Adriana Lopes dos Santos

Adriana Lopes dos Santos
Nanyang Technological University | ntu · Asian School of Environment

PhD in Microbiology

About

51
Publications
22,046
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,224
Citations
Additional affiliations
September 2012 - October 2017
French National Centre for Scientific Research
Position
  • PostDoc Position
September 2011 - August 2012
University of São Paulo
Position
  • PostDoc Position
Education
August 2006 - August 2010
Federal University of Rio de Janeiro
Field of study
  • Environmental Microbiology
August 2004 - August 2006

Publications

Publications (51)
Article
Planktonic protists are an essential component of marine pelagic ecosystems where they mediate important trophic and biogeochemical functions. Although these functions are largely influenced by their taxonomic affiliation, the composition and spatial variability of planktonic protist communities remain poorly characterized in vast areas of the ocea...
Preprint
Full-text available
Phytoplankton under-ice blooms have been recently recognized as an important Arctic phenomenon for global primary production and biogeochemical cycling. Drastic sea-ice decline enables the development of early blooms, sometimes hundreds of kilometers beneath the pack ice. Baffin Bay is a semi-enclosed sea where Arctic and North Atlantic water masse...
Preprint
The Southern Ocean (SO) contributes substantially to the global biological carbon pump (BCP). Salps in the SO, in particular Salpa thompsoni , are keystone grazers that produce large, fast-sinking fecal pellets with high export potential. In a first study of this kind, we conducted Lagrangian experiments to quantify the salp bloom impacts on export...
Preprint
Full-text available
In recent years, metabarcoding has become the method of choice for investigating the composition and assembly of microbial eukaryotic communities, and an increasing number of environmental datasets are being published. Although unprocessed sequence files are often publicly available, processed data, i.e. sequences clustered as operational taxonomic...
Chapter
Preprint is available here: https://daniel-vaulot.fr/files/papers/LopesdosSantos_chapter_2021.pdf. Metabarcoding or high-throughput sequencing of a specific genetic marker is a powerful technique, widely used today, to analyze biodiversity across distinct environments and taxonomic groups. Plankton ecologists have benefited tremendously from the g...
Article
Protists play a fundamental role in all ecosystems, but we are still far from estimating the total diversity of many lineages, in particular in highly diverse environments, such as freshwater. Here, we survey the protist diversity of the Paraná River using metabarcoding, and we applied an approach that includes sequence similarity and phylogeny to...
Preprint
Full-text available
Planktonic protists are an essential component of marine pelagic ecosystems where they mediate important trophic and biogeochemical functions. Although these functions are largely influenced by their taxonomic affiliation, the composition and spatial variability of planktonic protist communities remain poorly characterized in vast areas of the ocea...
Article
Cryptophytes are a small group of photosynthetic biflagellate organisms distributed worldwide in fresh, brackish and marine waters. Although members of this class are easily distinguished from other groups, species identification is difficult and studies concerning their diversity are scarce. Two strains of an undescribed Hemiselmis species were is...
Article
Full-text available
Year-round reports of phytoplankton dynamics in the West Antarctic Peninsula are rare and mainly limited to microscopy and/or pigment-based studies. We analyzed the phytoplankton community from coastal waters of Fildes Bay in the West Antarctic Peninsula between January 2014 and 2015 using metabarcoding of the nuclear and plastidial 18/16S rRNA gen...
Article
Full-text available
The haptophyte genus Pseudohaptolina (formerly Chrysochromulina clade B1-3) currently harbours two species: Pseudohaptolina arctica and Pseudohaptolina sorokinii. In addition, Chrysochromulina birgeri is expected to belong to this genus due to its morphological similarity to P. sorokinii, but it has not yet been genetically characterised. A strain...
Preprint
Full-text available
Year-round reports of phytoplankton dynamics in the West Antarctic Peninsula are rare and mainly limited to microscopy and/or pigment-based studies. We analyzed the phytoplankton community from coastal waters of Fildes Bay in the West Antarctic Peninsula between January 2014 and 2015 using metabarcoding of the nuclear and plastidial 18/16S rRNA gen...
Preprint
Full-text available
The haptophyte genus Pseudohaptolina (formerly Chrysochromulina clade B1-3) currently harbors two species: Pseudohaptolina arctica and Pseudohaptolina sorokinii . In addition, Chrysochromulina birgeri is expected to belong to this genus due to its morphological similarity to P. sorokinii , but has not yet been genetically characterized. A strain be...
Article
Full-text available
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
Full-text available
Massive phytoplankton blooms develop at the Arctic ice edge, sometimes extending far under the pack ice. An extensive culturing effort was conducted before and during a phytoplankton bloom in Baffin Bay between April and July 2016. Different isolation strategies were applied, including flow cytometry cell sorting, manual single cell pipetting, and...
Article
Full-text available
The Green Edge initiative was developed to investigate the processes controlling the primary productivity and fate of organic matter produced during the Arctic phytoplankton spring bloom (PSB) and to determine its role in the ecosystem. Two field campaigns were conducted in 2015 and 2016 at an ice camp located on landfast sea ice southeast of Qikiq...
Article
Full-text available
Members of the class Mamiellophyceae comprise species that can dominate picophytoplankton diversity in polar waters. Yet polar species are often morphologically indistinguishable from temperate species, although clearly separated by molecular features. Here we examine four Mamiellophyceae strains from the Canadian Arctic. The 18S rRNA and Internal...
