Hydrocarbon Degrading Candidate Bacteria Isolated From Qatar Polluted Soil and Molecular Identification of Key Enzymes Coding Genes

Abstract

Sixteen bacterial strains were isolated form contaminated soils and identified as Bacillus subtilis, Bacillus circulans, Burkholderia cepacia, Pseudomonas aeruginosa, Micrococcus luteus, Raoultella ornithinolytica and Staphylococcus capitis. The hydrocarbon degradation potentialities of these strains revealed that they can be considered as good degraders of diesel, toluene and xylene reaching high biomasses indiesel as sole carbon source and high efficiencies of degradation of different molecular weight hydrocarbons. These hydrocarbon catabolism potentialities were confirmed by the identification and sequencing of seven key genes encoding haloalkane dehalogenase, hydrocarbon binding protein, alkane 1-monooxygenase, alkane hydroxylase, naphthalene dihydrodiol dehydrogenase, 1,2-Dihydroxynaphthalene dioxygenase, toluene monooxygenase large ? subunit and xylanase. These findingsdemonstrate the importance of both the strains and gene bank since having very highvalues and can be exploited for many applications including the enhancement of the genes expression in order to create improved hydrocarbon degrading strains to becomeone of the best environmentally friendly solution in bioremediation, competing with chemical and physical methods and allowing to achieve highest remediation efficiencies.