JP2589264B2 - Alcohol production method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Saccharomyces cerevisiae (S
A novel brewer's yeast belonging to the genus accharomyces cerevisiae). That is, the present invention relates to a method for producing alcoholic beverages using Saccharomyces cerevisiae BAW-6 (Microtechnical Laboratory No. 12871).

[0002]

2. Description of the Related Art Since brewer's yeast has different properties required for alcoholic beverages, shochu yeast, sake yeast, brewer's yeast, wine yeast, etc., which are suitable for alcoholic beverages, are selected and used in accordance with the intended use. Kagoshima yeast and Miyazaki yeast are common as shochu yeasts. The yield of alcohol per ton of raw material when these yeasts are used is, for example, 450 to 460 liters for rice shochu and 200 to 210 liters for potato shochu.
1, 410 to 420 l for barley shochu. Sake yeast uses Association Yeast No. 7, No. 9 or Kumamoto yeast, and the yield of alcohol varies depending on the production method such as main brewing and ginjo brewing, but is about 350 l. In addition, wine yeast Nos. 1 and 3, etc. are used as wine yeasts.

[0003]

It is generally said that the yield of alcohol is dependent on the alcohol tolerance of the yeast. If a yeast having better alcohol tolerance than conventional yeasts is developed, an improvement in the yield of alcohol is expected. it can. However, in fact, the development of yeast with excellent alcohol tolerance has been attempted with sake yeast, but when it is diverted to the production of shochu, conventional shochu yeast in terms of citric acid resistance and temperature characteristics is used. Inferior, not used in shochu production.

[0004]

Means for Solving the Problems The present inventors conducted a search to isolate high-alcohol-producing bacteria having a high growth rate and alcohol tolerance in an alcohol fermentation medium. In addition, alcohol-resistant Saccharomyces cerevisiae (S. cerev)
new brewer's yeast Saccharomyces cerevisiae BAW-6 (Issiae) belonging to No. 12871
It has been found that when alcohol fermentation is performed using this, the alcohol yield is significantly improved.

[0005] The present invention is based on the above-mentioned findings, and provides alcohol-containing beverages such as liquors at low cost by performing alcohol fermentation using the above-described novel brewing yeast to improve the alcohol yield. The aim is to provide a method that allows to do this.

[0006]

According to the present invention, a method for producing alcoholic beverages which achieves the above-mentioned object is to use a novel brewer's yeast Saccharomyces cerevisiae BAW-6 (Microtechnical Laboratories No. 12871) discovered by the present inventors. It is characterized in that alcohol fermentation is performed by inoculating a fermentation medium.

[0007] According to the present invention, the alcohol concentration after alcohol fermentation is higher than when conventional yeast is used, the alcohol yield is improved, and desired alcoholic beverages are produced efficiently and at a high yield. be able to.

In the present invention, alcoholic beverages are those obtained through a fermentation process using koji, malt and / or enzymatic agents, and typically include shochu, sake, beer, whiskey and the like. However, the present invention is not limited to these.

By the way, the fermentation types of alcohol fermentation include simple fermentation for producing beer, whiskey, wine and the like, and parallel double fermentation for producing sake, shochu and the like. In addition, the preparation method is a two-stage preparation (primary preparation, secondary preparation) when producing shochu, a three-stage preparation (addition, intermediate preparation, and reservation preparation) when producing sake, or beer, whiskey, and wine. And one-stage preparation for producing awamori and the like. The present invention can be applied to any of these cases, and a desired effect is exhibited.

