Next-Gen Bioprocessing: Sustainable Scale-Up of Triple Algal Co-culture System

In recent years, microalgae have attracted considerable interest because of their diverse uses in sustainable biotechnology. The role of microalgae in industrial biotechnology is steadily increasing; however, limitations (e.g. cost, operations and maintenance) encountered during scaling-up processes necessitate the development of more efficient methods. The co-culture approach offers numerous advantages, including enhanced productivity, sustainability, product diversity, cost-effective operations, and eco-friendly processing. In this study, a triple algal co-culture of Haematococcus pluvialis Chlorella vulgaris, and Spirulina platensis was scaled up in air-lift photobioreactors (ALPBRs) from 2 L to 8 L using constant power consumption per unit volume as the scale-up strategy. The results indicated that scaling-up increased productivity (approximately 1.3-fold increase), with significant improvements in production parameters observed in the 8 L ALPBR. Biomass productivity showed a 1.75-fold increase when scaling from 2 L to 8 L. Protein, chlorophyll and carotenoid productivities increased 1.5-fold, 1.2-fold, and 1.1-fold, respectively, compared to the 2 L ALPBR. These results demonstrate that the triple algal co-culture system enhances both energy and product efficiency, confirming the effectiveness of scale-up using a constant power consumption per unit volume strategy and highlighting its potential for more sustainable and efficient microalgal production processes through increased biomass and bioactive product yields.