High pH value tolerant bacterial strain and novel fermentation method for producing lysine

Abstract

The invention discloses a high pH value tolerant bacterial strain and a novel fermentation method for producing lysine. A fermentation process by the high pH value tolerant bacterial strain does not use ammonium sulfate as an inorganic nitrogen source, and ammonia or liquefied ammonia is used for supplementing the nitrogen source in the fermentation broth to synthesize lysine. The fermentation process for producing lysine does not employ ammonium sulfate, and ammonia or liquefied ammonia is supplemented as the nitrogen source, so that the sulfate ion concentration in the fermentation broth is reduced greatly to facilitate subsequent treatment of fermentation broth; and purification by ion exchange for removing sulfate radical and other ions is not required, so as to simplify the production process of feed grade lysine hydrochloride and reduce the production cost. Supplement of ammonia or liquefied ammonia adjusts the pH value of the fermentation broth to control the inorganic nitrogen content in the fermentation broth, so as to ensure the content of inorganic nitrogen in the culture tank is in a reasonable range; and no ammonium sulfate is added, thereby reducing sulfate radical ions and other impurities in the fermentation broth, and facilitating extraction.

Description

technical field [0001] The invention belongs to a method for producing lysine by a fermentation method, and in particular relates to a strain resistant to high pH value and a method for producing lysine by a novel fermentation method. Background technique [0002] When the content of L-lysine in food or feed is insufficient, the utilization of other amino acids will be limited, so lysine is widely used in food fortification, animal feed additives and medicinal purposes. L-lysine is currently the The main additive of full-price compound feed can improve feed utilization, promote animal growth and improve meat quality. [0003] At present, in the process of producing feed-grade L-lysine hydrochloride, continuous fermentation culture is often used for fermentation, and in continuous fermentation culture, the method of feeding ammonium sulfate is mainly used to provide nitrogen source to ensure the synthesis of lysine. Nitrogen in ammonium sulfate is gradually consumed, while ...

AI Technical Summary

Problems solved by technology

[0005] The pH of the traditional lysine fermentation process is generally controlled to be less than 7.2, not lower than 6.5, and the preferred pH is 7.0. At this time, the production of lysine and the growth of bacteria are normal; too high or too low pH will affect or inhibit the fermentation process The production of lysine and the growth of the bacteria make the bacteria in the end of the fermentation process low, and the yield of lysine in the fermentation is low