Giri Sayani, Christudoss Abisha Christy, Chandrasekaran Natarajan, Peijnenburg Willie J G M, Mukherjee Amitava
Centre for Nanobiotechnology, Vellore Institute of Technology, Vellore, Tamil Nadu, India.
Institute of Environmental Sciences (CML), Leiden University, Leiden, 2300 RA, the Netherlands; National Institute of Public Health and the Environment, Center for the Safety of Substances and Products, Bilthoven, 3720 BA, the Netherlands.
Plant Physiol Biochem. 2023 Apr;197:107664. doi: 10.1016/j.plaphy.2023.107664. Epub 2023 Mar 24.
Both Bisphenol A (BPA) and polystyrene nanoplastics (PSNPs) are routinely found in several consumer products such as packaging materials, flame retardants, and cosmetics. The environment is seriously endangered by nano- and microplastics. In addition to harming aquatic life, nanoplastics (NPs) also bind to other pollutants, facilitating their dispersion in the environment and possibly promoting toxicity induced by these pollutants. The toxic effects of polystyrene nanoplastics (PS-NPs) and BPA were examined in this study, as well as the combined toxic impacts of these substances on the freshwater microalgae Scenedesmus obliquus. In addition, the exopolymeric substances (EPS) secreted by algae will interact with the pollutants modifying their physicochemical behaviour and fate. This work aimed to investigate how algal EPS alters the combined effects of BPA and PSNPs on the microalgae Scenedesmus obliquus. The algae were exposed to binary mixtures of BPA (2.5, 5, and 10 mg/L) and PSNPs (1 mg/L of plain, aminated, and carboxylated PSNPs) with EPS added to the natural freshwater medium. Cell viability, hydroxyl and superoxide radical generation, cell membrane permeability, antioxidant enzyme activity (catalase and superoxide dismutase), and photosynthetic pigment content were among the parameters studied to determine the toxicity. It was observed that for all the binary mixtures, the carboxylated PSNPs were most toxic when compared to the toxicity induced by the other PSNP particles investigated. The maximum damage was observed for the mixture of 10 mg/L of BPA with carboxylated PSNPs with a cell viability of 49%. When compared to the pristine mixtures, the EPS-containing mixtures induced significantly reduced toxic effects. A considerable decrease in reactive oxygen species levels, activity of antioxidant enzymes (SOD and CAT), and cell membrane damage was noted in the EPS-containing mixtures. Reduced concentrations of the reactive oxygen species led to improved photosynthetic pigment content in the cells.
双酚A（BPA）和聚苯乙烯纳米塑料（PSNPs）经常在多种消费品中被发现，如包装材料、阻燃剂和化妆品。纳米塑料和微塑料对环境造成了严重危害。除了危害水生生物外，纳米塑料（NPs）还会与其他污染物结合，促进其在环境中的扩散，并可能增强这些污染物所诱导的毒性。本研究考察了聚苯乙烯纳米塑料（PS-NPs）和双酚A的毒性效应，以及这些物质对淡水微藻斜生栅藻的联合毒性影响。此外，藻类分泌的胞外聚合物（EPS）会与污染物相互作用，改变其物理化学行为和归宿。这项工作旨在研究藻类EPS如何改变双酚A和PSNPs对微藻斜生栅藻的联合效应。将藻类暴露于双酚A（2.5、5和10毫克/升）和PSNPs（1毫克/升的普通型、胺化型和羧化型PSNPs）的二元混合物中，同时在天然淡水培养基中添加EPS。为确定毒性，研究的参数包括细胞活力、羟基和超氧自由基的产生、细胞膜通透性、抗氧化酶活性（过氧化氢酶和超氧化物歧化酶）以及光合色素含量。结果发现，对于所有二元混合物，与所研究的其他PSNP颗粒所诱导的毒性相比，羧化型PSNPs毒性最大。在10毫克/升双酚A与羧化型PSNPs的混合物中观察到最大损伤，细胞活力为49%。与原始混合物相比，含EPS的混合物诱导的毒性效应显著降低。含EPS的混合物中活性氧水平、抗氧化酶（SOD和CAT）活性以及细胞膜损伤均有显著降低。活性氧浓度的降低导致细胞中光合色素含量增加。
