KR0185018B1 - Saccharomyces cerevisiae ctb 14 used for the preparation of sake - Google Patents

Abstract

The present invention, Saccharomyces cerevisiae YBB yeast used in the brewing of Cheongju after treatment of the mutant of Ethyl Methanesulfonate (EMS Ethyl Methanesulfonate), the main flavor components of Cheongju separated and improved in a selective medium at high concentration The microorganism to be produced and the preparation method of the sake using the same, more specifically, Saccharomyces sebase YBB yeast is treated with EMS as a variant organic agent, the final concentration of trifluoroleucine is 50 ~ 500μM, celenolenin Resistant strains selected at the minimum concentration of 3 ~ 50μMC added to the final concentration inoculated again in the yeast screening medium to remove strains with respiratory distress, cultured in broth broth, and then analyzed by fragrance by gas chromatography in homegrown yeast Saccharomyces cerevis yeast strain producing a large amount of fragrance ingredients that give good flavor to sake CTB14 (KFCC-10936 Lake) and to a method for producing a fermented rice wine sikimeuroseo it in jeungmi medium.

Description

New Hometown Cheongju Yeast Strain Saccharomyces cerevisiae CTB14 and Manufacturing Method of Cheongju Using the Same.

The present invention is the main fragrance components of Saccharomyces cerevisiae (Saccharomyces cerevisiae) YBB yeast used in the brewing of Cheongju after mutated ethylmethanesulfonate (EMS, Ethyl Methanesulfonate), isolated from the selection medium It relates to a microorganism produced at a high concentration and a method of manufacturing cheongju using the same.

In recent years, in order to meet the various tastes of consumers, the consumption of sake has increased dramatically compared to beer and shochu, which were the representative alcohols. Cheongju is made from rice as the main ingredient and has a complex taste and aroma due to its manufacturing characteristics. Many flavors are involved in the taste and aroma of Cheongju, but those that directly affect acetaldehyde, diacetyl, ethyl acetate, isoamyl acetate and isoamyl alcohol Isoamyl alcohol, phenylethyl alcohol, phenylethyl acetate, and ethyl caproate.

Since existing methods for obtaining sake yeast strains with excellent taste and aroma do not have a clear selection method, many strains were isolated from artificial or natural mutations to prepare sake and then analyzed the fragrance components. Therefore, it takes a lot of time and manpower, and even after the strain was selected by this method, the selected strains often lost the excellent fermentation properties of the original parent strain. Therefore, the strain that produces a large amount of good fragrance components, but because the fermentation properties of the cheongju is not good in most cases was not suitable for practical use.

Trifluoroleucine (TFL, Trifluoroleucine) is a derivative of leucine (amino acid). Yeast strains that can survive in medium containing this substance are enzymes that play an important role in the biosynthetic pathway of isoacetate and isoamyl alcohol. The properties of alpha-IPM synthase are changed to overcome the inhibition by leucine to produce a large amount of isoamyl acetate and isoamyl alcohol. On the other hand, cerulenin is derived from the fungus, fatty acids inhibit the enzymes involved in the synthesis of the antifungal, antibacterial substances. However, it was reported that yeast strains grown in the medium containing cerulein produced a large amount of ethyl caproate, one of the important flavor components of saengju, compared to the existing strains.

Therefore, the inventors have focused on these properties of trifluoroleucine and cerulenin, and have selected excellent sake yeast strains that already secrete large amounts of isoacetate, isoamyl alcohol and ethyl caproate by adding both substances to the medium at the same time. As a result, the mutant strain CTB 14, which secretes a large amount of fragrance components, was selected while maintaining the fermentation properties originally possessed.

Therefore, the present invention, after treating Saccharomyces cerevisiae YBB yeast with EMS as a variant organic agent, the resistant strain selected from the minimum medium added 50 ~ 500μM final concentration of trifluoroleucine again for yeast After inoculation into the selective medium to remove strains with respiratory disorders, cultured in a broth medium, and analyzed the fragrance component by gas chromatography to separate the home yeast, the flavor component to give a good flavor to the sake obtained by producing a large amount of yeast bacteria The present invention relates to Saccharomyces cerevisiae CTB14 (KFCC-10936) and a method for producing sake by fermenting it in a thickening medium.

The minimum medium is 15-25 g / L glucose, 12-18 g / L agar, 4-6 g / L ammonium sulfate, 0.8-1.2 g / L potassium phosphate, 0.4-0.6 g / L magnesium sulfate and A medium containing a small amount of vitamins and inorganic salts is used, and the selective screening medium for yeast contains 40 to 60 g / L of glucose, 3 to 5 g / L of yeast extract, 4 to 6 g / L of carton and a small amount of inorganic salts. Use medium containing.

The method of inducing the mutant strain of the present invention is as follows.

