Isolation and Characterization of Cadmium and Lead Resistant Bacteria

Soumitra Nath^*1, Bibhas Deb¹, Indu Sharma²

¹Bioinformatics Centre, Gurucharan College, Silchar, Assam

²Department of Microbiology, Assam University, Silchar, Assam

*Corresponding author’s E-mail: nath.soumitra1@gmail.com;

Tel: +91-9401374737

Accepted 13 November, 2012

Abstract

Thirty heavy metal resistant bacteria were isolated from sewage of industrial effluents, garages and petrol pumps of Barak Valley region of Assam, India, against cadmium and lead. Samples were streaked on selective media; the predominant and distinct colonies were identified as Pseudomonas sp., Klebsellia sp., Staphylococcus sp., Proteus sp. and Bacillus sp. on the basis of their biochemical and morphological characters. Minimum inhibitory concentration (MIC) and antibiotic resistance pattern of the potent isolates was also studied. Among all, six isolates exhibited high resistance to heavy metals. Bacillus sp. was found to have high resistance pattern against Cadmium (1800 µg/ml) and Lead (1200 µg/ml). It was observed that the isolates having high MIC values for a set of metals exhibited high resistance pattern towards a group of antibiotics.

Keywords: heavy metal, Barak Valley, Minimum inhibitory concentration, antibiotics