The raw materials for alcoholic fermentation used for producing the above-mentioned alcoholic beverages according to the present invention include, for example, rice,
Examples include cereals such as barley, barley, buckwheat, barley, corn, and the like, as well as sweet potato, jujube or grape, tangerine, apple, starch, and the like. These raw materials are appropriately selected and used according to the type of alcoholic beverage to be produced. For example, in the case of producing sake, a raw material usually used for producing sake, typically, rice is used. When shochu is produced, raw materials usually used for shochu production, typically, rice, barley, rye, buckwheat, barley, corn and the like are used. In this case, an appropriate auxiliary material, for example, sweet potato, jujube, or the like can be used. When producing wine, grapes, tangerines, apples, etc., which are usually used for producing wine, are used. In the case of producing whiskey, cereals usually used for producing whiskey, typically barley, corn and the like are used. When producing beer, cereals usually used for producing beer, typically barley, are used.
In any case, when using cereals as a raw material,
The cereals may be whitened or untouched.

As described above, the present invention is effective for producing various types of alcoholic beverages, and particularly, alcoholic beverages using barley,
It is particularly effective for alcoholic beverages that produce a high concentration of alcohol.

In the present invention, when a raw material containing an enzyme is used, the raw material includes koji used in the production of sake, shochu, etc., malt used in the production of beer and whiskey. Saccharification enzymes are used when these enzyme activities are deficient. In the present invention, any raw material containing an enzyme may be used. In particular, when white koji mold is used, even if it is koji having a high acidity (eg, rice koji, barley koji, etc.) Where the novel brewer's yeast used in the invention has citric acid resistance,
The object of the present invention is achieved.

The fermentation temperature in the present invention is preferably from 10 to 40 ° C, more preferably from 15 to 35 ° C.

As described above, the present invention is effective for all types of alcohol fermentation, but particularly when koji containing citric acid is used, the difference from the case where conventional yeast is used is remarkable.

Saccharomyces cerevisiae BAW-6 used in the present invention (Microtechnical Laboratory No. 12871)
Are TTC stainability (i) and D. C. It is characterized by its dyeability (ii).

(I) TTC staining test according to the method of Furukawa and Akiyama (Toshio Furukawa, Yuichi Akiyama: 37, 398 (1963)), that is, the cells were appropriately diluted (about 200 per plate). ) On the colonies plated on the lower medium at 30 ° C for 2 days.
After dissolving the agar to about 45 ° C., gently overlay it. After hardening, leave it at 30 ° C. for 2 to 3 hours to observe the staining of the colonies. When the colony is stained, it shows pink color and (ii) the method of Mizoguchi and Fujita. (Haruhiko Mizoguchi, Eishin Fujita: Fermentation, 59, 185 (19
81)). C. Staining test, that is, the cells were appropriately diluted (to approximately 200 per plate), dissolved on a colony which was cultured in a TTC lower layer medium at 30 ° C for 2 days, and dissolved on a soft agar for upper layer at approximately 45 ° C. And then gently layer, and after hardening, leave at room temperature for 30 minutes.
When the staining of the colony is observed, it is characterized by showing a white color.

The Saccharomyces cerevisiae BAW-6 used in the present invention (Microorganisms No. 1287)
No. 1) has the mycological properties described below.

(A) Morphology of bacteria when cultured at 30 ° C. for 2 days using YM medium Size of vegetative cells: 4 to 9 μm Shape of vegetative cells: egg-shaped Growth form: budding

(B) Morphology of colonies when cultured on YM agar plate medium at 30 ° C. for 2 days: Morphology: Circular protuberance: On a convex circle Perimeter: Smooth Size (diameter): 2-3 mm Color tone: White Opaque surface: smooth and shiny

(C) Utilization of carbon source: Glucose, galactose, sucrose, D-maltose, trehalose, raffinose, inulin, mannose, ethanol, glycerol, lactic acid, citric acid, fructose and arabinose are used. Cellobiose, lactose, melibiose, melezitose, starch, α-methylglucoside, D-xylose, D-ribose, L-rhamnose, meso-erythritol, D-sorbitol,
D-mannitol, salicin, succinic acid and inositol do not assimilate.

(D) Vitamin requirement: Calcium pantothenate and biotin are required. It does not require pyridoxine, inositol or thiamine.