Saccharomyces fermented yeast Saccharomyces cerevisiae YBB was treated with a variant organic agent EMS to add a minimum concentration of trifluoro leucine 50 ~ 500μM, the final concentration of cerulenin 3 ~ 50μM (20g per glucose / l, ammonium sulfate 5g / L, biotin 2µg / L, calcium pantothenate 400µg / L, folic acid 2µg / L, inositol 2000µg / L, niacin 400µg / L, paraaminobenzoic acid 200µg / L, Pyridoxine hydrochloride 400 µg / L, riboflavin 200 µg / L, thiamine hydrochloride 400 µg / L, boric acid 500 µg / L, copper sulfate 40 µg / L, potassium iodide 100 µg / L, ferric chloride 200 µg / L, manganese sulfate 400 µg / L, sodium molybdate 020µg / L, zinc sulfate 400µg / L, potassium phosphate 1g / L, magnesium sulfate 0.5g / L, sodium chloride 0.1g / L, calcium chloride 0.1g / L, agar 15g / L) Plated and cultured at 23 to 27 ° C. for 7 to 8 days to obtain a trifluoroleucine-serulenin co-resistant strain.

Trifluoroleucine-serulenin co-resistant strains were again screened for yeast (4 g / L yeast extract, 5 g / L cachetium, 50 g / L glucose, 0.55 g / L potassium phosphate, 0.425 g / L potassium chloride, 0.125 calcium chloride) g / L, magnesium sulfate 0.125g / L, ferric chloride 0.0025g / L, manganese sulfate 0.0025g / L, agar 15g / L, Streaking in bromocresol green 0.022g / L) Single colonies (Colony) excluding these were separated.

The mutants obtained above were added to 20 ml of broth (250 g of naturally dried broth) in water, adjusted to 1.5 L, and then glycosylated at 65 ° C. for 8 hours, followed by centrifugation to separate only the supernatant. The supernatant was again inoculated with Whatman No. 4 filter paper and sterilized at 121 ° C. for 15 minutes), and then cultured at 10-14 ° C. for 15-19 days, and the culture solution was quantitatively analyzed by gas chromatography. Yeast producing a large amount of ingredients was selected and named as Saccharomyces cerevisiae ctb14. This strain was deposited on November 27, 1996 with the Korea Microbiological Conservation Center of the Korean spawn association and was given accession number to KFCC-10936.

Cheongju is prepared by fermenting in a conventional manner in a medium containing jeungmi as a main component and adding yeast, water, and a small amount of glycosylating enzyme using the improved strain isolated according to the above method.

Example 1

Use strain: Mother strain YBB and mutant strain CTB14 of the present invention (KFCC-10936)

Species medium: glucose 20g / L, peptone 20g / L, yeast extract 10g / L, malt extract 10g / L

Fermentation medium: broth

Fermentation method: 2 ml of the seed medium was dispensed into 4 ml vials, sterilized at 121 ° C. for 15 minutes, inoculated with the used strain, and incubated at 30 ° C. for 24 hours to use as a seed culture solution. 19 ml of the fermentation broth were dispensed into 100 ml test tubes, sterilized for 15 minutes at 121 ° C., 1 ml of the seed culture solution was inoculated, and then cultured at 12 ° C. for 17 days. The results of measuring the fragrance components by recovering the fermentation broth are shown in Table 1 below.

By preparing sake using Saccharomyces cerevisiae CTB14 obtained according to the present invention, savory sake containing a large amount of ammonium isoacetate, isoamyl alcohol and ethyl caproate can be easily produced.

Claims (5)

Saccharomyces cerevisiae YBB yeast was treated with EMS, a variant organic agent, and the final concentration of trifluoroleucine was 50-500 μM. Resistant strains selected from the minimum medium added with the final concentration of cellulenine 3 to 50μM was inoculated again into the selection medium for yeast to remove strains with respiratory distress, and then cultured in broth medium, and analyzed the fragrance components by gas chromatography Separation and improvement of homegrown yeast is a separation method of yeast strain Saccharomyces cerevisiae CTB14 (KFCC-10936) which produces a large amount of fragrance ingredient giving a good flavor to sake. The medium according to claim 1, wherein the minimum medium is 15-25 g / L glucose, 12-18 g / L agar, 4-6 g / L ammonium sulfate, 0.8-1.2 g / L potassium monophosphate, 0.4-0.6 g / L Separation method of yeast strain Saccharomyces cerevisiae CTB14 (KFCC-10936) comprising L magnesium sulfate and trace vitamins and inorganic salts. The yeast strain according to claim 1, wherein the yeast screening medium contains 40 to 60 g / L of glucose, 3 to 5 g / L of yeast extract, 4 to 6 g / L of cacitone and trace mineral salts. Separation method of Saccharomyces cerevisiae CTB14 (KFCC-10936). Yeast strain Saccharomyces cerevisiae CTB14 isolated according to the method of claim 1 (KFCC-10936). The yeast strain Saccharomyces cerevisiae CTB14 (KFCC-10936) strain of claim 4 is fermented in a thick medium medium to produce a sake.