Biotransformation of Fructose to Allose by a One-Pot Reaction Using Flavonifractor plautii ᴅ-Allulose 3-Epimerase and Clostridium thermocellum Ribose 5-Phosphate Isomerase

Biotransformation of Fructose to Allose by a One-Pot Reaction Using Flavonifractor plautii ᴅ-Allulose 3-Epimerase and Clostridium thermocellum Ribose 5-Phosphate Isomerase

${\text\tiny{D}}-Allose$ is a potential medical sugar because it has anticancer, antihypertensive, antiinflammatory, antioxidative, and immunosuppressant activities. Allose production from fructose as a cheap substrate was performed by a one-pot reaction using Flavonifractor plautii ${\text\tiny{D}}-allulose$ 3-epimerase (FP-DAE) and Clostridium thermocellum ribose 5-phosphate isomerase (CT-RPI). The optimal reaction conditions for allose production were pH 7.5, $60^{\circ}C$, 0.1 g/l FP-DAE, 12 g/l CT-RPI, and 600 g/l fructose in the presence of 1 mM $Co^{2+}$. Under these optimized conditions, FP-DAE and CT-RPI produced 79 g/l allose for 2 h, with a conversion yield of 13%. This is the first biotransformation of fructose to allose by a two-enzyme system. The production of allose by a one-pot reaction using FP-DAE and CT-RPI was 1.3-fold higher than that by a two-step reaction using the two enzymes.