Saccharomyces cerevisiae BAW-6 used in the present invention (Microtechnical Laboratory No. 12871)
Is a new strain found by the present inventors. Hereinafter, the process by which the present inventors have found the new strain BAW-6 will be described.

The present inventors performed a mutagenesis treatment on Kagoshima yeast as described below in order to isolate a high alcohol-producing bacterium having a high growth rate in barley koji juice and having alcohol tolerance. Among the yeasts obtained as a result of the treatment, it has excellent alcohol tolerance, its growth ability, especially at low temperatures, stands out, and its bacteriological properties are distinctly different from conventional Kagoshima yeast. The strain of the invention was obtained.

Hereinafter, the circumstances that led to the acquisition of the novel strain of the present invention will be described.

1. Mutation treatment and acquisition of useful yeast

[Mutation treatment] One platinum loop of commercially available Kagoshima yeast (Ko) was inoculated into 2 ml of YPD medium and cultured with shaking at 30 ° C overnight, and the obtained cells were added to 10 ml of YPD medium.
Inoculate 00 μl, perform shaking culture at 30 ° C. overnight, collect cells in the logarithmic growth phase (4 to 10 × 10 ⁷ cells / ml) by centrifugation, and wash twice with the same amount of sterile water. did.
The washed cells were placed in a 0.1 M phosphate buffer (pH 7.
0) Suspended in 10 ml, EMS (ethyl meth
anesulfonate) 0.3 ml, add 30 ml
Mutation treatment was performed by gently shaking at a liquid temperature of 40 ° C. for 40 minutes.

[Acquisition of useful yeast] The cells subjected to the mutation treatment are centrifuged, and the collected cells are washed once with 10 ml of a 5% sodium thiosulfate solution and twice with sterile water, and then with 10 ml of sterile water. Suspended in water. 400 μl of the resulting suspension
[Including about 2 × 10 ⁷ viable cells. The number of the cells was 10 m of cells having a survival rate of 50% by the EMS treatment.
400 μl of l suspension (2-5 × 10 ⁸ cells)
(0.4 / 10). Was introduced into 10 ml of Bllg ° 8 10 ml barley koji containing 8% alcohol and cultured at 30 ° C. for 7 days. The obtained culture was diluted with sterile water to 10 ³ , 1 ml of the culture was embedded in a YPD agar medium, cultured at 30 ° C. for 3 to 4 days, and 43 colonies that appeared were picked on a YPD slant medium. Next, the obtained fishing strain was cultured in 10 ml of YPD medium at 30 ° C. for 2 days, and 100 μl of the suspension was added to Bllg containing 9% alcohol.
Cultivation was carried out at 30 ° C. for 7 days in 10 ml of barley koji juice at 9 ° C. The same procedure was repeated to isolate 28 strains of colonies, which were further repeated in the same manner as described above using 10 ml of barley koji juice containing 10% alcohol at Bllg ° 10. Ten strains of yeast having resistance were obtained. Furthermore, a fermentation ability test was performed using these strains, and three strains having the best growth, fermentation ability, and alcohol tolerance were obtained. The temperature suitability of these three strains was examined, and the strain (BA
W-6) was isolated.

2. Bacteriological properties The strain BAW-6 isolated in the above (1) was obtained from both the parent strain Kagoshima yeast (Ko), the Miyazaki yeast (MK) known as yeast for shochu, and the association shochu yeast SH-4. To determine if they are distinct,
Observations were made on mycological properties (morphological and physiological properties).

2- (1). Morphological properties Using YM medium, K o, MK, SH-4 and BAW-6
Of each of the four yeasts at 30 ° C. for 2 days
After cultivation, the obtained product was observed with an optical microscope. View
The findings are summarized in Table 1. As is clear from Table 1
In addition, all vegetative cells are 4-8 μm in size and oval
Met. And, on YM agar medium, any strain
A lustrous white colony was formed.

