Isolation and characterization of Jatropha oildegradation by <i>Enterococcus faecalis</i> and <i>Burkholderia cenocepacia</i> W-1 under anaerobic condition

Abstract

Ground contamination by oily substances led to several environmental issues. This work focused on the isolation and characterization of micro-organisms which possess the capability of degrading Jatropha oil, a feed stock of biodiesel production, under anaerobic condition. The active isolated strains were tested for morphological, physiological and genotypic characteristics. Based on 16S rRNA sequence analysis, the Enterococcus faecalis and Burkholderia cenocepacia W-1 were selected due to their ability to produce large clear zones. Further studies were carried out for oil degradation using minimal M9 salt media supplemented with 1% Jatropha oil as the sole carbon source. Lipolytic activity assay showed that the highest activity was obtained at 532 U/L. In addition, GC/MS analysis revealed that different compounds from the head space and supernatant included several hydrocarbons. However, free fatty acids formed during hydrolytic activity resulted in the decrease of pH, and also retarded bacterial growth probably due to the toxicity of the fatty acids on the cells. The consequence of this study is the benefit of reduced environmental problems from Jatropha oil contamination as well as obtained useful gaseous biofuels.

Key words: Jatropha oil, anaerobic biodegradation, phylogenetic tree, lipolytic activity, hydrocarbons.