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Park H, Bulzu PA, Shabarova T, Kavagutti VS, Ghai R, Kasalický V, Jezberová J. Uncovering the genomic basis of symbiotic interactions and niche adaptations in freshwater picocyanobacteria. MICROBIOME 2024; 12:150. [PMID: 39127705 DOI: 10.1186/s40168-024-01867-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Accepted: 07/03/2024] [Indexed: 08/12/2024]
Abstract
BACKGROUND Picocyanobacteria from the genera Prochlorococcus, Synechococcus, and Cyanobium are the most widespread photosynthetic organisms in aquatic ecosystems. However, their freshwater populations remain poorly explored, due to uneven and insufficient sampling across diverse inland waterbodies. RESULTS In this study, we present 170 high-quality genomes of freshwater picocyanobacteria from non-axenic cultures collected across Central Europe. In addition, we recovered 33 genomes of their potential symbiotic partners affiliated with four genera, Pseudomonas, Mesorhizobium, Acidovorax, and Hydrogenophaga. The genomic basis of symbiotic interactions involved heterotrophs benefiting from picocyanobacteria-derived nutrients while providing detoxification of ROS. The global abundance patterns of picocyanobacteria revealed ecologically significant ecotypes, associated with trophic status, temperature, and pH as key environmental factors. The adaptation of picocyanobacteria in (hyper-)eutrophic waterbodies could be attributed to their colonial lifestyles and CRISPR-Cas systems. The prevailing CRISPR-Cas subtypes in picocyanobacteria were I-G and I-E, which appear to have been acquired through horizontal gene transfer from other bacterial phyla. CONCLUSIONS Our findings provide novel insights into the population diversity, ecology, and evolutionary strategies of the most widespread photoautotrophs within freshwater ecosystems. Video Abstract.
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Affiliation(s)
- Hongjae Park
- Institute of Hydrobiology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic.
| | - Paul-Adrian Bulzu
- Institute of Hydrobiology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Tanja Shabarova
- Institute of Hydrobiology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Vinicius S Kavagutti
- Institute of Hydrobiology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Rohit Ghai
- Institute of Hydrobiology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Vojtěch Kasalický
- Institute of Hydrobiology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Jitka Jezberová
- Institute of Hydrobiology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic
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2
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Muñoz-Marín MDC, López-Lozano A, Moreno-Cabezuelo JÁ, Díez J, García-Fernández JM. Mixotrophy in cyanobacteria. Curr Opin Microbiol 2024; 78:102432. [PMID: 38325247 DOI: 10.1016/j.mib.2024.102432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 12/22/2023] [Accepted: 01/10/2024] [Indexed: 02/09/2024]
Abstract
Cyanobacteria evolved the oxygenic photosynthesis to generate organic matter from CO2 and sunlight, and they were responsible for the production of oxygen in the Earth's atmosphere. This made them a model for photosynthetic organisms, since they are easier to study than higher plants. Early studies suggested that only a minority among cyanobacteria might assimilate organic compounds, being considered mostly autotrophic for decades. However, compelling evidence from marine and freshwater cyanobacteria, including toxic strains, in the laboratory and in the field, has been obtained in the last decades: by using physiological and omics approaches, mixotrophy has been found to be a more widespread feature than initially believed. Furthermore, dominant clades of marine cyanobacteria can take up organic compounds, and mixotrophy is critical for their survival in deep waters with very low light. Hence, mixotrophy seems to be an essential trait in the metabolism of most cyanobacteria, which can be exploited for biotechnological purposes.
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Affiliation(s)
- María Del Carmen Muñoz-Marín
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Universitario ceiA3, Universidad de Córdoba, Edificio Severo Ochoa, planta 1, ala Este, Campus de Rabanales, 14071 Córdoba, Spain
| | - Antonio López-Lozano
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Universitario ceiA3, Universidad de Córdoba, Edificio Severo Ochoa, planta 1, ala Este, Campus de Rabanales, 14071 Córdoba, Spain
| | - José Ángel Moreno-Cabezuelo
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Universitario ceiA3, Universidad de Córdoba, Edificio Severo Ochoa, planta 1, ala Este, Campus de Rabanales, 14071 Córdoba, Spain
| | - Jesús Díez
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Universitario ceiA3, Universidad de Córdoba, Edificio Severo Ochoa, planta 1, ala Este, Campus de Rabanales, 14071 Córdoba, Spain.
| | - José Manuel García-Fernández
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Universitario ceiA3, Universidad de Córdoba, Edificio Severo Ochoa, planta 1, ala Este, Campus de Rabanales, 14071 Córdoba, Spain.
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3
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Cagri Ozturk R, Feyzioglu AM, Capkin E, Yildiz I, Altinok I. Effects of environmental parameters on spatial and temporal distribution of marine microbial communities in the southern Black Sea. MARINE ENVIRONMENTAL RESEARCH 2024; 195:106344. [PMID: 38232435 DOI: 10.1016/j.marenvres.2024.106344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 12/27/2023] [Accepted: 01/07/2024] [Indexed: 01/19/2024]
Abstract
The Black Sea is a unique environment with strong and permanent vertical stratification, with a thin layer of oxic zone above and a permanent anoxic zone below. Few high-throughput genomic surveys have been conducted to examine microbiota in the Black Sea. Yet, there is no study on the seasonal and vertical variation in microbial community compositions, driving forces and mechanisms of community assembly. In this study, seasonal, vertical, and spatial microbial assemblages were studied in terms of diversity, abundance, and community structure using 16S rRNA metabarcoding. 16S rRNA metabarcoding confirmed seasonal changes in microbial communities and the presence of distinct microbial groups among different water layers. Taxa belonging to Cyanobiaceae contributed a large fraction of the total biomass and were the most abundant autotrophic bacteria found across the whole water column, including hydrogen sulfide-containing anoxic zone. Temperature, salinity, water density, conductivity, light, chlorophyll-a, O2, NO3, NH3, PO4, Si, and H2S had a significant influence on the vertical bacterial community assemblages. The copper mine discharge system at 180 m did not affect microbial community structure and composition. Temperature seemed to be a primary factor in the variance between shallow depths. In conclusion, the lack of light, low dissolved oxygen levels, and low temperature do not restrict microbial diversity, as proven by the higher diversity observed in deeper zones. Wastewater in Black Sea region may be discharged into the Black Sea to depth of 180 m or deeper without impacting microbial ecology.
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Affiliation(s)
- Rafet Cagri Ozturk
- Department of Fisheries Technology Engineering, Faculty of Marine Sciences, Karadeniz Technical University, 61530, Trabzon, Türkiye; Aquatic Animal Health and Molecular Genetics (AQUANETIC) Lab, Department of Chemistry C Block, 61080, Ortahisar, Trabzon, Türkiye.
| | - Ali Muzaffer Feyzioglu
- Department of Marine Science and Technology, Faculty of Marine Science, Karadeniz Technical University, 61530, Trabzon, Türkiye.
| | - Erol Capkin
- Department of Fisheries Technology Engineering, Faculty of Marine Sciences, Karadeniz Technical University, 61530, Trabzon, Türkiye.
| | - Ilknur Yildiz
- Institute of Marine Sciences and Technology, Karadeniz Technical University, 61080, Trabzon, Türkiye.
| | - Ilhan Altinok
- Department of Fisheries Technology Engineering, Faculty of Marine Sciences, Karadeniz Technical University, 61530, Trabzon, Türkiye; Aquatic Animal Health and Molecular Genetics (AQUANETIC) Lab, Department of Chemistry C Block, 61080, Ortahisar, Trabzon, Türkiye; Institute of Marine Sciences and Technology, Karadeniz Technical University, 61080, Trabzon, Türkiye.