2- (2). Physiological properties

A. Carbon source utilization was tested by the replica method using a solid medium. sand
About 1 liter of medium for carbon source utilization test manufactured by Wachi Bact
One carbon compound each (glucose, galacto
Each yeast on agar plate with 10g dissolved
Cells were inoculated (stamped) and assimilation was observed. Table 2
The results of carbon source utilization were shown. Association Shochu yeast SH-4,
It did not change much between BAW-6. Kagoshima yeast
Mother (K In o), there was no assimilation of ethanol. Also deer
Kojima yeast (K o) and Miyazaki yeast (MK) assimilate citric acid
Did not.

B. Vitamin Requirement Nakata et al.'S method (Kubo Nakata, Ken Hosaka, Satoshi Sakai: Fermentation, 6)
3,509 (1985)). sand
Wachi Bacto's liquid culture medium for vitamin requirement test 11
About calcium pantothenate 2mg, pyridoxine 4
00 μg, biotin 200 μg, inositol 10 m
g and thiamine 400 μg of vitamin were removed respectively.
Omit method, K o, MK, SH-4 and BAW-6
A diluted suspension of the washed cells of the four yeasts was added to 8 × 10⁸cel
1 / ml, inoculated at 30 ° C for 7 days,
Vitamin requirements were observed. Table 3 shows the view on vitamin requirement.
The result of the observation was shown. Miyazaki yeast (MK) is the key to thiamine
Kagoshima yeast (K o), SH-4, BA
There was no for W-6. Other vitamin requirements
Was almost the same for all four yeasts.

C. TTC dyeing method Furukawa, Akiyama method (Toshio Furukawa, Yuichi Akiyama: Agriculture, 37,
398 (1963)). That is, K
o, four types of yeasts, MK, SH-4 and BAW-6
Dilute each cell appropriately (about 200 per plate)
Plate culture at 30 ° C for 2 days
After dissolving TTC agar on the colonies
And then gently layer, and after setting, release at 30 ° C for 2-3 hours.
The colony was observed for staining. Table 1 shows TTC dyeing
The results of observation of the color were shown. Clear from the results shown in Table 1
Like, Kagoshima yeast (K o), SH-4 and BAW-
6 was pink, but Miyazaki yeast (MK) was red.
Met.

D. D. C. Dyeability Mizoguchi, Fujita's method (Haruhiko Mizoguchi, Eishin Fujita: Fermentation, 59,
185 (1981)). That is, K
o, four types of yeasts, MK, SH-4 and BAW-6
Dilute each cell appropriately (about 200 per plate)
), Play on TTC underlayer medium at 30 ° C for 2 days
After dissolving the soft agar for the upper layer on the colony
Approximately, layer gently and allow to set to room temperature for 30 minutes
The colony was left to observe the state of staining of the colony. Table 1 shows D.
C. The results of observation of the dyeability were shown. From the results shown in Table 1
As is evident, Kagoshima yeast (K o) and SH-4 are tea
However, Miyazaki yeast (MK) and BAW-6 were white.
Was.

E. Formation of ascospores (Takeshi Hasegawa, ed .: Classification and identification of microorganisms (1), 170)
(1984) Academic Publishing Center)
K o, MK, SH-4 and BAW-6
For each, form ascospores on potassium acetate medium
After that, the cells were stained and observed under a microscope. Observed in Table 4
The results showed the formation rate of ascospores. Results shown in Table 4
As is evident from the above, Miyazaki yeast (MK) has poor sporulation.
In addition, the sporulation rate of SH-4 was slightly low at 74.1%.
Was. In addition, Kagoshima yeast (K o) and BAW-6
Their sporulation rates were 86.5% and 83.3%, respectively.
And it was high.

