Green synthesis of isomaltulose from cane molasses by an immobilized recombinant Escherichia coli strain and its prebiotic activity

The specific properties of isomaltulose make it an ideal substitute for sucrose and it has broad application prospects in food, medicine and cosmetics. However, the high cost of isomaltulose has discouraged the substitution process of sugar. In the present study, we achieved low-cost production of isomaltulose from cane molasses using immobilized Escherichia coli cells (recombinant strain IS3). The maximum production, yield and productivity were 240 g/L, 94% and 48 g/L/h, respectively. Likewise, the relative enzyme activity of the immobilized recombinant cells was maintained at approximately 85% after 26 cycles. Additionally, we showed that isomaltulose significantly increased proliferation of various probiotic strains, including Lactobacillus paracasei ADP-1, Lactobacillus plantarum LPL28, Lactobacillus rhamnosus HN001, Lactobacillus acidophilus NCFM, Bifidobacterium animalis Bb-12, Bifidobacterium longum BL-05, Bifidobacterium breve Bv-77 and Bacillus coagulans GBI-30, 6086. Concurrently, the concentrations of short chain fatty acids, such as acetic acid and propionic acid, were profoundly affected by the combination of isomaltulose and probiotics. Thus, this study may provide the basis for the low-cost production of isomaltulose from industrial waste cane molasses, and its potential application as a prebiotic.