Integrated biorefinery strategy for tofu wastewater biotransformation and biomass valorization with the filamentous microalga Tribonema minus.

This study focused on the feasibility of using different concentrations of tofu wastewater (TW) as alternative media for Tribonema minus cultures to produce valuable biorefinery feedstock. T. minus grew mixotrophically in 100% TW with larger carbohydrate (30.99% of dry weight (DW)), protein (15.56% of DW) and chrysolaminarin (6.93% of DW) accumulations than that of in mBG-11 medium. The highest biomass concentration, 7.77 g/L, was achieved in 100% TW, and nutrient removal efficiencies of T. minus at this concentration ranged from 60.49% to 93.60%. Although smaller neutral lipid and palmitoleic acid amounts were detected in 100% TW, their productivities reached 133.77 and 67.19 mg/L/d, respectively, due to the largest biomass yield contribution, which were comparable to those in mBG-11 medium. These findings demonstrated that TW is a promising alternative medium, and an integrated TW biotransformation and biomass valorization process is proposed to achieve better economic performance and environmental sustainability.