From the above observation results of mycological properties, the following
It turns out. That is, this bacterium, that is, BAW-6,
Kagoshima yeast (K o) is Ethanor
About Miyazaki Yeast (MK)
About sake yeast and wine yeast (Kubo Nakata, Hosaka
Ken, Sakai Tetsu: Fermentation, 63, 509 (1985)
This is different from meleptose and α-methylglucoside.
(B) Regarding vitamin requirement, Miyazaki yeast
(MK) means thiamine, sake yeast (Kubo Nakada,
Ken Hosaka, Satoshi Sakai: About Fermentation, 63, 509 (1985)
Different for pantothenic acid, biotin; (c)
TTC stainability and D.I. C. About the dyeability, Kagoshima yeast
(K o) and SH-4. C. Stainability, Miyazaki yeast
(MK) is different in TTC staining property. Further these genders
The quality is maintained even after 20 passages of subculture.
This is a unique property of bacteria, that is, BAW-6. Therefore, this fungus
That is, BAW-6 is objectively distinguished from conventional yeast.
It was found that these were new bacteria.
The strain was identified, and this strain was named BAW-6. This strain is
On March 12, 1992, the Institute of Microbial Industry and Technology, National Institute of Advanced Industrial Science and Technology
Deposit No. 12871
Was.

3. Proliferation test in barley koji medium Medium similar to 100 ml of barley koji medium of Bllg ° 8
Kagoshima yeast (K o) and BA
2 ml each of W-6 was inoculated. Culture at 30 ° C after inoculation
OD every other hour₆₆₀It was measured. In this way,
Breeding test, the maximum specific growth rate μ_maxAre each
0.658 and 0.684. BAW-6 is the parent strain
Kagoshima yeast (K Proliferation in barley koji juice is better than in o)
It was quick.

4. Proliferation test at low temperature K o, MK, SH-4 and BAW-6
For each, a growth test at low temperature was performed as follows.
Test was carried out. That is, 2 ml of YPD medium at 30 ° C. for 2 days
Each yeast culture solution that had been cultured for 10 minutes was added to 10 ml of YPD medium.
Inoculate 0 μl and shake culture at 10 ° C after inoculation.
Photo Recorder TC-106 (Advantech Toyo Co., Ltd.)
OD at regular time intervals₆₆₀Was measured. this
Table 5 shows the results of the proliferation test. Table 5
From the results shown in Table 2, the maximum specific growth rate μ at 10 ° C.
_maxIndicates that BAW-6 is higher than other typical shochu yeasts.
I knew it.

5. Comparison of alcohol tolerance K o, MK, SH-4 and BAW-6
For each, adjust alcohol tolerance as follows:
Solid. That is, cultivation in 10 ml of YPD medium at 30 ° C. for 2 days.
Each of the washed yeast washed cells was dissolved in 8 to 14% ethanol,
Course 1%, 0.1 M acetate buffer (pH 4.3) 6 ml
Suspend in autoclave for 3 days at 30 ° C.
It was measured. Table 6 shows the results. Results shown in Table 6
From, the survival rate of BAW-6 at ethanol concentration of 8%,
Kagoshima yeast (K Approximately 15 times the ethanol concentration compared to o)
At 11%, it is about 5.5 times that of SH-4
understood.

6. Comparison of alcohol productivity The alcohol productivity of each of the four yeasts Ko, MK, SH-4 and BAW-6 was examined as follows. That is, each yeast-washed cell cultivated in 10 ml of YPD medium at 30 ° C. for 2 days is suspended in 10 ml of sterilized water, and B
Inoculate 1 ml at a time into 100 ml of barley koji juice of
After static culture at 0 ° C. for 2 days, 4 g of glucose was added, and after further culturing for 2 days, 4 g of glucose was added and cultured for 2 days. Then, the concentration of alcohol and the concentration of residual glucose in the culture solution were measured. Table 7 shows the results. From the results shown in Table 7, it was found that BAW-6 had higher alcohol productivity than any of the other shochu yeasts.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

