Thiamine Hydrochloride → L-Glutamic Acid

Participants

Reaction Steps

The thus obtained odhA gene-disrupted strain is isolated in a medium containing sugar. In the process of isolation, a spontaneous mutation is introduced into the chromosomal yggB gene at a high frequency. Then, the ability of the isolated strain to produce L-glutamic acid is evaluated by culturing the strain in a medium containing excess biotin. For example, a candidate strain is inoculated in 20 ml of culture medium (30 g/l glucose, 15 g/l ammonium sulfate, 1 g/l KH2PO4, 0.4 g/l MgSO4.7H2O, 0.01 g/l FeSO4.7H2O, 0.01 g/l MnSO4.4-5H2O, 200 μg/l vitamin B1, 300 μg/l biotin, 0.48 g/l soybean hydrolysates (total nitrogen), adjusted to pH 8.0 with KOH: autoclaved at 115° C. for 10 minutes), followed by addition of 1 g of heat-sterilized calcium carbonate, and the strain is cultured with shaking. After the sugar is completely consumed, the amount of accumulated L-glutamic acid is measured. Strains which produce L-glutamic acid, for example, those which produce not less than 50% (yield per sugar) of L-glutamic acid are selected, and the nucleotide sequence of the yggB gene of the selected strains are determined to obtain a strain in which a mutation is introduced into the yggB gene.

Provenance & Evidence