Integrated Mixotrophic Cultivation Strategy for Limnospira (Spirulina) Platensis using Vinegar Wastewater: Productivity Enhancement through Controlled Organic Supplementation and Salinity Optimization

Agro-industrial wastewaters rich in organic compounds represent both an environmental liability and a potential resource for sustainable bioprocesses. This study evaluated a cultivation strategy for Limnospira (Spirulina) platensis based on controlled mixotrophic supplementation with vinegar wastewater and salinity optimization to enhance biomass production while maintaining culture stability. Vinegar supplementation significantly improved growth compared to the control (Jourdan medium), with biomass concentrations ranging from 3.32 to 6.30 g · L⁻¹ within four days, versus 2.42 g · L⁻¹ in autotrophic conditions. The effect of NaCl under mixotrophy revealed a clear interaction between salinity and organic carbon availability, with optimal performance (5.85 g · L⁻¹) at 1 g · L⁻¹ NaCl. These results demonstrate that controlled mixotrophic supplementation defines an operational window that enhances biomass productivity without compromising physiological stability.