title: Effect of saponins on cell surface properties of Penicillium simplicissimum: performance on adsorption of cadmium(II).
abstract: Previous studies about the effect of biosurfactants on cell surface properties mainly focus on cell surface hydrophobicity. In the present study, the effects of plant-derived biosurfactants saponins on cell surface charge and the adsorption of cadmium(II) by Penicillium simplicissimum were studied. The pretreatment of saponins changed the optimal pH from 6 to 5 for Cd(II) adsorption. All the adsorption processes by the intact and saponins-pretreated biomasses followed the Langmuir isotherms better than the Freundlich isotherms. According to the Langmuir isotherms, the maximum adsorption of Cd(II) (qmax) was increased from 51.6 to 74.6 mg/l by the pretreatment of 0.025% saponins. The mechanisms were also analyzed by Fourier transform infrared spectrometer (FTIR), energy dispersive X-ray (EDAX), and scanning electron microscope (SEM) analysis. The results indicated that the pretreatment of saponins changed the cell surface charge of P. simplicissimum and therefore influenced the adsorption of cadmium(II).
authors.affiliation: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China.
authors.forename: Zhi-Feng
authors.initials: ZF
authors.lastname: Liu
authors.forename: Guang-Ming
authors.initials: GM
authors.lastname: Zeng
authors.forename: Hua
authors.initials: H
authors.lastname: Zhong
authors.forename: Xing-Zhong
authors.initials: XZ
authors.lastname: Yuan
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Jiang
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Fu
authors.forename: Xiao-ling
authors.initials: XL
authors.lastname: Ma
authors.forename: Jia-Chao
authors.initials: JC
authors.lastname: Zhang
mesh_terms: D000327:Adsorption / Q000187:drug effects; D018533:Biomass; D002104:Cadmium / Q000737:chemistry / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D010407:Penicillium / Q000737:chemistry / Q000378:metabolism*; D012503:Saponins / Q000737:chemistry / Q000494:pharmacology*; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D012503:Saponins; D013501:Surface-Active Agents; D002104:Cadmium