Growth Dynamics of Microalgae Encapsulated in Hydrogel Micro Beads

ABSTRACT Encapsulation of microalgae in hydrogel beads is a highly effective method for high‐yield microalgae cultivation. Emerging microfluidics‐based droplet generation techniques enable the miniaturization of the microalgae‐bead system. This provides enhanced control over encapsulation, precise droplet size manipulation, and the ability to study cell growth dynamics at the microscale. This paper explores the growth behavior and survivability of microalgae encapsulated in calcium alginate hydrogel micro beads, along with the structural stability of the beads in various solutions. The solutions under investigation were pure BG‐11 growth medium, copper ion solutions, and their mixtures. Encapsulated microalgae exhibited steady growth in BG‐11 medium, with the highest growth at a 1:50 dilution ratio. Exposure to copper ions, particularly at higher concentrations, adversely affected cell growth and viability. No major structural degradation occurred in hydrogel beads across all growth conditions. Additionally, we conducted short‐term storage followed by regrowth experiments to evaluate the resilience and recovery potential of encapsulated microalgae. The results indicated that microalgae remained viable and slowly proliferated during storage, although cell clustering at the end of storage impacted regrowth efficiency. During storage, we observed noticeable increases in bead size and shape changes. However, minimal geometric alterations occurred during the subsequent regrowth phase.