School of Arts and Sciences, Gwynedd Mercy University, Gwynedd Valley, PA 19437, USA.
Department of Environmental Engineering, Akdeniz University, Antalya 07058, Turkey.
Int J Environ Res Public Health. 2018 Mar 25;15(4):585. doi: 10.3390/ijerph15040585.
This work shows the influence of algae age (at the time of the exposure) and the initial algae population on the response of green algae to titanium dioxide nanoparticles (TiO₂ NPs). The different algae age was obtained by changes in flow rate of continually stirred tank reactors prior to NP exposure. Increased algae age led to a decreased growth, variations in chlorophyll content, and an increased lipid peroxidation. Increased initial algae population (0.3-4.2 × 10⁶ cells/mL) at a constant NP concentration (100 mg/L) caused a decline in the growth of algae. With increased initial algae population, the lipid peroxidation and chlorophyll both initially decreased and then increased. Lipid peroxidation had 4× the amount of the control at high and low initial population but, at mid-ranged initial population, had approximately half the control value. Chlorophyll a results also showed a similar trend. These results indicate that the physiological state of the algae is important for the toxicological effect of TiO₂ NPs. The condition of algae and exposure regime must be considered in detail when assessing the toxicological response of NPs to algae.
本研究展示了藻类年龄（暴露时）和初始藻类密度对绿藻响应二氧化钛纳米颗粒（TiO₂ NPs）的影响。在暴露于 NP 之前，通过连续搅拌槽反应器中流速的变化获得不同的藻类年龄。藻类年龄的增加导致生长减少、叶绿素含量变化和脂质过氧化增加。在恒定的 NP 浓度（100 mg/L）下，增加初始藻类密度（0.3-4.2×10⁶个细胞/mL）会导致藻类生长下降。随着初始藻类密度的增加，脂质过氧化和叶绿素最初先减少后增加。高初始种群和低初始种群的脂质过氧化分别是对照组的 4 倍，但在中初始种群时，脂质过氧化约为对照组的一半。叶绿素 a 的结果也表现出类似的趋势。这些结果表明，藻类的生理状态对 TiO₂ NPs 的毒理学效应很重要。在评估 NPs 对藻类的毒理学反应时，必须详细考虑藻类的状态和暴露条件。
