Keystone microalgae species determine the removal efficiency of sulfamethoxazole: a case study of Chlorella pyrenoidosa and microalgae consortia

Ruohan Huang; Wan Liu; Jinghua Su; Shihao Li; Liqing Wang; Erik Jeppesen; Wei Zhang

doi:10.3389/fpls.2023.1193668

Keystone microalgae species determine the removal efficiency of sulfamethoxazole: a case study of Chlorella pyrenoidosa and microalgae consortia

Front Plant Sci. 2023 Jul 5:14:1193668. doi: 10.3389/fpls.2023.1193668. eCollection 2023.

Authors

Ruohan Huang¹, Wan Liu¹, Jinghua Su², Shihao Li^{1

3}, Liqing Wang¹, Erik Jeppesen^{4

5

6

7}, Wei Zhang¹

Affiliations

¹ Key laboratory of Exploration and Utilization of Aquatic Genetic Resources of the Ministry of Education, Engineering Research Center of Environmental DNA and Ecological Water Health Assessment, Shanghai Ocean University, Shanghai, China.
² Research Institute of Natural Ecology Conservation, Shanghai Academy of Environmental Sciences, Shanghai, China.
³ Shanghai Aquatic Technology Co., Ltd, Shanghai, China.
⁴ Department of Ecoscience, Aarhus University, Aarhus, Denmark.
⁵ Sino-Danish Centre for Education and Research (SDC), University of Chinese Academy of Sciences, Beijing, China.
⁶ Limnology Laboratory and EKOSAM, Department of Biological Sciences, Middle East Technical University, Ankara, Türkiye.
⁷ Institute of Marine Sciences, Middle East Technical University, Mersin, Türkiye.

Abstract

In recent years, antibiotics pollution has caused serious harm to the aquatic environment, and microalgae mediated degradation of antibiotics has attracted increasing attention. However, the potential toxicity of antibiotics to keystone microalgae species or their microalgae consortia, and the impact of microalgal diversity on antibiotic removal need to be further studied. In this study, we investigated the removal efficiency and tolerance of five freshwater microalgae (Chlorella pyrenoidosa, Scenedesmus quadricauda, Dictyosphaerium sp., Haematoccocus pluvialis, and Botryococcus braunii) and their microalgae consortia to sulfamethoxazole (SMX). We found that the removal efficiency of SMX by C. pyrenoidosa reached 49%, while the other four microalgae ranged between 9% and 16%. In addition, C. pyrenoidosa, S. quadricauda, and Dictyosphaerium sp. had better tolerance to SMX than H. pluvialis, and their growth and photosynthesis were less affected. At 10 and 50 mg/L SMX, the removal capacity of SMX by mixed microalgae consortia was lower than that of C. pyrenoidos except for the consortium with C. pyrenoidos and S. quadricauda. The consortia generally showed higher sensitivity towards SMX than the individual species, and the biochemical characteristics (photosynthetic pigment, chlorophyll fluorescence parameters, superoxide anion (O₂ ^-), superoxide dismutase activity (SOD), malondialdehyde (MDA) and extracellular enzymes) were significantly influenced by SMX stress. Therefore, the removal of antibiotics by microalgae consortia did not increase with the number of microalgae species. Our study provides a new perspective for the selection of microalgal consortia to degrade antibiotics.

Keywords: diversity; ecotoxicity; microalgae consortia; removal; sulfamethoxazole.

Grants and funding

This work was supported by the Science and Technology Commission of Shanghai Municipality (Grant No.19DZ1203404 and No. 19DZ1204504). EJ was supported by the TÜBITAK program BIDEB2232 (project 118C250).