Tofu whey wastewater is a promising basal medium for microalgae culture

•Tofu whey wastewater was an efficient medium for the culture of C. pyrenoidosa.•A concentration of 2.01 g/L was obtained using pure TWW at autotrophic cultures.•High lipid and protein productivities were achieved at all trophic modes. Tofu whey wastewater (TWW) is an abundant, nutrient riched and safety wastewater and is regarded as an excellent alternative medium in fermentation. In this study, the feasibility of algal cultivation using TWW as the basal medium was investigated. Results indicated that through simple pH adjustment, TWW presented a better culture performance at autotrophic, heterotrophic, and mixotrophic modes compared with that of regular green algae medium, BG-11. The biomass productivities of Chlorella pyrenoidosa at each trophic mode were 4.76, 1.97, and 2.08 times higher than that cultured in BG-11 medium, respectively. Although a comparative or even lower lipid and protein content was obtained, much higher lipid and protein productivities were obtained in TWW compared to that of BG-11. The algal biomass accumulated in TWW can be used to produce high-value products. Therefore, TWW is a better alternative medium for efficient algal culture.