To impart significantly improved myo-inositol producing capability, suitable for use in recombinant DNA techniques and synthetic biology methods, to a host microorganism that does not possess an endogenous myo-inositol biosynthesis pathway, such as Escherichia coli. Inositol monophosphatase activity is strengthened in a transformant obtained by introducing a myo-inositol biosynthesis pathway into a host microorganism that does not possess an endogenous myo-inositol biosynthesis pathway.

An inositol preparation method by enzymatic catalysis uses starch and cellulose or substrates thereof as substrates. Raw materials are converted to inositol by in vitro multi-enzyme reaction system in one pot. The yield from the substrate to inositol is significantly improved by process optimization and adding new enzymes. The new enzymes can promote the phosphorolysis of starch or cellulose and utilization of glucose, which is the final production after the phosphorolysis of starch and cellulose. The inositol preparation method described herein has great potentials in industrial production of inositol because of high inositol yield, easy scale-up, low production cost, and lower impact to environment

The present application relates to a psicose-6-phosphate phosphatase comprising motif A and motif B, a composition for producing D-psicose comprising the enzyme, and a method for producing D-psicose using the enzyme.