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4
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Parsons RJ, Liu S, Longnecker K, Yongblah K, Johnson C, Bolaños LM, Comstock J, Opalk K, Kido Soule MC, Garley R, Carlson CA, Temperton B, Bates NR. Suboxic DOM is bioavailable to surface prokaryotes in a simulated overturn of an oxygen minimum zone, Devil's Hole, Bermuda. Front Microbiol 2023; 14:1287477. [PMID: 38179459 PMCID: PMC10765504 DOI: 10.3389/fmicb.2023.1287477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 11/17/2023] [Indexed: 01/06/2024] Open
Abstract
Oxygen minimum zones (OMZs) are expanding due to increased sea surface temperatures, subsequent increased oxygen demand through respiration, reduced oxygen solubility, and thermal stratification driven in part by anthropogenic climate change. Devil's Hole, Bermuda is a model ecosystem to study OMZ microbial biogeochemistry because the formation and subsequent overturn of the suboxic zone occur annually. During thermally driven stratification, suboxic conditions develop, with organic matter and nutrients accumulating at depth. In this study, the bioavailability of the accumulated dissolved organic carbon (DOC) and the microbial community response to reoxygenation of suboxic waters was assessed using a simulated overturn experiment. The surface inoculated prokaryotic community responded to the deep (formerly suboxic) 0.2 μm filtrate with cell densities increasing 2.5-fold over 6 days while removing 5 μmol L-1 of DOC. After 12 days, the surface community began to shift, and DOC quality became less diagenetically altered along with an increase in SAR202, a Chloroflexi that can degrade recalcitrant dissolved organic matter (DOM). Labile DOC production after 12 days coincided with an increase of Nitrosopumilales, a chemoautotrophic ammonia oxidizing archaea (AOA) that converts ammonia to nitrite based on the ammonia monooxygenase (amoA) gene copy number and nutrient data. In comparison, the inoculation of the deep anaerobic prokaryotic community into surface 0.2 μm filtrate demonstrated a die-off of 25.5% of the initial inoculum community followed by a 1.5-fold increase in cell densities over 6 days. Within 2 days, the prokaryotic community shifted from a Chlorobiales dominated assemblage to a surface-like heterotrophic community devoid of Chlorobiales. The DOM quality changed to less diagenetically altered material and coincided with an increase in the ribulose-1,5-bisphosphate carboxylase/oxygenase form I (cbbL) gene number followed by an influx of labile DOM. Upon reoxygenation, the deep DOM that accumulated under suboxic conditions is bioavailable to surface prokaryotes that utilize the accumulated DOC initially before switching to a community that can both produce labile DOM via chemoautotrophy and degrade the more recalcitrant DOM.
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Affiliation(s)
- Rachel J. Parsons
- Microbial Ecology Laboratory, Bermuda Institute of Ocean Sciences, St. George’s, Bermuda
- Julie Ann Wrigley Global Futures Laboratory, School of Ocean Futures, Arizona State University, Tempe, AZ, United States
| | - Shuting Liu
- Department of Ecology, Evolution and Marine Biology, Marine Science Institute, University of California, Santa Barbara, California, CA, United States
- Department of Environmental and Sustainability Sciences, Kean University, Union, NJ, United States
| | - Krista Longnecker
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, United States
| | - Kevin Yongblah
- Microbial Ecology Laboratory, Bermuda Institute of Ocean Sciences, St. George’s, Bermuda
- Department of Biology, University of Syracuse, Syracuse, NY, United States
| | - Carys Johnson
- Microbial Ecology Laboratory, Bermuda Institute of Ocean Sciences, St. George’s, Bermuda
| | - Luis M. Bolaños
- School of Biosciences, University of Exeter, Exeter, United Kingdom
| | - Jacqueline Comstock
- Department of Ecology, Evolution and Marine Biology, Marine Science Institute, University of California, Santa Barbara, California, CA, United States
| | - Keri Opalk
- Department of Ecology, Evolution and Marine Biology, Marine Science Institute, University of California, Santa Barbara, California, CA, United States
| | - Melissa C. Kido Soule
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, United States
| | - Rebecca Garley
- Microbial Ecology Laboratory, Bermuda Institute of Ocean Sciences, St. George’s, Bermuda
- Julie Ann Wrigley Global Futures Laboratory, School of Ocean Futures, Arizona State University, Tempe, AZ, United States
| | - Craig A. Carlson
- Department of Ecology, Evolution and Marine Biology, Marine Science Institute, University of California, Santa Barbara, California, CA, United States
| | - Ben Temperton
- School of Biosciences, University of Exeter, Exeter, United Kingdom
| | - Nicholas R. Bates
- Microbial Ecology Laboratory, Bermuda Institute of Ocean Sciences, St. George’s, Bermuda
- Julie Ann Wrigley Global Futures Laboratory, School of Ocean Futures, Arizona State University, Tempe, AZ, United States
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5
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Marguš M, Ahel M, Čanković M, Ljubešić Z, Terzić S, Hodak Kobasić V, Ciglenečki I. Phytoplankton pigment dynamics in marine lake fluctuating between stratified and holomictic euxinic conditions. MARINE POLLUTION BULLETIN 2023; 191:114931. [PMID: 37075558 DOI: 10.1016/j.marpolbul.2023.114931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 04/05/2023] [Accepted: 04/07/2023] [Indexed: 05/03/2023]
Abstract
Biomass dynamics in the marine lake are strongly dependent on seasonal variability in vertical stratification, indicating rapid adaptation of phytoplankton to short-term changes in the water column. A small marine lake (Rogoznica Lake, Croatia), which fluctuates between stably stratified and holomictic euxinic conditions, was used as a model to study the phytoplankton responses to environmental perturbations, in particular the anoxic stress, caused by periodic holomixia. The epilimnion showed significant temporal and vertical variability with a chlorophyll a subsurface maximum with the highest biomass near the chemocline. Fucoxanthin-containing biomass (diatoms) dominated in the epilimnion in colder seasons and was first to recover after holomictic euxinic events. The shift towards the smaller groups prevailed during highly stratified water column conditions in warmer seasons. Results for the hypolimnion were more enigmatic, with high concentrations of alloxanthin, zeaxanthin, and violaxanthin indicating the presence of a viable small-size mixotrophic community under extreme conditions.
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Affiliation(s)
- Marija Marguš
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia.
| | - Marijan Ahel
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia.
| | - Milan Čanković
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia
| | - Zrinka Ljubešić
- Department of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000 Zagreb, Croatia
| | - Senka Terzić
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia
| | - Vedranka Hodak Kobasić
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia
| | - Irena Ciglenečki
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia
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6
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Genomic and Transcriptomic Insights into Salinity Tolerance-Based Niche Differentiation of Synechococcus Clades in Estuarine and Coastal Waters. mSystems 2023; 8:e0110622. [PMID: 36622156 PMCID: PMC9948718 DOI: 10.1128/msystems.01106-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Cluster 5 Synechococcus is one of the most important primary producers on earth. However, ecotypes of this genus exhibit complex geographical distributions, and the genetic basis of niche partitioning is still not fully understood. Here, we report distinct distributions of subcluster 5.1 (SC5.1) and subcluster 5.2 (SC5.2) Synechococcus in estuarine waters, and we reveal that salinity is the main factor determining their distribution. Clade III (belonging to SC5.1) and CB4 (belonging to SC5.2) are dominant clades in the study region, with different ecological distributions. We further conducted physiological, genomic, and transcriptomic studies of Synechococcus strains YX04-3 and HK05, which are affiliated with clade III and CB4, respectively. Laboratory tests showed that HK05 could grow at low salinity (13 ppt), whereas the growth of YX04-3 was suppressed when salinity decreased to 13 ppt. Genomic and transcriptomic analysis suggested that euryhaline clade CB4 is capable of dealing with a sudden drop of salinity by releasing compatible solutes through mechanosensitive channels that are coded by the mscL gene, decreasing biosynthesis of organic osmolytes, and increasing expression of heat shock proteins and high light-inducible proteins to protect photosystem. Furthermore, CB4 strain HK05 exhibited a higher growth rate when growing at low salinity than at high salinity. This is likely achieved by reducing its biosynthesis of organic osmolyte activity and increasing its photosynthetic activity at low salinity, which allowed it to enhance the assimilation of inorganic carbon and nitrogen. Together, these results provide new insights regarding the ecological distribution of SC5.2 and SC5.1 ecotypes and their underlying molecular mechanisms. IMPORTANCE Synechococcus is a group of unicellular Cyanobacteria that are widely distributed in global aquatic ecosystems. Salinity is a factor that affects the distribution of microorganisms in estuarine and coastal environments. In this study, we studied the distribution pattern of Synechococcus community along the salinity gradient in a subtropical estuary. By using omic methods, we unveiled genetic traits that determine the niche partitioning of euryhaline and strictly marine Synechococcus. We also explored the strategies employed by euryhaline Synechococcus to cope with a sudden drop of salinity, and revealed possible mechanisms for the higher growth rate of euryhaline Synechococcus in low salinity conditions. This study provides new insight into the genetic basis of niche partitioning of Synechococcus clades.
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7
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Sabatino R, Cabello-Yeves PJ, Eckert EM, Corno G, Callieri C, Brambilla D, Dzhembekova N, Moncheva S, Di Cesare A. Antibiotic resistance genes correlate with metal resistances and accumulate in the deep water layers of the Black Sea. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 312:120033. [PMID: 36030962 DOI: 10.1016/j.envpol.2022.120033] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/25/2022] [Accepted: 08/20/2022] [Indexed: 06/15/2023]
Abstract
Seas and oceans are a global reservoir of antibiotic resistance genes (ARGs). Only a few studies investigated the dynamics of ARGs along the water column of the Black Sea, a unique environment, with a peculiar geology, biology and history of anthropogenic pollution. In this study, we analyzed metagenomic data from two sampling campaigns (2013 and 2019) collected across three different sites in the Western Black Sea at depths ranging from 5 to 2000 m. The data were processed to annotate ARGs, metal resistance genes (MRGs) and integron integrase genes. The ARG abundance was significantly higher in the deep water layers and depth was the main driver of beta-diversity both for ARGs and MRGs. Moreover, ARG and MRG abundances strongly correlated (r = 0.95). The integron integrase gene abundances and composition were not influenced by the water depth and did not correlate with ARGs. The analysis of the obtained MAGs showed that some of them harbored intI gene together with several ARGs and MRGs, suggesting the presence of multidrug resistant bacteria and that MRGs and integrons could be involved in the selection of ARGs. These results demonstrate that the Black Sea is not only an important reservoir of ARGs, but also that they accumulate in the deep water layers where co-selection with MRGs could be assumed as a relevant mechanism of their persistence.
