Isolation and Characterization of Halophilic Aromatic and Chloroaromatic Degrader from Wadi El-Natrun Soda lakes

Abstract

Extremophiles are microorganisms able to survive in extreme conditions. They are good candidates for the bioremediation of hypersaline environments and also for the treatment of saline effluents. A novel aerobic bacterial strain has been isolated on the basis of its ability to utilize benzene, and toluene from the extremely saline and alkaline lakes (Soda lakes) of Wadi El Natrun. The growth rates and biodegradation ability were investigated in mineral basic media supplemented with benzene, toluene, and chlorobenzene under various growth conditions including degradation rate in the presence of different salt concentrations. The new isolate was identified by 16S rRNA as Alcanivorax sp.HA03. Phylogenetic analysis indicated that our isolate has 99% sequence similarity with most closely related organism Alcanivorax sp. TE-9 in the GenBank, which is a hydrocarbon degrading bacterium, Alcanivorax sp.HA03 considered as the only reported halophilic alkalophilic strain from genus Alcanivorax that can degrade benzene and toluene, This finding may be necessary in order to estimate the true potential of this strain to be applied in the remediation of monoaromatic and chloroaromatic compounds. (Hamdy A. Hassan, Nashwa MH Rizk, M. A. Hefnawy, and Ahmad M. Awad. Isolation and Characterization of Halophilic Aromatic and Chloroaromatic Degrader from Wadi El-Natrun Soda lakes. Life Sci J 2012;9(3):1565- 1570) (ISSN:1097-8135). http://www.lifesciencesite.com. 227