Identification and characterization of o-xylene-degrading Rhodococcus spp. which were dominant species in the remediation of o-xylene-contaminated soils

Abstract

Soils contaminated with o-xylene were more difficult to bioremediate than those contaminated with other BTEX hydrocarbons (benzene, toluene, ethylbenzene, m-xylene and p-xylene). In order to identify microorganisms responsible for o-xylene degradation in soil, microbial community structure analyses were carried out with two soil samples in the presence of o-xylene and mineral nutrients. In two different soil samples, Rhodococcus opacus became abundant. We were also able to isolate o-xylene degrading Rhodococcus species from these soil samples. A primer set was developed to specifically detect a cluster of this Rhodococcus group including isolated Rhodococcus strains, Rhodococcus opacus and Rhodococcus koreensis. The growth of this bacterial group in an o-xylene-contaminated soil was followed by competitive PCR (cPCR). The decrease in o-xylene clearly paralleled the growth of the Rhodococcus group.

Degradation of a Mixture of Hydrocarbons, Gasoline, and Diesel Oil Additives by Rhodococcus aetherivorans and Rhodococcus wratislaviensis

“…The ability to degrade o-xylene is important since it is considered a difficult-to-degrade hydrocarbon and only a few Rhodococcus strains with this ability have been isolated (14,23,24,29,45). A nidA gene in R. wratislaviensis IFP 2016 was identified with 99% identity to a gene from Rhodococcus opacus TKN14 (29) that encodes the large subunit of a dioxygenase iron-sulfur protein.…”

“…It is also interesting that isooctane utilization was reduced considerably by the presence of BTEXs (9). This lack of information concerning isooctane biodegradation is an issue when considering the possibility of using it as a fuel additive (45). The biodegradation of 2-EHN, a recently used additive of diesel fuel, by M. austroafricanum IFP 2173 was recently reported, but metabolites accumulated in the medium during the degradation (36).…”

Isolation and characterization of a Rhodococcus strain able to degrade 2-fluorophenol

“…no. AB183440; sequence similarity 99% over 1,423 bases), which were both isolated from trichloroethylenecontaminated soil and are able to degrade ortho-xylene (Taki et al 2007). …”

Characterization and Evaluation of Polycyclic Aromatic Hydrocarbon (PAH) Degrading Bacteria Isolated from Oil Contaminated Soil

“…Hydrocarbon degradative process is widely distributed among numerous genera or taxa [14] and biodegradation of hydrocarbons using microorganisms has been established as an efficient, economic and versatile approach [15][16][17][18][19]. Microorganisms degrade hydrocarbon contaminants and utilize the resulting compounds as nutrients and energy sources for growth and reproduction [20] and are depending on the chemical nature of the compounds and on environmental determinants [21].…”