Eriksson K Martin, Johansson C Henrik, Fihlman Viktor, Grehn Alexander, Sanli Kemal, Andersson Mats X, Blanck Hans, Arrhenius Åsa, Sircar Triranta, Backhaus Thomas
Department of Shipping and Marine Technology, Chalmers University of Technology, Gothenburg, Sweden.
Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden.
Environ Toxicol Chem. 2015 Sep;34(9):2067-77. doi: 10.1002/etc.3030. Epub 2015 Jun 24.
Triclosan is a widely used antibacterial agent that has become a ubiquitous contaminant in freshwater, estuary, and marine environments. Concerns about potential adverse effects of triclosan have been described in several recent risk assessments. Its effects on freshwater microbial communities have been well studied, but studies addressing effects on marine microbial communities are scarce. In the present study, the authors describe short- and long-term effects of triclosan on marine periphyton (microbial biofilm) communities. Short-term effects on photosynthesis were estimated after 60 min to 210 min of exposure. Long-term effects on photosynthesis, chlorophyll a fluorescence, pigment content, community tolerance, and bacterial carbon utilization were studied after exposing periphyton for 17 d in flow-through microcosms to 0.316 nM to 10,000 nM triclosan. Results from the short-term studies show that triclosan is toxic to periphyton photosynthesis. Half maximal effective concentration (EC50) values of 1080 nM and 3000 nM were estimated using (14)CO2-incorporation and pulse amplitude modulation (PAM) fluorescence measurements, respectively. After long-term triclosan exposure in flow-through microcosms, photosynthesis estimated using PAM fluorometry was not inhibited by triclosan concentrations up to 1000 nM but instead increased with increasing triclosan concentration. Similarly, at exposure concentrations of 31.6 nM and higher, triclosan caused an increase in photosynthetic pigments. At 316 nM triclosan, the pigment amounts were increased by a factor of 1.4 to 1.9 compared with the control level. Pollution-induced community tolerance was observed for algae and cyanobacteria at 100 nM triclosan and higher. Despite the widespread use of triclosan as an antibacterial agent, the compound did not have any effects on bacterial carbon utilization after long-term exposure.
三氯生是一种广泛使用的抗菌剂，已成为淡水、河口和海洋环境中普遍存在的污染物。最近的几项风险评估中都提到了对三氯生潜在不利影响的担忧。其对淡水微生物群落的影响已得到充分研究，但针对海洋微生物群落影响的研究却很少。在本研究中，作者描述了三氯生对海洋附生植物（微生物生物膜）群落的短期和长期影响。在暴露60分钟至210分钟后估计对光合作用的短期影响。在流通式微观世界中将附生植物暴露于0.316 nM至10,000 nM三氯生17天后，研究了对光合作用、叶绿素a荧光、色素含量、群落耐受性和细菌碳利用的长期影响。短期研究结果表明，三氯生对附生植物光合作用有毒性。分别使用(14)CO2掺入法和脉冲幅度调制（PAM）荧光测量法估计的半数最大有效浓度（EC50）值为1080 nM和3000 nM。在流通式微观世界中进行长期三氯生暴露后，使用PAM荧光测定法估计的光合作用在三氯生浓度高达1000 nM时未受到抑制，反而随着三氯生浓度的增加而增加。同样，在暴露浓度为31.6 nM及更高时，三氯生导致光合色素增加。在316 nM三氯生时，色素含量与对照水平相比增加了1.4至1.9倍。在100 nM及更高浓度的三氯生中观察到藻类和蓝细菌的污染诱导群落耐受性。尽管三氯生作为抗菌剂被广泛使用，但长期暴露后该化合物对细菌碳利用没有任何影响。
