scholarly journals Evolutionary diversification of tiny ocean predators

2020 ◽  
Author(s):  
Francisco Latorre ◽  
Ina M. Deutschmann ◽  
Aurelie Labarre ◽  
Aleix Obiol ◽  
Anders Krabberød ◽  
...  
Keyword(s):  
Single Cells ◽  
Prey Type ◽  
Distribution Patterns ◽  
Trophic Levels ◽  
Glycoside Hydrolases ◽  
Global Ocean ◽  
Heterotrophic Flagellates ◽  
Evolutionary Diversification ◽  
Niche Adaptation ◽  
Different Temperatures

ABSTRACTUnicellular eukaryotic predators have a crucial role in the functioning of the ocean ecosystem by recycling nutrients and energy that are channeled to upper trophic levels. Traditionally, these evolutionary-diverse organisms have been combined into a single functional group (Heterotrophic flagellates), overlooking their organismal differences. Here we investigate four evolutionary related species belonging to one cosmopolitan family of uncultured marine picoeukaryotic predators: MAST-4 (species A, B, C, and E). Co-occurrence and distribution analyses in the global surface ocean indicated contrasting patterns in MAST-4A & C, suggesting adaptation to different temperatures. We then investigated whether these spatial distribution patterns were mirrored by MAST-4 genomic content using Single-Cell Genomics. Analyses of 69 single-cells recovered 66-83% of the MAST-4A/B/C/E genomes, which displayed substantial inter-species divergence. MAST-4 genomes were similar in terms of broad gene functional categories, but they differed in enzymes of ecological relevance, such as glycoside hydrolases (GHs), which are part of the food degradation machinery in MAST-4. Interestingly, MAST-4 species featuring a similar GH composition co-excluded each other (A & C) in the surface global ocean, while species with a different set of GHs appeared to be able to co-exist (species B & C) suggesting further niche diversification associated to prey digestion. We propose that differential niche adaptation to temperature and prey type has promoted adaptive evolutionary diversification in MAST-4. Altogether, we show that minute ocean predators from the same family may have different biogeography and genomic content, which need to be accounted to better comprehend marine food webs.

scholarly journals Niche adaptation promoted the evolutionary diversification of tiny ocean predators

2021 ◽  
Vol 118 (25) ◽  
pp. e2020955118
Author(s):  
Francisco Latorre ◽  
Ina M. Deutschmann ◽  
Aurélie Labarre ◽  
Aleix Obiol ◽  
Anders K. Krabberød ◽  
...  
Keyword(s):  
Single Cells ◽  
Prey Type ◽  
Distribution Patterns ◽  
Trophic Levels ◽  
Glycoside Hydrolases ◽  
Global Ocean ◽  
Heterotrophic Flagellates ◽  
Evolutionary Diversification ◽  
Niche Adaptation ◽  
Different Temperatures

Unicellular eukaryotic predators play a crucial role in the functioning of the ocean ecosystem by recycling nutrients and energy that are channeled to upper trophic levels. Traditionally, these evolutionarily diverse organisms have been combined into a single functional group (heterotrophic flagellates), overlooking their organismal differences. Here, we investigated four evolutionarily related species belonging to one cosmopolitan group of uncultured marine picoeukaryotic predators: marine stramenopiles (MAST)-4 (species A, B, C, and E). Co-occurrence and distribution analyses in the global surface ocean indicated contrasting patterns in MAST-4A and C, suggesting adaptation to different temperatures. We then investigated whether these spatial distribution patterns were mirrored by MAST-4 genomic content using single-cell genomics. Analyses of 69 single cells recovered 66 to 83% of the MAST-4A/B/C/E genomes, which displayed substantial interspecies divergence. MAST-4 genomes were similar in terms of broad gene functional categories, but they differed in enzymes of ecological relevance, such as glycoside hydrolases (GHs), which are part of the food degradation machinery in MAST-4. Interestingly, MAST-4 species featuring a similar GH composition (A and C) coexcluded each other in the surface global ocean, while species with a different set of GHs (B and C) appeared to be able to coexist, suggesting further niche diversification associated with prey digestion. We propose that differential niche adaptation to temperature and prey type has promoted adaptive evolutionary diversification in MAST-4. We show that minute ocean predators from the same phylogenetic group may have different biogeography and genomic content, which needs to be accounted for to better comprehend marine food webs.

