Microbial communities in wetlands of the Athabasca oil sands: genetic and metabolic characterization.
Naphthenic acids are a complex family of naturally occurring cyclic and acyclic carboxylic acids that are present in the acidic fraction of petroleum. Naphthenic acids are acutely toxic to aquatic organisms. Previous studies showed that wetland sediments exposed to oil sands process water containing naphthenic acids had higher rates of naphthenic acid degradation in vitro compared with unexposed wetlands. In this study we compare the microbial community structures in sediments from wetlands exposed to different amounts of oil sands process water using BIOLOG, phospholipid fatty acid analysis and denaturing gradient gel electrophoresis of total bacterial DNA. Community profiles were compared using cluster analysis. BIOLOG profiles were primarily influenced by seasonal trends rather than naphthenic acids content. In contrast, phospholipid fatty acid analysis comparisons clustered communities that had higher levels of residual oil, although this association was not strong. In contrast, cluster diagrams produced from the denaturing gradient gel electrophoresis data clearly separated bacterial communities according to naphthenic acids concentrations, indicating that naphthenic acids content was a major influence on the composition of the bacterial community. In addition, denaturing gradient gel electrophoresis profiles indicated that naphthenic acids-exposed bacterial communities were homogeneous on a scale of meters, whereas unexposed (off-site) wetlands were less homogeneous.
Hadwin
Alisonk M
AM
Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada V5A 1S6.
Del Rio
Luis F
LF
Pinto
Linda J
LJ
Painter
Morgan
M
Routledge
Richard
R
Moore
Margo M
MM
D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification*; D001673:Biodegradation, Environmental; D002170:Canada; D002264:Carboxylic Acids / Q000737:chemistry / Q000378:metabolism; D015169:Colony Count, Microbial / Q000379:methods*; D004269:DNA, Bacterial / Q000235:genetics; D004586:Electrophoresis; D005227:Fatty Acids / Q000032:analysis; D007218:Industrial Microbiology; D007220:Industrial Waste / Q000032:analysis; D010578:Petroleum; D016133:Polymerase Chain Reaction; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D014877:Water Pollution, Chemical / Q000032:analysis
D002264:Carboxylic Acids; D004269:DNA, Bacterial; D005227:Fatty Acids; D007220:Industrial Waste; D010578:Petroleum; D011933:Reagent Kits, Diagnostic; C046170:naphthenic acid