Bioengineering Laboratory, Chemical Engineering Department, Superior Institute of Engineering from Porto Polytechnic Institute, Rua Dr António Bernardino de Almeida, Porto, Portugal.
J Appl Microbiol. 2009 Jun;106(6):1792-804. doi: 10.1111/j.1365-2672.2009.04170.x. Epub 2009 Feb 25.
The capacities of live and heat-killed cells of Saccharomyces cerevisiae at 45 degrees C for the removal of copper, nickel and zinc from the solution were compared.
Kinetic studies have shown a maximum accumulation of Ni(2+) and Zn(2+) after 10 min for both types of cells, while for Cu(2+) this was attained after 30 and 60 min for dead and live cells, respectively. Equilibrium studies have shown that inactivated biomass displayed a greater Zn(2+) and Ni(2+) accumulation than live yeasts. For Cu(2+), live and dead cells showed similar accumulation. Fluorescence, scanning electron microscopy and infrared spectroscopy studies have shown that no appreciable structural or molecular changes occurred in the cells during the killing process. The increased metal uptake observed in dead cells can be most likely explained by the loss of membrane integrity, which allows the exposition of further metal-binding sites present inside the cells.
Heat-killed cells showed a higher degree of heavy metal removal than live cells, being more suitable for further bioremediation works.
Dead flocculent cells can be used in a low cost technology for detoxifying metal-bearing effluents as this approach combines an efficient metal removal with the ease of cell separation.
比较 45°C 下活细胞和热灭活细胞去除溶液中铜、镍和锌的能力。
动力学研究表明，两种细胞对 Ni(2+)和 Zn(2+)的最大积累均在 10 分钟后达到，而对于 Cu(2+)，死细胞和活细胞分别在 30 分钟和 60 分钟后达到。平衡研究表明，失活生物质显示出比活酵母更高的 Zn(2+)和 Ni(2+)积累。对于 Cu(2+)，活细胞和死细胞表现出相似的积累。荧光、扫描电子显微镜和红外光谱研究表明，在杀灭过程中细胞没有发生明显的结构或分子变化。在死细胞中观察到的金属摄取增加很可能可以用细胞膜完整性的丧失来解释，这使得细胞内进一步的金属结合位点暴露出来。
热灭活细胞比活细胞显示出更高程度的重金属去除，更适合进一步的生物修复工作。
死絮状细胞可用于成本低廉的技术，以去除含金属的废水，因为这种方法将高效的金属去除与细胞分离的简便性结合在一起。