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Affiliation(s)
- Raffaella Sabatino
- Water Research Institute - National Research Council of Italy (CNR-IRSA), Molecular Ecology Group (MEG), Largo Tonolli 50, 28922, Verbania (VB), Italy
| | - Pedro J Cabello-Yeves
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel, Hernández, San Juan de Alicante, Alicante, Spain
| | - Ester M Eckert
- Water Research Institute - National Research Council of Italy (CNR-IRSA), Molecular Ecology Group (MEG), Largo Tonolli 50, 28922, Verbania (VB), Italy
| | - Gianluca Corno
- Water Research Institute - National Research Council of Italy (CNR-IRSA), Molecular Ecology Group (MEG), Largo Tonolli 50, 28922, Verbania (VB), Italy
| | - Cristiana Callieri
- Water Research Institute - National Research Council of Italy (CNR-IRSA), Molecular Ecology Group (MEG), Largo Tonolli 50, 28922, Verbania (VB), Italy
| | - Diego Brambilla
- Water Research Institute - National Research Council of Italy (CNR-IRSA), Molecular Ecology Group (MEG), Largo Tonolli 50, 28922, Verbania (VB), Italy
| | - Nina Dzhembekova
- Institute for Oceanology Fridtj of Nansen, Bulgarian Academy of Sciences, First May Street 40, P.O. Box 152, 9000, Varna, Bulgaria
| | - Snejana Moncheva
- Institute for Oceanology Fridtj of Nansen, Bulgarian Academy of Sciences, First May Street 40, P.O. Box 152, 9000, Varna, Bulgaria
| | - Andrea Di Cesare
- Water Research Institute - National Research Council of Italy (CNR-IRSA), Molecular Ecology Group (MEG), Largo Tonolli 50, 28922, Verbania (VB), Italy.
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Cabello-Yeves PJ, Callieri C, Picazo A, Schallenberg L, Huber P, Roda-Garcia JJ, Bartosiewicz M, Belykh OI, Tikhonova IV, Torcello-Requena A, De Prado PM, Puxty RJ, Millard AD, Camacho A, Rodriguez-Valera F, Scanlan DJ. Elucidating the picocyanobacteria salinity divide through ecogenomics of new freshwater isolates. BMC Biol 2022; 20:175. [PMID: 35941649 PMCID: PMC9361551 DOI: 10.1186/s12915-022-01379-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 07/26/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cyanobacteria are the major prokaryotic primary producers occupying a range of aquatic habitats worldwide that differ in levels of salinity, making them a group of interest to study one of the major unresolved conundrums in aquatic microbiology which is what distinguishes a marine microbe from a freshwater one? We address this question using ecogenomics of a group of picocyanobacteria (cluster 5) that have recently evolved to inhabit geographically disparate salinity niches. Our analysis is made possible by the sequencing of 58 new genomes from freshwater representatives of this group that are presented here, representing a 6-fold increase in the available genomic data. RESULTS Overall, freshwater strains had larger genomes (≈2.9 Mb) and %GC content (≈64%) compared to brackish (2.69 Mb and 64%) and marine (2.5 Mb and 58.5%) isolates. Genomic novelties/differences across the salinity divide highlighted acidic proteomes and specific salt adaptation pathways in marine isolates (e.g., osmolytes/compatible solutes - glycine betaine/ggp/gpg/gmg clusters and glycerolipids glpK/glpA), while freshwater strains possessed distinct ion/potassium channels, permeases (aquaporin Z), fatty acid desaturases, and more neutral/basic proteomes. Sulfur, nitrogen, phosphorus, carbon (photosynthesis), or stress tolerance metabolism while showing distinct genomic footprints between habitats, e.g., different types of transporters, did not obviously translate into major functionality differences between environments. Brackish microbes show a mixture of marine (salt adaptation pathways) and freshwater features, highlighting their transitional nature. CONCLUSIONS The plethora of freshwater isolates provided here, in terms of trophic status preference and genetic diversity, exemplifies their ability to colonize ecologically diverse waters across the globe. Moreover, a trend towards larger and more flexible/adaptive genomes in freshwater picocyanobacteria may hint at a wider number of ecological niches in this environment compared to the relatively homogeneous marine system.
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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.
| | - Cristiana Callieri
- National Research Council (CNR), Institute of Water Research (IRSA), Verbania, Italy
| | - Antonio Picazo
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, E-46980, Paterna, Valencia, Spain
| | | | - Paula Huber
- Instituto Tecnológico de Chascomús (INTECH), UNSAM-CONICET, Av. Intendente Marino Km 8,200, (7130) Chascomús, Buenos Aires, Argentina.,Instituto Nacional de Limnología (INALI), CONICET-UNL, Ciudad Universitaria - Paraje el Pozo s/n, (3000), Santa Fé, Argentina
| | - Juan J Roda-Garcia
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel, Hernández, San Juan de Alicante, Alicante, Spain
| | - Maciej Bartosiewicz
- Department of Environmental Sciences, University of Basel, Basel, Switzerland
| | - Olga I Belykh
- Limnological Institute, Russian Academy of Sciences, P.O. Box 278, 664033, Irkutsk, Russia
| | - Irina V Tikhonova
- Limnological Institute, Russian Academy of Sciences, P.O. Box 278, 664033, Irkutsk, Russia
| | | | | | - Richard J Puxty
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Andrew D Millard
- Department of Genetics and Genome Biology, University of Leicester, Leicester, LE1 7RH, UK
| | - Antonio Camacho
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, E-46980, Paterna, Valencia, Spain
| | - Francisco Rodriguez-Valera
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel, Hernández, San Juan de Alicante, Alicante, Spain.,Moscow Institute of Physics and Technology, Dolgoprudny, 141701, Russia
| | - David J Scanlan
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.
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9
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Aptekmann AA, Buongiorno J, Giovannelli D, Glamoclija M, Ferreiro DU, Bromberg Y. mebipred: identifying metal binding potential in protein sequence. Bioinformatics 2022; 38:3532-3540. [PMID: 35639953 PMCID: PMC9272798 DOI: 10.1093/bioinformatics/btac358] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 03/27/2022] [Accepted: 05/22/2022] [Indexed: 11/23/2022] Open
Abstract
Motivation metal-binding proteins have a central role in maintaining life processes. Nearly one-third of known protein structures contain metal ions that are used for a variety of needs, such as catalysis, DNA/RNA binding, protein structure stability, etc. Identifying metal-binding proteins is thus crucial for understanding the mechanisms of cellular activity. However, experimental annotation of protein metal-binding potential is severely lacking, while computational techniques are often imprecise and of limited applicability. Results we developed a novel machine learning-based method, mebipred, for identifying metal-binding proteins from sequence-derived features. This method is over 80% accurate in recognizing proteins that bind metal ion-containing ligands; the specific identity of 11 ubiquitously present metal ions can also be annotated. mebipred is reference-free, i.e. no sequence alignments are involved, and is thus faster than alignment-based methods; it is also more accurate than other sequence-based prediction methods. Additionally, mebipred can identify protein metal-binding capabilities from short sequence stretches, e.g. translated sequencing reads, and, thus, may be useful for the annotation of metal requirements of metagenomic samples. We performed an analysis of available microbiome data and found that ocean, hot spring sediments and soil microbiomes use a more diverse set of metals than human host-related ones. For human microbiomes, physiological conditions explain the observed metal preferences. Similarly, subtle changes in ocean sample ion concentration affect the abundance of relevant metal-binding proteins. These results highlight mebipred’s utility in analyzing microbiome metal requirements. Availability and implementation mebipred is available as a web server at services.bromberglab.org/mebipred and as a standalone package at https://pypi.org/project/mymetal/. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- A A Aptekmann
- Department of Biochemistry and Microbiology, Rutgers University, 76 Lipman Dr, New Brunswick, NJ, 08873, USA.,Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, 08901, USA
| | | | - D Giovannelli
- Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, 08901, USA.,Department of Biology, University of Naples Federico II, Naples, Italy.,Institute for Marine Biological Resources and Biotechnology-IRBIM, National Research Council of Italy, CNR, Ancona, Italy
| | - M Glamoclija
- Department of Earth and Environmental Sciences, Rutgers University, New Brunswick, NJ, 07102, USA
| | - D U Ferreiro
- Protein Physiology Lab, Departamento de Quimica Biologica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires-CONICET-IQUIBICEN, Buenos Aires, 1428, Argentina
| | - Y Bromberg
- Department of Biochemistry and Microbiology, Rutgers University, 76 Lipman Dr, New Brunswick, NJ, 08873, USA
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10
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Wang T, Li J, Jing H, Qin S. Picocyanobacterial Synechococcus in marine ecosystem: Insights from genetic diversity, global distribution, and potential function. MARINE ENVIRONMENTAL RESEARCH 2022; 177:105622. [PMID: 35429822 DOI: 10.1016/j.marenvres.2022.105622] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 04/01/2022] [Accepted: 04/05/2022] [Indexed: 06/14/2023]
Abstract
Marine Synechococcus, a main group of picocyanobacteria, has been ubiquitously observed across the global oceans. Synechococcus exhibits high phylogenetical and phenotypical diversity, and horizontal gene transfer makes its genetic evolution much more intricate. With the development of measurement technologies and analysis methods, the genomic information and niche partition of each Synechococcus lineage tend to be precisely described, but the global analysis is still lacking. Therefore, it is necessary to summarize existing studies and integrate published data to gain a comprehensive understanding of Synechococcus on genetic variation, niche division, and potential functions. In this review, the maximum likelihood trees are constructed based on existing sequence data, including both phylogenetic and pigmentary gene markers. The global distribution characteristics of abundance, lineages, and pigment types are concluded through pooled analysis of more than 700 samples obtained from approximately 50 scientific research cruises. The potential functions of Synechococcus are explored in element cycles and biological interactions. Future work on Synechococcus is suggested to focus on not only elucidating the nature of Synechococcus biodiversity but also demonstrating its interactions with the ecosystem by combining bioinformatics and macroscopic isotope-labeled environmental parameters.