Article
Full-text available
The Green Edge initiative was developed to investigate the processes controlling the primary productivity and the fate of organic matter produced during the Arctic phytoplankton spring bloom (PSB) and to determine its role in the ecosystem. Two field campaigns were conducted in 2015 and 2016 at an ice camp located on landfast sea ice southeast of Q...
Preprint
Full-text available
Massive phytoplankton blooms develop at the Arctic ice edge, sometimes extending far under the pack ice. An extensive culturing effort was conducted before and during a phytoplankton bloom in Baffin Bay between April and July 2016. Different isolation strategies were applied, including flow cytometry cell sorting, manual single cell pipetting and s...
Article
Full-text available
The tiny green algae belonging to the Chloropicophyceae play a key role in marine phytoplankton communities; this newly erected class of prasinophytes comprises two genera (Chloropicon and Chloroparvula) containing each several species. We sequenced the plastomes and mitogenomes of eight Chloropicon and five Chloroparvula species to better delineat...
Article
Full-text available
Magnetotactic bacteria biomineralize intracellular magnetic nanocrystals surrounded by a lipid bilayer called magnetosomes. Due to their unique characteristics, magnetite magnetosomes are promising tools in Biomedicine. However, the uptake, persistence, and accumulation of magnetosomes within mammalian cells have not been well studied. Here, the en...
Data
Mean (A) size and (B) shape factor of magnetosomes in freshly purified (control), in endosomes and cytoplasm after HeLa cells internalization. No statically significant differences were observed among samples. (TIF)
Data
A) STEM-HAADF image of magnetosomes inside endosome; dashed square shows the crystal imaged by HRTEM (B). B) HRTEM image, and FFT (inset) of the magnetosome selected in the square of image (A), showing the crystalline structure of the prismatic magnetite crystal elongated in 111 direction in [0, –1, 1] zone axis. C) STEM-HAADF image of magnetosomes...
Preprint
Full-text available
Photosynthetic picoeukaryotes (PPE) are key components of primary production in marine and freshwater ecosystems. In contrast with those of marine environments, freshwater PPE groups have received little attention. In this work, we used flow cytometry cell sorting, microscopy and metabarcoding to investigate the composition of small photosynthetic...
Preprint
Full-text available
Members of the class Mamiellophyceae comprise species that can dominate picophytoplankton diversity in polar waters. Yet polar species are often morphologically indistinguishable from temperate species, although clearly separated by molecular features. Here we examine four Mamiellophyceae strains from the Canadian Arctic. The 18S rRNA and Internal...
Article
Full-text available
Passive sinking of particulate organic matter (POM) is the main mechanism through which the biological pump transports surface primary production to the ocean interior. However, the contribution and variability of different biological sources to vertical export is not fully understood. Here, we use DNA metabarcoding of the 18S rRNA gene and particl...
Article
Full-text available
Pico- and nano-phytoplankton (respectively, 0.2–2 and 2–20 μm in cell size) play a key role in many marine ecosystems. In this size range, Bolidophyceae is a group of eukaryotes that contains species with cells surrounded by 5 or 8 silica plates (Parmales) as well as naked flagellated species (formerly Bolidomonadales). Bolidophyceae share a common...
Article
Full-text available
Symbioses between eukaryotic algae and nitrogen-fixing cyanobacteria have been recognized in recent years as a key source of new nitrogen in the oceans. We investigated the composition of the small photosynthetic eukaryote communities associated with nitrogen-fixing cyanobacteria in the Brazilian South Atlantic Bight using a combination of flow cyt...
Article
Full-text available
Prasinophytes are a paraphyletic group of nine lineages of green microalgae that are currently classified either at the class or order level or as clades without formal taxonomic description. Prasinophyte clade VII comprises picoplanktonic algae that are important components of marine phytoplankton communities, particularly in moderately oligotroph...
Data
Marine phytoplankton are responsible for approximately 50% of global primary production and are at the base of marine food webs. In the Arctic Ocean, one important factor controlling phytoplankton productivity is sunlight, as sea-ice and snow cover limits light penetration in the water column. Over the last three decades, the extent of the seasonal...
Article
Full-text available
Phytoplankton is responsible for most primary production in Antarctica, but the short timescale dynamics of its size structure and composition are poorly described and understood. The abundance and composition of phytoplankton in Fildes Bay, western Antarctic Peninsula, was followed for 12 days during the summer using a range of methods, including...
Article
Full-text available
Pico and nanoplankton communities from the Southwest Atlantic Ocean along the Brazilian Bight are poorly described. The hydrography in this region is dominated by a complex system of layered water masses, which includes the warm and oligotrophic Tropical Water (TW), the cold and nutrient rich South Atlantic Central Water (SACW) and the Coastal Wate...
Article
Full-text available
Prasinophytes clade VII is a group of pico/nano-planktonic green algae (division Chlorophyta) for which numerous ribosomal RNA (rRNA) sequences have been retrieved from the marine environment in the last 15 years. A large number of strains have also been isolated but have not yet received a formal taxonomic description. A phylogenetic analysis of a...
Article
Full-text available
For almost three decades, flow cytometry has allowed researchers to investigate ocean planktonic communities using size and cell fluorescence properties. However, oceanographic applications must face two constraints. First, when dealing with marine microbes, instruments must be sensitive because these organisms are very small and with low fluoresce...
