Comparison study on copper bioaccumulation by growing Pichia kudriavzevii and Saccharomyces cerevisiae

Abstract

Bioaccumulation via growing microorganisms is a potential technique for treatment of heavy metal pollution. In this study, the Cu tolerance, bioaccumulation properties, and removal ability of growing Pichia kudriavzevii and Saccharomyces cerevisiae in complex environments were investigated comparatively. P. kudriavzevii displayed higher total Cu bioaccumulation capacity and Cu removal rate than S. cerevisiae at various bioaccumulation time and Cu concentrations. The Cu bioaccumulation in both yeasts was obviously improved at low pH and high concentrations of NaCl, which resulted in the increase of Cu removal rate. The maximum Cu removal rate of P. kudriavzevii respectively reached to 55.53% at 20 g/L NaCl and to 77.84% at pH 3, obviously higher than that in normal condition at pH 5 without NaCl addition (13.77%). High concentrations of Zn (0.05 2 0.5 mmol/L) significantly improved the Cu removal ability of P. kudriavzevii while the Cu removal rate was markedly inhibited with the addition of Cd (0.05 2 0.5 mmol/L). Compared with S. cerevisiae, the multi-stress-tolerant P. kudriavzevii possessed more powerful Cu tolerance and bioaccumulation ability at low pH, high concentrations of NaCl and with the addition of other heavy metal ions. It suggested that P. kudriavzevii could be used as a potential candidate for Cu removal in complex environments.