The present invention provides a process for the production of vitamin C from different substrates like D-sorbitol, L-sorbose, L-sorbosone or L-gulose using a microorganism selected from the group consisting of Gluconobacter oxydans DMS 4025 (FERM BP-3812), a microorganism belonging to the genus Gluconobacter and having identifying characteristics of G. oxydans DSM 4025 (FERM BP-3812) and mutants thereof.