Bioaccumulation of metal cations by free and immobilized cells of Kluyveromyces marxianus

Kluyveromyces marxianus yeast cells in suspension were able to accumulate heavy metal cations such as Cu 2+ , Co 2+ and Zn 2+ . The level of metal accumulation was dependent on the ambient metal concentration and the age of culture. Young cells (18 h) removed more Cu 2+ and Co 2+ than old cells (24 h), whereas Zn 2+ was more accumulated by old cells. Dead cells removed 61 and 75% more Co 2+ and Cu 2+ than the corresponding live cultures. Immobilized cells allowed for high removal capacity for Cu 2- , Co 2+ and Zn 2+ where 1.6, 1.5 and 1.3 fold increase were recorded compared to free cells..