Effects of pH, NaCl, ethanol, and drying methods on the solubility of Saccharomyces cerevisiae proteins

Abstract

Proteins were produced by fed-batch fermentation of Saccharomyces cerevisiae cultivated on date solution. Protein content was 52.5% (dry basis). Protein solubility was studied as a function of pH, NaCl concentration, and solvent. The minimum protein solubility was at pH 4 and the maximum was at pH 12. As a function of NaCl concentration, protein solubility was 647.6 g/kg for 1 M. The best solubility was 916.3 g/kg under pH 12 and 1 M NaCl. Solubility was very low, 2.1 g/kg, when ethanol was used as a solvent. Biomass was dried by air drying, vacuum drying, and freeze drying. The best solubility of 937.5 g/kg was obtained using freeze and vacuum drying methods. © 2012 Taylor & Francis.