Characterization of Cadmium and Lead Heavy Metals Resistant Fungal Isolates from Ghawar oil field, Saudi Arabia

Abstract

Contamination of soil with heavy metals is considered the main concern around the world due to dramatic increases in agricultural, industrial, and oil extraction activities. Highly potentials were recorded for fungi, which reflected heavy metal resistant patterns among microflora. Our investigation was carried out for isolating, identifying, and evaluating Cr and Pb resistant capabilities for fungal strains. By using morphological characterization, seventeen fungal strains which reflected resistance against Cr and Pb were identified as Aspergillus, Rhizomucor, Neosartorya, Penicilliumand Rhizomucor , Aspergillus , Penicillium , Cunninghamella and Fusarium for the second site. Among nine microorganisms isolated from the first site which reflected resistant against Cr, Aspergillus flavus reflected highly resistant against all Cr concentrations. Also, Aspergillus Ochraceus and Penicillium oxalicum were resistant to all Cr concentrations except the highest (750 ppm). Only Aspergillus flavus which was isolated from the first site reflected distingushable resistance to all Pb concentrations. Also, A. terreus showed resistant patterns against Cr at 50, 75, 150, and 300 ppm of Pb. At the second site, Aspergillus terreus, Penicillium aurantiogriseum and Aspergillus wentii showed resistant patterns against all Led concentrations. Four selected fungi which reflected resistance against all concentrations of Cr and Pb were identified via 18S rDNA molecular marker and assigned to GeneBank as follows: Aspergillus flavus (OP113794), Aspergillus terreus(OP113795), Penicillium aurantiogriseum (OP113796) and Aspergillus wentii (OP113797).