czjzek M, Marie D, Kotabová E, Felcmanová K, Prášil O. Comparison of photosynthetic performances of marine picocyanobacteria with different configurations of the oxygen-evolving complex. PHOTOSYNTHESIS RESEARCH 2018; 138:57-71. [PMID: 29938315 DOI: 10.1007/s11120-018-0539-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 06/20/2018] [Indexed: 06/08/2023]
Abstract
The extrinsic PsbU and PsbV proteins are known to play a critical role in stabilizing the Mn4CaO5 cluster of the PSII oxygen-evolving complex (OEC). However, most isolates of the marine cyanobacterium Prochlorococcus naturally miss these proteins, even though they have kept the main OEC protein, PsbO. A structural homology model of the PSII of such a natural deletion mutant strain (P. marinus MED4) did not reveal any obvious compensation mechanism for this lack. To assess the physiological consequences of this unusual OEC, we compared oxygen evolution between Prochlorococcus strains missing psbU and psbV (PCC 9511 and SS120) and two marine strains possessing these genes (Prochlorococcus sp. MIT9313 and Synechococcus sp. WH7803). While the low light-adapted strain SS120 exhibited the lowest maximal O2 evolution rates (Pmax per divinyl-chlorophyll a, per cell or per photosystem II) of all four strains, the high light-adapted strain PCC 9511 displayed even higher PChlmax and PPSIImax at high irradiance than Synechococcus sp. WH7803. Furthermore, thermoluminescence glow curves did not show any alteration in the B-band shape or peak position that could be related to the lack of these extrinsic proteins. This suggests an efficient functional adaptation of the OEC in these natural deletion mutants, in which PsbO alone is seemingly sufficient to ensure proper oxygen evolution. Our study also showed that Prochlorococcus strains exhibit negative net O2 evolution rates at the low irradiances encountered in minimum oxygen zones, possibly explaining the very low O2 concentrations measured in these environments, where Prochlorococcus is the dominant oxyphototroph.
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Affiliation(s)
- Frédéric Partensky
- Sorbonne Université, Station Biologique, CS 90074, 29688, Roscoff cedex, France.
- CNRS UMR 7144, Station Biologique, CS 90074, 29680, Roscoff, France.
| | - Daniella Mella-Flores
- Sorbonne Université, Station Biologique, CS 90074, 29688, Roscoff cedex, France
- CNRS UMR 7144, Station Biologique, CS 90074, 29680, Roscoff, France
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES-UC), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Christophe Six
- Sorbonne Université, Station Biologique, CS 90074, 29688, Roscoff cedex, France
- CNRS UMR 7144, Station Biologique, CS 90074, 29680, Roscoff, France
| | - Laurence Garczarek
- Sorbonne Université, Station Biologique, CS 90074, 29688, Roscoff cedex, France
- CNRS UMR 7144, Station Biologique, CS 90074, 29680, Roscoff, France
| | - Mirjam Czjzek
- Sorbonne Université, Station Biologique, CS 90074, 29688, Roscoff cedex, France
- CNRS UMR 8227, Marine Glycobiology Group, Station Biologique, CS 90074, 29680, Roscoff, France
| | - Dominique Marie
- Sorbonne Université, Station Biologique, CS 90074, 29688, Roscoff cedex, France
- CNRS UMR 7144, Station Biologique, CS 90074, 29680, Roscoff, France
| | - Eva Kotabová
- Laboratory of Photosynthesis, Institute of Microbiology, MBU AVČR, Opatovický mlýn, 37981, Třeboň, Czech Republic
| | - Kristina Felcmanová
- Laboratory of Photosynthesis, Institute of Microbiology, MBU AVČR, Opatovický mlýn, 37981, Třeboň, Czech Republic
- Faculty of Sciences, University of South Bohemia, Branišovská, 37005, České Budějovice, Czech Republic
| | - Ondřej Prášil
- Laboratory of Photosynthesis, Institute of Microbiology, MBU AVČR, Opatovický mlýn, 37981, Třeboň, Czech Republic
- Faculty of Sciences, University of South Bohemia, Branišovská, 37005, České Budějovice, Czech Republic
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176
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Ma X, Coleman ML, Waldbauer JR. Distinct molecular signatures in dissolved organic matter produced by viral lysis of marine cyanobacteria. Environ Microbiol 2018; 20:3001-3011. [PMID: 30047191 DOI: 10.1111/1462-2920.14338] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 06/21/2018] [Accepted: 06/21/2018] [Indexed: 11/29/2022]
Abstract
Dissolved organic matter (DOM) plays a central role in the microbial ecology and biogeochemistry of aquatic environments, yet little is known about how the mechanism of DOM release from its ultimate source, primary producer biomass, affects the molecular composition of the inputs to the dissolved pool. Here we used a model marine phytoplankton, the picocyanobacterium Synechococcus WH7803, to compare the composition of DOM released by three mechanisms: exudation, mechanical cell lysis and infection by the lytic phage S-SM1. A broad, untargeted analytical approach reveals the complexity of this freshly sourced DOM, and comparative analysis between DOM produced by the different mechanisms suggests that exudation and viral lysis are sources of unsaturated, oxygen-rich and possibly novel biomolecules. Furthermore, viral lysis of WH7803 by S-SM1 releases abundant peptides derived from specific proteolysis of the major light-harvesting protein phycoerythrin, raising the possibility that phage infection of these abundant cyanobacteria could be a significant source of high molecular weight dissolved organic nitrogen compounds.
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Affiliation(s)
- Xiufeng Ma
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, 60637, USA
| | - Maureen L Coleman
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, 60637, USA
| | - Jacob R Waldbauer
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, 60637, USA
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177
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Xie Y, Laws EA, Yang L, Huang B. Diel Patterns of Variable Fluorescence and Carbon Fixation of Picocyanobacteria Prochlorococcus-Dominated Phytoplankton in the South China Sea Basin. Front Microbiol 2018; 9:1589. [PMID: 30116223 PMCID: PMC6083051 DOI: 10.3389/fmicb.2018.01589] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 06/26/2018] [Indexed: 01/08/2023] Open
Abstract
The various photosynthetic apparatus and light utilization strategies of phytoplankton are among the critical factors that regulate the distribution of phytoplankton and primary productivity in the ocean. Active chlorophyll fluorescence has been a powerful technique for assessing the nutritional status of phytoplankton by studying the dynamics of photosynthesis. Further studies of the energetic stoichiometry between light absorption and carbon fixation have enhanced understanding of the ways phytoplankton adapt to their niches. To explore the ecophysiology of a Prochlorococcus-dominated phytoplankton assemblage, we conducted studies of the diel patterns of variable fluorescence and carbon fixation by phytoplankton in the oligotrophic South China Sea (SCS) basin in June 2017. We found that phytoplankton photosynthetic performance at stations SEATS and SS1 were characterized by a nocturnal decrease, dawn maximum, and midday decrease of the maximum quantum yield of PSII (Fv(′)/Fm(′), which has been denoted as both Fv/Fm and Fv′/Fm′) in the nutrient-depleted surface layer. That these diel patterns of Fv(′)/Fm(′) were similar to those in the tropical Pacific Ocean suggests macro-nutrient and potentially micro-nutrient stress. However, the fact that variations were larger in the central basin than at the basin's edge implied variability in the degree of nutrient limitation in the basin. The estimated molar ratio of gross O2 production to net production of carbon (GOP:NPC) of 4.9:1 was similar to ratios reported across the world's oceans. The narrow range of the GOP:NPC ratios is consistent with the assumption that there is a common strategy for photosynthetic energy allocation by phytoplankton. That photo-inactivated photosystems or nonphotochemical quenching rather than GOP accounted for most of the radiation absorbed by phytoplankton explains why the maximum quantum yield of carbon fixation was rather low in the oligotrophic SCS.
