Effect of lead on growth, protein and biosorption capacity of Bacillus cereus isolated from industrial effluent.

Abstract

A bacterial strain (Bacillus cereus) with the ability to grow under conditions of high concentrations of lead was isolated from the industrial effluent collected from Peenya Industrial Area, Bangalore. The effect of lead on growth, protein content and lead biosorption capacity of Bacillus cereus was investigated. The results revealed that with increase in lead concentration (100, 200, 300, 400 and 500 mg I(-1)) there was a decrease in growth, protein content (10.6, 8.2, 6.7, 3.8 and 1.9 mg g(-1) d. wt.) and lead biosorption (90.3, 57.8, 48.94, 31.3 and 22.24%) Bacillus cereus, signifying toxic effect of lead on the bacterial strain. Plasmid DNA was isolated from Bacillus cereus to study its resistance mechanism. The size of the plasmid was approximately 33kb. Transformation results suggest that lead resistance gene may be present on the chromosomal DNA ratherthan the plasmid DNA as the transformants did not show lead resistance.