Submerged fermentation (SmF) is an attractive biotechnological option for waste treatment, generating fungal bioprotein from food industry by-products. Using different Rhizopus sp. strains as fermentation agents, this paper describes a global strategy to identify interactions between cultivation parameters (pH 4.75-7.75, 7.5-82.5 g/l glucose, 0.75-3.75 g/l nitrogen, incubation time up to 5 days) for valorization of food industry by-products. Selected parameters and/or their interactions are critical for most of the proposed resulting values, giving the opportunity to optimize the process depending on the objective and making an "in silico" pre-evaluation of the process conditions. SmF of orange molasses leads to a high biomass and protein yield (11.9 g biomass/l and 4.0 g protein/l), with 43.1 ± 0.1% of essential amino acids and chemical oxygen demand (COD) reduction of almost 50%. Experiments with cheese whey result in 76.3 ± 1.1% of glucose consumption and a biomass production of 5.6 ± 2.2 g/l with 48.9 ± 5.1% of essential amino acids. SmF of orange molasses and cheese whey could contribute to promoting a sustainable feed industry while reducing by-product treatment.
Keywords: Food waste treatment; Fungal bioprotein; Parameters optimization; Rhizopus oryzae; Submerged fermentation.