Decoding the Cellular Green-to-Red Gold Transition: Harnessing AI-Integrated IoT-ML Framework for Boosting Haematococcus pluvialis Cultivation and Astaxanthin Bio-Production

Haematococcus pluvialis is a unicellular green microalga renowned as the natural source of astaxanthin with biotechnological applications. Its commercial value is closely linked to its distinctive two-stage life cycle. Under favourable conditions, H. pluvialis exists in a motile green vegetative stage, where cells actively grow and accumulate biomass. When exposed to environmental stressors such as high light intensity, nutrient limitation, salinity, or elevated temperature, the cells enter non-motile red cyst stage, characterised by the accumulation of astaxanthin as a protective response to oxidative stress. Despite the growing demand for microalgal products, cultivating H. pluvialis remains challenging due to the need for precise control of cultivation parameters, including biomass concentration, pH, light intensity and temperature. While the agriculture and aquaculture sectors have increasingly adopted Internet of Things (IoT) and artificial intelligence (AI) technologies, their application in microalgae farming is still at an early infant stage. This review provides an overview of H. pluvialis cultivation, emphasizing its two-stage growth strategy for astaxanthin production, and evaluates the potential of IoT-enabled smart farming systems. Monitoring this transformation is important for identifying the optimal harvesting stage to maximize astaxanthin production and biomass quality. The integration of sensors, automation, and machine learning (ML) for monitoring and predicting biomass growth is proposed to enhance efficiency and reduce reliance on manual analysis. However, challenges such as limited datasets and difficulties in accurate modelling persist, underscoring the need to further develop intelligent microalgae cultivation systems.