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Affiliation(s)
- Ting Wang
- Key Laboratory of Coastal Biology and Biological Resource Conservation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264000, China; CAS Key Laboratory for Experimental Study under Deep-sea Extreme Conditions, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China; University of Chinese Academy of Sciences, Beijing, China
| | - Jialin Li
- Key Laboratory of Coastal Biology and Biological Resource Conservation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264000, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China.
| | - Hongmei Jing
- CAS Key Laboratory for Experimental Study under Deep-sea Extreme Conditions, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China
| | - Song Qin
- Key Laboratory of Coastal Biology and Biological Resource Conservation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264000, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
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11
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Grébert T, Garczarek L, Daubin V, Humily F, Marie D, Ratin M, Devailly A, Farrant GK, Mary I, Mella-Flores D, Tanguy G, Labadie K, Wincker P, Kehoe DM, Partensky F. Diversity and evolution of pigment types in marine Synechococcus cyanobacteria. Genome Biol Evol 2022; 14:6547267. [PMID: 35276007 PMCID: PMC8995045 DOI: 10.1093/gbe/evac035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2022] [Indexed: 11/14/2022] Open
Abstract
Synechococcus cyanobacteria are ubiquitous and abundant in the marine environment and contribute to an estimated 16% of the ocean net primary productivity. Their light-harvesting complexes, called phycobilisomes (PBS), are composed of a conserved allophycocyanin core, from which radiates six to eight rods with variable phycobiliprotein and chromophore content. This variability allows Synechococcus cells to optimally exploit the wide variety of spectral niches existing in marine ecosystems. Seven distinct pigment types or subtypes have been identified so far in this taxon based on the phycobiliprotein composition and/or the proportion of the different chromophores in PBS rods. Most genes involved in their biosynthesis and regulation are located in a dedicated genomic region called the PBS rod region. Here, we examine the variability of gene content and organization of this genomic region in a large set of sequenced isolates and natural populations of Synechococcus representative of all known pigment types. All regions start with a tRNA-PheGAA and some possess mobile elements for DNA integration and site-specific recombination, suggesting that their genomic variability relies in part on a “tycheposon”-like mechanism. Comparison of the phylogenies obtained for PBS and core genes revealed that the evolutionary history of PBS rod genes differs from the core genome and is characterized by the co-existence of different alleles and frequent allelic exchange. We propose a scenario for the evolution of the different pigment types and highlight the importance of incomplete lineage sorting in maintaining a wide diversity of pigment types in different Synechococcus lineages despite multiple speciation events.
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Affiliation(s)
- Théophile Grébert
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation and Diversity in the Marine Environment, Station Biologique, 29680 Roscoff, France
| | - Laurence Garczarek
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation and Diversity in the Marine Environment, Station Biologique, 29680 Roscoff, France
| | - Vincent Daubin
- Université Lyon 1, UMR 5558 Biometry and Evolutionary Biology, 69622 Villeurbanne, France
| | - Florian Humily
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation and Diversity in the Marine Environment, Station Biologique, 29680 Roscoff, France
| | - Dominique Marie
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation and Diversity in the Marine Environment, Station Biologique, 29680 Roscoff, France
| | - Morgane Ratin
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation and Diversity in the Marine Environment, Station Biologique, 29680 Roscoff, France
| | - Alban Devailly
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation and Diversity in the Marine Environment, Station Biologique, 29680 Roscoff, France
| | - Gregory K Farrant
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation and Diversity in the Marine Environment, Station Biologique, 29680 Roscoff, France
| | - Isabelle Mary
- Université Clermont Auvergne, CNRS, Laboratoire Microorganismes: Génome et Environnement, 63000 Clermont-Ferrand, France
| | - Daniella Mella-Flores
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation and Diversity in the Marine Environment, Station Biologique, 29680 Roscoff, France
| | - Gwenn Tanguy
- Centre National de la Recherche Scientifique, FR 2424, Station Biologique, 29680 Roscoff, France
| | - Karine Labadie
- Genoscope, Institut de biologie François-Jacob, Commissariat à l'Énergie Atomique (CEA), Université Paris-Saclay, Evry, France
| | - Patrick Wincker
- Génomique Métabolique, Genoscope, Institut de biologie François Jacob, CEA, CNRS, Université d'Evry, Université Paris-Saclay, Evry, France
| | - David M Kehoe
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Frédéric Partensky
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation and Diversity in the Marine Environment, Station Biologique, 29680 Roscoff, France
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12
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The “Dark Side” of Picocyanobacteria: Life as We Do Not Know It (Yet). Microorganisms 2022; 10:microorganisms10030546. [PMID: 35336120 PMCID: PMC8955281 DOI: 10.3390/microorganisms10030546] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 02/22/2022] [Accepted: 02/28/2022] [Indexed: 12/12/2022] Open
Abstract
Picocyanobacteria of the genus Synechococcus (together with Cyanobium and Prochlorococcus) have captured the attention of microbial ecologists since their description in the 1970s. These pico-sized microorganisms are ubiquitous in aquatic environments and are known to be some of the most ancient and adaptable primary producers. Yet, it was only recently, and thanks to developments in molecular biology and in the understanding of gene sequences and genomes, that we could shed light on the depth of the connection between their evolution and the history of life on the planet. Here, we briefly review the current understanding of these small prokaryotic cells, from their physiological features to their role and dynamics in different aquatic environments, focussing particularly on the still poorly understood ability of picocyanobacteria to adapt to dark conditions. While the recent discovery of Synechococcus strains able to survive in the deep Black Sea highlights how adaptable picocyanobacteria can be, it also raises more questions—showing how much we still do not know about microbial life. Using available information from brackish Black Sea strains able to perform and survive in dark (anoxic) conditions, we illustrate how adaptation to narrow ecological niches interacts with gene evolution and metabolic capacity.
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13
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Schallenberg LA, Pearman JK, Burns CW, Wood SA. Metabarcoding Reveals Lacustrine Picocyanobacteria Respond to Environmental Change Through Adaptive Community Structuring. Front Microbiol 2021; 12:757929. [PMID: 34867882 PMCID: PMC8633389 DOI: 10.3389/fmicb.2021.757929] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 10/04/2021] [Indexed: 01/04/2023] Open
Abstract
Picocyanobacteria (Pcy) are important yet understudied components of lake foodwebs. While phylogenetic studies of isolated strains reveal a high diversity of freshwater genotypes, little is known about abiotic drivers associated with Pcy in different lakes. Due to methodological limitations, most previous studies assess potential drivers using total cell abundances as a response, with often conflicting and inconsistent results. In the present study, we explored how picocyanobacterial communities respond to environmental change using a combination of epifluorescence microscopy and community data determined using 16S rRNA gene metabarcoding. Temporal shifts in picocyanobacterial abundance, diversity and community dynamics were assessed in relation to potential environmental drivers in five contrasting lakes over 1year. Cell abundances alone were not consistently related to environmental variables across lakes. However, the addition of metabarcoding data revealed diverse picocyanobacterial communities that differed significantly between lakes, driven by environmental variables related to trophic state. Within each lake, communities were temporally dynamic and certain amplicon sequence variants (ASVs) were strongly associated with specific environmental drivers. Rapid shifts in community structure and composition were often related to environmental changes, indicating that lacustrine Pcy can persist at high abundances through collective community adaptation. These results demonstrate that a combination of microscopy and metabarcoding enables an in-depth characterisation of picocyanobacterial communities and reveals strain-specific drivers. We recommend that future studies cease referring to picocyanobacterial as one functional group and take strain specific variability into consideration.
