Efficient Biosynthesis\nof Theanderose, a Potent Prebiotic,\nUsing Amylosucrase from Deinococcus deserti

The study aimed to develop an efficient bioprocess for\nthe discovery\nand synthesis of theanderose by using amylosucrase from Deinococcus deserti (<i>Dd</i>AS). An unknown\ntrisaccharide produced by <i>Dd</i>AS was detected by high-performance\nanion-exchange chromatography-pulsed amperometric detection and high-performance\nliquid chromatography-evaporative light scattering detection, purified\nusing medium-pressure liquid chromatography, and identified as theanderose\n(α-d-glucopyranosyl-(1→6)-α-d-glucopyranosyl-(1→2)-β-d-fructofuranoside)\nthrough nuclear magnetic resonance and mass spectrometry. <i>Dd</i>AS synthesized theanderose with a 25.4% yield (174.1 g/L)\nusing 2.0 M sucrose at 40 °C for 96 h. In an in vitro digestion\nmodel, theanderose showed a 6.5% hydrolysis rate over 16 h. Prebiotic\nefficacy tests confirmed that theanderose significantly enhanced the\nproliferation of selected <i>Bifidobacterium</i> strains\nin the culturing medium with theanderose as the main carbon source.\nSubsequently, fecal fermentation was performed by adding theanderose\nto the feces of 20 individuals of varying ages to assess its effect\non the gut microbiota. Theanderose increased the relative abundance\nof <i>Bifidobacteriaceae</i> and <i>Prevotellaceae</i> while decreasing the population ratio of <i>Lachnospiraceae</i> and <i>Ruminococcaceae</i>. Conclusively, theanderose\ndisplayed excellent prebiotic potential when judged by low digestibility\nand selective growth of beneficial microbes over harmful microbes.