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Affiliation(s)
- Yuyuan Xie
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
| | - Edward A Laws
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, LA, United States
| | - Lei Yang
- Department of Environmental Sciences, Xiamen University, Xiamen, China
| | - Bangqin Huang
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China.,Department of Environmental Sciences, Xiamen University, Xiamen, China
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178
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Perez-Sepulveda B, Pitt F, N'Guyen AN, Ratin M, Garczarek L, Millard A, Scanlan DJ. Relative stability of ploidy in a marine Synechococcus across various growth conditions. ENVIRONMENTAL MICROBIOLOGY REPORTS 2018; 10:428-432. [PMID: 29327508 DOI: 10.1111/1758-2229.12614] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 01/06/2018] [Indexed: 06/07/2023]
Abstract
Marine picocyanobacteria of the genus Synechococcus are ubiquitous phototrophs in oceanic systems. Consistent with these organisms occupying vast tracts of the nutrient impoverished ocean, most marine Synechococcus so far studied are monoploid, i.e., contain a single chromosome copy. The exception is the oligoploid strain Synechococcus sp. WH7803, which on average possesses around 4 chromosome copies. Here, we set out to understand the role of resource availability (through nutrient deplete growth) and physical stressors (UV, exposure to low and high temperature) in regulating ploidy level in this strain. Using qPCR to assay ploidy status we demonstrate the relative stability of chromosome copy number in Synechococcus sp. WH7803. Such robustness in maintaining an oligoploid status even under nutrient and physical stress is indicative of a fundamental role, perhaps facilitating recombination of damaged DNA regions as a result of prolonged exposure to oxidative stress, or allowing added flexibility in gene expression via possessing multiple alleles.
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Affiliation(s)
| | - Frances Pitt
- School of Life Sciences, University of Warwick, Coventry, UK
| | - An N N'Guyen
- Sorbonne Universités, UPMC-Université Paris 06, CNRS UMR 7144, Station Biologique, Roscoff, France
| | - Morgane Ratin
- Sorbonne Universités, UPMC-Université Paris 06, CNRS UMR 7144, Station Biologique, Roscoff, France
| | - Laurence Garczarek
- Sorbonne Universités, UPMC-Université Paris 06, CNRS UMR 7144, Station Biologique, Roscoff, France
| | - Andrew Millard
- Department of Infection Immunity and Inflammation, University of Leicester, Leicester, UK
| | - David J Scanlan
- School of Life Sciences, University of Warwick, Coventry, UK
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179
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Zinser ER. Cross-protection from hydrogen peroxide by helper microbes: the impacts on the cyanobacterium Prochlorococcus and other beneficiaries in marine communities. ENVIRONMENTAL MICROBIOLOGY REPORTS 2018; 10:399-411. [PMID: 29411546 DOI: 10.1111/1758-2229.12625] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/25/2018] [Accepted: 01/27/2017] [Indexed: 05/27/2023]
Abstract
Hydrogen peroxide (HOOH) is a reactive oxygen species, derived from molecular oxygen, that is capable of damaging microbial cells. Surprisingly, the HOOH defence systems of some aerobes in the oxygenated marine environments are critically depleted, relative to model aerobes. For instance, the gene encoding catalase is absent in the numerically dominant photosynthetic cyanobacterium, Prochlorococcus. Accordingly, Prochlorococcus is highly susceptible to HOOH when exposed as pure cultures. Pure cultures do not exist in the marine environment, however. Catalase-positive community members can remove HOOH from the seawater medium, thus lowering the threat to Prochlorococcus and any other member that likewise lacks their own catalase. This cross-protection may constitute a loosely defined symbiosis, whereby the catalase-positive helper cells may benefit through the acquisition of nutrients released by the beneficiaries such as Prochlorococcus. Other members of the community that may be helped by the catalase-positive cells may include some lineages of Synechococcus - the sister genus of Prochlorococcus - as well as some lineages of SAR11 and ammonia oxidizing archaea and bacteria. The co-occurrence of catalase-positive and -negative members suggests that cross-protection from HOOH-mediated oxidative stress may play an important role in the construction of the marine microbial community.
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Affiliation(s)
- Erik R Zinser
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA
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180
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Manganese Is Essential for PlcP Metallophosphoesterase Activity Involved in Lipid Remodeling in Abundant Marine Heterotrophic Bacteria. Appl Environ Microbiol 2018; 84:AEM.01109-18. [PMID: 29802183 DOI: 10.1128/aem.01109-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 05/17/2018] [Indexed: 11/20/2022] Open
Abstract
In vast areas of the ocean, microbes must adapt to the availability of scarce nutrients, and a key strategy for reducing the cellular phosphorus (P) quota is to remodel membranes by replacing phospholipids with non-P surrogate lipids. A metallophosphoesterase, PlcP, is essential for lipid remodeling in cosmopolitan marine bacteria of the Roseobacter (e.g., Phaeobacter sp. strain MED193) and SAR11 (e.g., Pelagibacter sp. strain HTCC7211) clades, and transcription of plcP is known to be induced by P limitation. In order to better understand PlcP-mediated lipid remodeling, we sought to characterize PlcP for its metal ion requirement and to determine its selectivity for native bacterial phospholipids. Here, we report the occurrence of a highly conserved binuclear ion center in PlcPs from MED193 and HTCC7211 and show that manganese is the preferred metal for metallophosphoesterase activity. PlcP displayed high activity towards the major bacterial phospholipids, e.g., phosphatidylglycerol but also phosphatidic acid, a key intermediate in phospholipid biosynthesis. In contrast, phosphatidylserine and phosphatidylinositol, both of which are rare lipids in bacteria, are not preferred substrates. These data suggest that PlcP undertakes a generic lipid remodeling role during the cellular response of marine bacteria to P deficiency and that manganese availability may play a key role in regulating the lipid remodeling process.IMPORTANCE Membrane lipids form the structural basis of all cells. In the marine environment, it is well established that phosphorus availability significantly affects lipid composition in cosmopolitan marine bacteria, whereby non-phosphorus-containing lipids are used to replace phospholipids in response to phosphorus stress. Central to this lipid remodeling pathway is a newly identified phospholipase C-type metallophosphoesterase (PlcP). However, little is known about how PlcP activity is regulated. Here, we determined the role of metal ions in regulating PlcP activity and compared PlcP substrate specificities in PlcP enzymes from two model marine bacteria from the marine Roseobacter clade and the SAR11 clade. Our data provide new insights into the regulation of lipid remodeling in these marine bacteria.
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181
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Jing X, Gou H, Gong Y, Su X, Xu L, Ji Y, Song Y, Thompson IP, Xu J, Huang WE. Raman-activated cell sorting and metagenomic sequencing revealing carbon-fixing bacteria in the ocean. Environ Microbiol 2018; 20:2241-2255. [PMID: 29727057 PMCID: PMC6849569 DOI: 10.1111/1462-2920.14268] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 04/30/2018] [Accepted: 05/01/2018] [Indexed: 11/30/2022]
Abstract
It is of great significance to understand CO2 fixation in the oceans. Using single cell Raman spectra (SCRS) as biochemical profiles, Raman activated cell ejection (RACE) was able to link phenotypes and genotypes of cells. Here, we show that mini‐metagenomic sequences from RACE can be used as a reference to reconstruct nearly complete genomes of key functional bacteria by binning shotgun metagenomic sequencing data. By applying this approach to 13C bicarbonate spiked seawater from euphotic zone of the Yellow Sea of China, the dominant bacteria Synechococcus spp. and Pelagibacter spp. were revealed and both of them contain carotenoid and were able to incorporate 13C into the cells at the same time. Genetic analysis of the reconstructed genomes suggests that both Synechococcus spp. and Pelagibacter spp. contained all genes necessary for carotenoid synthesis, light energy harvesting and CO2 fixation. Interestingly, the reconstructed genome indicates that Pelagibacter spp. harbored intact sets of genes for β‐carotene (precursor of retional), proteorhodopsin synthesis and anaplerotic CO2 fixation. This novel approach shines light on the role of marine ‘microbial dark matter’ in global carbon cycling, by linking yet‐to‐be‐cultured Synechococcus spp. and Pelagibacter spp. to carbon fixation and flow activities in situ.