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Affiliation(s)
| | - John K. Pearman
- Coastal and Freshwater Group, Cawthron Institute, Nelson, New Zealand
| | - Carolyn W. Burns
- Department of Zoology, University of Otago, Dunedin, New Zealand
| | - Susanna A. Wood
- Coastal and Freshwater Group, Cawthron Institute, Nelson, New Zealand
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14
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Coe A, Biller SJ, Thomas E, Boulias K, Bliem C, Arellano A, Dooley K, Rasmussen AN, LeGault K, O'Keefe TJ, Stover S, Greer EL, Chisholm SW. Coping with darkness: The adaptive response of marine picocyanobacteria to repeated light energy deprivation. LIMNOLOGY AND OCEANOGRAPHY 2021; 66:3300-3312. [PMID: 34690365 PMCID: PMC8518828 DOI: 10.1002/lno.11880] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 03/22/2021] [Accepted: 05/29/2021] [Indexed: 06/13/2023]
Abstract
The picocyanobacteria Prochlorococcus and Synechococcus are found throughout the ocean's euphotic zone, where the daily light:dark cycle drives their physiology. Periodic deep mixing events can, however, move cells below this region, depriving them of light for extended periods of time. Here, we demonstrate that members of these genera can adapt to tolerate repeated periods of light energy deprivation. Strains kept in the dark for 3 d and then returned to the light initially required 18-26 d to resume growth, but after multiple rounds of dark exposure they began to regrow after only 1-2 d. This dark-tolerant phenotype was stable and heritable; some cultures retained the trait for over 132 generations even when grown in a standard 13:11 light:dark cycle. We found no genetic differences between the dark-tolerant and parental strains of Prochlorococcus NATL2A, indicating that an epigenetic change is likely responsible for the adaptation. To begin to explore this possibility, we asked whether DNA methylation-one potential mechanism mediating epigenetic inheritance in bacteria-occurs in Prochlorococcus. LC-MS/MS analysis showed that while DNA methylations, including 6 mA and 5 mC, are found in some other Prochlorococcus strains, there were no methylations detected in either the parental or dark-tolerant NATL2A strains. These findings suggest that Prochlorococcus utilizes a yet-to-be-determined epigenetic mechanism to adapt to the stress of extended light energy deprivation, and highlights phenotypic heterogeneity as an additional dimension of Prochlorococcus diversity.
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Affiliation(s)
- Allison Coe
- Department of Civil and Environmental EngineeringMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| | - Steven J. Biller
- Department of Biological SciencesWellesley CollegeWellesleyMassachusettsUSA
| | - Elaina Thomas
- Department of Civil and Environmental EngineeringMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| | - Konstantinos Boulias
- Division of Newborn MedicineBoston Children's HospitalBostonMassachusettsUSA
- Department of PediatricsHarvard Medical SchoolBostonMassachusettsUSA
| | - Christina Bliem
- Department of Civil and Environmental EngineeringMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| | - Aldo Arellano
- Department of Civil and Environmental EngineeringMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| | - Keven Dooley
- Department of Civil and Environmental EngineeringMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| | - Anna N. Rasmussen
- Department of Civil and Environmental EngineeringMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| | - Kristen LeGault
- Department of Civil and Environmental EngineeringMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| | - Tyler J. O'Keefe
- Department of Civil and Environmental EngineeringMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| | - Sarah Stover
- Department of Civil and Environmental EngineeringMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| | - Eric L. Greer
- Division of Newborn MedicineBoston Children's HospitalBostonMassachusettsUSA
- Department of PediatricsHarvard Medical SchoolBostonMassachusettsUSA
| | - Sallie W. Chisholm
- Department of Civil and Environmental EngineeringMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
- Department of BiologyMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
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15
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Prondzinsky P, Berkemer SJ, Ward LM, McGlynn SE. The Thermosynechococcus Genus: Wide Environmental Distribution, but a Highly Conserved Genomic Core. Microbes Environ 2021; 36. [PMID: 33952861 PMCID: PMC8209445 DOI: 10.1264/jsme2.me20138] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Cyanobacteria thrive in diverse environments. However, questions remain about possible growth limitations in ancient environmental conditions. As a single genus, the Thermosynechococcus are cosmopolitan and live in chemically diverse habitats. To understand the genetic basis for this, we compared the protein coding component of Thermosynechococcus genomes. Supplementing the known genetic diversity of Thermosynechococcus, we report draft metagenome-assembled genomes of two Thermosynechococcus recovered from ferrous carbonate hot springs in Japan. We find that as a genus, Thermosynechococcus is genomically conserved, having a small pan-genome with few accessory genes per individual strain as well as few genes that are unique to the genus. Furthermore, by comparing orthologous protein groups, including an analysis of genes encoding proteins with an iron related function (uptake, storage or utilization), no clear differences in genetic content, or adaptive mechanisms could be detected between genus members, despite the range of environments they inhabit. Overall, our results highlight a seemingly innate ability for Thermosynechococcus to inhabit diverse habitats without having undergone substantial genomic adaptation to accommodate this. The finding of Thermosynechococcus in both hot and high iron environments without adaptation recognizable from the perspective of the proteome has implications for understanding the basis of thermophily within this clade, and also for understanding the possible genetic basis for high iron tolerance in cyanobacteria on early Earth. The conserved core genome may be indicative of an allopatric lifestyle-or reduced genetic complexity of hot spring habitats relative to other environments.
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Affiliation(s)
- Paula Prondzinsky
- Department of Chemical Science and Engineering, Tokyo Institute of Technology.,Earth-Life Science Institute, Tokyo Institute of Technology
| | - Sarah J Berkemer
- Bioinformatics Group, Department of Computer Science, University Leipzig.,Competence Center for Scalable Data Services and Solutions
| | - Lewis M Ward
- Earth-Life Science Institute, Tokyo Institute of Technology.,Department of Earth and Planetary Sciences, Harvard University
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16
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Dynamics and Distribution of Marine Synechococcus Abundance and Genotypes during Seasonal Hypoxia in a Coastal Marine Ranch. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2021. [DOI: 10.3390/jmse9050549] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Marine Synechococcus are an ecologically important picocyanobacterial group widely distributed in various oceanic environments. Little is known about the dynamics and distribution of Synechococcus abundance and genotypes during seasonal hypoxia in coastal zones. In this study, an investigation was conducted in a coastal marine ranch along two transects in Muping, Yantai, where hypoxic events (defined here as the dissolved oxygen concentration <3 mg L−1) occurred in the summer of 2015. The hypoxia occurred in the bottom waters from late July and persisted until late August. It was confined at nearshore stations of the two transects, one running across a coastal ranch and the other one outside. During this survey, cell abundance of Synechococcus was determined with flow cytometry, showing great variations ranging from 1 × 104 to 3.0 × 105 cells mL−1, and a bloom of Synechococcus occurred when stratification disappeared and hypoxia faded out outside the ranch. Regression analysis indicated that dissolved oxygen, pH, and inorganic nutrients were the most important abiotic factors in explaining the variation in Synechococcus cell abundance. Diverse genotypes (mostly belonged to the sub-clusters 5.1 and 5.2) were detected using clone library sequencing and terminal restriction fragment length polymorphism analysis of the 16S–23S rRNA internal transcribed spacer region. The richness of genotypes was significantly related to salinity, temperature, silicate, and pH, but not dissolved oxygen. Two environmental factors, temperature and salinity, collectively explained 17% of the variation in Synechococcus genotype assemblage. With the changes in population composition in diverse genotypes, the Synechococcus assemblages survived in the coastal hypoxia event and thrived when hypoxia faded out.
