Physiological and Biochemical Studied on Lead, Copper and Mercury Resistance Actinomycetes

(Siham Abdul Mohsen penis and Nada Ibrahim Alsquiran)

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Abstract

It was observed that the highest heavy metals tolerance actinomycetes which isolated from soil samples collected from Second Industrial City, Riyadh Saudi Arabia, tolerate lead, mercury and copper at (1 mM/25 ml) were S. griseoflavus and S. pactum followed by S. albus and S. griseoflavus. Each of mercury and lead caused inhibition of the growth of the most isolates, while copper was a catalyst at that concentration. Results indicated that the presence of heavy metals in the culture media of S. griseoflavus and S. pactum decreased diameter of microbial colonies. The dry weight of S. griseoflavus was markedly affected by heavy metals containing media, where it was to lead inhibited the growth by increasing its concentrations in culture media, while mercury stimulate growth at low concentrations and the stimulation effect decreased when increasing concentration of mercury metal added to the media than 3 mmol/100 ml. For copper, it catalyst S. griseoflavus dry weight at low concentrations. While S. pactum dry weight inhibited by heavy metals containing media, and the effect of inhibition decrease with increasing heavy metals in the media. Studying the effect of heavy metals on the rates of carbohydrates, lipids and proteins in the cell extract of S. griseoflavus showed decrease in the rate of carbohydrate, when lead or copper presence in the media, but mercury has not been affected carbohydrate rates when its presence in the media, while the rates of protein and lipids were affected by all studied metals. As for S. pactum the rates of total carbohydrate in cell extract decreased in the presence of lead in the media, while copper and mercury presence increased it. Also the rates of total lipids increased in the presence of heavy metals. While the rates of total proteins increased in the presence of lead, but it decrease in the presence of copper and mercury in the media.
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