微塑料对微藻生长及其释放三卤代甲烷的影响

研究了聚苯乙烯微塑料（PS，0.5μm，10~100mg/L）在120h内对三角褐指藻（Phaeodactylum tricornutum）的生长及其释放三卤代甲烷的影响.结果表明，PS显著抑制三角褐指藻的生长.高浓度的PS （100mg/L）条件下，三角褐指藻的细胞生长，叶绿素a含量及光合效率的最大抑制率分别达31.75%，10.38%和8.82%.PS诱导微藻细胞内产生氧化应激，增加细胞内活性氧的含量.培养前期（0~48h），PS引起微藻细胞发生氧化应激，促进三角褐指藻释放3种三卤代甲烷；培养后期（72~120h），PS抑制细胞的生理状态及3种三卤代甲烷的释放.这些结果表明微塑料在一定浓度下会影响藻类细胞生长代谢，三卤甲烷的生产释放是一种通过细胞代谢来抵抗氧化应激的保护机制.

The influence of microplastic on the growth of microalage and their release of trihalomethane

The unialgal cultures of diatoms (Phaeodactylum tricornutum) were conducted to examine the influence of polystyrene microplastic (PS, 0.5μm, 10~100mg/L) on the growth of these diatoms and their release of trihalomethane during 120 hours. The results showed that the growth of these diatoms was inhibited by the addition of PS. At the high concentration (PS, 100mg/L), the maximum inhibition rates of the diatoms cell growth, of chlorophyll a concentration and of the photosynthetic efficiency of the diatoms were respectively 31.75%, 10.38% and 8.82%. PS induced the increase level of oxidative stress in microalgal cells and the increase level of the intracellular reactive oxygen. The release of three trihalomethanes by diatoms could be promoted by the addition of PS during the early stage of culture (0~48h) due to oxidative stress in microalgae cells. However, the addition of PS inhibited the physiological state of the cells during the late stage of the culture (72~120h), and led to less release of trihalomethanes by diatoms. These results demonstrated that microplastics could affect algal growth under certain concentrations and that the production and release of trihalomethanes were a protective mechanism against oxidative stress through cell metabolism.