scholarly journals Distribution of known macrozooplankton abundance and biomass in the global ocean

2013 ◽  
Vol 5 (2) ◽  
pp. 241-257 ◽  
Author(s):  
R. Moriarty ◽  
E. T. Buitenhuis ◽  
C. Le Quéré ◽  
M.-P. Gosselin
Keyword(s):  
Marine Ecosystem ◽  
Deep Ocean ◽  
Distribution Patterns ◽  
Data Depth ◽  
Trophic Levels ◽  
Global Ocean ◽  
Abundance Data ◽  
Carbon Biomass ◽  
Lack Of Information ◽  
Species Specific

Abstract. Macrozooplankton are an important link between higher and lower trophic levels in the oceans. They serve as the primary food for fish, reptiles, birds and mammals in some regions, and play a role in the export of carbon from the surface to the intermediate and deep ocean. Little, however, is known of their global distribution and biomass. Here we compiled a dataset of macrozooplankton abundance and biomass observations for the global ocean from a collection of four datasets. We harmonise the data to common units, calculate additional carbon biomass where possible, and bin the dataset in a global 1 × 1 degree grid. This dataset is part of a wider effort to provide a global picture of carbon biomass data for key plankton functional types, in particular to support the development of marine ecosystem models. Over 387 700 abundance data and 1330 carbon biomass data have been collected from pre-existing datasets. A further 34 938 abundance data were converted to carbon biomass data using species-specific length frequencies or using species-specific abundance to carbon biomass data. Depth-integrated values are used to calculate known epipelagic macrozooplankton biomass concentrations and global biomass. Global macrozooplankton biomass, to a depth of 350 m, has a mean of 8.4 μg C L−1, median of 0.2 μg C L−1 and a standard deviation of 63.5 μg C L−1. The global annual average estimate of macrozooplankton biomass in the top 350 m, based on the median value, is 0.02 Pg C. There are, however, limitations on the dataset; abundance observations have good coverage except in the South Pacific mid-latitudes, but biomass observation coverage is only good at high latitudes. Biomass is restricted to data that is originally given in carbon or to data that can be converted from abundance to carbon. Carbon conversions from abundance are restricted by the lack of information on the size of the organism and/or the absence of taxonomic information. Distribution patterns of global macrozooplankton biomass and statistical information about biomass concentrations may be used to validate biogeochemical and plankton functional type models. Macrozooplankton abundance and biomass dataset doi:10.1594/PANGAEA.777398.

scholarly journals Degradation of biological macromolecules supports uncultured microbial populations in Guaymas Basin hydrothermal sediments

2021 ◽  
Author(s):  
Sherlynette Pérez Castro ◽  
Mikayla A. Borton ◽  
Kathleen Regan ◽  
Isabella Hrabe de Angelis ◽  
Kelly C. Wrighton ◽  
...  
Keyword(s):  
Nucleic Acids ◽  
Extracellular Enzyme ◽  
Trophic Levels ◽  
Glycoside Hydrolases ◽  
Biological Macromolecules ◽  
Guaymas Basin ◽  
Bacterial Phyla ◽  
Sugar Transporters ◽  
Hydrothermal Sediments ◽  
Thermophilic Conditions

