Combined effects of Cu, Cd, Pb, and Zn on the growth and uptake of consortium of Cu-resistant Penicillium sp A1 and Cd-resistant Fusarium sp A19

Microorganisms can be important biosorbents for heavy metal remediation of contaminated soils and wastewaters. With different types and concentrations of heavy metals, strains display different resistance and removal abilities to the heavy metals. The objective of this study was to investigate the effects of single and multiple heavy metals on the growth and uptake of consortium of two types of fungal strains, Penicillium sp. A1 and Fusarium sp. A19. These fungal strains were tested to be tolerant to several heavy metals. A1, A19, and their combination (A1 + A19) were inoculated on potato dextrose agar (PDA), Czapek Dox agar (CDA), and potato dextrose broth (PDB) containing Cu2+, Cd2+, Pb2+, and Zn2+. Experimental results showed that the combined inoculation of A1 and A19 had profound effects on the growth of the two fungi in PDA and CDA under the treatments with Cu2+ and mixed Cd2+ + Zn2+. The amount of metals through bioaccumulation by A1, A19, and A1 + A19 was significantly higher than that through biosorption by these fungi. The highest amount of Cd, Cu, and Zn accumulated by fungal biomass was obtained in the presence of Cd2+ + Cu2+ + Zn2+ in PDB. Compared with the individual A1 or A19 used in PDB, All + A19 accumulated higher amount of Cu and Pb in the presence of Cd2+ + Cu2+ + Pb2+ and higher amount of Pb in the presence of Cd2+ + Cu2+ + Zn2+ + Pb2+. Our results indicated that there was no simple relationship between the metal biosorption by fungal biomass and the fungal metal tolerance. The biomass of A1 + A19 cultivated in PDB absorbed higher amount of metals than A1 or A19 in the presences of single metals and their combinations. The results suggested that the applicability of growing fungi tolerant to heavy metals provided a potential biotechnology for treatment of waste waters with heavy metal pollutions. (c) 2009 Elsevier B.V. All rights reserved.