View article

Cadmium (Cd) is an extremely toxic environmental pollutant with high mobility in soils, which can contaminate groundwater, increasing its risk of entering the food chain. Yeast biosorption can be a low-cost and effective method for removing Cd from contaminated aqueous solutions. We transformed wild-type Saccharomyces cerevisiae (WT) with two versions of a Populus trichocarpa gene (PtMT2b) coding for a metallothionein: one with the original sequence (PtMT2b ‘C’) and the other with a mutated sequence, with an amino acid substitution (C3Y, named here: PtMT2b ‘Y’). WT and both transformed yeasts were grown under Cd stress, in agar (0; 10; 20; 50 μM Cd) and liquid medium (0; 10; 20 μM Cd). Yeast growth was assessed visually and by spectrometry OD₆₀₀. Cd removal from contaminated media and intracellular accumulation were also quantified. PtMT2b ‘Y’ was also inserted into mutant strains: fet3fet4 …