Optimization of Culture Conditions for Arthrospira platensis Cultivation in Closed Tubular Photobioreactors
Phan Van Dan
Institute of Life Sciences, Vietnam Academy of Science and Technology, Ho Chi Minh City, Vietnam.
Nguyen Hoang Dung
Institute of Life Sciences, Vietnam Academy of Science and Technology, Ho Chi Minh City, Vietnam.
Do Dang Giap
Institute of Life Sciences, Vietnam Academy of Science and Technology, Ho Chi Minh City, Vietnam.
Le Quynh Loan
Institute of Life Sciences, Vietnam Academy of Science and Technology, Ho Chi Minh City, Vietnam.
Tran Thi My Ngoc
Institute of Life Sciences, Vietnam Academy of Science and Technology, Ho Chi Minh City, Vietnam.
Vu Thi Tuyet Nhung
Institute of Life Sciences, Vietnam Academy of Science and Technology, Ho Chi Minh City, Vietnam.
Tran Quang Vinh
Institute of Life Sciences, Vietnam Academy of Science and Technology, Ho Chi Minh City, Vietnam.
Nguyen Thi Thuy
Institute of Life Sciences, Vietnam Academy of Science and Technology, Ho Chi Minh City, Vietnam.
Tran Trung Kien *
Institute of Life Sciences, Vietnam Academy of Science and Technology, Ho Chi Minh City, Vietnam.
*Author to whom correspondence should be addressed.
Abstract
Background: Tubular photobioreactors (PBRs) enhance high-quality Arthrospira platensis biomass production. However, microalgae are highly susceptible to micro-environmental fluctuations, specifically the combined influence of photo-thermal stress, dissolved oxygen (DO) accumulation, and hydrodynamic shear stress.
Aims: To evaluate A. platensis growth dynamics and biochemical composition under environmental stressors to establish safe, sustainable operating limits.
Study Design: Experimental study utilizing a one-factor-at-a-time (OFAT) screening approach.
Place and Duration of Study: Institute of Life Sciences, Vietnam Academy of Science and Technology, Ho Chi Minh City, Vietnam, between March and July 2025.
Methodology: The experiments investigated illumination modes, circulation velocities (0.1-0.5 m/s), and aeration cycles (9 h/day and 24 h/day).
Results: We have established an optimal safe operation window using shading roof (28-32 °C), 0.3 m/s circulation velocity and continuous aeration (24 h/day). The maximum biomass production was 3.49 g/L after 7 days, corresponding to 0.456 g/L/day, with enhanced phycocyanin (123.37 mg/g), carotenoid (4.02 mg/g), and crude protein (59.20%) contents.
Conclusion: These findings provide practical guidance for alleviating environmental stress and improving large-scale cultivation of A. platensis under tropical conditions.
Keywords: Arthrospira platensis, closed tubular photobioreactors (PBR), phycocyanin, photo-thermal stress, gas-liquid mass transfer, shear stress.