Extremely high-performance production of Functional Soybean Oligosaccharides by advanced fed-batch fermentation with high cell density

Abstract

Abstract Soybean whey, which is a byproduct of soybean processing, is known to contain a significant quantity of functional low molecular weight substances that are challenging to separate, such as soybean oligosaccharides. This study aims to explore the high-density fermentation process of yeast PL08 fermentation process as a potential method for purifying functional soybean oligosaccharides from soybean whey, by constructing a fermentation kinetics model of PL08 cell growth, sucrose consumption, and ethanol production. The logistic model and the Luedeking-Piret model were used to analyze the data using nonlinear data fitting techniques. The linearity of the models resulted in a high coefficient of determination (R2) value of 0.98, indicating the method's effectiveness and reliability. At the 30-hour mark, the batch fermentation procedure exhibited a purity of functional oligosaccharides at 94.12%, accompanied by a simultaneous increase in ethanol concentration to 3.0% vol. In light of the results obtained from kinetic studies, a 10L exponential feeding culture was conducted, demonstrating successful maintenance of alcohol concentration below 0.10% vol. Furthermore, the maximum biomass concentration reached 50.01 g/L, while the functional soybean oligosaccharides achieved a peak purity of 95.59% within a 21-hour period.