Degradation of Phenanthrene in Liquid Culture and Sand Slurry by Corynebacterium urealyticum

Abstract

Most studies on PAHs biodegradation evaluated the degradation potential of microorganisms under indigenous condition in either liquid or solid. There are limited studies on evaluation of the same microorganisms in degrading PAHs under non-indigenous condition in both liquid and solid media. This study investigated the potential of the bacterium, Corynebacterium urealyticum isolated from municipal sludge in degrading phenanthrene in both liquid and solid media. Batch experiments were conducted over 20 days. Batch reactors containing artificially contaminated phenanthrene minimal media and sand slurry were inoculated with bacterium culture. Percentage phenanthrene degradation in liquid culture and sand slurry were found to be 87% and 29%, respectively. Apart of having higher rate in liquid culture, the degradation activity by bacterium remain active throughout the experiment.  There were no significant differences on the degradation of phenanthrene at low and high initial phenanthrene concentrations in liquid cultures, which differed to the observation in sand slurry. From the viable count analysis, it was observed that this bacterium immediately adapted to the new environment. This study shows that Corynebacterium urealyticum show better capability in degrading phenanthrene in liquid culture compared to sand slurry.

Keywords: Bioremediation, Corynebacterium urealyticum, liquid cultures, Phenanthrene, sand slurry