Interaction between Styrofoam and Microalgae Spirulina platensis in Brackish Water System

Area of Science:

• Materials Science
• Microbiology
• Biotechnology

Background:

• Styrofoam, a lightweight thermoplastic, possesses unique insulating and packaging properties.
• Understanding the interaction between synthetic materials and microorganisms is crucial for environmental and biotechnological applications.

Purpose of the Study:

• To investigate the interaction between Styrofoam and *Spirulina platensis* (*S. platensis*).
• To analyze *S. platensis* growth under Styrofoam exposure, changes in Styrofoam's chemical structure, and their mutual interactions.

Main Methods:

• *S. platensis* cultures were maintained in brackish water (12 mg/L salinity) for 30 days with varying Styrofoam concentrations.
• Fourier-transform infrared spectroscopy (FTIR) was used to analyze changes in Styrofoam functional groups.
• Scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) assessed *S. platensis* yields and elemental composition.

Main Results:

• The highest *S. platensis* growth rate (0.0401 day⁻¹) was observed in cultures with 150 mg of Styrofoam.
• FTIR analysis indicated changes in Styrofoam's functional groups, including the appearance of alcohol groups (3400-3200 cm⁻¹) and alkene groups (1680-1600 cm⁻¹).
• SEM-EDX confirmed an increase in carbon content (24.56%) in the cultures, suggesting Styrofoam serves as a carbon source for photosynthesis, but also revealed Styrofoam's capacity to damage *S. platensis* cells.

Conclusions:

• Styrofoam can act as a nutritional supplement, particularly as a carbon source, promoting *S. platensis* growth.
• Despite nutritional benefits, Styrofoam exhibits cytotoxic effects on *S. platensis* cells.
• Further research is needed to optimize the use of Styrofoam as a substrate while mitigating its detrimental impacts.