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Affiliation(s)
- Xiaoyan Jing
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, People's Republic of China.,Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK.,University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Honglei Gou
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Yanhai Gong
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Xiaolu Su
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - La Xu
- Disease and Fishery Drugs Research Center, Marine Biology Institute of Shandong Province, Qingdao, Shandong, People's Republic of China
| | - Yuetong Ji
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Yizhi Song
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
| | - Ian P Thompson
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
| | - Jian Xu
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, People's Republic of China.,University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Wei E Huang
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
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182
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Affe HMDJ, Rigonato J, Nunes JMDC, Menezes M. Metagenomic Analysis of Cyanobacteria in an Oligotrophic Tropical Estuary, South Atlantic. Front Microbiol 2018; 9:1393. [PMID: 29997603 PMCID: PMC6029486 DOI: 10.3389/fmicb.2018.01393] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 06/07/2018] [Indexed: 11/20/2022] Open
Abstract
This study assessed the species composition, distribution, and functional profiles of cyanobacteria in Camamu Bay, a tropical oligotrophic estuarine system on the northeast coast of Brazil, using shotgun metagenomic sequencing. Surface-water samples were evaluated in two different rainfall periods (rainy and dry seasons), at nine stations in the three hydrodynamic regions of the bay. At a fixed sampling station, on each season, samples were taken over a tidal cycle at 3-h intervals over 12 h. A total of 219 cyanobacterial taxa were identified, demonstrating a diverse community of freshwater, euryhaline, and marine cyanobacteria. The genera of greater relative abundance, Synechococcus and Prochlorococcus, corresponded to the picoplankton fraction. Although Camamu Bay has conspicuous marine characteristics, the contribution of freshwater during the rainy season caused variation in cyanobacteria community, with an increase in species richness. Due the high prevalence of Synechococcus (90% of the sequences), the functional analysis revealed only minor differences in gene content between the dry and rainy seasons. In both rainy and dry seasons, an increase in Prochlorococcus relative abundance occurred during high tide, demonstrating the tidal influence in the bay. The environmental characteristics of the bay provide niche conditions for a wide variety of cyanobacteria, including freshwater, euryhaline, and marine strains.
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Affiliation(s)
- Helen M de Jesus Affe
- Laboratório de Algas Marinhas, Instituto de Biologia, Universidade Federal da Bahia, Salvador, Brazil
| | - Janaina Rigonato
- Centro de Energia Nuclear e Agricultura, Universidade de São Paulo, Piracicaba, Brazil.,CEA, Centre de Sequençage Genoscope, Institut de Biologie François Jacob, Evry, France
| | - José M de Castro Nunes
- Laboratório de Algas Marinhas, Instituto de Biologia, Universidade Federal da Bahia, Salvador, Brazil
| | - Mariângela Menezes
- Laboratório de Ficologia, Departamento de Botânica, Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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183
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Swapnil P, Rai AK. Physiological responses to salt stress of salt-adapted and directly salt (NaCl and NaCl+Na 2SO 4 mixture)-stressed cyanobacterium Anabaena fertilissima. PROTOPLASMA 2018; 255:963-976. [PMID: 29352355 DOI: 10.1007/s00709-018-1205-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 01/10/2018] [Indexed: 05/13/2023]
Abstract
Soil salinity in nature is generally mixed type; however, most of the studies on salt toxicity are performed with NaCl and little is known about sulfur type of salinity (Na2SO4). Present study discerns the physiologic mechanisms responsible for salt tolerance in salt-adapted Anabaena fertilissima, and responses of directly stressed parent cells to NaCl and NaCl+Na2SO4 mixture. NaCl at 500 mM was lethal to the cyanobacterium, whereas salt-adapted cells grew luxuriantly. Salinity impaired gross photosynthesis, electron transport activities, and respiration in parent cells, but not in the salt-adapted cells, except a marginal increase in PSI activity. Despite higher Na+ concentration in the salt mixture, equimolar NaCl appeared more inhibitive to growth. Sucrose and trehalose content and antioxidant activities were maximal in 250 mM NaCl-treated cells, followed by salt mixture and was almost identical in salt-adapted (exposed to 500 mm NaCl) and control cells, except a marginal increase in ascorbate peroxidase activity and an additional fourth superoxide dismutase isoform. Catalase isoform of 63 kDa was induced only in salt-stressed cells. Salinity increased the uptake of intracellular Na+ and Ca2+ and leakage of K+ in parent cells, while cation level in salt-adapted cells was comparable to control. Though there was differential increase in intracellular Ca2+ under different salt treatments, ratio of Ca2+/Na+ remained the same. It is inferred that stepwise increment in the salt concentration enabled the cyanobacterium to undergo priming effect and acquire robust and efficient defense system involving the least energy.
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Affiliation(s)
- Prashant Swapnil
- Department of Botany, Banaras Hindu University, Varanasi, 221005, India
| | - Ashwani K Rai
- Department of Botany, Banaras Hindu University, Varanasi, 221005, India.
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184
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Thiel V, Tank M, Bryant DA. Diversity of Chlorophototrophic Bacteria Revealed in the Omics Era. ANNUAL REVIEW OF PLANT BIOLOGY 2018; 69:21-49. [PMID: 29505738 DOI: 10.1146/annurev-arplant-042817-040500] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Because of recent advances in omics methodologies, knowledge of chlorophototrophy (i.e., chlorophyll-based phototrophy) in bacteria has rapidly increased. Chlorophototrophs currently are known to occur in seven bacterial phyla: Cyanobacteria, Proteobacteria, Chlorobi, Chloroflexi, Firmicutes, Acidobacteria, and Gemmatimonadetes. Other organisms that can produce chlorophylls and photochemical reaction centers may still be undiscovered. Here we summarize the current status of the taxonomy and phylogeny of chlorophototrophic bacteria as revealed by genomic methods. In specific cases, we briefly describe important ecophysiological and metabolic insights that have been gained from the application of genomic methods to these bacteria. In the 20 years since the completion of the Synechocystis sp. PCC 6803 genome in 1996, approximately 1,100 genomes have been sequenced, which represents nearly the complete diversity of known chlorophototrophic bacteria. These data are leading to new insights into many important processes, including photosynthesis, nitrogen and carbon fixation, cellular differentiation and development, symbiosis, and ecosystem functionality.
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Affiliation(s)
- Vera Thiel
- Department of Biological Sciences, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan; ,
| | - Marcus Tank
- Department of Biological Sciences, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan; ,
| | - Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA;
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, USA
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185
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O'Brien S, Hesse E, Luján A, Hodgson DJ, Gardner A, Buckling A. No effect of intraspecific relatedness on public goods cooperation in a complex community. Evolution 2018; 72:1165-1173. [PMID: 29611186 PMCID: PMC5969229 DOI: 10.1111/evo.13479] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/06/2018] [Accepted: 03/14/2018] [Indexed: 01/06/2023]
Abstract
Many organisms—notably microbes—are embedded within complex communities where cooperative behaviors in the form of excreted public goods can benefit other species. Under such circumstances, intraspecific interactions are likely to be less important in driving the evolution of cooperation. We first illustrate this idea with a simple theoretical model, showing that relatedness—the extent to which individuals with the same cooperative alleles interact with each other—has a reduced impact on the evolution of cooperation when public goods are shared between species. We test this empirically using strain of Pseudomonas aeruginosa that vary in their production of metal‐chelating siderophores in copper contaminated compost (an interspecific public good). We show that nonsiderophore producers grow poorly relative to producers under high relatedness, but this cost can be alleviated by the presence of the isogenic producer (low relatedness) and/or the compost microbial community. Hence, relatedness can become unimportant when public goods provide interspecific benefits.
