| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4407456 | Chemosphere | 2016 | 12 Pages |
•Pichia hampshirensis 4Aer showed high resistance against heavy metal ions.•The yeast could remove nearly 80% Cd+2 from the medium over a period of 8 days.•The yeast followed pseudo second order kinetics, making it a good biosorbent for metal ions.•FTIR analysis showed the active participation of amide and carbonyl moieties in Cd+2 adsorption.•Increased GSH level played a significant role in thriving oxidative stress generated by metals.
Pichia hampshirensis 4Aer is first ever used yeast for the bioremediation of environmental cadmium (Cd+2) which could maximally remove 22 mM/g and 28 mM/g Cd+2 from aqueous medium at lab and large scales, respectively. The biosorption was found to be the function of temperature, pH of solution, initial Cd+2 concentration and biomass dosage. Competitive biosorption was investigated in binary and multi-metal system which indicated the decrease in Cd+2 biosorption with increasing the competitive metal ions attributed to their higher electronegativity and larger radius. FTIR analysis revealed the active participation of amide and carbonyl moieties in Cd+2 adsorption confirmed by EDX analysis. Electron micrographs summoned further surface adsorption and increased cell size due to intracellular Cd+2 accumulation. Cd+2 was the causative agent of some metal binding proteins as well as prodigious increase in glutathione and other non-protein thiols levels which is the crucial for the yeast to thrive oxidative stress generated by Cd+2. Our experimental data were consistent with Langmuir as well as Freundlich isotherm models. The yeast obeyed pseudo second order kinetic model which makes it an effective biosorbent for Cd+2. High bioremediation potential and spontaneity and feasibility of the process make P. hampshirensis 4Aer an impending foundation for green chemistry to exterminate environmental Cd+2.
