Abstract
A novel fermentation process for simultaneous and high production of L-lysine and L-glutamic acid was established. This process was characterized by cultivating an L-lysine-producing strain with the cultivating methods for the production of L-glutamic acid, that is, cultivations with the addition of surface-active agents or penicillin. By these methods, without the addition of ammonium sulfate to culture medium, simultaneous and high production of L-lysine and L-glutamic acid with 1.3-1.4 fold higher productivity than that of the control was achieved. Various expected merits of this process from the viewpoint of industrial production of amino acids are discussed. It was suggested from the analysis of this newly-found fermentation process that the accumulation of L-glutamic acid could not be explained only the usual "leakage model" through the injury of cell membrane, but it would be necessary to consider the alterations in L-glutamic acid biosynthetic system.
