Fermentation method of L-lysine

Abstract

The invention provides a fermentation method of L-lysine. According the invention, nutrient division fermentation and high-density fermentation are combined, a fermentation medium is prepared according to a ratio of 4: 6, 40% as a fermentation base material and 60% into a concentrated fermentation medium, fed batch is started 2 h after the beginning of fermentation and stopped 4 h before the end of fermentation, and the concentration of the initial fermentation medium is reduced to prevent the excessive osmotic pressure of bacteria due to excessive nutrition, which inhibit the growth of the bacteria. Nutrient division fermentation started 2 h after the beginning of fermentation makes up for nutrient deficiency and imbalance in the bacteria growth process, so that the bacteria activity is improved, the bacteria density in fermentation liquor is increased, the bacteria amount is increased by about 20%, the fermentation period is shortened to 40 h from 44 h, and the cost is reduced; in the fermentation process, balanced nutrition supplementation enables metabolic flow to flow to the L-lysine more, the conversion rate is increased from 70% to 73%, generation of byproducts such as acetic acid and alanine is effectively reduced, and the yield of the L-lysine is increased from 223 g / L to 261 g / L.

Description

technical field [0001] The invention relates to the field of amino acid fermentation, in particular to a fermentation method of L-lysine. Background technique [0002] L-Lysine is one of the eight essential amino acids, widely used in the feed industry, food and pharmaceutical industries, of which about 90% are used in feed additives. Compared with other essential amino acids, L-lysine content in grains is the lowest, so it can be used to balance the proportion of amino acids in feed and improve the absorption of grain protein in the body. In the food industry, L-lysine is mainly used in food nutrition enhancers, deodorants and coloring agents. In the pharmaceutical industry, L-lysine is the raw material for the synthesis of hormones, enzymes, antibodies and various amino acid infusions. [0003] In conventional L-lysine fermentation, due to the high concentration of the culture medium in the early stage of fermentation, excessive osmotic pressure is generated on the bacte...

AI Technical Summary

Problems solved by technology

[0003] In the conventional L-lysine fermentation, due to the high concentration of the culture medium in the early stage of fermentation, excessive osmotic pressure is generated on the bacteria, which makes the growth of the bacteria slow and the fermentation period is prolonged.

In the middle and late stages of fermentation, the nutrients in the fermentation broth are unevenly consumed and unbalanced, and some nutrients may be lacking or accumulating, resulting in a decrease in the vitality of the bacteria, slow growth and premature decline, low acid production efficiency, and by-products will also follow. increase, the fermentation period is prolonged, and the economic benefit is reduced

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