Strouhal Martin, Kizek René, Vacek Jan, Trnková Libuse, Nemec Miroslav
Department of Microbiology, Faculty of Science, Masaryk University, CZ-602 00 Brno, Czech Republic.
Bioelectrochemistry. 2003 Aug;60(1-2):29-36. doi: 10.1016/s1567-5394(03)00043-4.
The bioaccumulation of heavy metals (cadmium, nickel, cobalt and zinc) and the effect of these metals on the production of metallothionein and metallothionein-like proteins (MT) in Yarrowia lipolytica was studied by electrochemical methods. The concentrations of heavy metals were determined by differential pulse voltammetry (DPV). A combination of the constant current chronopotentiometric stripping analysis (CPSA) and adsorptive transfer stripping technique (AdTS) was used to determine the content of MT in cells. Both the bioaccumulation of heavy metals and the production of MT in different cell compartments of Y. lipolytica exposed to heavy metals were monitored. The LD(50) of each metal was determined from the number of viable cells in yeast cultures: LD(50)Cd (37.5 microM), LD(50)Ni (570 microM), LD(50)Co (700 microM), and LD(50)Zn (1800 microM). The highest concentrations of heavy metals were found in the cell wall and membrane debris while the lowest concentrations were detected in the cytoplasm. Cadmium and nickel showed the most significant effect on the production of MT. This study provides new insights into the ecophysiology of microorganisms and demonstrates the potential use of these electrochemical methods in biotechnology.
采用电化学方法研究了解脂耶氏酵母中重金属（镉、镍、钴和锌）的生物积累以及这些金属对金属硫蛋白和类金属硫蛋白（MT）产生的影响。通过差分脉冲伏安法（DPV）测定重金属浓度。采用恒电流计时电位溶出分析（CPSA）和吸附转移溶出技术（AdTS）相结合的方法测定细胞中MT的含量。监测了解脂耶氏酵母暴露于重金属时不同细胞区室中重金属的生物积累和MT的产生情况。根据酵母培养物中活细胞数量确定每种金属的半数致死剂量（LD50）：Cd的LD50为37.5 μM，Ni的LD50为570 μM，Co的LD50为700 μM，Zn的LD50为1800 μM。在细胞壁和膜碎片中发现重金属浓度最高，而在细胞质中检测到的浓度最低。镉和镍对MT产生的影响最为显著。本研究为微生物的生态生理学提供了新的见解，并证明了这些电化学方法在生物技术中的潜在应用。
