Effect of Tofu Wastewater Addition on the Growth and Carbohydrate-Protein-Lipid Content of Spirulina platensis

This study was conducted to investigate the effect of tofu wastewater (TW) addition to the growth medium on the growth of Spirulina platensis. The TW addition was varied in range of 0 – 8 v/v%. The results showed that the growth rate (μ) of S. platensis at TW addition of 0, 2, 4, 6, 8 v/v% was 0.007, 0.084, 0.074, 0.088, 0.086 mg/L.d, respectively. The medium with TW content of 6 v/v% (carbon:nitrogen:phosphorous=161:17:1; carbon/nitrogen=9.55) was the best medium for biomass production. The growth rate of S. platensis was successfully modeled using modified Gompertz equation (R² =0.93–0.98). In prediction through modified Gompertz, the maximum biomass production (2.17 mg/L) was resulted from medium IV (TW of 6 v/v%). Medium IV (TW of 6 v/v%), medium II (TW of 2 v/v%) and medium III (TW of 4 v/v%) resulted in biomass containing the highest amount of protein (66.62%), carbohydrate (61.23%) and lipid (19.66%), respectively.