Alexandre Six

All Publications

• Microalgae, sunlight, and starch: low cell concentration is optimal for outdoor production under nutrient stress BIORESOURCE TECHNOLOGY Six, A., Chambonniere, P., Alvarez, P., Fon-Sing, S., Lancelon-Pin, C., Putaux, J., Sassi, J., Li-Beisson, Y., Fleury, G. 2026; 443: 133840

  Abstract

  Microalgae, particularly Chlorella vulgaris, are promising sustainable sources of starch for bioplastics and biofuels. Economically viable production requires optimizing starch accumulation, typically triggered by nutrient starvation, a process often facilitated by culture dilution to enhance light homogeneity. This study proposes an empirical model to predict the optimal cell concentration for starch accumulation under nitrogen starvation based on available light. The model, developed using 1-L outdoor cultures, was successfully applied to a 180-L photobioreactor. The theoretical optimal concentration under 330 µmolphotons m-2 s-1 (average absorbed photon flux density during daylight) was found at 0.8 gDWL-1. The corresponding carbohydrate productivity (43 mgcarbohydrate L-1 h-1 during daylight), carbohydrate content (57 %) and photosynthesis efficiency (6.8 % expressed as kJcarbohydrate kJphotonsPAR-1) aligned with experimental results. This study indicates that optimal carbohydrate accumulation occurs at low cell concentration, which is a critical guideline for the future industrialization of microalgae production.

  View details for DOI 10.1016/j.biortech.2025.133840

  View details for Web of Science ID 001658794400001

  View details for PubMedID 41453536