Campisi T, Abbondanzi F, Casado-Martinez C, DelValls T A, Guerra R, Iacondini A
Centro Ricerche e Servizi Ambientali Fenice, via C. Menotti, 48 I-48023 Marina di Ravenna (RA), Italy.
Chemosphere. 2005 Jun;60(1):9-15. doi: 10.1016/j.chemosphere.2004.12.052.
In this work, sediment samples collected from several Spanish harbours were tested with two toxicity procedures, designed for solid samples: the Microtox Basic Solid-Phase Test (BSPT) and a modified procedure of the previous test protocol (mBSPT). According to the BSPT procedure, after initial light readings, pure bacteria were exposed to sediment suspension dilutions and light production was directly measured on suspended sediments without any further manipulation. As measurements are likely to be affected by sediment turbidity and color, a variation in initial light measurement has been here suggested, in order to consider the sample effect at all time readings during the test. Firstly, when sediment suspensions at different concentrations were added to bacteria suspension, immediately the initial light output drastically decayed by more than 50% in signal difference, resulting in a false inhibition, as effect of sample turbidity/color. This effect was more evident at high EC50 values, when slightly or not toxic samples were assessed. Secondly, the comparison of the EC50 obtained with both procedures, demonstrated that the mBSPT produced higher EC50 values (less toxic) than those obtained with the standard procedure. The mBSPT procedure resulted rapid and effective and it could be applied simultaneously with BSPT, in order to better evaluate the toxicity.
在这项工作中，从西班牙几个港口采集的沉积物样本采用了两种针对固体样本设计的毒性测试方法进行测试：微毒性基本固相测试（BSPT）和前一测试方案的改进方法（mBSPT）。根据BSPT方法，在初始光读数后，将纯细菌暴露于沉积物悬浮液稀释液中，并且直接在悬浮沉积物上测量光产生，无需任何进一步处理。由于测量可能会受到沉积物浊度和颜色的影响，因此这里建议对初始光测量进行变化，以便在测试期间的所有时间读数中考虑样本效应。首先，当将不同浓度的沉积物悬浮液添加到细菌悬浮液中时，初始光输出立即在信号差异上急剧衰减超过50％，导致假抑制，这是样本浊度/颜色的影响。当评估轻微或无毒样本时，这种效应在高EC50值时更为明显。其次，两种方法获得的EC50的比较表明，mBSPT产生的EC50值（毒性较小）高于标准方法获得的值。mBSPT方法快速有效，可以与BSPT同时应用，以便更好地评估毒性。
