Biomass Production of Chlorella vulgaris var. vulgaris TISTR 8261 During Cultivation in Modified Food Industry Wastewater

Industrial wastewater can serve as a low-cost nutritional source for sustainable microalgal biomass production. This study investigated the biomass of Chlorella vulgaris var. vulgaris TISTR 8261 grown in untreated wastewater collected from four food industry factories in Phra Nakhon Sri Ayutthaya Province, Thailand. Among them, wastewater from a processed food production plant (PFPP) supported the highest algal growth. Supplementation with 17.4 mM sodium acetate significantly improved algal biomass yield. Further optimization with 3.7 mM NH₄Cl, 1.0 mM KH₂PO₄, 0.2 mM MgSO₄, and a moderate concentration of trace minerals enhanced the specific growth rate and chlorophyll concentration. Scaled-up cultivation in 3.5 L culture bottles in optimized PFPP yielded a maximum biomass yield of 8.436 ± 0.378 g L⁻¹, comparable to 6.498 ± 0.436 g L⁻¹ in standard TAP medium. Biomass composition analysis after 15 days of cultivation revealed 42.70 ± 1.40% protein, 17.10 ± 1.60% carbohydrate, and 1.90 ± 0.10% lipid on a dry weight basis. These findings demonstrate that optimized PFPP wastewater can effectively support high-density cultivation of C. vulgaris var. vulgaris TISTR 8261, yielding nutritionally rich biomass, and offering a cost-effective and environmentally sustainable strategy for industrial-scale microalgal production.