Method for increasing sugar-to-acid conversion rate during fermentation of L-glutamic acid

Abstract

The invention relates to the field of fermentation and production of L-glutamic acid, in particular to a method for increasing the sugar-to-acid conversion rate during fermentation of L-glutamic acid. At the period of fermentation and acid production, the fermentation is performed based on continuous flow-adding sugar extended to a pipeline in a fermentation tank at the flow rate of not larger than 10m<3> / h; an outlet of the pipeline is located above a mixing blade of the bottom end; the vertical distance from the outlet of the pipeline to the mixing blade at the bottom end is 0.75% to 2.25% of the height of the side wall of the fermentation tank; and the horizontal distance from the outlet to a mixing shaft of the fermentation tank is 2.35% to 7% of the horizontal distance from the mixing shaft to the side wall. In the invention, the route of flow-adding sugar is improved; the concentration of sugar liquid in the process of adding the flow sugar is increased; and the problem of the nonuniform distribution of oxygen content is solved, so that the fermentation liquid is under preferable fermentation conditions; moreover, the sugar-to-acid conversion rate is increased.

Description

technical field [0001] The invention relates to the field of L-glutamic acid fermentation production, in particular to a method for improving the sugar-acid conversion rate of L-glutamic acid fermentation. Background technique [0002] Monosodium glutamate is a kind of freshness-enhancing condiment commonly used in our daily life, and its main component is L-sodium glutamate. The production of monosodium glutamate usually first adopts strain fermentation to prepare L-glutamic acid fermentation liquid, then extracts L-glutamic acid from the fermentation liquid, and finally obtains L-sodium glutamate through neutralization. [0003] L-glutamic acid is an indispensable raw material in the production of monosodium glutamate, and its fermentation liquid is obtained by fermenting the strain and sugar liquid in a fermenter. During the fermentation process, the concentration of the sugar solution in the fermenter will become lower and lower as the fermentation continues. In order t...

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Problems solved by technology

[0004] For a long time, the flow-added sugar enters the fermenter directly from the top of the side wall of the fermenter, but the agitation and centrifugation in the fermenter greatly hinders the diffusion of the flow-fed sugar to the center of the cross-section of the fermentation broth, and the updraft in the fermenter The convective addition of sugar also hinders the diffusion of sugar to the bottom, which causes the concentration of sugar solution to gradually decrease from the edge to the center of the fermenter and from the top to the bottom.

The concentration of sugar solution at the bottom and center is low, and the acid production level of the strain will be limited; the concentration of sugar solution at the top and edge is high, the osmotic pressure in the environment is high, and the sugar consumption rate of the strain is slow, which is not conducive to the secretion of glutamic acid and Utilization of sugar solution

To sum up, due to the uneven distribution of sugar solution concentration, the metabolic level of the strain is affected, and the sugar solution is converted to metabolic by-products, which ultimately leads to a decrease in the sugar-acid conversion rate.

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