Project description:Analysis of microbial gene expression in response to physical and chemical gradients forming in the Columbia River, estuary, plume and coastal ocean was done in the context of the environmental data base. Gene expression was analyzed for 2,234 individual genes that were selected from fully sequenced genomes of 246 prokaryotic species (bacteria and archaea) as related to the nitrogen metabolism and carbon fixation. Seasonal molecular portraits of differential gene expression in prokaryotic communities during river-to-ocean transition were created using freshwater baseline samples (268, 270, 347, 002, 006, 207, 212). Total RNA was isolated from 64 filtered environmental water samples collected in the Columbia River coastal margin during 4 research cruises (14 from August, 2007; 17 from November, 2007; 18 from April, 2008; and 16 from June, 2008), and analyzed using microarray hybridization with the CombiMatrix 4X2K format. Microarray targets were prepared by reverse transcription of total RNA into fluorescently labeled cDNA. All samples were hybridized in duplicate, except samples 212 and 310 (hybridized in triplicate) and samples 336, 339, 50, 152, 157, and 199 (hybridized once). Sample location codes: number shows distance from the coast in km; CR, Columbia River transect in the plume and coastal ocean; NH, Newport Hydroline transect in the coastal ocean at Newport, Oregon; AST and HAM, Columbia River estuary locations near Astoria (river mile 7-9) and Hammond (river mile 5), respectively; TID, Columbia River estuary locations in the tidal basin (river mile 22-23); BA, river location at Beaver Army Dock (river mile 53) near Quincy, Oregon; UP, river location at mile 74.
Project description:To characterize the taxonomic and functional diversity of biofilms on plastics in marine environments, plastic pellets (PE and PS, ø 3mm) and wooden pellets (as organic control) were incubated at three stations: at the Baltic Sea coast in Heiligendamm (coast), in a dead branch of the river Warnow in Warnemünde (inlet), and in the Warnow estuary (estuary). After two weeks of incubation, all pellets were frozen for subsequent metagenome sequencing and metaproteomic analysis. Biofilm communities in the samples were compared on multiple levels: a) between the two plastic materials, b) between the individual incubation sites, and c) between the plastic materials and the wooden control. Using a semiquantitative approach, we established metaproteome profiles, which reflect the dominant taxonomic groups as well as abundant metabolic functions in the respective samples.