Abstract

The purpose of this study was to determinate the dynamics of the bacterial community composition, that is, diversity and abundance of microbial soil communities through PCR-DGGE of 16S rDNA gene fragments from a saline-alkaline soil. The soil and/or wastewater sludge were contaminated or not with phenanthrene and anthracene and spiked or not with acetone or polycyclic aromatic hydrocarbons (PAHs)-solution through an aerobic incubation during 56 days. The result obtained using denaturing gradient gel electrophoresis (DGGE) revealed that at the onset of the experiment, there were no differences between rybotipes in the nine treatments, but at 56 days, soil plus waste water sludge treatment showed the highest rybotipes number when spiked or not with acetone or PAH’s. Additionally, soil amended with wastewater sludge increased significantly the dissipation of phenanthrene and anthracene. It was found that soils amended with wastewater sludge increased the number of rybotipes and accelerated removal of phenanthrene and anthracene from soil.    

Key words: Microbial diversity, polycyclic aromatic hydrocarbons (PAHs) dissipation, polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) of ribosomal DNA, microbial communities, soil, sludge.