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17
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Abstract
Cyanophages are viruses that target cyanobacteria and directly control their abundance via viral lysis. Cyanobacteria are known to cause large blooms in water bodies, substantially contributing to oxygen depletion in bottom waters resulting in areas called dead zones. Up to 20% of prokaryotic organisms in the oceans are estimated to die every day due to viral infection and lysis. Viruses can therefore alter microbial diversity, community structure, and biogeochemical processes driven by these organisms. Cyanophages are viruses that infect and lyse cyanobacterial cells, adding bioavailable carbon and nutrients into the environment. Cyanobacteria are photosynthesizing bacteria, with some species capable of N2 fixation, which are known to form large blooms as well as resistant resting cells known as akinetes. Here, we investigated cyanophage diversity and community structure plus cyanobacteria in dead zone sediments. We sampled surface sediments and sequenced DNA and RNA, along an oxygen gradient—representing oxic, hypoxic, and anoxic conditions—in one of the world’s largest dead zones located in the Baltic Sea. Cyanophages were detected at all stations and, based on partial genome contigs, had a higher alpha diversity and different beta diversity in the hypoxic-anoxic sediments, suggesting that cyanobacteria in dead zone sediments and/or environmental conditions select for specific cyanophages. Some of these cyanophages can infect cyanobacteria with potential consequences for gene expression related to their photosystem and phosphate regulation. Top cyanobacterial genera detected in the anoxic sediment included Dolichospermum/Anabaena, Synechococcus, and Cyanobium. RNA transcripts classified to cyanobacteria were associated with numerous pathways, including anaerobic carbon metabolism and N2 fixation. Cyanobacterial blooms are known to fuel oxygen-depleted ecosystems with phosphorus (so-called internal loading), and our cyanophage data indicate the potential for viral lysis of cyanobacteria which might explain the high nutrient turnover in these environments. IMPORTANCE Cyanophages are viruses that target cyanobacteria and directly control their abundance via viral lysis. Cyanobacteria are known to cause large blooms in water bodies, substantially contributing to oxygen depletion in bottom waters resulting in areas called dead zones. Our knowledge of cyanophages in dead zones is very scarce, and so far, no studies have assembled partial cyanophage genomes and investigated their associated cyanobacteria in these dark and anoxic sediments. Here, we present the first study using DNA and RNA sequencing to investigate in situ diversity of cyanophages and cyanobacteria in dead zones. Our study shows that dead zone sediments contain different cyanophages compared to oxic sediments and suggest that these viruses are able to affect cyanobacterial photosystem and phosphate regulation. Furthermore, cyanophage-controlled lysis of cyanobacteria might also increase the turnover of carbon, phosphorus, and nitrogen in these oxygen-free environments at the bottom of the sea.
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18
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Cabello-Yeves PJ, Callieri C, Picazo A, Mehrshad M, Haro-Moreno JM, Roda-Garcia JJ, Dzhembekova N, Slabakova V, Slabakova N, Moncheva S, Rodriguez-Valera F. The microbiome of the Black Sea water column analyzed by shotgun and genome centric metagenomics. ENVIRONMENTAL MICROBIOME 2021; 16:5. [PMID: 33902743 PMCID: PMC8067304 DOI: 10.1186/s40793-021-00374-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 02/18/2021] [Indexed: 05/03/2023]
Abstract
BACKGROUND The Black Sea is the largest brackish water body in the world, although it is connected to the Mediterranean Sea and presents an upper water layer similar to some regions of the former, albeit with lower salinity and temperature. Despite its well-known hydrology and physicochemical features, this enormous water mass remains poorly studied at the microbial genomics level. RESULTS We have sampled its different water masses and analyzed the microbiome by shotgun and genome-resolved metagenomics, generating a large number of metagenome-assembled genomes (MAGs) from them. We found various similarities with previously described Black Sea metagenomic datasets, that show remarkable stability in its microbiome. Our datasets are also comparable to other marine anoxic water columns like the Cariaco Basin. The oxic zone resembles to standard marine (e.g. Mediterranean) photic zones, with Cyanobacteria (Synechococcus but a conspicuously absent Prochlorococcus), and photoheterotrophs domination (largely again with marine relatives). The chemocline presents very different characteristics from the oxic surface with many examples of chemolithotrophic metabolism (Thioglobus) and facultatively anaerobic microbes. The euxinic anaerobic zone presents, as expected, features in common with the bottom of meromictic lakes with a massive dominance of sulfate reduction as energy-generating metabolism, a few (but detectable) methanogenesis marker genes, and a large number of "dark matter" streamlined genomes of largely unpredictable ecology. CONCLUSIONS The Black Sea oxic zone presents many similarities to the global ocean while the redoxcline and euxinic water masses have similarities to other similar aquatic environments of marine (Cariaco Basin or other Black Sea regions) or freshwater (meromictic monimolimnion strata) origin. The MAG collection represents very well the different types of metabolisms expected in this kind of environment. We are adding critical information about this unique and important ecosystem and its microbiome.
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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
| | - Cristiana Callieri
- National Research Council (CNR), Institute of Water Research (IRSA), Verbania, Italy
| | - Antonio Picazo
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, E-46980, Paterna, Valencia, Spain
| | - Maliheh Mehrshad
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Lennart Hjelms väg 9, 75651, Uppsala, Sweden
| | - Jose M Haro-Moreno
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel, Hernández, San Juan de Alicante, Alicante, Spain
| | - Juan J Roda-Garcia
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel, Hernández, San Juan de Alicante, Alicante, Spain
| | - Nina Dzhembekova
- Institute of Oceanology "Fridtjof Nansen" - Bulgarian Academy of Sciences, Varna, Bulgaria
| | - Violeta Slabakova
- Institute of Oceanology "Fridtjof Nansen" - Bulgarian Academy of Sciences, Varna, Bulgaria
| | - Nataliya Slabakova
- Institute of Oceanology "Fridtjof Nansen" - Bulgarian Academy of Sciences, Varna, Bulgaria
| | - Snejana Moncheva
- Institute of Oceanology "Fridtjof Nansen" - Bulgarian Academy of Sciences, Varna, Bulgaria
| | - Francisco Rodriguez-Valera
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel, Hernández, San Juan de Alicante, Alicante, Spain.
- Moscow Institute of Physics and Technology, Dolgoprudny, 141701, Russia.
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19
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Anoxic chlorophyll maximum enhances local organic matter remineralization and nitrogen loss in Lake Tanganyika. Nat Commun 2021; 12:830. [PMID: 33547297 PMCID: PMC7864930 DOI: 10.1038/s41467-021-21115-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 01/08/2021] [Indexed: 01/12/2023] Open
Abstract
In marine and freshwater oxygen-deficient zones, the remineralization of sinking organic matter from the photic zone is central to driving nitrogen loss. Deep blooms of photosynthetic bacteria, which form the suboxic/anoxic chlorophyll maximum (ACM), widespread in aquatic ecosystems, may also contribute to the local input of organic matter. Yet, the influence of the ACM on nitrogen and carbon cycling remains poorly understood. Using a suite of stable isotope tracer experiments, we examined the transformation of nitrogen and carbon under an ACM (comprising of Chlorobiaceae and Synechococcales) and a non-ACM scenario in the anoxic zone of Lake Tanganyika. We find that the ACM hosts a tight coupling of photo/litho-autotrophic and heterotrophic processes. In particular, the ACM was a hotspot of organic matter remineralization that controlled an important supply of ammonium driving a nitrification-anammox coupling, and thereby played a key role in regulating nitrogen loss in the oxygen-deficient zone. Enigmatic blooms of phytoplankton in aquatic oxygen-deficient zones could exacerbate depletion of nitrogen. Here the authors perform stable isotope experiments on the oxygen-deficient waters of Lake Tanganyika in Africa, finding that blooms drive down fixed nitrogen and could expand as a result of climate change.
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20
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Discovery of Euryhaline Phycoerythrobilin-Containing Synechococcus and Its Mechanisms for Adaptation to Estuarine Environments. mSystems 2020; 5:5/6/e00842-20. [PMID: 33323414 PMCID: PMC7771541 DOI: 10.1128/msystems.00842-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Understanding the strategies developed by different microbial groups to adapt to specific niches is critical. Through genome and transcriptome analyses of two newly isolated novel euryhaline Synechococcus strains, this study revealed that cluster 5 phycoerythrobilin-containing Synechococcus, which are thought to be strictly marine strains, could be abundant in low-salinity waters of the Pearl River estuary (salinity <15 ppt) and explained the molecular mechanisms that enabled them to adapt the low and fluctuating salinity in the estuarine environment. Synechococcus are among the most abundant and widely distributed picocyanobacteria on earth. Cluster 5 phycoerythrobilin-containing (PEB-containing) Synechococcus, the major marine Synechococcus, were considered to prefer high salinity, and they are absent in estuarine ecosystems. However, we have detected PEB-containing Synechococcus in some low-salinity (<15-ppt) areas of the Pearl River estuary at an abundance up to 1.0 × 105 cells ml−1. Two PEB-containing Synechococcus strains (HK01 and LTW-R) were isolated, and tests on them revealed their ability to cope with variations in the salinity (from 14 to 44 ppt). Phylogenetic analysis showed that HK01 belonged to a novel Synechococcus clade (HK1), whereas LTW-R was clustered with S5.2 strains. Whole-genome analysis revealed that a membrane channel protein with glycine zipper motifs is unique to euryhaline Synechococcus. The upregulation of this protein, the osmotic sensors, and the heat shock protein HSP20 and the downregulation of the osmolyte biosynthesis enable euryhaline Synechococcus to well adapt to the low and fluctuating salinity in the estuarine environment. In addition, decreasing the salinity in LTW-R strongly downregulated several important metabolic pathways, including photosynthesis, and the Calvin-Benson cycle, whereas its growth was not significantly affected. Moreover, obtaining PEB genes from horizontal gene transfer expands the light niche significantly for euryhaline Synechococcus. These results provided new insights into the life strategies and ecological function of marine PEB-containing Synechococcus under the unique environmental condition of estuarine waters, particularly in response to salinity variations. IMPORTANCE Understanding the strategies developed by different microbial groups to adapt to specific niches is critical. Through genome and transcriptome analyses of two newly isolated novel euryhaline Synechococcus strains, this study revealed that cluster 5 phycoerythrobilin-containing Synechococcus, which are thought to be strictly marine strains, could be abundant in low-salinity waters of the Pearl River estuary (salinity <15 ppt) and explained the molecular mechanisms that enabled them to adapt the low and fluctuating salinity in the estuarine environment. This study expands current understanding on mechanisms involved in niche separation of marine Synechococcus lineages.
