Complete mineralization of benzene by aquifer microorganisms under strictly anaerobic conditions

Abstract

Benzene was mineralized to CO2 by aquifer-derived microorganisms under strictly anaerobic conditions. The degradation occurred in microcosms containing gasoline-contaminated subsurface sediment from Seal Beach, California, and anaerobic, sulfide-reduced defined mineral medium supplemented with 20 mM sulfate. Benzene, at initial concentrations ranging from 40 to 200 microM, was depleted in all microcosms and more than 90% of 14C-labeled benzene was mineralized to 14CO2.

Functional characterization of an anaerobic benzene‐degrading enrichment culture by DNA stable isotope probing

“…Since contaminant plumes generally become anoxic due to the rapid microbial consumption of oxygen, the more important natural attenuation process is therefore benzene degradation under anoxic conditions. This process was observed in laboratory enrichment cultures under methanogenic (Grbic-Galic and Vogel, 1987;Kazumi et al, 1997), nitrate-reducing (Nales et al, 1998;Burland and Edwards, 1999;Kasai et al, 2006), iron-reducing (Lovley et al, 1996;Kazumi et al, 1997;Nales et al, 1998;Jahn et al, 2005;Botton and Parsons, 2006;Kunapuli et al, 2007) and sulfatereducing conditions (Edwards and Grbic-Galic, 1992;Lovley et al, 1995;Kazumi et al, 1997;Phelps and Young, 1999;Vogt et al, 2007;Herrmann et al, 2008;Musat and Widdel, 2008;Abu Laban et al, 2009). However, today the true identity and physiology of the organisms involved are still enigmatic, and no strictly anaerobic pure cultures have been described.…”

Cultivating microbial dark matter in benzene‐degrading methanogenic consortia

“…In laboratory-enriched cultures, anaerobic benzene degradation can be sustained under different electronaccepting conditions, for example, under iron-reducing (Lovley et al, 1996;Nales et al, 1998;Weiner and Lovley, 1998;Zhang et al, 2012), nitrate-reducing (Burland and Edwards, 1999;Coates et al, 2002;Ulrich and Edwards, 2003;Kasai et al, 2006;van der Zaan et al, 2012), sulfate-reducing (Edwards and Grbić-Galić, 1992;Nales et al, 1998;Caldwell and Suflita, 2000;Kleinsteuber et al, 2008;Abu Laban et al, 2009) and methanogenic conditions (Grbić-Galić and Vogel, 1987;Kazumi et al, 1997;Ulrich and Edwards, 2003;Sakai et al, 2009;Noguchi et al, 2014). In petroleum contaminated aquifers, regions close to the contaminated source are typically predominantly methanogenic (Lovley, 1997).…”

Identification of intermediates formed during anaerobic benzene degradation by an iron‐reducing enrichment culture

“…Anaerobic benzene degradation has been described in several publications with nitrate, sulfate and ferric iron as electron acceptors in microcosms and enrichments (Vogel and Grbic-Galic, 1986;Edwards and Grbic-Galic, 1992;Lovley et al, 1994;Phelps et al, 1996;Kazumi et al, 1997;Burland and Edwards, 1999;Lovley, 2000;Zwolinski et al, 2000;Jahn et al, 2005;Kunapuli et al, 2007). Even methanogenic cultures are known (Vogel and Grbic-Galic, 1986;Ulrich et al, 2005) and two denitrifying pure cultures degrading benzene have been described (Coates et al, 2001a;Kasai et al, 2006).…”