| abstract |
For the preparation of amino acids by fermentation, bacterial strains are used in which the activity of the secretion system is increased due to chemical or physical mutation. Appropriate strains can be selected by a secretion screening method, in which in particular the variation, with time, of the concentration of intracellular and extracellular amino acids is measured. Furthermore, the dependence between the pH and the secretory activity of the selected strain should be small. For the formation of lysine, a strain is used having a secretion rate> 10 mumol / min.g in the dry state, at pH <7.5. The strain of Corynebacterium glutamicum DSM 5714 with enhanced secretory activity, obtained by mutation from strain DSM 6870, is particularly suitable for the production of lysine. |