Programmed gradient descent biosorption of strontium ions by Saccaromyces cerevisiae and ashing analysis: A decrement solution for nuclide and heavy metal disposal

Contribution of surface functional groups and interface interaction to biosorption of strontium ions by Saccharomyces cerevisiae under culture conditions

“…27,29 The cell viability assays was carried out with uorophores SYT09 and propidium iodide (PI) dual staining (ThermoFisher), which was observed through confocal laser scanning microscope (Leica TCS SP8), as well as MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide, Beyotime, China) assay according to literatures. 30,31 2.4 Biosorption of strontium ions by control and chemically modied as well as living S. cerevisiae 4 The calculated volumes of strontium stock solutions were mixed with suspensions of S. cerevisiae cells prepared as described above to yield the following starting concentrations of strontium ions: 0.0, 10.0, 50.0, and 100.0 mg L À1 . Aer a preset biosorption time, cell suspensions were centrifuged (RT, 15 min, 4000 rpm).…”

“…The free strontium ions in solution (c Me , mg g À1 ), the strontium ion concentration on the cell walls (c pas , mg g À1 ) and the strontium ion concentration in the cytoplasm (c act , mg g À1 ) were measured according to literatures. 4,6…”

“…27,32 2.6 FTIR, SEM, AFM and TEM analysis Fourier transform infrared (FTIR, Nicolet-5700, THERMO) and scanning electron microscopy (SEM, Leica-S440; Ultra 55, ZEISS) samples were prepared and analyzed according to a previous report. 4 Atomic force microscopy (AFM, SPA300HV, Seiko Instruments) samples were prepared and analyzed according to the literature. 18 Microstructures on the cell surface were observed by JEOL JSM-6700F eld-emission scanning electron microscopy (FESEM) at Hefei National Laboratory for Physical Sciences at the Microscale (HFNL), Hefei, Anhui.…”

“…The biosorption of strontium ions has been carried out with different biomasses. [1][2][3][4][5][6] However, the mechanism underpinning the biosorption interface interaction is not fully understood, particularly with respect to following points. (1) Electrostatic interaction and ion exchange: electrostatic interactions are thought to exist in many instances of biosorption for heavy metals.…”

“…High concentration strontium ions (c 0 > 100 mg L À1 ) may form precipitate with culture medium, 4 while biosorption under culture conditions was a valid method for treatment of low concentration strontium ions. 4,6 In this research, we evaluated the contribution of different functional groups to biosorption of strontium ions (c 0 # 100 mg L À1 ) by yeast cells before and aer shielding the functional groups. Interface interaction between strontium ions and yeast cell was investigated through a chemical modication method, followed by spectroscopic and mesoscopic analyses, as well as mathematical methods.…”