The effect of salinity and tofu whey wastewater on the growth kinetics, biomass, and primary metabolites in Euglena sp.

The nutritional content of tofu whey wastewater (TWW) has potential as a culture medium for microalgae Euglena sp. through salinity adjustment. We considered combinations of TWW consisting of 0 (CM), 75 (MI), and 100 (L) with combination salinity levels consisting of 0 g/L (CM/MI0/L0), 2 g/L (CM2/MI2/L2), and 4 g/L (CM4/MI4/ L4). The analyses were carried out on the cell density, growth kinetics (logic and Gompertz equation), biomass, total lipid (Bligh and Dyar method), total carbohydrate (phenol-sulfuric acid method), total protein (Bradford method), and pigments. Based on the study, the combination with highest cell density, biomass, total lipid, total carbohydrate, and total protein was obtained in L4 (14.375 ×105 ± 0.375 cells/mL), MI2 (2.77 ± 0.118 mg/mL), L4 (0.81 ± 0.020 mg/mL), MI (0.48 ± 0.014 mg/mL), and MI4 (0.14 ± 0.005 mg/mL), respectively. Moreover, the combinations with the highest chlorophyll A, chlorophyll B, and carotenoid were 10.74 ± 0.14 mg/L (L4), 2.53 ± 0.07 mg/L (L4), and 2.57 ± 0.003 mg/L (L4), respectively. The addition of TWW combined with specific salinity enhanced growth and biomass composition of Euglena sp. Furthermore, TWW could be an effective and inexpensive alternative medium in Euglena sp. for biorefinery activity. © 2023 Ahmad Saifun Naser, et al.