Article
Full-text available
Green algae (Chlorophyta) are an important group of microalgae whose diversity and ecological importance in marine systems has been little studied. In this review, we first present an overview of Chlorophyta taxonomy and detail the most important groups from the marine environment. Then, using public 18S rRNA Chlorophyta sequences from culture and...
Article
Full-text available
Bolidomonas is a genus of picoplanktonic flagellated algae that is closely related to diatoms. Triparma laevis, a species belonging to the Parmales, which are small cells with a siliceous covering, has been shown to form a monophyletic group with Bolidomonas. We isolated several novel strains of Bolidophyceae that have permitted further exploration...
Article
Full-text available
The ecological importance and diversity of pico/ nanoplanktonic algae remains poorly studied in marine waters, in part because many are tiny and without distinctive morphological features. Amongst green algae, Mamiellophyceae such as Micromonas or Bathycoccus are dominant in coastal waters while prasinophytes clade VII, yet not formerly described,...
Article
Full-text available
Photosynthetic eukaryotes have a critical role as the main producers in most ecosystems of the biosphere. The ongoing environmental metabarcoding revolution opens the perspective for holistic eco-systems biological studies of these organisms, in particular the unicellular microalgae that often lack distinctive morphological characters and have comp...
Article
Full-text available
Cáhuil Lagoon in central Chile harbors distinct microbial communities in various solar salterns that are arranged as interconnected ponds with increasing salt concentrations. Here, we report the metagenome of the 3.0- to 0.2-µm fraction of the microbial community present in a crystallizer pond with 34% salinity.
Article
Full-text available
The Brazilian Cerrado is one of the most important biodiversity reservoirs in the world. The sugarcane cultivation is expanding in this biome and necessitates the study of how it may impact the soil properties of the Cerrado. There is a lack of information especially about the impacts of different sugarcane management on the native bacterial commun...
Article
Full-text available
Exiguobacterium antarcticum is a psychotropic bacterium isolated for the first time from microbial mats of Lake Fryxell in Antarctica. Many organisms of the genus Exiguobacterium are extremophiles and have properties of biotechnological interest, e.g., the capacity to adapt to cold, which make this genus a target for discovering new enzymes, such a...
Article
Full-text available
This study performed barcoded multiplex pyrosequencing with a 454 FLX instrument to compare the microbiota of dental root canal infections associated with acute (symptomatic) or chronic (asymptomatic) apical periodontitis. Analysis of samples from 9 acute abscesses and 8 chronic infections yielded partial 16S rRNA gene sequences that were taxonomic...
Article
Full-text available
Mangroves are transitional coastal ecosystems in tropical and sub-tropical regions and represent biologically important and productive ecosystems. Despite their great ecological and economic importance, mangroves are often situated in areas of high anthropogenic influence, being exposed to pollutants, such as those released by oil spills. A microco...
Article
Full-text available
Bacteria located in the apical root canal system potentially participate in the pathogenesis of apical periodontitis. Detection and identification of apical bacteria can be compromised because of limitations in conventional sampling and identification procedures. This study identified several bacterial taxa in the apical and middle/coronal segments...
Article
Full-text available
Population growth is accompanied by an alarming increase of solid and liquid waste production worldwide. The maintenance of soil and water reservoirs as well as their protection against pollution effects are of extreme importance for human civilization. Microorganisms are directly involved in biogeochemical cycles, being key drivers of the degradat...
Article
Infection with Simian Immunodeficiency Virus (SIV) leads to high viral loads and progression to Simian AIDS (SAIDS) in rhesus macaques. The viral accessory protein Nef is required for this phenotype in monkeys as well as in HIV-infected humans. Previously, we determined that HIVNef binds HIVGagPol and Alix for optimal viral replication in cells. In...
Article
Full-text available
Bacteria located at the apical part of infected root canals are arguably directly involved in the pathogenesis of apical periodontitis. This study was conducted to profile and further compare the bacterial communities established at the apical and middle/coronal segments of infected root canals. Extracted teeth with attached apical periodontitis le...
Article
Full-text available
Different human immunodeficiency virus type 1 (HIV-1) subtypes may have distinct biological, immunological and pathogenic properties. Efficiency of mother-to-child transmission (MTCT) may be among those properties, but few and controversial results have been described so far. In this study, 102 children born from HIV-1-infected mothers between 1998...
Article
Full-text available
Nef is an accessory protein of primate lentiviruses, HIV-1, HIV-2 and SIV. Besides removing CD4 and MHC class I from the surface and activating cellular signaling cascades, Nef also binds GagPol during late stages of the viral replicative cycle. In this report, we investigated further the ability of Nef to facilitate the replication of HIV-1. To th...
Article
Full-text available
Differential Display RT-PCR is a powerful technique that has been used to isolate differentially expressed genes. This technique was first described by Liang & Pardee, in 1992. Afterwards, several modifications were introduced in the original version, including a simplification described by Sokolov & Prockop, in 1994. In this work, we describe an a...

