Bioaccumulation of cadmium by growing Zygosaccharomyces rouxii and Saccharomyces cerevisiae

• More than 94% Cd2+ was removed by Z. rouxii below 0.04 mmol/L Cd2+ within 24 h.
• Low pH improves the Cd2+ tolerance of Z. rouxii and S. cerevisiae.
• Zn2+, Cu2+ or low pH decreases intracellular Cd2+ bioaccumulation of both yeasts.
• Zn2+ or Cu2+ improves Cd2+ tolerance and cell-surface bioaccumulation of Z. rouxii.
• Cd2+ removal of Z. rouxii is enhanced by Cu2+ and Zn2+ in certain conditions.

Bioaccumulation via growing cells is a potential technique for heavy metal removal from food materials. The cadmium bioaccumulation characteristics by growing Zygosaccharomyces rouxii and Saccharomyces cerevisiae were investigated. Z. rouxii displayed powerful cadmium removal ability at low cadmium concentrations, which mainly depended on the intracellular cadmium bioaccumulation. The percentage of intracellular cadmium bioaccumulation of both yeasts obviously decreased with the increase of initial biomass and cadmium concentrations. Low pH and elevated concentrations of zinc and copper significantly decreased the intracellular cadmium bioaccumulation of both yeasts but improved the cadmium tolerance and the cell-surface cadmium bioaccumulation of Z. rouxii. Cadmium removal of Z. rouxii was improved by zinc and copper conditionally. Z. rouxii that possessed more powerful cadmium tolerance and removal ability at low pH and high concentration of competing ions can be developed into a potential cadmium removal agent using in complex food environment in future.