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Affiliation(s)
- Siobhán O'Brien
- Center for Adaptation to a Changing Environment (ACE), ETH Zürich, 8092, Zürich, Switzerland.,ESI & CEC, Biosciences, University of Exeter, TR10 9FE, Cornwall, United Kingdom
| | - Elze Hesse
- ESI & CEC, Biosciences, University of Exeter, TR10 9FE, Cornwall, United Kingdom
| | - Adela Luján
- ESI & CEC, Biosciences, University of Exeter, TR10 9FE, Cornwall, United Kingdom.,CIQUIBIC, Departamento de Química Biológica, Facultad de Ciencias Químicas, CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - David J Hodgson
- CEC, University of Exeter, TR10 9FE, Cornwall, United Kingdom
| | - Andy Gardner
- School of Biology, Dyers Brae, University of St Andrews, Fife KY16 9TH, St Andrews, United Kingdom
| | - Angus Buckling
- ESI & CEC, Biosciences, University of Exeter, TR10 9FE, Cornwall, United Kingdom
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186
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Di Cesare A, Cabello-Yeves PJ, Chrismas NAM, Sánchez-Baracaldo P, Salcher MM, Callieri C. Genome analysis of the freshwater planktonic Vulcanococcus limneticus sp. nov. reveals horizontal transfer of nitrogenase operon and alternative pathways of nitrogen utilization. BMC Genomics 2018; 19:259. [PMID: 29661139 PMCID: PMC5902973 DOI: 10.1186/s12864-018-4648-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 04/05/2018] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Many cyanobacteria are capable of fixing atmospheric nitrogen, playing a crucial role in biogeochemical cycling. Little is known about freshwater unicellular cyanobacteria Synechococcus spp. at the genomic level, despite being recognised of considerable ecological importance in aquatic ecosystems. So far, it has not been shown whether these unicellular picocyanobacteria have the potential for nitrogen fixation. Here, we present the draft-genome of the new pink-pigmented Synechococcus-like strain Vulcanococcus limneticus. sp. nov., isolated from the volcanic Lake Albano (Central Italy). RESULTS The novel species Vulcanococcus limneticus sp. nov. falls inside the sub-cluster 5.2, close to the estuarine/marine strains in a maximum-likelihood phylogenetic tree generated with 259 marker genes with representatives from marine, brackish, euryhaline and freshwater habitats. V.limneticus sp. nov. possesses a complete nitrogenase and nif operon. In an experimental setup under nitrogen limiting and non-limiting conditions, growth was observed in both cases. However, the nitrogenase genes (nifHDK) were not transcribed, i.e., V.limneticus sp. nov. did not fix nitrogen, but instead degraded the phycobilisomes to produce sufficient amounts of ammonia. Moreover, the strain encoded many other pathways to incorporate ammonia, nitrate and sulphate, which are energetically less expensive for the cell than fixing nitrogen. The association of the nif operon to a genomic island, the relatively high amount of mobile genetic elements (52 transposases) and the lower observed GC content of V.limneticus sp. nov. nif operon (60.54%) compared to the average of the strain (68.35%) support the theory that this planktonic strain may have obtained, at some point of its evolution, the nif operon by horizontal gene transfer (HGT) from a filamentous or heterocystous cyanobacterium. CONCLUSIONS In this study, we describe the novel species Vulcanococcus limneticus sp. nov., which possesses a complete nif operon for nitrogen fixation. The finding that in our experimental conditions V.limneticus sp. nov. did not express the nifHDK genes led us to reconsider the actual ecological meaning of these accessory genes located in genomic island that have possibly been acquired via HGT.
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Affiliation(s)
- Andrea Di Cesare
- National Research Council CNR-ISE, Largo Tonolli 50, 28922, Verbania, Italy.,Department of Earth, Environmental, and Life Sciences, University of Genoa, 16132, Genoa, Italy
| | - Pedro J Cabello-Yeves
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, San Juan de Alicante, Spain
| | - Nathan A M Chrismas
- School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, UK.,Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, UK
| | | | - Michaela M Salcher
- Limnological Station, Institute of Plant and Microbial Biology, University of Zurich, Kilchberg, Switzerland
| | - Cristiana Callieri
- National Research Council CNR-ISE, Largo Tonolli 50, 28922, Verbania, Italy.
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187
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Salhi N, Zmerli Triki H, Molinero JC, Laabir M, Sehli E, Bellaaj-Zouari A, Daly Yahia N, Kefi-Daly Yahia O. Seasonal variability of picophytoplankton under contrasting environments in northern Tunisian coasts, southwestern Mediterranean Sea. MARINE POLLUTION BULLETIN 2018; 129:866-874. [PMID: 29042106 DOI: 10.1016/j.marpolbul.2017.10.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 09/27/2017] [Accepted: 10/05/2017] [Indexed: 06/07/2023]
Abstract
We investigated at the single cell level during 16months (June 2012 to September 2013) the temporal distribution of picophytoplankton (picoeukaryotes, Synechococcus and Prochlorococcus) communities in two contrasted ecosystems: the Bay of Bizerte characterised by an oligotrophic regime typical of the Mediterranean Sea and the Bizerte Lagoon that exhibits a mesotrophic/eutrophic state. We aimed at depicting seasonal variations and quantifying the relationships between the environmental factors and the structure and abundance of picophytoplankton communities. Results showed that picophytoplankton groups were able to grow under a wide range of environmental conditions varying seasonally, although their abundances and contributions to the total chlorophyll biomass significantly varied and showed importance in the Bay of Bizerte. Synechococcus was the most abundant group reaching 225∗103cells·cm-3 in the Bay and 278∗103cells·cm-3 in the lagoon. This group was present all over the year in both ecosystems. Structural equation model results pointed out a different configuration regarding the picophytoplankton environmental drivers. The complexity of the configuration, i.e. number of significant links within the system, decreased under enhanced eutrophication conditions. The less exposure to anthropogenic stress, i.e. in the Bay of Bizerte, highlight a larger role of nutrient and hydrological conditions on the seasonal variations of picophytoplankton, whereas a negative effect of eutrophication on picophytoplankton communities was unveiled in the Bizerte Lagoon. We stress that such influence may be exacerbated under expected scenarios of Mediterranean warming conditions and nutrient release in coastal ecosystems.
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Affiliation(s)
- N Salhi
- Institut National Agronomique de Tunisie, IRESA - Université de Carthage, 43 avenue Charles Nicolle, 1082 Tunis, Tunisia; Laboratoire de Biodiversité et Fonctionnement des Systèmes Aquatiques, Faculté des Sciences de Bizerte, Université de Carthage, 7021 Zarzouna, Tunisia; Laboratory of Water, Membrane and Biotechnologies of Environnement, Centre of Research and Water Technologies (CERTE), Technopark of Borj-Cedria, Tunisia
| | - H Zmerli Triki
- Institut National Agronomique de Tunisie, IRESA - Université de Carthage, 43 avenue Charles Nicolle, 1082 Tunis, Tunisia
| | - J C Molinero
- GEOMAR Helmholtz Center for Ocean Research, Kiel, Germany; Marine Ecology/Food Webs, Duesternbrooker Weg 20, D-24105 Kiel, Germany
| | - M Laabir
- Center for Marine Biodiversity, Exploitation and Conservation (MARBEC), Montpellier University, CNRS, IRD, Ifremer, Place Eugène, Bataillon, CC093, 34095 Montpellier Cedex 5, France
| | - E Sehli
- Institut National des Sciences et Technologies de la Mer, 28 rue 2 Mars 1934, 2025 Carthage Salammbô, Tunisia
| | - A Bellaaj-Zouari
- Institut National des Sciences et Technologies de la Mer, 28 rue 2 Mars 1934, 2025 Carthage Salammbô, Tunisia
| | - N Daly Yahia
- Laboratoire de Biodiversité et Fonctionnement des Systèmes Aquatiques, Faculté des Sciences de Bizerte, Université de Carthage, 7021 Zarzouna, Tunisia
| | - O Kefi-Daly Yahia
- Institut National Agronomique de Tunisie, IRESA - Université de Carthage, 43 avenue Charles Nicolle, 1082 Tunis, Tunisia.
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188
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Chrismas NAM, Anesio AM, Sánchez-Baracaldo P. The future of genomics in polar and alpine cyanobacteria. FEMS Microbiol Ecol 2018; 94:4904125. [PMID: 29506259 PMCID: PMC5939894 DOI: 10.1093/femsec/fiy032] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 02/23/2018] [Indexed: 01/01/2023] Open
Abstract
In recent years, genomic analyses have arisen as an exciting way of investigating the functional capacity and environmental adaptations of numerous micro-organisms of global relevance, including cyanobacteria. In the extreme cold of Arctic, Antarctic and alpine environments, cyanobacteria are of fundamental ecological importance as primary producers and ecosystem engineers. While their role in biogeochemical cycles is well appreciated, little is known about the genomic makeup of polar and alpine cyanobacteria. In this article, we present ways that genomic techniques might be used to further our understanding of cyanobacteria in cold environments in terms of their evolution and ecology. Existing examples from other environments (e.g. marine/hot springs) are used to discuss how methods developed there might be used to investigate specific questions in the cryosphere. Phylogenomics, comparative genomics and population genomics are identified as methods for understanding the evolution and biogeography of polar and alpine cyanobacteria. Transcriptomics will allow us to investigate gene expression under extreme environmental conditions, and metagenomics can be used to complement tradition amplicon-based methods of community profiling. Finally, new techniques such as single cell genomics and metagenome assembled genomes will also help to expand our understanding of polar and alpine cyanobacteria that cannot readily be cultured.
