Exploring biochemical responses and cellular adaptations of Chlorella sorokiniana to polyethylene microplastic exposure

Sci Rep. 2025 Jul 2;15(1):23551. doi: 10.1038/s41598-025-08674-z.

Abstract

Microplastics (MPs) are a common long-lasting pollutant of aquatic ecosystems. Microalgae are primary producers of aquatic systems, and MP contamination could have a high impact on the aquatic food web. Therefore, the present study utilized polyethylene (PE) particles (0 to 150 mg/L) for investigating the half-maximal inhibitory concentrations (IC50) of Chlorella sorokiniana and also studied their impacts on growth rate, biomass, pigments and other biochemical components of the microalgae. After 96 h of incubation, PE of 100 mg/L resulted in the half-maximum inhibition (IC50). After reaching the stationary phase (14 d), harvesting was made for MP-exposed cultures to reveal a biomass production of 0.89 g/L, while it was 0.96 g/L for the control. A slight reduction in pigment and lipid contents was also observed, while the protein and carbohydrate contents were high in MP-exposed C. sorokiniana cells. Under the MP stress, reactive oxygen species (ROS) and phenolic levels were reduced, whereas flavonoid content increased. PE particles were characterized using Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDX) and Fourier Transform infrared spectroscopy (FT-IR) for their size, shape, chemical composition, and interaction with C. sorokiniana, followed by micro-Fourier Transform infrared spectroscopy (µ-FT-IR) for the mapping of MP. This research contributes to a deeper understanding of how MP contamination can disrupt aquatic food webs, guiding future ecological assessments and pollution management strategies.

Keywords: Chlorella sorokiniana; Biochemical compounds; Biomass content; Polyethylene (PE); Reactive oxygen species (ROS).

MeSH terms

  • Adaptation, Physiological* / drug effects
  • Biomass
  • Chlorella* / drug effects
  • Chlorella* / growth & development
  • Chlorella* / metabolism
  • Chlorella* / physiology
  • Microalgae / drug effects
  • Microalgae / metabolism
  • Microplastics* / toxicity
  • Polyethylene* / toxicity
  • Reactive Oxygen Species / metabolism
  • Spectroscopy, Fourier Transform Infrared
  • Water Pollutants, Chemical* / toxicity

Substances

  • Microplastics
  • Polyethylene
  • Reactive Oxygen Species
  • Water Pollutants, Chemical