Investigation of Resistant to the Nickel and Some Toxic Metals by Moderately Halophilic Bactery Isolated from Aran-Bidgol Salt Lake and Their Phylogenetic Characterization by 16S rDNA Gene

Abstract

Backgrounds and Objectives: Heavy metals are toxic for human and animals and plants. For example nickel can cause contact dermatitis and may have carcinogenic effect. There are physicochemical and biological methods for removal of these elements from the environment. Some bacterial species are able to remove the elements by bioremediation mechanism. These types of bacteria could resist heavy metals and grow in the presence of these elements. In this research, the resistance of the nature of a heavy metal resistance bacteria’s that is bacteria’s living in Aran-Bidgol Lake has been evaluated. Materials and Methods: Seven Bacterial samples of the Lake were transferred on ventosa culture medium. Isolated colonies were grown on the media containing nickel transferred to mediums with other heavy metal elements. Biochemical and morphologic and also phylogenies studies based on sequencing of the 16S rDNA gene were performed in order to characterization genus and species of resistant isolates. Enzyme production of these bacteria’s was also investigated. Results: From 46 isolated halophilic bacteria, one isolate that was able to grow in the medium containing 1-25% NaCl and also was resistant to nickel and other toxic metal was considered for future study and characterization by sequencing of the 16S rDNA. This isolate had more 97% homology with Halomonas elongate species. Conclusion: Microorganism those are isolated from Aran-Bidgol Lake and are resistant to toxic metals have the potential usage for removal of environment toxins such as Nickel.

Keywords: Halomonadaceae, Halomonas elongate, Heavy metal toxicity, Nickel, Resistance