• 文献标题:   The cytotoxicity of nano- and micro-sized graphene oxides on microalgae depends on the characteristics of cell wall and flagella
  • 文献类型:   Article
  • 作  者:   KIM KY, KIM JY, PARK J, CHOI YE
  • 作者关键词:   chlamydomonas reinhardtii, graphene oxide, flagella, cell wall, cytotoxicity
  • 出版物名称:   SCIENCE OF THE TOTAL ENVIRONMENT
  • ISSN:   0048-9697 EI 1879-1026
  • 通讯作者地址:  
  • 被引频次:   0
  • DOI:   10.1016/j.scitotenv.2023.161783 EA FEB 2023
  • 出版年:   2023

▎ 摘  要

Cytotoxic effects of emerging contaminants in aquatic environments have been widely studied using diverse microalgal species. However, the role of microalgal characteristics such as presence/absence of cell wall or flagella on cytotoxicity of contaminants was not elucidated yet. In this study, four different Chlamydomonas reinhardtii strains that have different characteristics were used to confirm how these characteristics affect toxicity of contaminants, nano-/micro-sized graphene oxide (GO). The nano-sized GO inhibited the growth of cell wall-deficient strains and re-duced the photosynthetic activity. The micro-sized GO inhibited the growth of all strains, but the inhibition efficiency was higher in flagella-deficient strains, indicating that cell wall and flagella have different roles in response to contam-inant exposure. The electron microscopy analysis demonstrated that nano-sized GO caused the cell rupture in cell wall -deficient strains. In flagella-deficient strains, the nano-and micro-sized GOs were parallelly attached on the surface of cells, covering the cells. The wrapping of flagella-deficient cells by GO led to the increase of reactive oxygen species (ROS) contents. These results indicate main cytotoxic mechanism of nano-sized GO was the membrane damage of cells, and the presence of cell wall can protect the cells from the attack of nano-sized GO. On the one hand, the presence of flagella might help to avoid the attachment of GO while the cell proliferation and photosynthesis were inhibited in flagella-deficient cells due to the GO wrapping. Overall, given that different microalgal species have different charac-teristics and these characteristics might affect the cytotoxic effect of the contaminants, it is of great importance to con-sider the characteristics of test microalgal species when evaluating the cytotoxic mechanism of the nano-/micro-sized pollutants.