Abstract: An acidic substance having a carboxyl group is produced by culturing in a medium a microorganism which has been modified to enhance expression of the ybjL gene, and collecting the acidic substance having a carboxyl group from the medium.

Abstract: An acidic substance having a carboxyl group is produced by culturing in a medium a microorganism which has been modified to enhance expression of the ybjL gene, and collecting the acidic substance having a carboxyl group from the medium.

Abstract: An acidic substance having a carboxyl group is produced by culturing in a medium a microorganism which has been modified to enhance expression of the ybjL gene, and collecting the acidic substance having a carboxyl group from the medium.

Abstract: An organic acid is produced by allowing a bacterium which has an ability to produce an organic acid and has been modified so that expression of yidE gene is enhanced, or a product obtained by processing the bacterium, to act on an organic raw material in a reaction mixture containing carbonate ions, bicarbonate ions, or carbon dioxide gas to produce the organic acid, and collecting the organic acid.

Abstract: An acidic substance having a carboxyl group is produced by culturing in a medium a microorganism which has been modified to enhance expression of the ybjL gene, and collecting the acidic substance having a carboxyl group from the medium.

Abstract: An organic acid is produced by allowing a bacterium which has an ability to produce an organic acid and has been modified so that expression of yidE gene is enhanced, or a product obtained by processing the bacterium, to act on an organic raw material in a reaction mixture containing carbonate ions, bicarbonate ions, or carbon dioxide gas to produce the organic acid, and collecting the organic acid.

Abstract: A bacterium belonging to the genus Escherichia, which is transformed by introducing, into its cells, a DNA coding for a dihydrodipicolinate synthase originating from a bacterium belonging to the genus Escherichia having mutation to desensitize feedback inhibition by L-lysine and a DNA coding for an aspartokinase III originating from a bacterium belonging to the genus Escherichia having mutation to desensitize feedback inhibition by L-lysine; preferably a bacterium belonging to the genus Escherichia in which a dihydrodipicolinate reductase gene and a diaminopimelate dehydrogenase gene originating from Brevibacterium lactofermentum (or a succinyldiaminopimelate transaminase gene and a succinyldiaminopimelate deacylase gene) are further enhanced, is cultivated in an appropriate medium, L-lysine is produced and accumulated in a culture thereof, and L-lysine is collected from the culture.

Abstract: A bacterium belonging to the genus Serratia, which is transformed by introducing into its cells, a DNA coding for a dihydrodipicolinate synthase originating from a bacterium belonging to the genus Escherichia or Serratia having mutation to desensitize feedback inhibition by L-lysine and a DNA coding for an aspartokinase originating from a bacterium belonging to the genus Escherichia or Serratia having mutation to desensitize feedback inhibition by L-lysine is cultivated in an appropriate medium, L-lysine is produced and accumulated in a culture thereof, and L-lysine is collected from the culture.

Abstract: A process for the production of L-threonine, comprising cultivating a mutant bacterial species belonging to the genus Brevibacterium from which dihydrodipicolinate synthase has been deleted or removed in a liquid medium; accumulating the L-threonine as a product of cultivation; and harvesting the L-threonine from the culture medium.

Abstract: A method for producing L-tryptophan by fermentation which comprises aerobically culturing in a culture medium a mutant of the genus Corynebacterium or genus Brevibacterium which is resistant to sulfaguanidine and capable of producing L-tryptophan, and recovering the L-tryptophan which has accumulated in the culture medium.

Abstract: A method for producing L-tryptophan by fermentation, which comprises, culturing aerobically in a culture medium a mutant of the genus Brevibacterium which is resistant to azaserine and tryptophan analogue and capable of producing L-tryptophan, and recovering the L-tryptophan which accumulates in the culture medium.