Environmental Impacts of Different Bacterial Strains on Uptake of Chromium

Abstract

 

Environmental Impacts of Different Bacterial Strains Uptake of Chromium VI

 

Rula Najeeb Al-Buqain

 

Mu'tah University, 2007

 

Seven bacterial strains were isolated from As- Samra/Jordan industrial-polluted soil and identified on the basis of Gram reaction as well as other biochemical characteristics. Moreover, growth curves, chromate MICs, plasmid-curing and plasmid DNA electrophoresis were tested for each isolate. All the identified strains were Gram-negative and resistant to high concentrations of chromate. The most Cr (VI)-resistant isolate (115x105 μg. mL-1) was identified as Alcaligenes feciasl type 11. All Cr (VI)-resistant strains except the isolate Morxella sp were found to harbor plasmids as indicated by the plasmid-curing experiment and, proved by detecting plasmid DNA on gel electrophoresis. The isolated plasmids showed high molecular weight compared to the pUC9 plasmid as a reference. This approach permitted selection of some bacterial strains, which could be beneficially used for the bioremediation of Cr (VI)-polluted environments