Production of single-cell protein from vinegar residue by Rhodotorula glutinis and techno-economic analysis

Single-cell protein (SCP) is attracting attention due to its high value. This study aimed to produce SCP by Rhodotorula glutinis from vinegar residue (VR). The fermentation conditions were optimized by using glucose and then VR was utilized to produce SCP. The titer of SCP was 32.14 g/L, and the protein content and lipid content were 26.67 % and 7.94 %. The yield of SCP was 0.32 g/g VR. Economic analysis of producing SCP from VR showed that processing 100,000 tons of VR annually can produce 32,140 tons of SCP at a production cost of 1,308.38 USD/ton. Sensitivity analysis revealed that the costs of cellulase and yeast were the main factors influencing the production cost of SCP, accounting for 33.6 % and 51.1 % of the raw material cost. Substituting urea for yeast powder could reduce the production cost of SCP to 761.65 USD/ton. This study provided important insights into the industrial production of SCP from VR.