In vitro degradation of benzene by the use of ubiquitous bacteria

Abstract

This study focuses on specifying a number of ubiquitous non-fastidious bacteria isolated from urine hospitalized patients for their abilities to degrade benzene. Using the MALDI-Tof technique (Bruker Daltonics), these opportunist bacteria have been identified. The bacteria were inoculated and incubated in sterile water contaminated with pure benzene (99.98% purity) for 63 days, at room temperature with continuous oxygenation. Analysis by Gas Chromatography/Mass Spectrometry (GC/MS) HP6890/HP 5973 MS (Agilent Technologies) allowed us to determine the concentration of benzene and its derivatives. The results showed that not only the strains were able to completely degrade benzene in a single derivative: cyclohexane after less than 30 days. But also reveals variations in cyclohexane concentrations from one strain to another. The 2 strains belonging to the family Moraxellaceae S1670 and S1671 degrade benzene faster with concentrations 0.0475 μg/μl and 0.0727 μg/μl respectively, While both strains S5 and S476 of the Enterobacteriaceae family, had consumed totally and more easily cyclohexane with the lowest concentrations 0.0316 μg/μl and 0.0449 μg/μl respectively, this research confirmed that benzene and cyclohexane were completely consumed without producing other identifiable intermediate metabolites.