Green biotechnological synthesis of rare sugars/alcohols: D-allulose, allitol, D-tagatose, L-xylulose, L-ribose.

Rare sugars are paid more attention because of which have the characteristics of low calorie, low absorption and excellent physiological functions. Biotechnological synthesis of rare sugars has the advantages of being green, clean, simple and economic compared to chemical synthesis. Abundant enzymes for rare sugars biosynthesis are introduced and multienzyme cascade catalytic system (MECCS) used in biosynthesis of rare sugars is highlighted in this paper.

Construction of recombinant Escherichia coli expressing xylitol-4-dehydrogenase and optimization for enhanced L-xylulose biotransformation from xylitol.

L-Xylulose is a rare ketopentose which inhibits α-glucosidase and is an indicator of hepatitis or liver cirrhosis. This pentose is also a precursor of other rare sugars such as L-xylose, L-ribose or L-lyxose. Recombinant E.