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Affiliation(s)
- Nathan A M Chrismas
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, University Road, Bristol, BS8 1SS, UK
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, PL1 2PB, UK
| | - Alexandre M Anesio
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, University Road, Bristol, BS8 1SS, UK
| | - Patricia Sánchez-Baracaldo
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, University Road, Bristol, BS8 1SS, UK
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189
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Berthold M, Karstens S, Buczko U, Schumann R. Potential export of soluble reactive phosphorus from a coastal wetland in a cold-temperate lagoon system: Buffer capacities of macrophytes and impact on phytoplankton. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 616-617:46-54. [PMID: 29107778 DOI: 10.1016/j.scitotenv.2017.10.244] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 10/24/2017] [Accepted: 10/24/2017] [Indexed: 06/07/2023]
Abstract
The main pathways for phosphorus flux from land to sea are particle-associated (erosion) and dissolved runoff (rivers, groundwater, and agricultural drainage systems). These pathways can act as diffused sources for aquatic systems and support primary production, therefore, counteracting the efforts aimed at reducing phosphorus input from point sources such as sewage treatment plants. Phosphorus supports primary production in the water column and can elevate phytoplankton and macrophyte growth. Coastal wetlands with emerged (Phragmites australis) and submerged (Stuckenia pectinata and Chara sp.) macrophytes can affect phosphorus fluxes in the land-water transitional zone. The macrophytes have the potential to act as a buffer for phosphorus run-off. The aim of this study was to determine the phosphorus stocks in the transitional land-sea zone of a cold temperate lagoon at the southern Baltic Sea. Phosphorus in macrophytes, water samples, and phytoplankton growth were analyzed along a gradient moving away from the wetland. The phosphorus stocks in the above ground biomass of the Phragmites plants were the highest at the end of August and with more than 8000mgPm-2 in the interior zone of the wetland, threefold the amount of P in Phragmites plant tissue at the wetland fringe. The submerged macrophytes stored only 300mgPm-2, close to the wetland. Concentrations of soluble reactive phosphorus in the water column were higher in the zones of emerged macrophytes than in the zones of submerged macrophytes and decreased along the land-sea transect. Phytoplankton could grow proximal to the wetland during all seasons, but not further away. This study indicates that macrophytes can act as phosphorus sinks. However, short-term releases of phosphate within the Phragmites wetland have the potential to lead to phytoplankton growth. Phytoplankton can use these nutrient pulses either immediately or later, and support high biomass and turbidity within the system.
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Affiliation(s)
- M Berthold
- University of Rostock, Applied Ecology and Phycology, Biological Station Zingst, Mühlenstraße, 2718374 Zingst, Germany.
| | - S Karstens
- EUCC - Coastal Union Germany, Technologiezentrum Warnemünde, Friedrich-Barnewitz-Straße 3, 18119 Rostock, Germany; University of Rostock, Landscape Ecology and Site Evaluation, Justus-von-Liebig-Weg 6, 18059 Rostock, Germany
| | - U Buczko
- University of Rostock, Landscape Ecology and Site Evaluation, Justus-von-Liebig-Weg 6, 18059 Rostock, Germany
| | - R Schumann
- University of Rostock, Applied Ecology and Phycology, Biological Station Zingst, Mühlenstraße, 2718374 Zingst, Germany
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190
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Clark RL, Gordon GC, Bennett NR, Lyu H, Root TW, Pfleger BF. High-CO 2 Requirement as a Mechanism for the Containment of Genetically Modified Cyanobacteria. ACS Synth Biol 2018; 7:384-391. [PMID: 29320853 DOI: 10.1021/acssynbio.7b00377] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
As researchers engineer cyanobacteria for biotechnological applications, we must consider potential environmental release of these organisms. Previous theoretical work has considered cyanobacterial containment through elimination of the CO2-concentrating mechanism (CCM) to impose a high-CO2 requirement (HCR), which could be provided in the cultivation environment but not in the surroundings. In this work, we experimentally implemented an HCR containment mechanism in Synechococcus sp. strain PCC7002 (PCC7002) through deletion of carboxysome shell proteins and showed that this mechanism contained cyanobacteria in a 5% CO2 environment. We considered escape through horizontal gene transfer (HGT) and reduced the risk of HGT escape by deleting competence genes. We showed that the HCR containment mechanism did not negatively impact the performance of a strain of PCC7002 engineered for L-lactate production. We showed through coculture experiments of HCR strains with ccm-containing strains that this HCR mechanism reduced the frequency of escape below the NIH recommended limit for recombinant organisms of one escape event in 108 CFU.
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Affiliation(s)
- Ryan L. Clark
- Department
of Chemical and Biological Engineering, University of Wisconsin − Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Gina C. Gordon
- Department
of Chemical and Biological Engineering, University of Wisconsin − Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
- Microbiology
Doctoral Training Program, University of Wisconsin − Madison, 1550 Linden Drive, Madison, Wisconsin 53706, United States
| | - Nathaniel R. Bennett
- Department
of Chemical and Biological Engineering, University of Wisconsin − Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Haoxiang Lyu
- Department
of Chemical and Biological Engineering, University of Wisconsin − Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Thatcher W. Root
- Department
of Chemical and Biological Engineering, University of Wisconsin − Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Brian F. Pfleger
- Department
of Chemical and Biological Engineering, University of Wisconsin − Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
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191
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Zheng Q, Wang Y, Xie R, Lang AS, Liu Y, Lu J, Zhang X, Sun J, Suttle CA, Jiao N. Dynamics of Heterotrophic Bacterial Assemblages within Synechococcus Cultures. Appl Environ Microbiol 2018; 84:e01517-17. [PMID: 29150500 PMCID: PMC5772231 DOI: 10.1128/aem.01517-17] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 11/02/2017] [Indexed: 02/01/2023] Open
Abstract
Interactions between photoautotrophic and heterotrophic microorganisms are central to the marine microbial ecosystem. Lab cultures of one of the dominant marine photoautotrophs, Synechococcus, have historically been difficult to render axenic, presumably because these bacteria depend upon other organisms to grow under these conditions. These tight associations between Synechococcus and heterotrophic bacteria represent a good relevant system to study interspecies interactions. Ten individual Synechococcus strains, isolated from eutrophic and oligotrophic waters, were chosen for investigation. Four to six dominant associated heterotrophic bacteria were detected in the liquid cultures of each Synechococcus isolate, comprising members of the Cytophaga-Flavobacteria-Bacteroides (CFB) group (mainly from Flavobacteriales and Cytophagales), Alphaproteobacteria (mainly from the Roseobacter clade), Gammaproteobacteria (mainly from the Alteromonadales and Pseudomonadales), and Actinobacteria The presence of the CFB group, Gammaproteobacteria, and Actinobacteria showed clear geographic patterns related to the isolation environments of the Synechococcus bacteria. An investigation of the population dynamics within a growing culture (XM-24) of one of the isolates, including an evaluation of the proportions of cells that were free-living versus aggregated/attached, revealed interesting patterns for different bacterial groups. In Synechococcus sp. strain XM-24 culture, flavobacteria, which was the most abundant group throughout the culture period, tended to be aggregated or attached to the Synechococcus cells, whereas the actinobacteria demonstrated a free-living lifestyle, and roseobacters displayed different patterns depending on the culture growth phase. Factors contributing to these succession patterns for the heterotrophs likely include interactions among the culture community members, their relative abilities to utilize different compounds produced by Synechococcus cells and changes in the compounds released as culture growth proceeds, and their responses to other changes in the environmental conditions throughout the culture period.IMPORTANCE Marine microbes exist within an interactive ecological network, and studying their interactions is an important part of understanding their roles in global biogeochemical cycling and the determinants of microbial diversity. In this study, the dynamic relationships between Synechococcus spp. and their associated heterotrophic bacteria were investigated. Synechococcus-associated heterotrophic bacteria had similar geographic distribution patterns as their "host" and displayed different lifestyles (free-living versus attached/aggregated) according to the Synechococcus culture growth phases. Combined organic carbon composition and bacterial lifestyle data indicated a potential for succession in carbon utilization patterns by the dominant associated heterotrophic bacteria. Comprehending the interactions between photoautotrophs and heterotrophs and the patterns of organic carbon excretion and utilization is critical to understanding their roles in oceanic biogeochemical cycling.