[Table 3]

[0044]

[Table 4]

[0045]

[Table 5]

[0046]

[Table 6]

[0047]

[Table 7]

[0048]

The contents of the present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Example 1 and Comparative Examples 1 and 2

[0050]

Example 1 Saccharomyces cerevisiae BAW-6
Was used to produce barley shochu. The charging ratio was as shown in Table 8. Barley (70% refined) was used as a raw material. The primary preparation was fermented for 5 days using barley koji (300 g as barley), water (360 ml) and yeast produced by the method described below. The secondary charge is 1
1140 ml of water and steamed barley (700 g as barley) were added to the mash produced in the next preparation, and fermented for 12 to 20 days.

For the production of koji, barley was made to absorb 40% (W / W), steamed for 40 minutes, allowed to cool to 40 ° C., inoculated with 1 g of seed koji (white koji mold) per kg of barley, and , RH95
% For 24 hours, 32 ° C., RH 92% for 20 hours. Steamed barley was made to absorb 40% (W / W) of barley, steamed for 40 minutes, allowed to cool to 40 ° C., and added to the primary preparation. The yeast was pre-cultured in 10 ml of 2% YPD medium, and 2 × 10 ⁹ were added to the primary preparation. Fermentation temperature is 2 for both primary and secondary
5 ° C. Thus, barley shochu was produced. The progress of the fermentation at that time was examined by measuring the weight including the charging vessel every day to determine the amount of reduction in carbon dioxide gas. In addition, the alcohol concentration after the fermentation was examined by the flotation method in accordance with the comment provided by the National Tax Agency. Furthermore, the alcohol yield per ton of raw material was determined by dividing the pure alcohol calculated by multiplying the mash capacity and the alcohol concentration by the amount of raw material used.

In addition, the above-mentioned technique was separately applied to a fermentation temperature of 15
The barley shochu was produced by repeating at a constant temperature of ° C.

Comparative Example 1-a Barley shochu was produced in the same manner as in Example 1 except that Kagoshima yeast was used as the brewing yeast. The progress of the fermentation at that time was examined in the same manner as in Example 1. Further, the alcohol concentration after completion of fermentation and the yield of alcohol per ton of raw material were determined by the same method as in Example 1.

Comparative Example 1-b Barley shochu was produced in the same manner as in Example 1 except that Miyazaki yeast was used as the brewing yeast. The progress of the fermentation at that time was examined in the same manner as in Example 1. Further, the alcohol concentration after completion of fermentation and the yield of alcohol per ton of raw material were determined by the same method as in Example 1.

Evaluation The fermentation processes examined in Example 1 and Comparative Examples 1-a and 1-b are collectively shown in FIGS. 1 and 2 as graphs. Table 9 shows the alcohol concentration after completion of fermentation and the yield of alcohol per ton of raw material in Example 1 and Comparative Examples 1-a and 1-b, respectively.

From the results shown in FIGS. 1 and 2, the following was found. That is, the yeast Saccharomyces cerevisiae BAW-6 used in the present invention is fermented at a fermentation temperature of 25 ° C. faster than Kagoshima yeast and Miyazaki yeast, and the yeast of the present invention ferments smoothly even at a fermentation temperature of 15 ° C. The difference from Miyazaki yeast is even more remarkable than 25 ° C and is excellent even at low temperatures. In addition, the following was found from the results shown in Table 9. That is, in the case of the present invention using Saccharomyces cerevisiae BAW-6, the alcohol yield is 446 liters at a fermentation temperature of 25 ° C., an increase of 5% or more compared to 421 to 425 liters when Kagoshima yeast and Miyazaki yeast are used. ,
The alcohol yield is clearly improved. At a fermentation temperature of 15 ° C., in the present invention, the alcohol yield was 395
1, 378 to 370 l when Kagoshima yeast and Miyazaki yeast are used, increasing by 4.5 to 6.8%,
The alcohol yield obviously increases.

