Bioremediation of toxic heavy metals by waste water actinomycetes

Efficient and safe wastewater treatment methods with low costs with minimum requirements are urgently needed instead of conventional and currently used methods. The aim of the present study was to isolate resistant microbes from wastewater treatment plant and selection of the most active isolate for bioremediation process. Three different waste water samples were collected from Bani Malek, heated and used for actinomycetes isolation on starch nitrate agar with Cu++ and Cd++. All plates were incubated at 45ᵒC for 10 days and the obtained bacterial colonies were purified and preserved. Growth and resistance to different concentration of heavy metals including Cu++, Cd++, Ni++ and Pb++ of the five obtained bacterial isolates were determined in minimum broth medium. The isolate WW1 was the most resistant isolate, thus it was identified as Streptomyces sp WW1 using different methods including morphological, physiological and biochemical methods .The selected and identified Streptomyces sp was used for removal of heavy metals from treated waste water of Bani Malek Plant. The removal percentages (%) were 12%, 22%, 16%, 24%,12% and 11% for Cd++, Cr++, Cu++, Fe++, Ni++ and Zn++. Moreover, it was 79 and 32% for Mn++ and Pb++ respectively. In conclusion, actinomycetes genus Streptomyces can be used safely for heavy metal bioremediation processes.