Insights into Microalgae Growth Performance Under Varying Blue LED Light Intensities Using the Monod Model Framework

Abstract

This study investigates the effects of varying blue LED light intensities on the growth performance and lipid production of the microalga Chlorella vulgaris using a Monod Model framework. Cultures were exposed to eight light intensities ranging from 14.7 to 370 µmol m⁻² s⁻¹ over 12 days. Results indicate that while higher intensities (120 and 370 µmol m⁻² s⁻¹) increase growth coefficients (0.43-0.60 d⁻¹), optimal biomass accumulation occurred at a lower intensity of 55.5 µmol m⁻² s⁻¹ when growth is sustained uninhibited over a longer period. In contrast to recent suggestions of using light intensities close to 200 µmol m⁻² s⁻¹, the findings suggest that efficient growth can be achieved with lower, less energy-consuming light intensities, as biomass production with blue LED light was approximately 50% higher than with white light. Although cellular lipid accumulation was higher under white light (27%), the increased biomass production from blue light compensates for total lipid yield. Overall, optimizing blue LED light intensity represents a promising strategy for enhancing microalgae productivity, reducing energy consumption, and mitigating the effects of potential inhibitors in cultivation systems.