80 research outputs found
Metagenomic analysis of the bacterial microbiota associated with cultured oysters (Crassostrea sp.) in estuarine environments
Characterization of Geographically Distinct Bacterial Communities Associated with Coral Mucus Produced by Acropora spp. and Porites spp
ABSTRACT
Acropora
and
Porites
corals are important reef builders in the Indo-Pacific and Caribbean. Bacteria associated with mucus produced by
Porites
spp. and
Acropora
spp. from Caribbean (Punta Maroma, Mexico) and Indo-Pacific (Hoga and Sampela, Indonesia) reefs were determined. Analysis of pyrosequencing libraries showed that bacterial communities from Caribbean corals were significantly more diverse (H′, 3.18 to 4.25) than their Indonesian counterparts (H′, 2.54 to 3.25). Dominant taxa were
Gammaproteobacteria
,
Alphaproteobacteria
,
Firmicutes
, and
Cyanobacteria
, which varied in relative abundance between coral genera and region. Distinct coral host-specific communities were also found; for example,
Clostridiales
were dominant on
Acropora
spp. (at Hoga and the Mexican Caribbean) compared to
Porites
spp. and seawater. Within the
Gammproteobacteria
,
Halomonas
spp. dominated sequence libraries from
Porites
spp. (49%) and
Acropora
spp. (5.6%) from the Mexican Caribbean, compared to the corresponding Indonesian coral libraries (<2%). Interestingly, with the exception of
Porites
spp. from the Mexican Caribbean, there was also a ubiquity of
Psychrobacter
spp., which dominated
Acropora
and
Porites
libraries from Indonesia and
Acropora
libraries from the Caribbean. In conclusion, there was a dominance of
Halomonas
spp. (associated with
Acropora
and
Porites
[Mexican Caribbean]),
Firmicutes
(associated with
Acropora
[Mexican Caribbean] and with
Acropora
and
Porites
[Hoga]), and
Cyanobacteria
(associated with
Acropora
and
Porites
[Hoga] and
Porites
[Sampela]). This is also the first report describing geographically distinct
Psychrobacter
spp. associated with coral mucus. In addition, the predominance of
Clostridiales
associated with
Acropora
spp. provided additional evidence for coral host-specific microorganisms.
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Transient Changes in Bacterioplankton Communities Induced by the Submarine Volcanic Eruption of El Hierro (Canary Islands)
Postprint4,411
Mendelian Randomization and mediation analysis of leukocyte telomere length and risk of lung and head and neck cancers
16S rRNA gene metabarcoding and TEM reveals different ecological strategies within the genus Neogloboquadrina (planktonic foraminifer)
CB was supported on a Daphne Jackson Fellowship sponsored by Natural Environmental Research Council (www.nerc.ac.uk) and the University of Edinburgh via the Daphne Jackson Trust. Field collections were supported by the National Science Foundation (www.nsf.gov) grant number OCE-1261519 to ADR and JSF.Uncovering the complexities of trophic and metabolic interactions among microorganisms is essential for the understanding of marine biogeochemical cycling and modelling climate-driven ecosystem shifts. High-throughput DNA sequencing methods provide valuable tools for examining these complex interactions, although this remains challenging, as many microorganisms are difficult to isolate, identify and culture. We use two species of planktonic foraminifera from the climatically susceptible, palaeoceanographically important genus Neogloboquadrina, as ideal test microorganisms for the application of 16S rRNA gene metabarcoding. Neogloboquadrina dutertrei and Neogloboquadrina incompta were collected from the California Current and subjected to either 16S rRNA gene metabarcoding, fluorescence microscopy, or transmission electron microscopy (TEM) to investigate their species-specific trophic interactions and potential symbiotic associations. 53–99% of 16S rRNA gene sequences recovered from two specimens of N. dutertrei were assigned to a single operational taxonomic unit (OTU) from a chloroplast of the phylum Stramenopile. TEM observations confirmed the presence of numerous intact coccoid algae within the host cell, consistent with algal symbionts. Based on sequence data and observed ultrastructure, we taxonomically assign the putative algal symbionts to Pelagophyceae and not Chrysophyceae, as previously reported in this species. In addition, our data shows that N. dutertrei feeds on protists within particulate organic matter (POM), but not on bacteria as a major food source. In total contrast, of OTUs recovered from three N. incompta specimens, 83–95% were assigned to bacterial classes Alteromonadales and Vibrionales of the order Gammaproteobacteria. TEM demonstrates that these bacteria are a food source, not putative symbionts. Contrary to the current view that non-spinose foraminifera are predominantly herbivorous, neither N. dutertrei nor N. incompta contained significant numbers of phytoplankton OTUs. We present an alternative view of their trophic interactions and discuss these results within the context of modelling global planktonic foraminiferal abundances in response to high-latitude climate change.Publisher PDFPeer reviewe
Differences in structure of northern Australian hypolithic communities according to location, rock type, and gross morphology
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