A novel photobioreactor generating the light/dark cycle to improve microalgae cultivation

Area of Science:

• Biotechnology
• Algal Biotechnology
• Photobioreactor Design

Background:

• Microalgae cultivation is crucial for biofuels and bioproducts.
• Efficient light delivery remains a challenge in photobioreactor design.
• Optimizing light/dark cycles can enhance microalgal photosynthetic efficiency.

Purpose of the Study:

• To develop and evaluate a novel tubular photobioreactor with periodic shading.
• To investigate the impact of controllable light/dark cycles on microalgae growth.
• To determine the optimal frequency of light/dark cycles for enhanced biomass productivity.

Main Methods:

• Fabrication of a tubular photobioreactor with a periodically shading outer surface.
• Cultivation of Chlorella pyrenoidosa under varying light/dark cycle frequencies and light intensities.
• Measurement of microalgae growth, biomass productivity, and light-to-biomass conversion efficiency.

Main Results:

• The developed photobioreactor significantly enhanced microalgae growth and light-to-biomass conversion efficiency.
• A frequency of 100 Hz for the artificial light/dark cycle resulted in a 21.6% increase in average biomass productivity.
• Photosynthetic efficiency was markedly improved compared to conventional photobioreactors.

Conclusions:

• The novel tubular photobioreactor with periodic shading offers an efficient method for microalgae cultivation.
• This design provides a promising approach for large-scale outdoor microalgae applications.
• Optimized light/dark cycling is a key factor in maximizing microalgal biomass production.