Identification and characterization of novel bacterial polyaromatic hydrocarbon-degrading enzymes as potential tools for cleaning up hydrocarbon pollutants from different environmental sources

Publication date: Available online 20 February 2019Source: Environmental Toxicology and PharmacologyAuthor(s): Heba A.R. Abdelhaleem, Haggag S. Zein, Ahmed Z. Abdel Azeiz, Ahmed N. Sharaf, Abdelhadi A. AbdelhadiAbstractPolycyclic aromatic hydrocarbons (PAHs) are recalcitrant hazardous environmental contaminants. Various strategies, including chemical and physical like oxidation, fixation, leaching, and electrokinetic or biological-based techniques are used for remediation of polluted sites. Bioremediation of PAHs, via PAH-degrading endophytic and rhizospheric microbes, represent 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 with 16S rRNA 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 µg and Vmax 178U/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 o...
Source: Environmental Toxicology and Pharmacology - Category: Environmental Health Source Type: research