Full Length Research Paper

Identification and molecular analysis of mercury resistant bacteria in Kor River, Iran

Mehdi Kargar¹, Mohammad Zareain Jahromi¹*, Mahmood Najafian¹, Parastoo Khajeaian¹, Reza Nahavandi^2,3, Sareh Raeiszadeh Jahromi¹ and Mohammad Firoozinia¹

¹Department of Biology, Islamic Azad University, Jahrom Branch, Jahrom, Iran.

²Laboratory of Marine biotechnology, Institute of Bioscience, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.

³Iranian Fisheries Research Organization (I.F.R.O.), P.O. Box 14155-6116, Tehran, Iran.

*Corresponding author. E-mail: obeidatgh@yahoo.com. Tel: +962775609847. Fax: +96253530469.

Accepted 17 February, 2012

   Abstract

Mercury (Hg) is one of the most important toxic pollutants widespread in the environment. It is being extensively used in industrial applications (chlor-alkali electrolysis, fungicides, disinfectants, dental products, etc), resulting in local hot spots of pollution and serious effects on biota and humans. The aim of this study was to identify mercury resistant bacteria and extract their plasmids and DNA. In this study, mercury-resistant bacteria were isolated and characterized from mercury-polluted sediments in Kor River in Iran. The samples were cultured in different media cultures, identified using biochemical tests, and due to the relationship between antibiotic and mercury resistance, they were isolated based on these two factors. The plasmids and DNA were extracted from the most resistant bacteria to both antibiotic and mercury and the sizes were determined using agarose gel electrophoresis. A 12.3 Kb plasmid from Serattia sp. and Escherichia coli and using Sau3A1 enzyme, some DNA fragments (4, 6, 8 and 10 Kb) from Pseudomonas sp., Serattia sp. and Escherichia coli were also extracted.

Key words: Mercury, resistant, bacteria, DNA, plasmid extraction, restriction endonuclease.