Catabolic genes in monitoring the bioremediation of mixed pollutants

A dot blot hybridization method, a quantitative real-time PCR method, and a gene array method were developed and compared for monitoring the biodegradation of mono- and polyaromatic hydrocarbons. The method was applied for monitoring the biodegradation of naphthalene and toluene, and the results were in good agreement with the mineralization data. To increase the sensitivity of detection and to decrease the duration of the analysis, a quantitative real-time PCR was developed for the determination of naphthalene dioxygenase (nahA)-like genes. Significant correlation was obtained between the results obtained by quantitative real-time PCR and those observed with dot blot analysis. A model array was constructed for developing a quantitative gene array method for monitoring bioremediation. The following bacterial genes responsible for the degradation of mono- and polyaromatic hydrocarbons were selected for the model array:todC1, xylA, xylE, nahA, nanH, and nahE. Several gene probes from the same pathway were included to increase the reliability of the method, and to ensure that the biodegradation of the compounds will be complete. The results of all the methods developed and tested in this study were in good agreement with each other and with other data.