Example 2, Comparative Examples 3 and 4

[0058]

Example 2 Saccharomyces cerevisiae BAW-6
Was used to produce rice shochu. Table 1 shows the ratio of preparation
0. Milled rice (70% milled) was used as a raw material. The primary preparation was fermented for 5 days using rice koji (300 g as raw rice), water (360 ml) and yeast produced by the method described below. In the secondary preparation, 1140 ml of water and steamed rice (700 g as a raw material) were added to the mash produced in the primary preparation, and fermented for 12 to 17 days.

For the production of koji, rice was absorbed by 35% (W / W), steamed for 40 minutes, allowed to cool to 40 ° C., inoculated with 1 g of white koji mold per kg of rice, and incubated at 38 ° C. and RH 95%. Performed for 24 hours at 32 ° C. and RH 92% for 20 hours. Steamed rice absorbs 35% (W / W) of rice and steams for 40 minutes.
After cooling to ℃, it was added to the primary charge. Yeast is 2% YPD
Preculture was performed in 10 ml of the medium, and 2 × 10 ⁹ cells were added to the primary preparation. The fermentation temperature was 25 ° C. for both primary and secondary. The progress of the fermentation at that time was examined by measuring the weight including the charging vessel every day to determine the amount of reduction in carbon dioxide gas. In addition, the alcohol concentration after the fermentation was examined by the flotation method in accordance with the comment provided by the National Tax Agency. Furthermore, the alcohol yield per ton of raw material was determined by dividing the pure alcohol calculated by multiplying the mash capacity and the alcohol concentration by the amount of raw material used.

In addition, the above-mentioned technique was separately applied to a fermentation temperature of 15
It was operated at a constant temperature of ℃ to produce rice shochu.

Comparative Example 2-a Rice shochu was produced in the same manner as in Example 2 except that Kagoshima yeast was used as the brewing yeast. The progress of fermentation at that time was examined in the same manner as in Example 2. Further, the alcohol concentration after the fermentation was completed and the alcohol yield per ton of raw material were determined by the same method as in Example 2.

Comparative Example 2-b Rice shochu was produced in the same manner as in Example 2 except that Miyazaki yeast was used as the yeast for brewing. The progress of fermentation at that time was examined in the same manner as in Example 2. Further, the alcohol concentration after the fermentation was completed and the alcohol yield per ton of raw material were determined by the same method as in Example 2.

Evaluation The fermentation processes examined in Example 2 and Comparative Examples 2-a and 2-b are shown in FIGS. 3 and 4 in a graph. Table 9 summarizes the alcohol concentration after completion of fermentation and the yield of alcohol per ton of raw material in Example 2 and Comparative Examples 2-a and 2-b.

The following was found from the results shown in FIGS. That is, similar to the case of producing barley shochu, Saccharomyces cerevisiae BA used in the present invention is used.
In the case of W-6, the fermentation proceeds remarkably fast, and the speed is clearly higher than when using Kagoshima yeast or Miyazaki yeast. In addition, as is apparent from the results shown in Table 9, 25
The yield of alcohol at the fermentation temperature of ° C. is 467 l in the case of the embodiment of the present invention using Saccharomyces cerevisiae BAW-6, which is 3 to 4 compared to 453 to 448 l when using Kagoshima yeast and Miyazaki yeast. % Or more, and the alcohol yield clearly increases. Similarly, 1
The yield of alcohol at a fermentation temperature of 5 ° C. is 444 l in the case of the example of the present invention, which is 4.5 to 6.8% as compared with 421 to 416 l when Kagoshima yeast and Miyazaki yeast are used.
Increase, and the alcohol acquisition clearly increases.

