Instead, other members of the Proteobacteria, known for hosting many known hydrocarbon degraders (Widdel & Rabus, 2001), were identified (Fig. S2 in Appendix S1). One sequence was closely related to a clone identified at the Gullfaks and Tommeliten oil field methane seeps of the North Sea (Wegener et al., 2008). AOM rates were determined to assess potential methane losses
during incubation time. These rates were selleck products in good agreement with those observed typically in methane-fed environments (Knittel & Boetius, 2009). However, methane seepage was apparently not the major energy source of Zeebrugge sediments. Therefore, in situ AOM possibly depended on hydrocarbon-derived methane, as indicated by the growth of the AOM community in hexadecane-amended microcosms (Fig. 5). Based on the methane partial pressure-dependent and cell-specific AOM rate constant reported by Thauer & Shima (2008), we calculated a loss of no more than 12% of the produced methane in hydrocarbon-amended microcosms. To fully exploit exhausted oil reservoirs, the conversion of residual oil to methane seems to be a viable technique to recover energy that would otherwise be lost. As a possible contribution for this application, our experiments demonstrated that additional sulfate or trivalent iron accelerated methanogenesis in aliphatic and
aromatic hydrocarbon (e.g. BTEX)-degrading communities. In contrast, the inhibitory effect selleck compound of nitrate, commonly used to suppress sulfate reducers in oil fields, most likely prohibits its application for oil recovery as methane. Additionally, we present convincing evidence for the conversion of a PAH to methane. Consequently, our results also provide novel insights for bioremediation, where the conversion of hydrocarbon contaminants to
volatile methane Gemcitabine mouse seems to be an option. Nevertheless, methane is a much more potent greenhouse gas than CO2. Therefore, the addition of high amounts of nitrate or sulfate may be preferred to stimulate biodegradation when methanogenesis is unwanted and oxygen treatment is impossible. Funding was partially provided by the Deutsche Forschungsgemeinschaft (grants KR 3311/5-1 & 6-1), the Bundesministerium für Bildung und Forschung (grant 03G0189A), the Landesanstalt für Altlastenfreistellung Magdeburg and the Flemish Environmental and Technology Innovation Platform (MIP, project ‘In situ conditioning of dredged and mineral sludge’). We thank Dr Axel Schippers for fruitful discussions and for improving the manuscript. Appendix S1. Eckernförde Bay. Please note: Wiley-Blackwell is not responsible for the content or functionality of any supporting materials supplied by the authors. Any queries (other than missing material) should be directed to the corresponding author for the article. “
“Listeria monocytogenes is a food-borne pathogen that causes severe opportunistic infection in humans and animals.