Exploration of a metallothionein in cyanobacteria and bacteria for chromium remediation from industrial wastes`

Rini Roy; Madhulika Gupta; Aditi Nag Chaudhuri

Volume : IV, Issue : VI, June - 2015

Exploration of a metallothionein in cyanobacteria and bacteria for chromium remediation from industrial wastes`

Rini Roy, Madhulika Gupta, Aditi Nag Chaudhuri

Abstract :

Environment pollution by heavy metals which are released into the environment through various anthropogenic activities is one of the world�s major environmental problem. The presence of heavy metals like Chromium (Cr) in cyanobacteria isolated from water sample of Wetland Ecopark, Bantala and bacteria isolated from soil of coal mine areas was confirmed by Atomic Absorption Spectroscopy (AAS) and Chromate reductase assay. After incubation with cyanobacteria the chromium content of water was decreased as observed from the results of AAS. Chromate reductase assay showed the increased conversion of Cr (VI) to Cr (III), the less toxic form by the isolated soil bacteria. In response to chromium stress the Nitric Oxide Synthase (NOS) activity increased than control at 10mg/l––25mg/l and decreased beyond 50mg/l in case of cyanobacteria. NOS activity was also affected in case of soil bacteria for Cr (VI). Upon metal stress thiol containing proteins are activated and hence the expression of metallothionein has been observed in case of soil bacteria and cyanobacteria with transition metal Cr. SDS PAGE followed by Western Blot analysis confirms the presence of metallothionein in bacteria with Cr treatment by a single band near 14 KDa protein marker. Morphological changes due to treatment were studied by Scanning Electron Microscopy (SEM) in cyanobacteria. FTIR study reveals the interaction of metals with cell surface components both in cyanobacteria and bacteria. Here is a comparative studies to achieve more useful and active immobilized metallothionein to remove Cr from waste water.