This dataset contains experimental results from shake-flask and bioreactor cultivation of Candida utilis for the production of protein-rich biomass. The study includes medium optimization, mutagenesis, and screening of mutant strains with improved protein synthesis.The dataset comprises results from media screening experiments with different carbon and nitrogen sources, as well as Response Surface Methodology (RSM) designs used to evaluate the effect of medium composition on biomass yield and protein production. Mutants were generated using EMS treatment, screened in the presence of amino acid inhibitors, and evaluated for performance in shake flasks.The best-performing mutant and optimized medium were validated in batch fermentation in a 5 L stirred bioreactor under controlled conditions.The dataset includes biomass concentration, protein content, protein yield, and, where applicable, amino acid composition, along with information on medium composition, cultivation conditions, and process parameters.