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Sabatino R, Di Cesare A, Dzhembekova N, Fontaneto D, Eckert EM, Corno G, Moncheva S, Bertoni R, Callieri C. Spatial distribution of antibiotic and heavy metal resistance genes in the Black Sea. MARINE POLLUTION BULLETIN 2020; 160:111635. [PMID: 32919124 DOI: 10.1016/j.marpolbul.2020.111635] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/06/2020] [Accepted: 08/30/2020] [Indexed: 06/11/2023]
Abstract
Antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB) are worldwide considered as emerging contaminants of large interest, and a primary threat to human health. It is becoming clear that the environment plays a central role in the transmission, spread, and evolution of antibiotic resistance. Although marine systems have been largely investigated, only a few studies have considered the presence of ARGs in meso- and bathypelagic waters. To date, no molecular based studies have yet been made to investigate the occurrence of ARGs in the Black Sea, the largest meromictic basin in the world, receiving water from a number of important European rivers and their residues of anthropogenic activities in permanently stratified mesopelagic water masses. In this study, we determined the presence and the abundance of five ARGs (blaCTXM, ermB, qnrS, sul2, tetA) and of the heavy metal resistance gene (HMRG) czcA, in different sampling sites in the eastern and western Black Sea, at several depths (up to 1000 m) and various distances from the shoreline. Three ARGs (blaCTXM, sul2, and tetA) and czcA were present in at least 43% of the analysed samples, whereas ermB and qnrS were never detected. In particular, sul2 abundances increased significantly in coastal location, whereas tetA increased with sampling depth. These findings point out the Black Sea as a source of ARGs and HMRGs distributed along the whole water column.
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Affiliation(s)
- Raffaella Sabatino
- Water Research Institute - National Research Council of Italy (CNR-IRSA), Molecular Ecology Group (MEG), Largo Tonolli 50, 28922 Verbania (VB), Italy.
| | - Andrea Di Cesare
- Water Research Institute - National Research Council of Italy (CNR-IRSA), Molecular Ecology Group (MEG), Largo Tonolli 50, 28922 Verbania (VB), Italy
| | - Nina Dzhembekova
- Institute for Oceanology Fridtjof Nansen, Bulgarian Academy of Sciences, First May Street 40, P.O. Box 152, 9000 Varna, Bulgaria
| | - Diego Fontaneto
- Water Research Institute - National Research Council of Italy (CNR-IRSA), Molecular Ecology Group (MEG), Largo Tonolli 50, 28922 Verbania (VB), Italy
| | - Ester M Eckert
- Water Research Institute - National Research Council of Italy (CNR-IRSA), Molecular Ecology Group (MEG), Largo Tonolli 50, 28922 Verbania (VB), Italy
| | - Gianluca Corno
- Water Research Institute - National Research Council of Italy (CNR-IRSA), Molecular Ecology Group (MEG), Largo Tonolli 50, 28922 Verbania (VB), Italy
| | - Snejana Moncheva
- Institute for Oceanology Fridtjof Nansen, Bulgarian Academy of Sciences, First May Street 40, P.O. Box 152, 9000 Varna, Bulgaria
| | - Roberto Bertoni
- Water Research Institute - National Research Council of Italy (CNR-IRSA), Molecular Ecology Group (MEG), Largo Tonolli 50, 28922 Verbania (VB), Italy
| | - Cristiana Callieri
- Water Research Institute - National Research Council of Italy (CNR-IRSA), Molecular Ecology Group (MEG), Largo Tonolli 50, 28922 Verbania (VB), Italy
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Firidin S, Ozturk RC, Alemdag M, Eroglu O, Terzi Y, Kutlu I, Duzgunes ZD, Cakmak E, Aydin I. Population genetic structure of turbot (Scophthalmus maximus L., 1758) in the Black Sea. JOURNAL OF FISH BIOLOGY 2020; 97:1154-1164. [PMID: 32767370 DOI: 10.1111/jfb.14487] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/23/2020] [Accepted: 08/05/2020] [Indexed: 06/11/2023]
Abstract
Turbot, Scophthalmus maximus, is a commercially important demersal flatfish species distributed throughout the Black Sea. Several studies performed locally with a limited number of specimens using both mitochondrial DNA (mtDNA) and microsatellite markers evidenced notable genetic variation among populations. However, comprehensive population genetic studies are required to help management of the species in the Black Sea. In the present study eight microsatellite loci were used to resolve the population structure of 414 turbot samples collected from 12 sites across the Black Sea. Moreover, two mtDNA genes, COI and Cyt-b, were used for taxonomic identification. Microsatellite markers of Smax-04 and B12-I GT14 were excluded from analysis due to scoring issues. Data analysis was performed with the remaining six loci. Loci were highly polymorphic (average of 17.8 alleles per locus), indicating high genetic variability. Locus 3/20CA17, with high null allele frequency (>30%), significantly deviated from HW equilibrium. Pairwise comparison of the FST index showed significant differences between most of the surveyed sampling sites (P < 0.01). Cluster analysis evidenced the presence of three genetic groups among sampling sites. Significant genetic differentiation between Northern (Sea of Azov and Crimea) and Southern (Turkish Black Sea Coast) Black Sea sampling sites were detected. The Mantel test supported an isolation by distance model of population structure. These findings are vital for long-term sustainable management of the species and development of conservation programs. Moreover, generated mtDNA sequences would be useful for the establishment of a database for S. maximus.
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Affiliation(s)
- Sirin Firidin
- Central Fisheries Research Institute, Trabzon, Turkey
| | - Rafet Cagri Ozturk
- Department of Fisheries Technology Engineering, Faculty of Marine Sciences, Karadeniz Technical University, Trabzon, Turkey
| | | | - Oguzhan Eroglu
- Republic of Turkey Ministry of Agriculture and Forestry Kayseri Directorate of Provincial Agriculture and Forestry, Kayseri, Turkey
| | - Yahya Terzi
- Department of Fisheries Technology Engineering, Faculty of Marine Sciences, Karadeniz Technical University, Trabzon, Turkey
| | - Ilyas Kutlu
- Central Fisheries Research Institute, Trabzon, Turkey
| | | | - Eyup Cakmak
- Central Fisheries Research Institute, Trabzon, Turkey
| | - Ilhan Aydin
- Republic of Turkey Ministry of Agriculture and Forestry General Directorate of Agricultural Research and Policies, Ankara, Turkey
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Di Cesare A, Dzhembekova N, Cabello-Yeves PJ, Eckert EM, Slabakova V, Slabakova N, Peneva E, Bertoni R, Corno G, Salcher MM, Kamburska L, Bertoni F, Rodriguez-Valera F, Moncheva S, Callieri C. Genomic Comparison and Spatial Distribution of Different Synechococcus Phylotypes in the Black Sea. Front Microbiol 2020; 11:1979. [PMID: 32903389 PMCID: PMC7434838 DOI: 10.3389/fmicb.2020.01979] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 07/27/2020] [Indexed: 11/24/2022] Open
Abstract
Picocyanobacteria of the genus Synechococcus are major contributors to global primary production and nutrient cycles due to their oxygenic photoautotrophy, their abundance, and the extensive distribution made possible by their wide-ranging biochemical capabilities. The recent recovery and isolation of strains from the deep euxinic waters of the Black Sea encouraged us to expand our analysis of their adaptability also beyond the photic zone of aquatic environments. To this end, we quantified the total abundance and distribution of Synechococcus along the whole vertical profile of the Black Sea by flow cytometry, and analyzed the data obtained in light of key environmental factors. Furthermore, we designed phylotype-specific primers using the genomes of two new epipelagic coastal strains – first described here – and of two previously described mesopelagic strains, analyzed their presence/abundance by qPCR, and tested this parameter also in metagenomes from two stations at different depths. Together, whole genome sequencing, metagenomics and qPCR techniques provide us with a higher resolution of Synechococcus dynamics in the Black Sea. Both phylotypes analyzed are abundant and successful in epipelagic coastal waters; but while the newly described epipelagic strains are specifically adapted to this environment, the strains previously isolated in mesopelagic waters are able, in low numbers, to withstand the aphotic and oxygen depleted conditions of deep layers. This heterogeneity allows different Synechococcus phylotypes to occupy different niches and underscores the importance of a more detailed characterization of the abundance, distribution, and dynamics of individual populations of these picocyanobacteria.
