Högskolan i Skövde

Rapid industrialization usually is the cause of increase in pollutants in the natural river bodies. This pollution is attributed to lack of improper treatment and inadequate disposal mechanisms of the waste generated thereof. The aim of present investigation was to screen actinomycetes for their ability to adsorb heavy metals. Actinomycetes belong to most diverse group of filamentous prokaryotes with ubiquitous presence in different ecological niches. This ubiquity is due to their ability to degrade almost any type of polymer and to use several compounds as carbon sources. Nearly 200 actinomycetes from different niches like fresh water, soda lake, geothermal springs, acid soils, etc from different locations in India were screened for ability to grow in presence of 1 to 5 mM of heavy metals like Cd, Hg, Pb, Ni, Sr, Fe, Mo, Zn and Mn. Most of the strains tolerant to heavy metals belonged to the genus Streptomyces spp. Five strains could grow in presence of 5 mM Cd²⁺, 4 strains in presence of 0.1 mM Hg²⁺, 18 strains in presence of 5 mM Pb²⁺, 21 strains in presence of 5 mM Ni²⁺, whereas 34 strains grew in presence of 5 mM Fe²⁺. One of the most promising strain was studied for its ability to absorb cadmium where 2x10¹¹ cells or spores could adsorb 0.32 mM to 0.33 mM of cadmium. Spores and vegetative cells showed nearly similar level of adsorbtion ability. This strain can be very useful in developing a bioreactor for the adsorption of heavy metals from industrial effluents containing cadmium.