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Affiliation(s)
- Qiang Zheng
- State Key Laboratory for Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, People's Republic of China
| | - Yu Wang
- State Key Laboratory for Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, People's Republic of China
| | - Rui Xie
- State Key Laboratory for Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, People's Republic of China
| | - Andrew S Lang
- Department of Biology, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Yanting Liu
- State Key Laboratory for Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, People's Republic of China
| | - Jiayao Lu
- State Key Laboratory for Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, People's Republic of China
| | - Xiaodong Zhang
- College of Marine and Environmental Sciences, Tianjin University of Science and Technology, Tianjin, People's Republic of China
| | - Jun Sun
- College of Marine and Environmental Sciences, Tianjin University of Science and Technology, Tianjin, People's Republic of China
| | - Curtis A Suttle
- Departments of Earth, Ocean and Atmospheric Sciences, Microbiology and Immunology, and Botany and Institute for the Oceans and Fisheries, The University of British Columbia, Vancouver, British Columbia, Canada
- Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario, Canada
| | - Nianzhi Jiao
- State Key Laboratory for Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, People's Republic of China
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192
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Ma L, Calfee BC, Morris JJ, Johnson ZI, Zinser ER. Degradation of hydrogen peroxide at the ocean's surface: the influence of the microbial community on the realized thermal niche of Prochlorococcus. THE ISME JOURNAL 2018; 12:473-484. [PMID: 29087377 PMCID: PMC5776462 DOI: 10.1038/ismej.2017.182] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 09/14/2017] [Accepted: 09/22/2017] [Indexed: 02/06/2023]
Abstract
Prochlorococcus, the smallest and most abundant phytoplankter in the ocean, is highly sensitive to hydrogen peroxide (HOOH), and co-occurring heterotrophs such as Alteromonas facilitate the growth of Prochlorococcus by scavenging HOOH. Temperature is also a major influence on Prochlorococcus abundance and distribution in the ocean, and studies in other photosynthetic organisms have shown that HOOH and temperature extremes can act together as synergistic stressors. To address potential synergistic effects of temperature and HOOH on Prochlorococcus growth, high- and low-temperature-adapted representative strains were cultured at ecologically relevant concentrations under a range of HOOH concentrations and temperatures. Higher concentrations of HOOH severely diminished the permissive temperature range for growth of both Prochlorococcus strains. At the permissive temperatures, the growth rates of both Prochlorococcus strains decreased as a function of HOOH, and cold temperature increased susceptibility of photosystem II to HOOH-mediated damage. Serving as a proxy for the natural community, co-cultured heterotrophic bacteria increased the Prochlorococcus growth rate under these temperatures, and expanded the permissive range of temperature for growth. These studies indicate that in the ocean, the cross-protective function of the microbial community may confer a fitness increase for Prochlorococcus at its temperature extremes, especially near the ocean surface where oxidative stress is highest. This interaction may play a substantial role in defining the realized thermal niche and habitat range of Prochlorococcus with respect to latitude.
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Affiliation(s)
- Lanying Ma
- Department of Microbiology, University of Tennessee, Knoxville, TN, USA
| | - Benjamin C Calfee
- Department of Microbiology, University of Tennessee, Knoxville, TN, USA
| | - J Jeffrey Morris
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Zackary I Johnson
- Nicholas School of the Environment and Biology Department, Duke University Marine Laboratory, Beaufort, NC, USA
| | - Erik R Zinser
- Department of Microbiology, University of Tennessee, Knoxville, TN, USA.
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193
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Puxty RJ, Evans DJ, Millard AD, Scanlan DJ. Energy limitation of cyanophage development: implications for marine carbon cycling. ISME JOURNAL 2018; 12:1273-1286. [PMID: 29379179 PMCID: PMC5931967 DOI: 10.1038/s41396-017-0043-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 11/25/2017] [Accepted: 12/09/2017] [Indexed: 11/16/2022]
Abstract
Marine cyanobacteria are responsible for ~25% of the fixed carbon that enters the ocean biosphere. It is thought that abundant co-occurring viruses play an important role in regulating population dynamics of cyanobacteria and thus the cycling of carbon in the oceans. Despite this, little is known about how viral infections ‘play-out’ in the environment, particularly whether infections are resource or energy limited. Photoautotrophic organisms represent an ideal model to test this since available energy is modulated by the incoming light intensity through photophosphorylation. Therefore, we exploited phototrophy of the environmentally relevant marine cyanobacterium Synechococcus and monitored growth of a cyanobacterial virus (cyanophage). We found that light intensity has a marked effect on cyanophage infection dynamics, but that this is not manifest by a change in DNA synthesis. Instead, cyanophage development appears energy limited for the synthesis of proteins required during late infection. We posit that acquisition of auxiliary metabolic genes (AMGs) involved in light-dependent photosynthetic reactions acts to overcome this limitation. We show that cyanophages actively modulate expression of these AMGs in response to light intensity and provide evidence that such regulation may be facilitated by a novel mechanism involving light-dependent splicing of a group I intron in a photosynthetic AMG. Altogether, our data offers a mechanistic link between diurnal changes in irradiance and observed community level responses in metabolism, i.e., through an irradiance-dependent, viral-induced release of dissolved organic matter (DOM).
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Affiliation(s)
- Richard J Puxty
- School of Life Sciences, University of Warwick, Coventry, West Midlands, CV4 7AL, UK
| | - David J Evans
- School of Biology and BSRC, Biomolecular Sciences Building, North Haugh, St Andrews, KY16 9AJ, UK
| | - Andrew D Millard
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, LE1 9HNL, UK
| | - David J Scanlan
- School of Life Sciences, University of Warwick, Coventry, West Midlands, CV4 7AL, UK.
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194
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Morimoto D, Kimura S, Sako Y, Yoshida T. Transcriptome Analysis of a Bloom-Forming Cyanobacterium Microcystis aeruginosa during Ma-LMM01 Phage Infection. Front Microbiol 2018; 9:2. [PMID: 29403457 PMCID: PMC5780444 DOI: 10.3389/fmicb.2018.00002] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 01/03/2018] [Indexed: 01/21/2023] Open
Abstract
Microcystis aeruginosa forms massive blooms in eutrophic freshwaters, where it is constantly exposed to lytic cyanophages. Unlike other marine cyanobacteria, M. aeruginosa possess remarkably abundant and diverse potential antiviral defense genes. Interestingly, T4-like cyanophage Ma-LMM01, which is the sole cultured lytic cyanophage infecting M. aeruginosa, lacks the host-derived genes involved in maintaining host photosynthesis and directing host metabolism that are abundant in other marine cyanophages. Based on genomic comparisons with closely related cyanobacteria and their phages, Ma-LMM01 is predicted to employ a novel infection program that differs from that of other marine cyanophages. Here, we used RNA-seq technology and in silico analysis to examine transcriptional dynamics during Ma-LMM01 infection to reveal host transcriptional responses to phage infection, and to elucidate the infection program used by Ma-LMM01 to avoid the highly abundant host defense systems. Phage-derived reads increased only slightly at 1 h post-infection, but significantly increased from 16% of total cellular reads at 3 h post-infection to 33% of all reads by 6 h post-infection. Strikingly, almost none of the host genes (0.17%) showed a significant change in expression during infection. However, like other lytic dsDNA phages, including marine cyanophages, phage gene dynamics revealed three expression classes: early (host-takeover), middle (replication), and late (virion morphogenesis). The early genes were concentrated in a single ∼5.8-kb window spanning 10 open reading frames (gp054-gp063) on the phage genome. None of the early genes showed homology to the early genes of other T4-like phages, including known marine cyanophages. Bacterial RNA polymerase (σ70) recognition sequences were also found in the upstream region of middle and late genes, whereas phage-specific motifs were not found. Our findings suggest that unlike other known T4-like phages, Ma-LMM01 achieves three sequential gene expression patterns with no change in host promoter activity. This type of infection that does not cause significant change in host transcriptional levels may be advantageous in allowing Ma-LMM01 to escape host defense systems while maintaining host photosynthesis.
