Degradation of mixtures of aromatic and chloroaliphatic hydrocarbons by aromatic hydrocarbon-degrading bacteria

Abstract

The well-characterized toluene-oxidizing bacteria Pseudomonas putida PaW1, P. putida F1, P. mendocina KR1, Burkholderia cepacia G4, B. cepacia JS150, and Ralstonia pickettii PKO1, as well as several strains of bacteria isolated from activated sludge, were examined for their ability to degrade mixtures of aromatic and chloroaliphatic hydrocarbons. Collectively, the strains tested were able to transform all of the 14 aromatic hydrocarbons included in the mixtures, with most strains degrading five or more. Few strains degraded trichloroethylene well under these conditions, only one degraded methylene chloride, and none were able to transform chloroform. G4, PKO1, KR1, F1, and JS150 exhibited generally broad but oxygenase-specific degradation profiles, with the three monooxygenase strains degrading significantly more o-xylene and trichloroethylene, and F1 and JS150 degrading greater quantities of isopropylbenzene and 1,4dichlorobenzene. PaW1 degraded only the methylaromatic hydrocarbons and styrene. Sludge isolates enriched on benzene, toluene, styrene and the xylenes exhibited degradation profiles similar to F1 or PaW1, while the pattern of hydrocarbon degradation for the ethylbenzene, isopropylbenzene, 1,3,5-trimethylbenzene, and 1,3-dichlorobenzene isolates were distinct from the other strains and from each other. Overall, our results showed that many of the bacteria which utilize aromatic compounds are capable of degrading a diverse array of aromatic hydrocarbons in mixtures, but that chloroaliphatics such as methylene chloride and chloroform may be recalcitrant to co-oxidation in the presence of aromatics or trichloroethylene.

Bioremediation and reclamation of soil contaminated with petroleum oil hydrocarbons by exogenously seeded bacterial consortium: a pilot-scale study

“…Xylene is metabolized to mono-methylated catechol. Therefore, it is quite obvious that bacteria in a combination would be able to utilize BTX compounds more effectively and efficiently than degradation by an individual isolate of the same consortium, which may be by virtue of the production of different degradative enzymes by mixed microbial population (Leahy et al 2003). …”

Novel aerobic benzene degrading microorganisms identified in three soils by stable isotope probing

“…Commonly identified isolates appear to fall within two phyla, the Proteobacteria (c and b Proteobacteria) and Actinobacteria. Proteobacteria (c or b) include, for example, microorganisms within the genera Pseudomonas (Alagappan and Cowan 2003; Bertoni et al 1996;Irie et al et al 2003;Reardon et al 2002), Burkholderia (Alagappan and Cowan 2003;Johnson and Olsen 1997;Leahy et al 2003;Radway et al 1998;Reardon et al 2002), Ralstonia (Alagappan and Cowan 2003;Leahy et al 2003;Olsen et al 1994), Achromobacter (Yeom et al 1998;Yeom and Yoo 1999), Pseudoxanthomonas (Kim et al 2008), Hydrogenophaga (Fahy et al 2008b), Alicycliphilus (Weelink et al 2008) and Acinetobacter (Kim and Jeon 2009). Benzene degraders belonging to the phylum Actinobacteria include microorganisms in the genera Rhodococcus (Deeb and Alvarez-Cohen 1999;Fahy et al 2008b;Jung and Park 2004;Na et al 2005) and Arthrobacter (Fahy et al 2008b).…”

Removal of heavy metals by an enriched consortium

“…Therefore, we referred to the HM-1 isolate as Ralstonia sp. The activities of Ralstonia picketti such as poly (3-hydroxybutyrate)-degradation (Takanashi and Saito, 2006), removal of phenanthrene (Chávez-Gómez et al, 2003), and aromatic hydrocarbon-degradation (Leahy et al, 2003) have been reported.…”