Microbial diversity analysis of pipe-associated water (PAW) and pipe-associated solid (PAS) samples from a hydrocarbon resource environments using next-generation 16S pyrosequencing
Microbial diversity analysis of pipe-associated water (PAW) and pipe-associated solid (PAS) samples from a hydrocarbon resource environments using next-generation 16S pyrosequencing
In this study, 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. 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. PAS-616 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 PAS-821LP 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-821TP 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). Reducing the SBS dose to reduce formation of a very active sulfur cycling microbial community, including SRB, on the pipe surface downstream of the injection point might be beneficial. This research was supported by funding from Genome Canada, Genome Alberta, the Government of Alberta and Genome BC.
Corrosion problems in the brackish water gathering and treatment facilities at a Foster Creek site prompted investigation of possible corrosion mechanisms. Our previous work have shown that microorganisms associated with microbially influenced corrosion (MIC) including sulfate-reducing bacteria (SRB) as well as methanogens influenced the system upstream and downstream of the treatment facilities. In this study, we present the use of high throughput DNA pyrosequencing to specifically characterize the microbial diversity of all the samples (both water and pipeline) and to assess which microorganisms are involved in the corrosion observed.