AbstractHydrothermal sediments contain large numbers of uncultured heterotrophic microbial lineages. Here, we amended Guaymas Basin sediments with proteins, polysaccharides, nucleic acids or lipids under different redox conditions and cultivated heterotrophic thermophiles with the genomic potential for macromolecule degradation. We reconstructed 20 metagenome-assembled genomes (MAGs) of uncultured lineages affiliating with known archaeal and bacterial phyla, including endospore-forming Bacilli and candidate phylum Marinisomatota. One Marinisomatota MAG had 35 different glycoside hydrolases often in multiple copies, seven extracellular CAZymes, six polysaccharide lyases, and multiple sugar transporters. This population has the potential to degrade a broad spectrum of polysaccharides including chitin, cellulose, pectin, alginate, chondroitin, and carrageenan. We also describe thermophiles affiliating with the genera Thermosyntropha, Thermovirga, and Kosmotoga with the capability to make a living on nucleic acids, lipids, or multiple macromolecule classes, respectively. Several populations seemed to lack extracellular enzyme machinery and thus likely scavenged oligo- or monomers (e.g., MAGs affiliating with Archaeoglobus) or metabolic products like hydrogen (e.g., MAGs affiliating with Thermodesulfobacterium or Desulforudaceae). The growth of methanogens or the production of methane was not observed in any condition, indicating that the tested macromolecules are not degraded into substrates for methanogenesis in hydrothermal sediments. We provide new insights into the niches, and genomes of microorganisms that actively degrade abundant necromass macromolecules under oxic, sulfate-reducing, and fermentative thermophilic conditions. These findings improve our understanding of the carbon flow across trophic levels and indicate how primary produced biomass sustains complex and productive ecosystems.

scholarly journals Genomic and Transcriptome Analyses of a Thermophilic Bacterium Geobacillus stearothermophilus B5 Isolated from Compost Reveal Its Enzymatic Basis for Lignocellulose Degradation

2020 ◽  
Vol 8 (9) ◽  
pp. 1357
Author(s):  
Mengmeng Wang ◽  
Jiaxi Miao ◽  
Xuanqing Wang ◽  
Tuo Li ◽  
Han Zhu ◽  
...  
Keyword(s):  
Thermophilic Bacterium ◽  
Glycoside Hydrolases ◽  
Lignocellulose Degradation ◽  
Geobacillus Stearothermophilus ◽  
Carbohydrate Active Enzymes ◽  
Transcriptional Responses ◽  
Protein Coding ◽  
Clusters Of Orthologous Groups ◽  
Different Temperatures ◽  
Shock Proteins

A lignocellulose-degrading strain isolated from thermophilic compost was identified as Geobacillus stearothermophilus B5, and found able to secrete considerable amounts of enzymes at optimal temperature (60 °C) and pH (7.5). One circular contig of 3.37 Mbp was assembled from raw data, and 3371 protein-coding genes were predicted. Clusters of orthologous groups (COG) analysis revealed various genes with functions in polymeric substrate degradation, especially for Carbohydrate Active enZymes (CAZymes), such as glycoside hydrolases (GHs) and glycosyl transferases (GTs). Furthermore, the transcriptional responses of B5 at different temperatures—with rice straw provided as the sole carbon source—were analyzed. The results revealed that B5 could resist high temperature by upregulating heat shock proteins (HSPs), enhancing protein synthesis, and decreasing carbon catabolism. Briefly, B5 possesses the ability of lignocellulose degradation, and might be considered a potential inoculant for improving composting efficiency.

The intertidal macrofauna of Nigg Bay

1986 ◽  
Vol 91 ◽  
pp. 113-141
Author(s):  
D. Raffaelli ◽  
P. R. Boyle
Keyword(s):  
Particle Diameter ◽  
Detrended Correspondence Analysis ◽  
Distribution Patterns ◽  
Trophic Levels ◽  
Median Particle Diameter ◽  
Moray Firth ◽  
Median Particle ◽  
Biological Characters ◽  
Rich Fauna ◽  
Factor Governing

