organism: hydrocarbon metagenome
description: Pipelines at a Foster Creek site, transporting water from the Grand Rapids and the McMurray formation to the steam-generating facility, are subject to frequent corrosion failures. In the current experiment, the microbial community composition, determined with state-of-the-art DNA sequencing technology, is determined for transported water samples, collected mainly prior to the SBS injection point, and for pipe-associated solids (PAS) scraped from the walls of pipe cutouts and collected upstream , and downstream of the SBS injection point. Genomic DNA was isolated using a procedure modified from that of Marmur method. Some water samples were processed without bead-beating , while all the other samples were processed with bead-beating . The transported water had a large fraction of Pseudomonas (46%), not found in the pipe samples, demonstrating that the planktonic (=water) and sessile (=PAS) populations were distinct. Methanogens and acetogens ranked 2nd and 3rd in the planktonic population at 10.5 and 1.4%, respectively. SRB were relatively rare. Upstream PAS had methanogens as the main community component (54%), followed by Desulfuromonas (10.6%) and acetogens (2.4%). The most prevalent SRB was present at 0.1%. The microbial community in downstream PAS was dominated by SRB of the genus Desulfomicrobium (36.3%), Desulfocapsa (24%) and Desulfurivibrio (3.7%). Methanogens and acetogens were at 0.4 and 0.3%, respectively, whereas the community at PAS downstream was once again dominated by methanogens (39%), followed by SRB of the genera Desulfocapsa (33%) and Desulfomicrobium (19%). The results indicate that the pipeline-associated sessile microbial community is strongly influenced by SBS injection, leading to a shift in microbial community from methanogens (upstream PAS) to SRB (downstream PAS).