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Affiliation(s)
- Daichi Morimoto
- Laboratory of Marine Microbiology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Shigeko Kimura
- Laboratory of Marine Microbiology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
- School of Environmental Science, University of Shiga Prefecture, Hikone, Japan
| | - Yoshihiko Sako
- Laboratory of Marine Microbiology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Takashi Yoshida
- Laboratory of Marine Microbiology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
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195
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Domínguez-Martín MA, López-Lozano A, Clavería-Gimeno R, Velázquez-Campoy A, Seidel G, Burkovski A, Díez J, García-Fernández JM. Differential NtcA Responsiveness to 2-Oxoglutarate Underlies the Diversity of C/N Balance Regulation in Prochlorococcus. Front Microbiol 2018; 8:2641. [PMID: 29375510 PMCID: PMC5767323 DOI: 10.3389/fmicb.2017.02641] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 12/19/2017] [Indexed: 11/29/2022] Open
Abstract
Previous studies showed differences in the regulatory response to C/N balance in Prochlorococcus with respect to other cyanobacteria, but no information was available about its causes, or the ecological advantages conferred to thrive in oligotrophic environments. We addressed the changes in key enzymes (glutamine synthetase, isocitrate dehydrogenase) and the ntcA gene (the global nitrogen regulator) involved in C/N metabolism and its regulation, in three model Prochlorococcus strains: MED4, SS120, and MIT9313. We observed a remarkable level of diversity in their response to azaserine, a glutamate synthase inhibitor which increases the concentration of the key metabolite 2-oxoglutarate, used to sense the C/N balance by cyanobacteria. Besides, we studied the binding between the global nitrogen regulator (NtcA) and the promoter of the glnA gene in the same Prochlorococcus strains, and its dependence on the 2-oxoglutarate concentration, by using isothermal titration calorimetry, surface plasmon resonance, and electrophoretic mobility shift. Our results show a reduction in the responsiveness of NtcA to 2-oxoglutarate in Prochlorococcus, especially in the MED4 and SS120 strains. This suggests a trend to streamline the regulation of C/N metabolism in late-branching Prochlorococcus strains (MED4 and SS120), in adaptation to the rather stable conditions found in the oligotrophic ocean gyres where this microorganism is most abundant.
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Affiliation(s)
- María A Domínguez-Martín
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain
| | - Antonio López-Lozano
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain
| | - Rafael Clavería-Gimeno
- Institute of Biocomputation and Physics of Complex Systems (BIFI), Joint Units BIFI-IQFR-CSIC and GBsC-BIFI-CSIC, Universidad de Zaragoza, Zaragoza, Spain.,Aragon Institute for Health Research (IIS Aragon), Zaragoza, Spain.,Instituto Aragonés de Ciencias de la Salud, Zaragoza, Spain
| | - Adrián Velázquez-Campoy
- Institute of Biocomputation and Physics of Complex Systems (BIFI), Joint Units BIFI-IQFR-CSIC and GBsC-BIFI-CSIC, Universidad de Zaragoza, Zaragoza, Spain.,Aragon Institute for Health Research (IIS Aragon), Zaragoza, Spain.,Centro de Investigación Biomédica en Red en el Área Temática de Enfermedades Hepáticas y Digestivas, Barcelona, Spain.,Fundación ARAID, Gobierno de Aragón, Zaragoza, Spain
| | - Gerald Seidel
- Professur für Mikrobiologie, Department Biologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Andreas Burkovski
- Professur für Mikrobiologie, Department Biologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jesús Díez
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain
| | - José M García-Fernández
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain
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196
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Berthold M, Karsten U, von Weber M, Bachor A, Schumann R. Phytoplankton can bypass nutrient reductions in eutrophic coastal water bodies. AMBIO 2018; 47:146-158. [PMID: 29164540 PMCID: PMC5722746 DOI: 10.1007/s13280-017-0980-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The EU-water framework directive aims at nutrient reductions, since anthropogenically induced eutrophication is a major threat for coastal waters. However, phytoplankton biomass in southern Baltic Sea coastal water bodies (CWB) remains high and the underlying mechanisms are not well understood. Therefore, a CWB data set was analysed regarding changes in phytoplankton biomass and nutrient concentration of nitrogen (N) and phosphorus (P) from 2000 to 2014. It was expected to find imbalances between produced phytoplankton biomass and total nutrient concentrations. Inner CWB were cyanobacteria-dominated and showed up to five times higher chlorophyll a-concentrations compared to outer CWB with similar total phosphorus-concentrations. Phytoplankton tended to be P-limited during spring and N-limited during summer. Phytoplankton biomass and nutrient concentrations were even higher during very humid years, which indicated a close coupling of the CWB with their catchment areas. This study suggests that re-mesotrophication efforts need to consider the importance of changed phytoplankton composition and nutrient availabilities.
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Affiliation(s)
- Maximilian Berthold
- Institute of Biological Sciences, Applied Ecology and Phycology, Biological Station Zingst, University of Rostock, Mühlenstraße 27, 18374 Zingst, Germany
| | - Ulf Karsten
- Institute of Biological Sciences, Applied Ecology and Phycology, University of Rostock, Albert-Einsteinstraße 3, 18051 Rostock, Germany
| | - Mario von Weber
- State Agency for Environment, Nature Conservation and Geology Mecklenburg-Vorpommern, Goldberger Straße 12, 18273 Güstrow, Germany
| | | | - Rhena Schumann
- Institute of Biological Sciences, Applied Ecology and Phycology, Biological Station Zingst, University of Rostock, Mühlenstraße 27, 18374 Zingst, Germany
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197
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Cabello-Yeves PJ, Zemskaya TI, Rosselli R, Coutinho FH, Zakharenko AS, Blinov VV, Rodriguez-Valera F. Genomes of Novel Microbial Lineages Assembled from the Sub-Ice Waters of Lake Baikal. Appl Environ Microbiol 2018; 84:e02132-17. [PMID: 29079621 PMCID: PMC5734018 DOI: 10.1128/aem.02132-17] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 10/19/2017] [Indexed: 11/20/2022] Open
Abstract
We present a metagenomic study of Lake Baikal (East Siberia). Two samples obtained from the water column under the ice cover (5 and 20 m deep) in March 2016 have been deep sequenced and the reads assembled to generate metagenome-assembled genomes (MAGs) that are representative of the microbes living in this special environment. Compared with freshwater bodies studied around the world, Lake Baikal had an unusually high fraction of Verrucomicrobia Other groups, such as Actinobacteria and Proteobacteria, were in proportions similar to those found in other lakes. The genomes (and probably cells) tended to be small, presumably reflecting the extremely oligotrophic and cold prevalent conditions. Baikal microbes are novel lineages recruiting very little from other water bodies and are distantly related to other freshwater microbes. Despite their novelty, they showed the closest relationship to genomes discovered by similar approaches from other freshwater lakes and reservoirs. Some of them were particularly similar to MAGs from the Baltic Sea, which, although it is brackish, connected to the ocean, and much more eutrophic, has similar climatological conditions. Many of the microbes contained rhodopsin genes, indicating that, in spite of the decreased light penetration allowed by the thick ice/snow cover, photoheterotrophy could be widespread in the water column, either because enough light penetrates or because the microbes are already adapted to the summer ice-less conditions. We have found a freshwater SAR11 subtype I/II representative showing striking synteny with Pelagibacterubique strains, as well as a phage infecting the widespread freshwater bacterium PolynucleobacterIMPORTANCE Despite the increasing number of metagenomic studies on different freshwater bodies, there is still a missing component in oligotrophic cold lakes suffering from long seasonal frozen cycles. Here, we describe microbial genomes from metagenomic assemblies that appear in the upper water column of Lake Baikal, the largest and deepest freshwater body on Earth. This lake is frozen from January to May, which generates conditions that include an inverted temperature gradient (colder up), decrease in light penetration due to ice, and, especially, snow cover, and oligotrophic conditions more similar to the open-ocean and high-altitude lakes than to other freshwater or brackish systems. As could be expected, most reconstructed genomes are novel lineages distantly related to others in cold environments, like the Baltic Sea and other freshwater lakes. Among them, there was a broad set of streamlined microbes with small genomes/intergenic spacers, including a new nonmarine Pelagibacter-like (subtype I/II) genome.
