Is it possible to shape the microalgal biomass composition with operational parameters for target compound accumulation?

Microalgae, as photosynthetic microorganisms, offer a sustainable source of proteins, lipids, carbohydrates, pigments, vitamins, and antioxidants. Leveraging their advantages, such as fast growth, CO fixation, cultivation without arable land, and wastewater utilisation, microalgae can produce a diverse range of compounds. The extracted products find applications in bioenergy, animal feed, pharmaceuticals, nutraceuticals, cosmetics, and food industries. The selection of microalgal species is crucial, and their biochemical composition varies during growth phases influenced by environmental factors like light, salinity, temperature, and nutrients. Manipulating growth conditions shapes biomass composition, optimising the production of target compounds. This review synthesises research from 2019 onwards, focusing on stress induction and two-stage cultivation in microalgal strategies. This review takes a broader approach, addressing the effects of various operating conditions on a range of biochemical compounds. It explores the impact of operational parameters (light, nutrient availability, salinity, temperature) on biomass composition, elucidating microalgal mechanisms. Challenges include species-specific responses, maintaining stable conditions, and scale-up complexities. A two-stage approach balances biomass productivity and compound yield. Overcoming challenges involves improving upstream and downstream processes, developing sophisticated monitoring systems, and conducting further modelling work. Future efforts should concentrate on strain engineering and refined monitoring, facilitating real-time adjustments for optimal compound accumulation. Moreover, conducting large-scale experiments is essential to evaluate the feasibility and sustainability of the process through techno-economic analysis and life cycle assessments.