الفهرس 
Title : Identification and characterization of some genes related to hydrocarbon compounds degradation
AbstractOnly 14 pages are availabe for public view
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Abstract
Polycyclic aromatic hydrocarbons (PAHs) are recalcitrant hazardous environmental contaminants. Various strategies, including chemical and physical like oxidation, fixation, leaching, and electrokinetic or biological-based techniques were used for remediation of polluted sites. Bioremediation of PAHs, via PAH-degrading endophytic and rhizospheric microbes, represented as a time-/cost-effective way for ecorestoration. Four bacterial strains were isolated from contaminated soil on MSM supplemented with anthracene, alpha-naphthalene or catechol as sole carbon sources. These isolates were identified by 16S rRNA gene as Bacillus anthracis, B. cereus, B. mojavensis and B. subtilis. The degradation efficiency on the selected aromatic compounds was tested by HPLC analysis. B. subtilis showed the highest degradation efficiency of anthracene (99%) after five days of incubation. B. subtilis showed the highest catechol 1, 2 dioxygenase activity in MSM supplemented with anthracene. The enzyme was purified by gel filtration chromatography and characterized (70 kD, Km 2.7 æg and Vmax 178 U/mg protein). The catechol 1,2 dioxygenase gene from the identified four bacterial strains were isolated and submitted to GenBank (accession numbers MG255165-MG255168). The gene expression level of catechol 1,2 dioxygenase gene was upregulated {u2243} 2.5fold during the 24 hr of incubation period in the presence of Fe3+. Furthermore, B. subtilis is a promising strain to be used in bioremediation of aromatic compounds-contaminated environments