Abstract

A study was undertaken to detect and monitor the degradation of hexadecane by three potential degrading bacteria (Pseudomonas putida, Rhodococcus erythroplolis and Bacillus thermoleovorans) isolated from contaminated soils in Riyadh, Saudi Arabia. The extraction of the bacterial populations from these polluted soils were 5.25 x 10⁵, 1.76 x 10⁶ and 5.11 x 10⁵ cells/ml, respectively with three different colony types of bacterial strains. Microbial population diversity studies were carried out by microbial enumeration identification and determination of growth responses of bacterial isolates in different concentrations of hexadecane. Phenotypic examination of the heterotrophic bacteria belonged mainly to the genusPseudomonas, Rhodococcus and Bacillus. The mixed populations were capable of degrading hexadecane up to 120 ppm. The biodegradation of hexadecane by P. putida, R. erythroplolis and B. thermoleovorans together, was fast when compared to the biodegradation of hexadecane by each strain separately. This study reported on how to change contaminated soils to a non contaminated state. Healthy soils are essential not only to sustain production of food and fibber for citizens of the world, but also to provide a good quality life.

Key words: Hexadecane, biodegradation, Pseudomonas putida, Rhodococcus erythroplolis, Bacillus thermoleovorans.