Biosorption and tolerance of Pb, Cr and Cd by the biomass of Pleurotus ostreatus (Jacq. Ex Fr.) P. Kumm

Abstract

Globally, the indiscriminate use of metal products discharged into water used in agriculture has led to severe contamination, therefore it is important to establish a methodology for decontamination through biological processes, with basidiomycete fungi because it has been shown to degrade a number of persistent organic pollutants using extracellular enzymes, in addition to removing dissolved metals from the water by biosorption, acting, as a natural exchanger. The objectives of this work were to determine between three metals (Pb, Cr and Cd) which was most efficiently removed from the aqueous solution by the fungus mycelium of Pleurotus ostreatus, as well as to evaluate its tolerance and describe the effects caused by each on its cellular structure. The adsorption of metals by mycelium in liquid medium was evaluated using modified Kirk medium, the concentrations retained for 8 days in solution of 20 mg L-1 of each element were quantified, the results indicated that the adsorption of Pb (75%) was the most efficient, followed by Cr (42%) Cd (2.25%). In the results in solid culture medium (PDA) no concentration of Pb and Cr inhibited mycelium growth, however, with Cd was inhibited from 60 mg L-1; however, the three elements caused structural alterations in mycelium. In conclusion, the P. ostreatus strain had tolerance and significant biosorption (p≤ 0.05) for Pb and Cr, so it could be a specific bioremediation biomaterial for Pb and Cr.