Chlorella vulgaris cultivation using ricotta cheese whey as substrate for biomass production

The batch production of Chlorella vulgaris and its potential to profit the remnant nutritional components from ricotta cheese whey (RCW) were evaluated. From a first screening test, undiluted ricotta cheese whey was selected to be used as a growth media in the subsequent assays. Three different RCW pre-treatment methods were tested and compared: centrifugation, heat treatment (HT) and tangential flow microfiltration (TFMF). Based on the results of the screening test, a macronutrient supplementation assay was performed to increase the biomass production. A central composite design was used to analyse the effect of supplementing the media with nitrogen (0; 3.3 and 6.6 g L−1) and phosphorous (0; 0.27 and 0.55 g L−1). Chlorella vulgaris was able to grow in all tested RCW concentrations. All RCW pre-treatment methods resulted in an enhancement of the growth kinetic parameters (GKP) of Chlorella vulgaris. Among them, TFMF technology presented the best performance. The macronutrient supplementation did not show an enhancement in GKP. The scaled-up production until 400 mL batch using micro-filtered RCW showed a μmax value of 0.41 ± 0.05 h−1 (9.9 ± 1.2 day−1), a lag period of 19.9 ± 0.7 h and a Cmax of 2.52 ± 0.09. A final biomass concentration of 2.28 g L−1 was obtained. In addition, chemical oxygen demand (COD), phosphorus and nitrogen removals of 26 ± 1%, 75 ± 1% and 55 ± 1% were respectively achieved. The use of TFMF and Chlorella vulgaris cultivation represents a sustainable proposal for contributing to the circular economy.Fil: Casá, Nahuel Esteban. Universidad Tecnológica Nacional; ArgentinaFil: Lois Milevicich, Julieta. Universidad Tecnológica Nacional; ArgentinaFil: Alvarez, Paola. Universidad Tecnológica Nacional; ArgentinaFil: Mateucci, Ricardo Rafael. Universidad Tecnológica Nacional; ArgentinaFil: de Escalada Pla, Marina Francisca. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Instituto de Tecnología de Alimentos y Procesos Químicos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnología de Alimentos y Procesos Químicos; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Universidad Tecnológica Nacional; Argentin