Nutrient screening of Chlorella vulgaris and C. variabilis using high-throughput biolog phenotype arrays

Microalgae, particularly Chlorella species, are versatile microorganisms with significant scientific potential in various domains, including recombinant protein production, wastewater treatment, biofuel production, bio-fertilizers, food source, pharmaceuticals, and carbon capture. However, conventional growth media have often been the default choice for Chlorella cultivation. This study utilizes Biolog phenotype array plates to explore the growth responses of Chlorella vulgaris and Chlorella variabilis to a broad spectrum of carbon, nitrogen, phosphorus, and sulfur sources. The growth dynamics were captured by integrating the area under the OD-time curve. The results revealed growth preferences for both Chlorella species, emphasizing their unique nutrient source requirements and illuminated some unexpected growth behaviors. C. vulgaris exhibited equal preference for trehalose as glucose, and C. variabilis was unable to metabolize nitrate or sucrose, two staples of modified BBM media most commonly used for its cultivation. These findings contribute to a deeper understanding of the metabolic capacities of C. vulgaris and C. variabilis, informing potentially more efficient and tailored microalgal cultivation practices across diverse applications.