Abstract

In this study, a gram negative, non- motile short rod-shaped and heavy metal resistant bacterial strain was isolated from effluents. The optimum temperature and pH for the growth of the strain were 33°C and 7, respectively. The minimum inhibitory concentrations (MICs) of zinc (Zn), copper (Cu), chromium (Cr) and mercury (Hg) against the isolate were determined. The isolate showed MICs of 5, 4, 3 and 2 mM when grown on Zn, Cu, Cr and Hg, respectively. The isolate was assessed for its ability to remove zinc from medium amended with different concentrations of zinc. Up to 65% of zinc was removed at the zinc concentration of 1 mM. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate belongs to the genusAcinetobacter with 98% similarity to Acinetobacter junni. It was then designated asAcinetobacter sp. HM_AF14. Based on the data obtained in this study, it can be concluded that Acinetobacter sp. HM_AF14 can be used for bioremediation of zinc from effluents.

Key words: Heavy metals, Acinetobacter sp., bioremediation, 16S rRNA, zinc removal.