Cell surface characteristics of the intact cells of Saccharomyces cerevisiae before and after interaction with silver ions detected by SEM-EDX, TEM-EDX and AFM
Backgrounds: Metal-microbe interaction is a key problem of the biotechnology application in heavy metal pollution control. Biosorption of heavy metals is regarded as a novel wastewater treatment technology. However, the understanding on the complex metal-microbe interactions is limited, which restricted the successful application of biosorption. It is necessary to deeply explore the mechanisms of metal biosorption. The cell surface especially cell wall plays an important role in metal biosorption. The yeast of Saccharomyces cerevisiae is an excellent model microbe in biological research, and has been used in our lab for metal biosorption research. Great progress has been made in exploring the cell surface ultrastructure of yeasts owing to the development of techniques such as the scanning electron microscopy with the energy-dispersive X-ray analysis (SEM-EDX), the transmission electron microscopy with energydispersive X-ray analysis (TEM-EDX) as well as atomic force microscopy (AFM). Micro surface topogra phy, surface chemical composition, 3-dimensional ultrastructure imaging could be offered by the above three technologies from the different angles, which are helpful for increasing the understanding of the metal biosorption process at micro level. However, comprehensive use of SEM-EDX, TEM-EDX and AFM is seldom reported in heavy metal biosorption. Silver is a kind of representative noble metal, widely used in modern industry, medicine, aerospace and scientific study. Because of the shortage of Ag natural resources, toxic to microbes, and also a pollutant when discharged to the environment, the removal and recovery of Ag from wastewater is of importance in both economy and environment. In our lab, characteristics and mechanisms of some metal biosorption (Zn, Pb, Ag, Cu, Co, Sr, Cs, Cr etc.) by the S cerevisiae cells have been attempted to be explored investigated at macro and micro level, including biosorption capacities, influential factors, kinetics, equilibriums, thermodynamics, etc. and use of some methods, such as SEM, infrared spectroscopy (IR), synchrotron-based X-ray absorption fine structure spectroscopy (XAFS), etc. Part of the results and analysis have been published. The characteristics and mechanisms of Ag+ uptake by the dry waste yeast from a local brewery industry were reported (Chen and Wang, 2008a, b).
Chen Can Wang Jian-long
Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084, China
国际会议
北京
英文
23-24
2011-11-24（万方平台首次上网日期，不代表论文的发表时间）