Microbial Communities Associated with Zones of Elevated Magnetic Susceptibility in Hydrocarbon-Contaminated Sediments |
| |
| Authors: | Carol L Beaver Anja E Williams Estella A Atekwana Farag M Mewafy Gamal Abdel Aal Lee D Slater |
| |
| Institution: | 1. Department of Biological Sciences, Western Michigan University, Kalamazoo, Michigan, USA;2. Boone Pickens School of Geology, Oklahoma State University, Stillwater, Oklahoma, USA;3. Geology Department, Faculty of Science, Assiut University, Assiut, Egypt;4. Earth and Environmental Sciences, Rutgers University–Newark, Newark, New Jersey, USA |
| |
| Abstract: | Recent studies suggest that magnetic susceptibility (MS) measurements can play an important role in identifying zones where microbial-mediated iron mineral transformations are occurring. Here we investigated the microbial community variations within zones of elevated MS in a petroleum hydrocarbon-contaminated aquifer near Bemidji, Minnesota, USA. Our main objective was to 1) identify the key microbial populations that may play a role in hydrocarbon degradation, 2) analyze which microbial populations could be connected to the elevated MS and 3) explore the use of non-destructive geophysical techniques as a tool to guide microbial sampling. Clone libraries based on the 16S rRNA gene revealed the presence of iron-reducing β-Proteobacteria in the vadose zone, whereas the free petroleum phase on the water table was characterized by a methanogenic consortium, in which the syntrophic δ-proteobacterium Smithella and the hydrogenotrophic Methanoregula predominated. Nonmetric multidimensional scaling (NMDS) found a close relationship between elevated MS values and the methanogenic hydrocarbon-degrading consortium. Our results suggest that magnetic susceptibility measurements can guide microbiologists to zones of active microbial biodegradation in aged petroleum spills. |
| |
| Keywords: | 16S rRNA gene clone libraries magnetic susceptibility hydrocarbon contamination Smithella |
|
|