SynopsisSurveys of the intertidal macrofauna and sediment characters of Nigg Bay, Moray Firth, were carried out between 1981 and 1985. Permanent stations were located at the intersections of a half-kilometre grid covering the entire intertidal area and sampled for infauna, using replicate cores. Estimates were also made of mussel and lugworm densities from quadrats and cast counts respectively. The biomasses of selected species that constitute important resources for higher trophic levels were also estimated. The sediment for each station was analysed for median particle diameter and silt content.The infaunal data were analysed by Detrended Correspondence Analysis. This indicated that tidal height was the most important factor governing the distribution and abundance of the intertidal communities. Sediment characters were only poorly related to distribution patterns.The bay has a rich fauna and is biologically similar to other outer bays of the Moray Firth, which, like Nigg, are important areas for wildfowl and waders. Comparisons of survey data from different years indicate that there are natural cycles in some sediment and biological characters of Nigg Bay.

From cells to globe: approaching the dynamics of DMS(P) in the ocean at multiple scales

2004 ◽  
Vol 61 (5) ◽  
pp. 673-684 ◽  
Author(s):  
Rafel Simó
Keyword(s):  
Multiple Scales ◽  
Cellular Level ◽  
Trophic Levels ◽  
Global Ocean ◽  
Surface Mixed Layer ◽  
Sulfur Transfer ◽  
Ocean Level ◽  
Ecosystem Level ◽  
Major Carrier ◽  
The Individual

Major advances in dimethylated sulfur research are being made by approaching its dynamics at multiple scales. At the molecular to cellular level, single-cell techniques in molecular biology allow us to identify the microbes involved in cycling of dimethylated sulfur. Also, we find that dimethylsulfoxide (DMSO) is as ubiquitous as dimethyl sulfoniopropionate (DMSP) in marine plankton, which supports the recent suggestion that both compounds are involved in coping with oxidative stress. At the community level, there is recent evidence for the role of DMSP as a major carrier in organic sulfur transfer and cycling through trophic levels, from phytoplankton to bacteria and to zooplankton through herbivore protozoans. As a consequence, the food web dynamics drive the oceanic emission of atmospheric sulfur. At the ecosystem level, the diverse and intricate effects of the physicochemical setting (light, wind, nutrients) on the oceanic cycling of dimethylated sulfur are being uncovered. A proposed shortcut to detailed understanding of the individual processes presents the depth of the surface mixed layer as the variable that integrates most of the environmental effects and serves for predicting dimethylsulfide (DMS) concentrations, even at the global ocean level. This opens the door to assessing the strength of the DMS biogeophysical system as a climate regulator.

scholarly journals Marine Cyanophages Demonstrate Biogeographic Patterns throughout the Global Ocean

2014 ◽  
Vol 81 (1) ◽  
pp. 441-452 ◽  
Author(s):  
Sijun Huang ◽  
Si Zhang ◽  
Nianzhi Jiao ◽  
Feng Chen
Keyword(s):  
Strong Correlation ◽  
Multivariate Analyses ◽  
Distribution Patterns ◽  
Mantel Test ◽  
Global Ocean ◽  
Broad Host Range ◽  
Content Type ◽  
Biogeographic Patterns ◽  
Phylogenetic Lineages ◽  
Distinct Distribution

