Process for preparing 2-keto-L-gulonic acid and mutants therefor.

摘要

A fermentative or enzymatic production of 2-keto-L-gulonic acid from 2,5-diketo-D-gluconic acid using living or processed mutants, being defective in metabolizing 5-keto-D-gluconic acid and incapable of producing 2-keto-D-gluconic acid, is disclosed. The mutant is derived from 2-keto-L-gluconic acid producing microorganisms of the genus Corynebacterium. The production is carried out in the presence of nitrates and/or hydrogen donors in a preliminarily sterilized fermentation broth in which a 2,5-diketo-D-gluconic acid producing microorganism of genus Gluconobacter or Erwinia has been cultivated.