Bioengineering Laboratory, Chemical Engineering Department, Superior Institute of Engineering from Porto Polytechnic Institute, Rua Dr António Bernardino de Almeida, 431, 4200-072 Porto, Portugal.
Appl Microbiol Biotechnol. 2010 Dec;88(6):1355-61. doi: 10.1007/s00253-010-2799-5. Epub 2010 Sep 1.
The effect of Pb on Saccharomyces cerevisiae cell structure and function was examined. Membrane integrity was assessed by the release of UV-absorbing compounds and by the intracellular K(+) efflux. No leakage of UV(260)-absorbing compounds or loss of K(+) were observed in Pb (until 1,000 μmol/l) treated cells up to 30 min; these results suggest that plasma membrane seems not to be the immediate and primary target of Pb toxicity. The effect of Pb on yeast metabolism was examined using the fluorescent probe FUN-1 and compared with the ability to reproduce, evaluated by colony-forming units counting. The exposition of yeast cells, during 60 min to 1,000 μmol/l Pb, induces a decrease in the ability to process FUN-1 although the cells retain its proliferation capacity. A more prolonged contact time (120 min) of yeast cells with Pb induces a marked (> 50%) loss of yeast cells metabolic activity and replication competence through a mechanism which most likely requires protein synthesis.
研究了 Pb 对酿酒酵母细胞结构和功能的影响。通过释放紫外吸收化合物和细胞内 K(+)流出来评估膜的完整性。在 30 分钟内，用 Pb（直到 1000μmol/L）处理的细胞中没有观察到紫外（260）吸收化合物的泄漏或 K(+)的损失；这些结果表明，质膜似乎不是 Pb 毒性的直接和主要靶标。使用荧光探针 FUN-1 研究了 Pb 对酵母代谢的影响，并与通过菌落形成单位计数评估的繁殖能力进行了比较。在 60 分钟至 1000μmol/L Pb 的暴露下，酵母细胞的处理能力下降，尽管细胞保持其增殖能力。酵母细胞与 Pb 的更长接触时间（120 分钟）通过一种很可能需要蛋白质合成的机制，导致酵母细胞代谢活性和复制能力明显下降（超过 50%）。
