Removal of Heavy Metals from Aqueous Solutions Using Multi-Metals and Antibiotics Resistant Bacterium Isolated from the Red Sea, Egypt

Abstract

This investigation was incorporate screening for the highest multiple metal and antibiotics resistant marine bacteria at the Northern Red Sea. The two selected bacterial isolates were identified on the basis of phenotypic and genotypic characterization through 16S rDNA gene technique as Alteromonas macleodii and Nitratireductor basaltis. A. macleodii revealed high efficiency in the removal of heavy metals from aqueous solution. Different factors influenced the removal of heavy metals from aqueous solution by A. macleodii such salinity, pH, temperature, biomass and contact time were optimized. The metal removal was greater at the lowest initial metal concentration (50 mg l-1) and decreased with increase in the metal concentration. A. macleodii showed high efficiency in biosorption of different metals in single and multiple metal solution systems. Removal percentage of different metals by A. macleadii in a single metal system at the highest tested metal concentrations (200 mg l-1) reached Pb, 73.8%; Mn, 66%; Fe, 65%; Cu, 64%; Zn, 62%; Ni, 54%; and Cd, 53%. In multiple metal systems containing 30 mg l-1 of different metals, biosorption percentage was Pb, 93%; Fe, 89%; Zn, 55%; Cd, 50%; Cu, 44.5%; Mn, 40% and Ni, 36%. These findings suggest the possibility of using these bacterial isolates for bioremediation of heavy metals from heavy metal contaminated ecosystem.