Project description:Sequencing the metatranscriptome can provide information about the response of organisms to varying environmental conditions. We present a methodology for obtaining random whole-community mRNA from a complex microbial assemblage using Pyrosequencing. The metatranscriptome had, with minimum contamination by ribosomal RNA, significant coverage of abundant transcripts, and included significantly more potentially novel proteins than in the metagenome. Keywords: metatranscriptome, mesocosm, ocean acidification
Project description:Sequencing the metatranscriptome can provide information about the response of organisms to varying environmental conditions. We present a methodology for obtaining random whole-community mRNA from a complex microbial assemblage using Pyrosequencing. The metatranscriptome had, with minimum contamination by ribosomal RNA, significant coverage of abundant transcripts, and included significantly more potentially novel proteins than in the metagenome. Keywords: metatranscriptome, mesocosm, ocean acidification This experiment is part of a much larger experiment. We have produced 4 454 metatranscriptomic datasets and 6 454 metagenomic datasets. These were derived from 4 samples. The experiment is an ocean acidification mesocosm set up in a Norwegian Fjord in 2006. We suspended 6 bags containing 11,000 L of sea water in a Coastal Fjord and then we bubbled CO2 through three of these bags to simulate ocean acidification conditions in the year 2100. The other three bags were bubbled with air. We then induced a phytoplankton bloom in all six bags and took measurements and performed analyses of phytoplankton, bacterioplankton and physiochemical characteristics over a 22 day period. We took water samples from the peak of the phytoplankton bloom and following the decline of the phytoplankton bloom to analyses using 454 metagenomics and 454 metatranscriptomics. Day 1, High CO2 Bag and Day 1, Present Day Bag, refer to the metatranscriptomes from the peak of the bloom. Day 2, High CO2 Bag and Day 2, Present Day Bag, refer to the metatranscriptomes following the decline of the bloom. Obviously High CO2 refers to the ocean acidification mesocosm and Present Day refers to the control mesocosm. Raw data for both the metagenomic and metatranscriptomic components are available at NCBI's Short Read Archive at ftp://ftp.ncbi.nlm.nih.gov/sra/Studies/SRP000/SRP000101
Project description:Mesocosms (600 L) were deployed at the Southern Ocean Time Series (SOTS) in Austral late summer during a high nutrient, low chlorophyll period. One mesocosm represented control, present-day conditions (high nutrients/low temperature/low pCO2/low Fe/low irradiance), while the other was amended to represent a projected 2100 scenario (low nutrients/high temperature/high pCO2/high Fe/high irradiance). Approximately 2 L were filtered from the mesocosms onto 5 µm filters at Days 0, 2, 4, and 7 of the incubation.
Project description:The pollution of the marine environment with plastic debris is expected to increase, where ocean currents and winds cause their accumulation in convergence zones like the North Pacific Subtropical Gyre (NPSG). Surface-floating plastic (>330 μm) was collected in the North Pacific Ocean between Vancouver (Canada) and Singapore using a neuston catamaran and identified by Fourier-transform infrared spectroscopy (FT-IR). Baseline concentrations of 41,600-102,700 items km-2 were found, dominated by polyethylene and polypropylene. Higher concentrations (factors 4-10) of plastic items occurred not only in the NPSG (452,800 items km-2) but also in a second area, the Papaha̅naumokua̅kea Marine National Monument (PMNM, 285,200 items km-2). This second maximum was neither reported previously nor predicted by the applied ocean current model. Visual observations of floating debris (>5 cm; 8-2565 items km-2 and 34-4941 items km-2 including smaller "white bits") yielded similar patterns of baseline pollution (34-3265 items km-2) and elevated concentrations of plastic debris in the NPSG (67-4941 items km-2) and the PMNM (295-3748 items km-2). These findings suggest that ocean currents are not the only factor provoking plastic debris accumulation in the ocean. Visual observations may be useful to increase our knowledge of large-scale (micro)plastic pollution in the global oceans.
Project description:The comparision between gradual ocean acidification (GC) and one way ocean acidification (HC) of physiological and molecular responses on diatom Skeletonema costatum
Project description:Pseudomonas aeruginosa is a critical priority pathogen, whose proclivity to establish chronic infections and to resist antibiotic treatment is intimately linked to its ability to form biofilms at the infection site. Recent developments in our understanding of these biofilms has pointed to the fact that the surface-bound biofilms recapitulated by in vitro models do not sufficiently capture the type of biofilms that occur in infection sites, such as the CF lung. This study aimed to develop a straightforward and medium throughput model for free floating biofilms, alongside a protocol that permits fractionating of the biofilm into its constituent parts. The RNA-seq investigation takes the cells fraction at three timepoints in biofilm development (and one point in a planktonic culture for comparison), to ask what genes are driving the development of these free floating aggregate biofilms.
Project description:To test whether elevated CO2 , which drives seawater below pH 7.9, would shift the dynamical expression patterns diatoms in a more natural environment, we designed a controlled mesocosm study at Friday Harbor Laboratories (FHL) Ocean Acidification Environmental Laboratory (OAEL). Briefly, four independent mesocosm tanks were set up with continuous flow (10-12 mL/min) of filtered seawater from the Puget Sound to simulate mid-century (pH 7.9) and acidified oceanic conditions (pH 7.6) in duplicate. Mesocosm reservoirs were supplemented with nutrients and inoculated with T. pseudonana acclimated in FHL seawater. Mesocosms were outfitted with custom enclosures to simulate a 12:12 light:dark diel cycle. Cells for RNA extraction were sampled in the middle of the light and dark cycle and sequenced on Illumina NextSeq 500 platform.