Bioremediation of lead and chromium by bacteria isolated from coal mining areas

Abstract

The microorganisms present in the soil of coal mining areas are naturally exposed to various heavy metals. Bacterial strain was isolated from soil of the coal mining areas of Raniganj. Metallothioneins (MTs) are a group of low molecular mass, cysteine-rich proteins used in metal homeostasis. The main objective of this study was to isolate and extract MT from the isolated bacterial culture. Induction of MT having molecular weight 14 kD occurs in isolated bacteria upon treatment with heavy metals like lead (Pb) and chromium (Cr) as evidenced from SDS PAGE. The thiol content increased in metal treated cultures when compared to the control sample. FTIR study shows the interaction of Pb (II) and Cr (VI) with cell wall components. The expression of MT was confirmed by Western blot technique. Heavy metal tolerating mechanisms within the isolated bacterial cells may be exhibited in the form of metallothioneins for their survival.