Intracellular distribution of cadmium during the growth of Abortiporus biennis on cadmium-amended media.

ABSTRACT

Heavy metals are difficult to remediate and traditional remedial processes are expensive, so bioremediation technology using bacteria, fungi, or plants is of interest. Many studies have demonstrated that basidiomycetes fungi are able to growth under heavy metals stress. In this study the distribution of cadmium (Cd) in Abortiporus biennis cells was studied. Cd accumulated especially within cytoplasm and its presence caused changes in the cytoplasm appearance, which became denser in comparison to the cytoplasm of control cells. Vacuolization of cytoplasm and periplasmic region in A. biennis cells was also observed. The growth rate of A. biennis was inhibited up to 75% during the growth on medium amended with 1 mmol/L cadmium oxide. The presence of Cd in growing media inhibited oxalic acid secretion by A. biennis, but oxalate concentration increased together with elevated Cd concentration in growing medium. The influence of initial pH of growing media on the accumulation of Cd by A. biennis was also observed. The highest accumulation of Cd in mycelium was detected during A. biennis growth on media with a pH of 6. Studies addressing metals uptake by fungi and metal distribution in fungal cells may allow these organisms to be applied in bioremediation processes more effectively or to be used as bioindicators of contaminated environmental pollutions.