PRODUCTION OF IDOHEPTULOSAN FROM SEDOHEPTULOSAN BY MICROORGANISMS

Microbial production of idoheptulosan has been established using a two -stage fermentation system. Sedoheptulosan was first converted to 5-ke tosedoheptulosan by a strain of Agrobacterium, 449-1, in a medium cont aining sorbitol as the energy source. After 4 d of cultivation, sedohe ptulosan (100 g/l) was almost completely converted to its 5-keto form. Many strains of Gluconobacter were also found to have the same oxidiz ing activity. Asymmetric reduction of 5-ketosedoheptulosan to idoheptu losan was performed with strains of Aureobacterium, Pseudomonas, Parac occus, Micrococcus or soil isolates of coryneform bacteria. By incubat ing these bacteria with 5-ketosedoheptulosan in medium containing D-gl ucose as the hydrogen donor for reduction, 5-ketosedoheptulosan was co nverted specifically to idoheptulosan after 5 d. The overall yield of idoheptulosan was about 60% when soil isolate CF-987 was used. Other s tereoisomers of idoheptulosan and other metabolites were not detected in the final broth of the strain.