Enhanced production of lactosucrose using an integrated levansucrase–yeast system with an invertase-deficient Saccharomyces cerevisiae strain

ATCC 56741. Unlike conventional wine yeasts, the selected strain preferentially reduced glucose while minimizing sucrose and lactosucrose degradation under the tested conditions, thereby maintaining favorable conditions for transfructosylation. The integrated system was optimized by evaluating various relative proportions of enzyme activity and yeast biomass standardized by cell density. Under the optimized yeast-dominant condition (activity-to-biomass ratio of 1:3), a maximum lactosucrose concentration of 128.2 g/L was achieved. Furthermore, the biological removal of glucose may simplify downstream processing by reducing byproduct interference. Unlike glucose oxidase-based systems, which generate gluconic acid and require pH control, the present approach utilizes biological glucose removal without introducing additional acidic byproducts. These results suggest that the integrated levansucrase-yeast system is a promising preparative-scale strategy for lactosucrose production.