Genomic signatures of cold adaptation in the family Colwelliaceae.

Psychrophily is a phenotype describing microbial growth at low temperatures; elucidating the biomolecular and genomic adaptations necessary for survival in the cold is important for understanding life in extreme environments on Earth and in outer space. We used comparative genomics and temperature growth experiments of bacteria from the family Colwelliaceae to identify genomic factors correlated with optimal growth temperature (OGT). A phylogenomic analysis of 67 public and 39 newly sequenced strains revealed three main clades of Colwelliaceae.

Microbial community transcriptional patterns vary in response to mesoscale forcing in the North Pacific Subtropical Gyre.

The physical and biological dynamics that influence phytoplankton communities in the oligotrophic ocean are complex, changing across broad temporal and spatial scales. Eukaryotic phytoplankton (e.g.

Progress and promise of omics for predicting the impacts of climate change on harmful algal blooms.

Climate change is predicted to increase the severity and prevalence of harmful algal blooms (HABs). In the past twenty years, omics techniques such as genomics, transcriptomics, proteomics and metabolomics have transformed that data landscape of many fields including the study of HABs. Advances in technology have facilitated the creation of many publicly available omics datasets that are complementary and shed new light on the mechanisms of HAB formation and toxin production.

Transcriptional patterns of Emiliania huxleyi in the North Pacific Subtropical Gyre reveal the daily rhythms of its metabolic potential.

Emiliania huxleyi is a calcifying haptophyte, contributing to both the organic and inorganic marine carbon cycles. In marine ecosystems, light is a major driver of phytoplankton physiology and ultimately carbon flow through the ecosystem. Here, we analysed a Lagrangian time-series of metatranscriptomes collected in the North Pacific Subtropical Gyre (NPSG) to examine how in situ populations of E.

Non-linear Physiology and Gene Expression Responses of Harmful Alga Heterosigma akashiwo to Rising CO.

Heterosigma akashiwo is a raphidophyte known for forming ichthyotoxic blooms. In order to predict the potential impacts of rising CO on H. akashiwo it is necessary to understand the factors influencing growth rates over a range of CO concentrations.

Diverse CO-Induced Responses in Physiology and Gene Expression among Eukaryotic Phytoplankton.

With rising atmospheric CO, phytoplankton face shifts in ocean chemistry including increased dissolved CO and acidification that will likely influence the relative competitive fitness of different phytoplankton taxa. Here we compared the physiological and gene expression responses of six species of phytoplankton including a diatom, a raphidophyte, two haptophytes, and two dinoflagellates to ambient (~400 ppm) and elevated (~800 ppm) CO. Dinoflagellates had significantly slower growth rates and higher, yet variable, chlorophyll per cell under elevated CO.

Acclimation conditions modify physiological response of the diatom Thalassiosira pseudonana to elevated CO2 concentrations in a nitrate-limited chemostat.

Diatoms are responsible for a large proportion of global carbon fixation, with the possibility that they may fix more carbon under future levels of high CO2 . To determine how increased CO2 concentrations impact the physiology of the diatom Thalassiosira pseudonana Hasle et Heimdal, nitrate-limited chemostats were used to acclimate cells to a recent past (333 ± 6 μatm) and two projected future concentrations (476 ± 18 μatm, 816 ± 35 μatm) of CO2 . Samples were harvested under steady-state growth conditions after either an abrupt (15-16 generations) or a longer acclimation process (33-57 generations) to increased CO2 concentrations.