Phosphorus conditions change the cellular responses of Microcystis aeruginosa to perfluorooctanoic acid

Hanqi Wu; Weizheng Zhang; Xuhui Huang; Peng Gu; Qi Li; Xingzhang Luo; Zheng Zheng

doi:10.1016/j.scitotenv.2023.166707

Phosphorus conditions change the cellular responses of Microcystis aeruginosa to perfluorooctanoic acid

Sci Total Environ. 2023 Dec 10:903:166707. doi: 10.1016/j.scitotenv.2023.166707. Epub 2023 Sep 3.

Authors

Hanqi Wu¹, Weizheng Zhang², Xuhui Huang¹, Peng Gu³, Qi Li², Xingzhang Luo¹, Zheng Zheng⁴

Affiliations

¹ Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China.
² College of Ecology and Environment, Chengdu University of Technology, Chengdu 610059, PR China.
³ School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, PR China.
⁴ Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China. Electronic address: zzhenghj@fudan.edu.cn.

PMID: 37660808
DOI: 10.1016/j.scitotenv.2023.166707

Abstract

Perfluorooctanoic acid (PFOA), a widespread and emerging organic contaminant of aquatic environments, has high bioaccumulation potential and high toxicity. Consequently, major concerns have been raised worldwide regarding the management of this pollutant in aquatic ecosystems. To thoroughly understand PFOA's toxic effects on aquatic organisms, systematic investigations were conducted on the cellular responses of Microcystis aeruginosa to the environmental concentrations of PFOA under various concentrations as well as phosphorus (P) conditions (concentrations and forms). The results showed that P conditions remarkably affected cyanobacterial growth as well as photosynthetic pigment content, triggered oxidative stress to disrupt the function and structure of the cell membrane, and caused changes in the extracellular and intracellular contents of microcystin-LR (MC-LR). Furthermore, PFOA (100 μg/L) was absorbed by cyanobacterial cells through the stimulation of the secretion of extracellular polymeric substances (EPS) by M. aeruginosa. After entering the cyanobacterial cells, PFOA inhibited photosynthesis, reduced P absorption, induced oxidative damage, lead to a loss of cell integrity evident in scanning electron microscope images, and increased mcyA gene expression to promote MC-LR production. Moreover, the limited P concentration and forms conditions led to increased PFOA absorption by cyanobacterial cells, which further upregulated mcyA gene expression and increased the risk of MC-LR diffusion into the aquatic environment. Our present study provided a theoretical basis and new ideas for understanding and addressing safety issues related to the presence of PFOA in aquatic environments with varying nutritional statuses.

Keywords: Cellular responses; Microcystin-LR; Microcystis aeruginosa; Perfluorooctanoic acid; Phosphorus.