Tubbing D M, Admiraal W
National Institute of Public Health and Environmental Protection, BA Bilthoven, The Netherlands.
Appl Environ Microbiol. 1991 Dec;57(12):3616-22. doi: 10.1128/aem.57.12.3616-3622.1991.
The effects of a quaternary ammonium compound, ditallowdimethylammonium chloride (DTDMAC), on natural populations of bacteria and phytoplankton from the lower River Rhine were examined to estimate their sensitivity to the discharges of cationic surfactants in the river basin. In short-term experiments, significant decreases in the growth rate of bacterioplankton and in the photosynthetic rate of phytoplankton were observed at a nominal concentration of 0.03 to 0.1 mg of DTDMAC liter-1. Nitrification was measured with an ion-selective electrode and by the rate of acid production in ammonium-spiked river water and was found to be only sensitive to the addition of concentrations higher than 1 mg of DTDMAC liter-1. This does not support an earlier suggestion that ammonium-oxidizing bacteria are specifically sensitive to quaternary ammonium compounds. The effect of DTDMAC on thymidine incorporation was shown to depend strongly on the concentration of suspended material, which varied with the sampling date. This effect was also quantified in experimental manipulations with Rhine water. Calculations on the partitioning of DTDMAC between water and suspended matter confirmed the role of suspended solids and showed that an increase of the dissolved DTDMAC concentration in Rhine water by circa 0.01 mg liter-1 leads to a slight inhibition of the growth of heterotrophic bacteria. It is concluded that a total concentration of circa 0.01 mg of DTDMAC liter-1 measured in the River Rhine is likely to have biological consequences.
研究了季铵化合物二牛脂二甲基氯化铵（DTDMAC）对莱茵河下游细菌和浮游植物自然种群的影响，以评估它们对流域内阳离子表面活性剂排放的敏感性。在短期实验中，当DTDMAC的标称浓度为0.03至0.1毫克/升时，观察到浮游细菌的生长速率和浮游植物的光合速率显著下降。用离子选择性电极以及加氨河水的产酸速率来测量硝化作用，发现其仅对添加浓度高于1毫克/升的DTDMAC敏感。这并不支持早期关于铵氧化细菌对季铵化合物特别敏感的观点。结果表明，DTDMAC对胸腺嘧啶核苷掺入的影响很大程度上取决于悬浮物质的浓度，而悬浮物质的浓度随采样日期而变化。在莱茵河水的实验操作中也对这种影响进行了量化。关于DTDMAC在水和悬浮物之间分配的计算证实了悬浮固体的作用，并表明莱茵河水中溶解的DTDMAC浓度增加约0.01毫克/升会导致异养细菌生长受到轻微抑制。得出的结论是，在莱茵河中测得的DTDMAC总浓度约为0.01毫克/升可能会产生生物学后果。