ABSTRACTMyoviruses and podoviruses that infect cyanobacteria are the two major groups of marine cyanophages, but little is known of how their phylogenetic lineages are distributed in different habitats. In this study, we analyzed the phylogenetic relationships of cyanopodoviruses and cyanomyoviruses based on the existing genomes. The 28 cyanomyoviruses were classified into four clusters (I to IV), and 19 of the 20 cyanopodoviruses were classified into two clusters, MPP-A and MPP-B, with four subclusters within cluster MPP-B. These genomes were used to recruit cyanophage-like fragments from microbial and viral metagenomes to estimate the relative abundances of these cyanophage lineages. Our results showed that cyanopodoviruses and cyanomyoviruses are both abundant in various marine environments and that clusters MPP-B, II and III appear to be the most dominant lineages. Cyanopodoviruses and cluster I and IV cyanomyoviruses exhibited habitat-related variability in their relative levels of abundance, while cluster II and III cyanomyoviruses appeared to be consistently dominant in various habitats. Multivariate analyses showed that reads that mapped toSynechococcusphages andProchlorococcusphages had distinct distribution patterns that were significantly correlated to those ofSynechococcusandProchlorococcus, respectively. The Mantel test also revealed a strong correlation between the community compositions of cyanophages and picocyanobacteria. Given that cyanomyoviruses tend to have a broad host range and some can cross-infectSynechococcusandProchlorococcus, while cyanopodoviruses are commonly host specific, the observation that their community compositions both correlated significantly with that of picocyanobacteria was unexpected. Although cyanomyoviruses and cyanopodoviruses differ in host specificity, their biogeographic distributions are likely both constrained by the picocyanobacterial community.

Micrograzer Impact and Substrate Limitation of Bacterioplankton in Lake Michigan

1990 ◽  
Vol 47 (9) ◽  
pp. 1836-1841 ◽  
Author(s):  
Gwenyth Laird Pernie ◽  
Donald Scavia ◽  
Michael L. Pace ◽  
Hunter J. Carrick
Keyword(s):  
Bacterial Growth ◽  
Growth Rates ◽  
Lake Michigan ◽  
Heterotrophic Bacteria ◽  
Organic Substrate ◽  
Trophic Levels ◽  
Heterotrophic Flagellates ◽  
Bacterial Cells ◽  
Substrate Limitation ◽  
Loss Rates

We estimated Lake Michigan epilimnetic heterotrophic bacterial loss rates, predator size, and substrate limitation in 1986 and 1987. The bacterial growth rates were always enhanced by organic substrate additions indicating that bacterial growth is limited, to some degree, by substrate availablility. In this study we obtained loss rates and intrinsic growth rates each between 0.32 and 1.45 d−1. The grazers were predominantly picoplankton-size organisms, presumably heterotrophic flagellates. Using radiolabeled bacteria, only a small percentage (2–3%) of bacterial cells were incorporated into larger size fractions after 24 h. These results indicate that during our experiments heterotrophic bacteria were not a direct, significant, carbon source for the upper trophic levels.

scholarly journals Argon as a Tracer of Cross-Isopycnal Mixing in the Thermocline

2006 ◽  
Vol 36 (11) ◽  
pp. 2090-2105 ◽  
Author(s):  
Cara C. Henning ◽  
David Archer ◽  
Inez Fung
Keyword(s):  
General Circulation Model ◽  
General Circulation ◽  
Vertical Mixing ◽  
Circulation Model ◽  
Ocean General Circulation Model ◽  
Global Ocean ◽  
Equatorial Pacific Ocean ◽  
Subsurface Waters ◽  
Different Temperatures ◽  
Ocean Gyre

Abstract Noble gases such as argon are unaffected by chemical reactions in the ocean interior, but a number of physical mechanisms can lead to measurable sea level atmospheric disequilibrium in subsurface waters of the ocean. One such mechanism is the mixing of waters of different temperatures, which can lead to supersaturation in the ocean interior. The authors simulate the supersaturation mixing signature in the thermocline in a global ocean general circulation model, Parallel Ocean Program model, version 1.4 (POP 1.4). In contrast to existing mixing diagnostics such as dye tracers or microstructure measurements, which yield the local, recent rate of diabatic mixing, argon disequilibrium traces an integrated lifetime history of subsurface mixing. A theoretical model of the subtropical Atlantic Ocean gyre is built, based on the competing time scales of horizontal and vertical mixing, that agrees well with the full general circulation model argon supersaturation gradient in the thermocline. These results suggest that gyre-scale argon data from the real ocean could be similarly interpreted. The variation of the argon supersaturation with diffusivity in the equatorial Pacific Ocean is also investigated.

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