Abstract Heavy metal pollution has become one of the most serious environmental problems today. Biosorption, regarded as a costeffective biotechnology for treating heavy metal of low concentration in wastewater, has not been utilized at large scale successfully. It’s helpful to increase the knowledge of biosorption mechanism and decreasing the costs of biosorbents for the biosorption application. The yeast of Saccharomyces cerevisiae is an ideal biomaterial to be used for exploring the mechanism and for actual utilization because of its unique characteristics in spite of its relatively mediocre capacity of metal uptake to other fungi. The yeast can grow easily in cheap media, and is widely used in food and beverage manufacture. It’s also a safe byproduct in large quantity as a waste of the fermentation industry, and easily manipulated at molecular level. The metal uptake specifically by S. cerevisiae was addressed. Firstly, it was discussed to use dead or live cells in biosorption . The yeast can absorb toxic heavy metals (Pb, Hg, Cd, etc), precious metals (Au, Ag, Pd, etc) and radionuclides (U, Am, etc). Secondry, metalbinding capacity of various heavy metals by S. cerevisiae in different conditions were compared. Lead and uranium, for instances, can be effectively removed from dilute solutions, while copper is not easily removed. Thirdly, various mechanism of metal uptake by S. cerevisiae were summarized in details according to the position in which metals are located. Metal uptake process is influenced by the ratio of the initial concentration of metal ions and the concentration of biomass. Cellular wall and its components are important for metal uptake. Functional groups for metallic ion fixation have been identified. Uptake is typically accompanied by ion exchange and complexation, sometimes with precipitation (for Pb) and redox (for Au or Ag). Intracellularly accumulated metal is associated with the cell membrane, vacuole and GSH, but may also be bound to other cellular organelles and biomolecules. The equilibrium and kinetic models used in the metalyeast biosorption systems were also introduced. In most cases, classic Langmiur model and Freundlich model, widely used to describe single metal biosorption system of equilibrium, fit the experimental data very well. Pseudosecond order equation is often employed to describe biosorption process by S. cerevisiae. Finally, futher researches in metal biosorpiton by S. cerevisiae were proposed.
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