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Affiliation(s)
- Pedro J Cabello-Yeves
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, San Juan de Alicante, Alicante, Spain
| | - Tamara I Zemskaya
- Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia
| | - Riccardo Rosselli
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, San Juan de Alicante, Alicante, Spain
| | - Felipe H Coutinho
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, San Juan de Alicante, Alicante, Spain
| | - Alexandra S Zakharenko
- Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia
| | - Vadim V Blinov
- Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia
| | - Francisco Rodriguez-Valera
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, San Juan de Alicante, Alicante, Spain
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198
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Domínguez-Martín MA, López-Lozano A, Rangel-Zúñiga OA, Díez J, García-Fernández JM. Distinct features of C/N balance regulation in Prochlorococcus sp. strain MIT9313. FEMS Microbiol Lett 2017; 365:4757061. [DOI: 10.1093/femsle/fnx278] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 12/17/2017] [Indexed: 11/13/2022] Open
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199
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Kaur A, Hernandez-Fernaud JR, Aguilo-Ferretjans MDM, Wellington EM, Christie-Oleza JA. 100 Days of marine Synechococcus-Ruegeria pomeroyi interaction: A detailed analysis of the exoproteome. Environ Microbiol 2017; 20:785-799. [PMID: 29194907 PMCID: PMC5839243 DOI: 10.1111/1462-2920.14012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 11/23/2017] [Indexed: 12/03/2022]
Abstract
Marine phototroph and heterotroph interactions are vital in maintaining the nutrient balance in the oceans as essential nutrients need to be rapidly cycled before sinking to aphotic layers. The aim of this study was to highlight the molecular mechanisms that drive these interactions. For this, we generated a detailed exoproteomic time‐course analysis of a 100‐day co‐culture between the model marine picocyanobacterium Synechococcus sp. WH7803 and the Roseobacter strain Ruegeria pomeroyi DSS‐3, both in nutrient‐enriched and natural oligotrophic seawater. The proteomic data showed a transition between the initial growth phase and stable‐state phase that, in the case of the heterotroph, was caused by a switch in motility attributed to organic matter availability. The phototroph adapted to seawater oligotrophy by reducing its selective leakiness, increasing the acquisition of essential nutrients and secreting conserved proteins of unknown function. We also report a surprisingly high abundance of extracellular superoxide dismutase produced by Synechococcus and a dynamic secretion of potential hydrolytic enzyme candidates used by the heterotroph to cleave organic groups and hydrolase polymeric organic matter produced by the cyanobacterium. The time course dataset we present here will become a reference for understanding the molecular processes underpinning marine phototroph‐heterotroph interactions.
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Affiliation(s)
- Amandeep Kaur
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
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200
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Pittera J, Jouhet J, Breton S, Garczarek L, Partensky F, Maréchal É, Nguyen NA, Doré H, Ratin M, Pitt FD, Scanlan DJ, Six C. Thermoacclimation and genome adaptation of the membrane lipidome in marine Synechococcus. Environ Microbiol 2017; 20:612-631. [PMID: 29124854 DOI: 10.1111/1462-2920.13985] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 10/20/2017] [Accepted: 11/02/2017] [Indexed: 12/01/2022]
Abstract
The marine cyanobacteria of the genus Synechococcus are important primary producers, displaying a wide latitudinal distribution that is underpinned by diversification into temperature ecotypes. The physiological basis underlying these ecotypes is poorly known. In many organisms, regulation of membrane fluidity is crucial for acclimating to variations in temperature. Here, we reveal the detailed composition of the membrane lipidome of the model strain Synechococcus sp. WH7803 and its response to temperature variation. Unlike freshwater strains, membranes are almost devoid of C18, mainly containing C14 and C16 chains with no more than two unsaturations. In response to cold, we observed a rarely observed process of acyl chain shortening that likely induces membrane thinning, along with specific desaturation activities. Both of these mechanisms likely regulate membrane fluidity, facilitating the maintenance of efficient photosynthetic activity. A comprehensive examination of 53 Synechococcus genomes revealed clade-specific gene sets regulating membrane lipids. In particular, the genes encoding desaturase enzymes, which is a key to the temperature stress response, appeared to be temperature ecotype-specific, with some of them originating from lateral transfers. Our study suggests that regulation of membrane fluidity has been among the important adaptation processes for the colonization of different thermal niches by marine Synechococcus.
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Affiliation(s)
- Justine Pittera
- Marine Phototrophic Prokaryotes group, Station Biologique, Place Georges Teissier, Sorbonne Universités, Université Pierre and Marie Curie (Paris 06) and Centre National de la Recherche Scientifique, UMR 7144, 29688 Roscoff cedex, CS 90074, France
| | - Juliette Jouhet
- Institut de Biosciences et Biotechnologies de Grenoble, CEA Grenoble, Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 Centre National de la Recherche Scientifique, Commissariat à l'Energie Atomique, Institut National de la Recherche Agronomique, Université Grenoble Alpes, 38054 Grenoble cedex 9, France
| | - Solène Breton
- Marine Phototrophic Prokaryotes group, Station Biologique, Place Georges Teissier, Sorbonne Universités, Université Pierre and Marie Curie (Paris 06) and Centre National de la Recherche Scientifique, UMR 7144, 29688 Roscoff cedex, CS 90074, France
| | - Laurence Garczarek
- Marine Phototrophic Prokaryotes group, Station Biologique, Place Georges Teissier, Sorbonne Universités, Université Pierre and Marie Curie (Paris 06) and Centre National de la Recherche Scientifique, UMR 7144, 29688 Roscoff cedex, CS 90074, France
| | - Frédéric Partensky
- Marine Phototrophic Prokaryotes group, Station Biologique, Place Georges Teissier, Sorbonne Universités, Université Pierre and Marie Curie (Paris 06) and Centre National de la Recherche Scientifique, UMR 7144, 29688 Roscoff cedex, CS 90074, France
| | - Éric Maréchal
- Institut de Biosciences et Biotechnologies de Grenoble, CEA Grenoble, Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 Centre National de la Recherche Scientifique, Commissariat à l'Energie Atomique, Institut National de la Recherche Agronomique, Université Grenoble Alpes, 38054 Grenoble cedex 9, France
| | - Ngoc A Nguyen
- Marine Phototrophic Prokaryotes group, Station Biologique, Place Georges Teissier, Sorbonne Universités, Université Pierre and Marie Curie (Paris 06) and Centre National de la Recherche Scientifique, UMR 7144, 29688 Roscoff cedex, CS 90074, France
| | - Hugo Doré
- Marine Phototrophic Prokaryotes group, Station Biologique, Place Georges Teissier, Sorbonne Universités, Université Pierre and Marie Curie (Paris 06) and Centre National de la Recherche Scientifique, UMR 7144, 29688 Roscoff cedex, CS 90074, France
| | - Morgane Ratin
- Marine Phototrophic Prokaryotes group, Station Biologique, Place Georges Teissier, Sorbonne Universités, Université Pierre and Marie Curie (Paris 06) and Centre National de la Recherche Scientifique, UMR 7144, 29688 Roscoff cedex, CS 90074, France
| | - Frances D Pitt
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - David J Scanlan
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Christophe Six
- Marine Phototrophic Prokaryotes group, Station Biologique, Place Georges Teissier, Sorbonne Universités, Université Pierre and Marie Curie (Paris 06) and Centre National de la Recherche Scientifique, UMR 7144, 29688 Roscoff cedex, CS 90074, France
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