Screening and Isolation of Metal Resistant Bacteria to be Used for Environmental Pollution

Abstract

A total of 35 isolates were isolated from metal contaminated sites as reported in the first report. Most of the isolates showed resistance against copper, zinc and ferric after treatment with EDTA except eight of these, which exhibited, reduces ability to tolerate high concentrations of heavy metals these were CMG20, CMG23, CMG25, CMG27, CMG29, CMG30, CMG32 and CMG35. No plasmid DNA was isolated from these isolates, however rest showed the presence of single plasmid DNA having molecular weight ranging from 16.53kb to 32.20kb. among all the isolates, only two of the isolates CMG11 and CMG12 showed maximum accumulation of copper i.e., 25.9% and 43.0% respectively while others showed negligible accumulation. CMG13 and CMG14 accumulated iron from the medium at the conc. Of 15.02% and 40.3% respectively. A quantitative and qualitative analysis of total proteins, CMG14 revealed increase in total protein content and production of two additional protein bands in the presence of metal salts. However the role of plasmid in metal tolerance/accumulation could not be established. This suggested that the resistance mechanism in CMG14 could be due to the production of the metal complexing and/or extracellular metal binding proteins. This suggested that these metal-accumulating isolates could be exploited for the treatment of the target metals such as copper and Iron.