CS238800B1 - Method of fermenting of l-lysine - Google Patents

Abstract

The invention relates to a fermentation process the preparation of L-lysine in liquid culture media that contain as a carbon source sucrose and as the main nitrogen source is acidic profocarp flour hydrolysate (finely ground bean Psophocarpus tetragonolobus). This by hydrolysis can be replaced by standard used peanut flour hydrolysate as nitrogen source in the fermentation media. They are used as production microorganisms mutant Brevibacterium strains flavum and Corynebacteriura glutamicum, which are characterized by resistance to amino acid analogs and further require growth some essential amino acids.

Description

The present invention relates to a process for the fermentation of L-lysine in liquid nutrient media containing sucrose as a carbon source and a psofocarp flour hydrolyzate as a carbon source, corn extract, mineral salts, vitamins and other growth agents. This process allows the use of a new type of complex nitrogen source for the peanut flour hydrolyzate hitherto used. To prepare said hydrolysate, finely ground Psophocarpus tetragonolobus bean flour is used and is further hydrolyzed by a mineral acid standard procedure. The amino acid composition of psofocarp flour hydrolyzate is analogous to soy flour hydrolyzate; furthermore, the content of some essential amino acids exceeds the commonly used peanut flour hydrolysate.

Mutant strains of Brevibacterium flavum and Corynebacterium glutamicum are used as production microorganisms, which are characterized by resistance to amino acid analogues and further require some essential amino acids to grow. Various types of nitrogen substrate hydrolysates are mentioned as nitrogen sources in the patents; eg frano. U.S. Pat. No. 2,033,119 discloses a soy protein hydrolyzate as the nitrogen source; the same nitrogen source has been reported for a longer time by the German Patent Specifications 2,100,159 and 2,321,461; other nitrogen sources include casein hydrolyzate in U.S. Pat. No. 3,595,751; Japanese Patent 515,775 discloses NZ-amine as the nitrogen source; Yeast biomass hydrolysates and other nitrogenous substances are also used as a suitable nitrogen source.

The fermentation process for the preparation of L-lysine according to the invention discloses: the following examples.

Example 1

A 500 ml boiling flask containing 50 ml of an inoculum medium of the following composition is inoculated with Brevibacterium flavum (homoserine ”, AEC ^r ): sucrose 30 g, sodium acetate crystals.

g, corn extract 30 g, water dest. ad 1 liter; pH media 7.0. After seeding, the flasks were cultured on a rotary shaker (6.7 Hz) for 18-24 hours at 29 ° C.

A 500 ml boiling flask containing 20 ml of a fermentation medium of the following composition is inoculated at 10% by volume of the grown culture: sucrose 180 g, psofocarp acid acid hydrolyzate (7.0 to 8.1 mg total N / ml) 200 ml, corn extract 10 g, potassium hydrogen phosphate 1 g, magnesium sulfate crystals. 0.1 g, micronized calcium carbonate 30 g, water dest. ad 1 liter; pH media 7.0; cultivation takes place on a rotary shaker at 29 ° C for 96 hours.

During fermentation, the pH of the culture is adjusted to 7.0-7.2 with 10% ammonia solution. L-lysine production reaches 42.4 g / liter of fermentation medium in 96 hours of culture.

Example 2

The Corynebacterium glufcamicum (homoserine®, AEC ^r ) strain is seeded with an inoculation flask as described in Example 1 and the further culture and fermentation preparation of L-lysine is the same as described in Example 1. Production of 39.8 hours is achieved in 96 hours of culture g of L-lysine / liter of fermentation medium.

Example 3

A 500 ml boiling flask containing 50 ml of inoculation medium of the composition as described in Example 1 is inoculated with Brevibacterium flavum (homoserine®, AEC ^r ). A 2-liter laboratory fermentation tank containing 800 ml of fermentation medium containing is described in Example 1. An acid hydrolyzate of psopocarp flour from Psophocarpus tetragonolobus, var.Binh-Minh is used as a complex nitrogen source. By further cultivation with adequate stirring and air, pH adjustment and temperature of 29 ° C, after 96 hours of fermentation, 70.9 g of L-lysine / liter of culture medium are produced.

Example 4

The procedure for the fermentative preparation of L-lysine by Brevibacterium flavum is the same as described in Example 3 except that the acidic hydrolyzate of psofocarp flour from Psophocarpus tetragonolobus, var. Chiabu. With the above fermentation parameters, production of 71.2 g of L-lysine / liter of fermentation medium is achieved in 96 hours of culture.

Claims (2)

SUBJECT OF THE INVENTION 1. A method for the fermentation preparation of L-lysine by culturing production microorganisms such as production strains of Brevibacterium flavum or Corynebacterium glutamicum in liquid nutrient media containing carbon sources, growth factors and minerals, characterized in that the fermentation medium contains an acidic hydrolyzate of psofocarp flour which is prepared by finely grinding the beans of Psophocarpus tetragonolobus and further processed to form the hydrolyzate by the action of mineral acids. 2. A process according to claim 1, wherein the total nitrogen content of the psofocarp flour hydrolyzate is between 7.0 and 10.0 mg total. N in 1 ml of solution.