Method for preparing fermented liquid rich in L-tryptophan by utilizing rice

Abstract

The invention relates to a method for preparing fermented liquid rich in L-tryptophan by utilizing rice, which is applied in the preparation of fermented liquid containing L-tryptophan. The method comprises the following steps of: (1) preparation of double enzyme glucose solution, which includes zymohydrolysis and saccharification of rice slurry by using high-temperature amylase and efficient saccharifying enzyme; (2) preparation of seed culture, which includes the steps of (2.1) dividing the double enzyme glucose solution obtained in (1) into three parts of X, Y and Z by weight according to the proportion that X : Y : Z is equal to 1 : 4 : 95, wherein X is used as sugar liquid needed by seed culture medium, Y is used as sugar liquid needed by fermentation medium and Z is used as sugar liquid needed by fed-batch sugar; and (2.2) preparing seed culture medium containing double enzyme glucose solution with the amount of X by using a conventional method and equally dividing the seed culture medium into two parts: one part is used as seed culture medium for recombinant Escherichia coli; and the other part is used as seed culture medium for corynebacterium glutamicum; and (3) fed-batch sugar fermentation by using the seed culture. The method has the advantages of improving the acid yield and the yield coefficient, shortening the fermentation period and saving the energy consumption.

Description

technical field [0001] The invention relates to a method for preparing a fermented liquid rich in L-tryptophan by using rice, which is applied to prepare the fermented liquid rich in L-tryptophan. Background technique [0002] The scientific name of L-tryptophan is β-indolylalanine, the chemical name is L-2-amino-3-indolylpropionic acid, alias L-trypsin amino acid, L-aminoindolepropionic acid, molecular formula C11H12O2N2, The relative molecular mass is 204.21. L-Tryptophan (L-Tryptophan) is a neutral aromatic amino acid containing indolyl, white or slightly yellow leaf-like crystals or powder, odorless or slightly smelly, soluble in hot pyridine, slightly soluble in ethanol , Insoluble in chloroform and ether. It is soluble in dilute acid or alkali, and it will be colored under long-term light. Co-heating with water produces a small amount of indole, and heating in the presence of NaOH or CuSO4 produces a large amount of indole. Unstable when heated with acid in the dar...

AI Technical Summary

Problems solved by technology

[0006] L-tryptophan fermentation is a microbial metabolic process. The metabolic flow of L-tryptophan strains that appear now is very weak, and is inhibited or interfered by a large number of substances, thereby changing the metabolic pathway of the strain and resulting in changes in the target product

Therefore, the acid production in the current fermentation process is unstable, or the metabolism changes due to inhibition or interference in the middle, resulting in low acid production or even no target product

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