Journal of Petroleum & Environmental Biotechnology

Abstract

Enhancement of Hydrocarbons Degradation by Use of PseudomonasBiosurfactants and Biofilms

Amina Meliani and Ahmed Bensoltane

Biofilm-mediated bioremediation presents a proficient alternative to bioremediation with planktonic microorganisms and are generally associated with microbial hydrocarbons resistance or tolerance. Here we report on the ability of three species of Pseudomonas biofilm-associated cells (P. fluorescens, P. putida and P. aeruginosa) to degrade gasoline (hydrocarbon mixtures), xylene and benzene (monoaromatic compounds) and cyclohexane (cyclic compounds). Changes in biofilm formation and siderophores production were monitored in the presence of different concentrations of benzene and xylene. All strains were able to synthesize biosurfactant compounds and were able to tolerate aromatic hydrocarbon more than the cyclic compounds. Our results indicated that hydrocarbon mixture or gasoline could be better biodegraded by bacterial consortia; P. aeruginosa exhibited the best tolerance to gasoline but not to benzene and cyclohexane. It is interesting to point out that P. fluorescens was able to use xylene and benzene even though P. putida was incapable to grow on benzene as a carbon source. Statistically no significant positive correlation (r = 0.94; p > 0.01) between biofilm formation and surface tension, whereas with E24 and cells hydrophobicity we signaled a linear negative relationship (r = - 93, r = - 086). This study is essential since Pseudomonas biofilms are found to have implication in bioremediation of hydrocarbons.