Effect of biotin and a similar compound on succinic acid fermentation by Actinobacillus succinogenes in a chemically defined medium

A minimal chemically defined medium (CDM) was created and used to study the effect of biotin on the metabolism of Actinobacillus succinogenes NJ 113. The medium contained four amino acids and vitamins as key growth factors. To gain insight into the effect of biotin, different concentrations of this compound were added, and glucose utilisation, cell growth, and the succinic acid concentration were investigated. Anaerobic batch fermentation was carried out at optimised conditions in a 3. L fermentor with a succinic acid concentration of 45.2. g/L and a yield of 90.4%. A metabolic pathway was proposed after further study of the mechanism underlying the metabolism of biotin. The same results were obtained when 5-aminolevulinate (5-ALA) was used instead of biotin. We suggest that 5-ALA is a great alternative to biotin for the preparation of succinic acid by biological fermentation.