ENZYMATIC PRODUCTION OF D-MANNOSE FROM D-FRUCTOSE BY MANNOSE ISOMERASE

An enzymatic process for the production of D-mannose from D-fructose w as investigated by using a thermostable mannose isomerase from Pseudom onas sp. MI which was isolated from soil. The optimum temperature was around 60-degrees-C. The isomerization reaction progressed effectively at pH 8.0-8.5 within the tested pH range of 7.0 to 8.5 and with incre asing concentrations Of D-fructose between 5 and 40%, and about 25% Of D-fructose was converted to D-mannose. The conversion Of D-glucose to D-mannose was also investigated under 30% D-glucose concentration wit h both mannose isomerase and glucose isomerase. At equilibrium, a mixt ure containing D-glucose (about 50%), D-fructose (about 38%) and D-man nose (about 12%) was obtained.