Enhancement of ornithine production in proline-supplemented Corynebacterium glutamicum by ornithine cyclodeaminase.

In this study, Corynebacterium glutamicum and its derived mutants were used to demonstrate the relationship between proline, glutamate and ornithine. The maximum ornithine production was shown in the culture medium (3295.0 mg/l) when the cells were cultured with 20 mM proline and was 15.5 times higher than in the presence of 1 mM proline. However, glutamate, which known as an intermediate in the process of converting proline to ornithine, did not have any positive effect on ornithine production. This suggests that the conversion of proline to ornithine through glutamate, is not possible in C. glutamicum. Comparative analysis between the wild-type strain, SJC8043 (argF-, argR-) and SJC8064 (argF-, argR- and ocd-), showed that C. glutamicum could regulate ornithine production by ornithine cyclodeaminase (Ocd) under proline-supplemented conditions. Therefore, proline directly caused an increase in the endogenous level of ornithine by Ocd, which would be a primary metabolite in the ornithine biosynthesis pathway.