Patent ID: 9334511
Filing Date: 2016-05-10
CPC Classification: C12N,C12P

Claim Text:
1. A method for producing a basic amino acid by fermentation comprising culturing a microorganism having an ability to produce the basic amino acid in a liquid medium contained in a fermentation tank to produce and accumulate the basic amino acid in the medium; wherein the amount of sulfate and/or chloride ions used as counter ions of the basic amino acid is reduced by adjusting the total ammonia concentration in the medium to be 300 mM or lower during at least a part of the total period of the culture process including a period where the pH of the medium increases due to shortage of the counter ions caused by accumulation of the objective basic amino acid; wherein the total ammonia concentration in the medium is adjusted by adding ammonia or urea to the medium when an activity of the microorganism is reduced or ceases as determined based on the indicators: dissolved oxygen concentration in the medium, consumption rate of carbon source in the medium, turbidity of the medium, productivity of the basic amino acid, and pH change in the medium; and wherein the microorganism is an