Novel bionanocomposites, S. cerevisiae-AgNPs, were synthesized by in situ formation of AgNPs on S. cerevisiae surface using fulvic acids as reductants under simulated sunlight. S. cerevisiae-AgNPs were characterized using UV-Vis spectroscopy, scanning electron microscope, transmission electron microscope and Fourier transform infrared spectroscopy. These analyses showed that AgNPs were distributed on the surface of S. cerevisiae. The application of S. cerevisiae-AgNPs in bacteria killing and heavy metal removal was studied. S. cerevisiae-AgNPs effectively inhibited the growth of E. coli with increasing concentrations of S. cerevisiae-AgNPs. E. coli was killed completely at high concentration S. cerevisiae-AgNPs (e.g., 100 or 200 lg mL-1). S. cerevisiae-AgNPs as excellent heavy metal absorbents also have been studied. Using Cd 2? as model heavy metal, batch experiments confirmed that the adsorption behavior fitted the Langmuir adsorption isotherms and the Cd 2? adsorption capacity of S. cerevisiae-AgNPs was 15.01 mg g-1. According to adsorption data, the kinetics of Cd 2? uptake by S. cerevisiae-AgNPs followed pseudo second-order kinetic model. Moreover, S. cerevisiae-AgNPs possessed ability of different heavy metals' removal (e.g., Cr 5? , As 5? , Pb 2? , Cu 2? , Mn 2? , Zn 2? , Hg 2? , Ni 2?). The simulated contaminated water containing E. coli, Cd 2? and Pb 2? was treated using S. cerevisiae-AgNPs. The results indicated that the bionanocomposites can be used to develop antibacterial agents and bioremediation agents for water treatment.

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