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Affiliation(s)
- Andrea Di Cesare
- National Research Council (CNR), Institute of Water Research (IRSA), Verbania, Italy
| | - Nina Dzhembekova
- Institute of Oceanology "Fridtjof Nansen" - Bulgarian Academy of Sciences, Varna, Bulgaria
| | - Pedro J Cabello-Yeves
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, San Juan de Alicante, Spain
| | - Ester M Eckert
- National Research Council (CNR), Institute of Water Research (IRSA), Verbania, Italy
| | - Violeta Slabakova
- Institute of Oceanology "Fridtjof Nansen" - Bulgarian Academy of Sciences, Varna, Bulgaria
| | - Nataliya Slabakova
- Institute of Oceanology "Fridtjof Nansen" - Bulgarian Academy of Sciences, Varna, Bulgaria
| | - Elisaveta Peneva
- Faculty of Physics, Sofia University "St. Kliment Ohridski", Sofia, Bulgaria
| | - Roberto Bertoni
- National Research Council (CNR), Institute of Water Research (IRSA), Verbania, Italy
| | - Gianluca Corno
- National Research Council (CNR), Institute of Water Research (IRSA), Verbania, Italy
| | - Michaela M Salcher
- Biology Centre Czech Academy of Science (CAS), Institute of Hydrobiology, Czechia
| | - Lyudmila Kamburska
- National Research Council (CNR), Institute of Water Research (IRSA), Verbania, Italy
| | | | - Francisco Rodriguez-Valera
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, San Juan de Alicante, Spain.,Laboratory for Theoretical and Computer Studies of Biological Macromolecules and Genomes, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Snejana Moncheva
- Institute of Oceanology "Fridtjof Nansen" - Bulgarian Academy of Sciences, Varna, Bulgaria
| | - Cristiana Callieri
- National Research Council (CNR), Institute of Water Research (IRSA), Verbania, Italy
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Panwar P, Allen MA, Williams TJ, Hancock AM, Brazendale S, Bevington J, Roux S, Páez-Espino D, Nayfach S, Berg M, Schulz F, Chen IMA, Huntemann M, Shapiro N, Kyrpides NC, Woyke T, Eloe-Fadrosh EA, Cavicchioli R. Influence of the polar light cycle on seasonal dynamics of an Antarctic lake microbial community. MICROBIOME 2020; 8:116. [PMID: 32772914 PMCID: PMC7416419 DOI: 10.1186/s40168-020-00889-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 06/30/2020] [Indexed: 05/10/2023]
Abstract
BACKGROUND Cold environments dominate the Earth's biosphere and microbial activity drives ecosystem processes thereby contributing greatly to global biogeochemical cycles. Polar environments differ to all other cold environments by experiencing 24-h sunlight in summer and no sunlight in winter. The Vestfold Hills in East Antarctica contains hundreds of lakes that have evolved from a marine origin only 3000-7000 years ago. Ace Lake is a meromictic (stratified) lake from this region that has been intensively studied since the 1970s. Here, a total of 120 metagenomes representing a seasonal cycle and four summers spanning a 10-year period were analyzed to determine the effects of the polar light cycle on microbial-driven nutrient cycles. RESULTS The lake system is characterized by complex sulfur and hydrogen cycling, especially in the anoxic layers, with multiple mechanisms for the breakdown of biopolymers present throughout the water column. The two most abundant taxa are phototrophs (green sulfur bacteria and cyanobacteria) that are highly influenced by the seasonal availability of sunlight. The extent of the Chlorobium biomass thriving at the interface in summer was captured in underwater video footage. The Chlorobium abundance dropped from up to 83% in summer to 6% in winter and 1% in spring, before rebounding to high levels. Predicted Chlorobium viruses and cyanophage were also abundant, but their levels did not negatively correlate with their hosts. CONCLUSION Over-wintering expeditions in Antarctica are logistically challenging, meaning insight into winter processes has been inferred from limited data. Here, we found that in contrast to chemolithoautotrophic carbon fixation potential of Southern Ocean Thaumarchaeota, this marine-derived lake evolved a reliance on photosynthesis. While viruses associated with phototrophs also have high seasonal abundance, the negative impact of viral infection on host growth appeared to be limited. The microbial community as a whole appears to have developed a capacity to generate biomass and remineralize nutrients, sufficient to sustain itself between two rounds of sunlight-driven summer-activity. In addition, this unique metagenome dataset provides considerable opportunity for future interrogation of eukaryotes and their viruses, abundant uncharacterized taxa (i.e. dark matter), and for testing hypotheses about endemic species in polar aquatic ecosystems. Video Abstract.
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Affiliation(s)
- Pratibha Panwar
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, 2052, Australia
| | - Michelle A Allen
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, 2052, Australia
| | - Timothy J Williams
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, 2052, Australia
| | - Alyce M Hancock
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, 2052, Australia
- Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Tasmania, Australia
| | - Sarah Brazendale
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, 2052, Australia
- , 476 Lancaster Rd, Pegarah, Australia
| | - James Bevington
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, 2052, Australia
| | - Simon Roux
- Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | - David Páez-Espino
- Department of Energy Joint Genome Institute, Berkeley, CA, USA
- Mammoth BioSciences, 279 East Grand Ave, South San Francisco, CA, USA
| | - Stephen Nayfach
- Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | - Maureen Berg
- Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | - Frederik Schulz
- Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | - I-Min A Chen
- Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | | | - Nicole Shapiro
- Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | | | - Tanja Woyke
- Department of Energy Joint Genome Institute, Berkeley, CA, USA
| | | | - Ricardo Cavicchioli
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, 2052, Australia.
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Čanković M, Žučko J, Radić ID, Janeković I, Petrić I, Ciglenečki I, Collins G. Microbial diversity and long-term geochemical trends in the euxinic zone of a marine, meromictic lake. Syst Appl Microbiol 2019; 42:126016. [PMID: 31635887 DOI: 10.1016/j.syapm.2019.126016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 08/30/2019] [Accepted: 09/07/2019] [Indexed: 01/04/2023]
Abstract
Hypoxic and anoxic niches of meromictic lakes are important sites for studying the microbial ecology of conditions resembling ancient Earth. The expansion and increasing global distribution of such environments also means that information about them serves to understand future phenomena. In this study, a long-term chemical dataset (1996-2015) was explored together with seasonal (in 2015) information on the diversity and abundance of bacterial and archaeal communities residing in the chemocline, monimolimnion and surface sediment of the marine meromictic Rogoznica Lake. The results of quantitative PCR assays, and high-throughput sequencing, targeting 16S rRNA genes and transcripts, revealed a clear vertical structure of the microbial community with Gammaproteobacteria (Halochromatium) and cyanobacteria (Synechococcus spp.) dominating the chemocline, Deltaproteobacteria and Bacteroidetes dominating the monimolimnion, and significantly more abundant archaeal populations in the surface sediment, most of which affiliated to Nanoarchaeota. Seasonal changes in the community structure and abundance were not pronounced. Diversity in Rogoznica Lake was found to be high, presumably as a consequence of stable environmental conditions accompanied by high dissolved carbon and nutrient concentrations. Long-term data indicated that Rogoznica Lake exhibited climate changes that could alter its physico-chemical features and, consequently, induce structural and physiological changes within its microbial community.
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Affiliation(s)
- Milan Čanković
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička cesta 54, 10 000 Zagreb, Croatia.
| | - Jurica Žučko
- Department of Biochemical Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10 000 Zagreb, Croatia
| | - Iris Dupčić Radić
- Institute for Marine and Coastal Research, University of Dubrovnik, Ul. kneza Damjana Jude 12, 20 000, Dubrovnik, Croatia
| | - Ivica Janeković
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička cesta 54, 10 000 Zagreb, Croatia
| | - Ines Petrić
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička cesta 54, 10 000 Zagreb, Croatia
| | - Irena Ciglenečki
- Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička cesta 54, 10 000 Zagreb, Croatia
| | - Gavin Collins
- Microbial Communities Laboratory, Microbiology, School of Natural Sciences, National University of Ireland Galway, University Road, Galway, H91 TK33, Ireland
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