The degradation of trichloroethylene (TCE) by toluene-oxidizing bacteria has been extensively studied, and yet the influence of environmental conditions and physiological characteristics of individual strains has received little attention. To consider these effects, the levels of TCE degradation by strains distinguishable on the basis of toluene and nitrate metabolism were compared under aerobi...

In the present work, kinetics of the biodegradation of benzene, toluene and phenol by using a pure culture of Pseudomonas putida (MTCC 1194) was determined by measuring the specific growth rate and degradation rate with substrate concentration as a function of time in a batch reactor. In general, the degradation rate of benzene, toluene and phenol increased with the increase in the initial subs...

A toluene-degrading sulfate-reducing bacterium, strain Tol2, was isolated from marine sediment under strictly anoxic conditions. Toluene was toxic if applied directly to the medium at concentrations higher than 0.5 mM. To provide toluene continuously at a nontoxic concentration, it was supplied in an inert hydrophobic carrier phase. The isolate had oval, sometimes motile cells (1.2 to 1.4 by 1....

Previously, Planted Fixed-Bed Reactors (PFRs) have been used to investigate microbial toluene removal in the rhizosphere of constructed wetlands. Aerobic toluene degradation was predominant in these model systems although bulk redox conditions were hypoxic to anoxic. However, culture-independent approaches indicated also that microbes capable of anaerobic toluene degradation were abundant. Ther...

Toluene dioxygenase from Pseudomonas putida F1 has been implicated as an enzyme capable of degrading trichloroethylene. This has now been confirmed with Escherichia coli JM109(pDTG601) that contains the structural genes (todC1C2BA) of toluene dioxygenase under the control of the tac promoter. The extent of trichloroethylene degradation by the recombinant organism depended on the cell concentrat...

Anaerobic biodegradation of toluene and ethylbenzene is of environmental concern and biochemical interest due to toxicity and novel reactions, respectively. The denitrifying strain EbN1 is unique in anaerobically degrading both alkylbenzenes via different pathways which converge at benzoyl coenzyme A. The organization of genes involved in both pathways was only recently determined for strain Eb...

The stimulation of the microbial population by a more bioavailable supplementary carbon source and by a surfactant pretreatment was studied in petroleum hydrocarbon-polluted soils bioremediation. Two types of soils were used, Soil A which had been recently polluted and the aged Soil B. They contained 52.4 and 50.4 g of total petroleum hydrocarbons per kg of dry soil, respectively. The effect of...

A newly isolated denitrifying bacterium, Thauera sp. strain DNT-1, grew on toluene as the sole carbon and energy source under both aerobic and anaerobic conditions. When this strain was cultivated under oxygen-limiting conditions with nitrate, first toluene was degraded as oxygen was consumed, while later toluene was degraded as nitrate was reduced. Biochemical observations indicated that initi...

Primary features of hydrogen and carbon isotope fractionation during toluene degradation were studied to evaluate if analysis of isotope signatures can be used as a tool to monitor biodegradation in contaminated aquifers. D/H hydrogen isotope fractionation during microbial degradation of toluene was measured by gas chromatography. Per-deuterated toluene-d(8) and nonlabeled toluene were supplied...

Methanogenic flowthrough aquifer columns were used to investigate the potential of bioaugmentation to enhance anaerobic benzene-toluene-ethylbenzene-xylene (BTEX) degradation in groundwater contaminated with ethanol-blended gasoline. Two different methanogenic consortia (enriched with benzene or toluene and o-xylene) were used as inocula. Toluene was the only hydrocarbon degraded within 3 years...