[0065]

Example 3 Saccharomyces cerevisiae BAW-6
Was used to produce sake. The charging ratio was as shown in Table 11. Milled rice (70% milled) was used as a raw material. That is, the addition was performed using steamed rice (630 g as raw rice) and rice koji (270 g as raw material), 1080 ml of water, 5.4 ml of yeast and lactic acid for rot prevention for 15 days for 2 days.
Fermented at 0 ° C. In the intermediate preparation, steamed rice (1400g as raw rice) and rice koji (40 as raw rice)
0g) was added with 2250 ml of water and fermented at 13 ° C for 1 day. As for the preparation, steamed rice (1970 g as raw rice) and rice koji (530 g as raw rice) are added to the moromi mash and water 3.
Add 430 ml and charge at 12 ° C.
The product temperature was increased, and after 7 days, the temperature was decreased to 1 ° C. in steps of 1 ° C. and fermented for 20 days. Koji production is 35 rice
% (W / W), steamed for 40 minutes, allowed to cool to 40 ° C., inoculated with 1 g of seed koji (Koji mold) per kg of rice,
The reaction was performed at 32 ° C., RH 95% for 21 hours, 35 ° C., RH 92% for 8 hours, and 39 ° C. for 13 hours. Steamed rice is 35% rice
(W / W) After absorbing water and steaming for 30 minutes, the mixture was allowed to cool to 40 ° C. and added to each preparation. Yeast is 10% 2% YPD medium
and 2 × 10 ⁹ cells were added to the primary preparation.
The fermentation temperature was 25 ° C. for both primary and secondary. The progress of fermentation at that time was examined in the same manner as in Example 1. In addition, the sake degree, acidity and amino acid degree were analyzed and examined in accordance with the analysis method prescribed by the National Tax Agency. Table 1 shows the obtained analysis results.
2 together.

As is clear from the results shown in Table 12,
The alcohol concentration was 18.1%. The alcohol yield was 382 l.

As is apparent from the above description, according to the present invention using the above-described novel brewer's yeast, namely, Saccharomyces cerevisiae BAW-6 (Microtechnical Laboratory No. 12871), a conventional shochu is used. Even at a lower fermentation temperature than in the case of the production method, the yield of alcohol per ton of raw material is improved, and alcoholic beverages can be produced at low cost. Also, in sake brewing, alcohol fermentation can be performed even at a sufficiently low temperature to obtain a high concentration of alcohol.

[0068]

[Table 8]

[0069]

[Table 9]

[0070]

[Table 10]

[0071]

[Table 11] Note: 5.4 ml of lactic acid was added to the pumped water.

[0072]

[Table 12]

[0073]

SUMMARY OF THE INVENTION A novel brewer's yeast, namely Saccharomyces cerevisiae BAW-6 (Microtechnical Lab.
No. 871) can improve the yield of alcohol per ton of raw material even at a lower fermentation temperature than in conventional shochu production, and can produce alcoholic beverages at low cost. Also, in sake brewing, alcohol fermentation can be performed even at a sufficiently low temperature to obtain a high concentration of alcohol.

[Brief description of the drawings]

FIG. 1 is a fermentation curve showing the fermentation state in the production of barley shochu at a fermentation temperature of 25 ° C.

FIG. 2 is a fermentation curve showing a fermentation state in production of barley shochu at a fermentation temperature of 15 ° C.

FIG. 3 is a fermentation curve showing a fermentation state in the production of rice shochu at a fermentation temperature of 25 ° C.

FIG. 4 is a fermentation curve showing a fermentation state in the production of rice shochu at a fermentation temperature of 15 ° C.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication (C12N 1/16 C12R 1: 865)

Claims (2)

(57) [Claims] 1. Saccharomyces cerevisiae BAW-
6. A method for producing alcoholic beverages, comprising inoculating a medium for alcohol fermentation with No. 6 (Microtechnical Laboratory No. 12871) and performing alcohol fermentation. 2. The method for producing liquor according to claim 1, wherein the fermentation is performed at a temperature of 10 to 40 ° C.