Utilization of monocyclic aromatic hydrocarbons individually and in mixture by bacteria isolated from petroleum-contaminated soil

Abstract

The fate of benzene, ethylbenzene, toluene, xylenes (BTEX) compounds through biodegradation was investigated using two different bacteria, Ralstonia picketti (BP-20) and Alcaligenes piechaudii (CZOR L-1B). These bacteria were isolated from extremely polluted soils contaminated with petroleum hydrocarbons. PCR and Fatty Acid Methyl Ester (FAME) were used to identify the isolates. In this study, BTEX biodegradation, applied as a mixture or as individual compounds by the bacteria was evaluated. Both bacteria were shown to degrade each of the BTEX compounds individually and in mixture. However, Alcaligenes piechaudii was a better degrader of BTEXs both in the mixture and individually. Differences between BTEX biodegradation in the mixture and individually were observed, especially in the case of benzene. The degradation of all BTEXs in the mixture was lower than the degradation of individual compounds for both bacteria tested. In the all experiments, toluene and m + p-xylenes were better removed than the other BTEXs. No intermediates of biodegradation were detected. Biosurfactant production was observed by culture techniques. In addition, 3-hydroxy fatty acids, important in biosurfactant production, were observed by FAME analysis. The test results indicate that the bacteria could contribute to bioremediation of aromatic hydrocarbon pollution.

Reduction of Petroleum Hydrocarbons and Toxicity in Refinery Wastewater by Bioremediation

“…The present study investigated the bacterial isolates from a hydrocarbon-contaminated site belonging to the genus Ralstonia, Alcaligenes and Bacillus. The isolates Ralstonia picketti SRS and Alcaligenes piechaudii SRS, their surface active and biodegradation properties were described previously (Płaza et al , 2007. The capacity of these natural bacterial strains to produce biosurfactants and degrade petroleum hydrocarbons is promising for environmental restoration applications.…”

“…The aged sludge was acidic (pH 2) and highly contaminated with polycyclic aromatic hydrocarbons. The isolates were selected based on their ability to produce biosurfactant and degrade of aliphatic and aromatic petroleum hydrocarbons as reported earlier (Płaza et al , 2007. Strains were maintained on nutrient agar (SMA, bioMerieux) slants and subcultured every 3 weeks.…”

Oxidative stress and DNA damage in the earthworm Eisenia fetida induced by toluene, ethylbenzene and xylene

“…Monocyclic aromatic hydrocarbons such as toluene, ethylbenzene and three isomers of xylene are commonly associated with crude petroleum and petroleum products such as gasoline and diesel fuels. For example, it has been reported that toluene, ethylbenzene and xylene make up about 18% by volume in gasoline (An 2004;Plaza et al 2007). Because of the relatively high water solubility and low K ow values, these compounds are highly mobile in the environment (Dou et al 2008).…”

“…Because of the relatively high water solubility and low K ow values, these compounds are highly mobile in the environment (Dou et al 2008). The presence of these hydrocarbons in the environment is a hazard to public health and an ecological concern due to their toxicity and ability to bioaccumulate through food chain, and they are classified as environmental priority pollutants in many countries (Plaza et al 2007). Toluene, ethylbenzene, and xylene can cause nonspecific narcosis above certain level in tissue (particularly membrane) lipids.…”

Preferential utilization of petroleum oil hydrocarbon components by microbial consortia reflects degradation pattern in aliphatic–aromatic hydrocarbon binary mixtures

“…Plaza et al (2007) found that individual BTEX compounds are degraded to a greater extent than the combined mixture by microbial isolates. Chang et al (2001) reported a range of substrate interactions including no interaction, positive and negative interactions, and co-metabolism in binary mixtures of BTEX.…”