Projects

Projects (2)
Project
The Roscoff Culture is one of the largest collection of marine micro-organisms including phytoplankton, bacteria, heterotrophic eukaryotes and viruses. Our web site is : http://www.roscoff-culture-collection.org/
Project
The aim of the French Canadian Green Edge project is to study the phytoplankton that develops at the edge of the ice pack during the Spring. Climate change has triggered fundamental modifications of marine biotopes in the Arctic Ocean. The decrease in the extent of the ice pack during summer has led to a 20% increase in pan-Arctic primary production over the last decade. Phytoplankton blooms now occur earlier in several parts of the Arctic Ocean. In other parts, the structure of the phytoplankton community is shifting toward smaller species, typical of more oligotrophic conditions and some species found in warmer waters now migrate into the Arctic Ocean. Phytoplankton grow in the top tens of meters of both ice-free and ice-covered waters. The phytoplankton spring bloom (PSB) that develops at the ice-edge accounts for >50% of annual primary production in the AO and is generally associated with both large energy transfer to higher trophic levels and export of carbon to the bottom. In turn, the culture, health and economic capacity building of Northerners are closely associated with marine resources supported by the PSB. The Arctic PSB develops in the seasonally-covered ice zone, the extent of which is expected to increase significantly during the next years, possibly over the whole AO as early as in 2030. How the PSB will evolve in this context is currently unknown. The aim of Green Edge is to study the development of the Phytoplankton Bloom that takes place at the ice edge when the ice melts. The project focuses on the Baffin Bay and combines an Ice Camp which samples under the ice during the three months prior to the bloom and a cruise with the Amundsen Ice Breaker that will follow the development of the bloom.