Strain of saccharomycopsis fibuligera SF2312 with high yield of saccharifying enzyme and liquefying enzyme and application thereof

Abstract

The invention discloses saccharomycopsis fibuligera SF2312 with high yield of saccharifying enzyme and liquefying enzyme and application of the saccharomycopsis fibuligera SF2312, and belongs to the technical field of fermentation engineering. The saccharomycopsis fibuligera SF2312 is preserved in the Guangdong Province Microbial Culture Collection Center, and the preservation number of the saccharomycopsis fibuligera SF2312 is GDMCC No: 66046. The saccharifying enzyme activity of the saccharomycopsis fibuligera SF2312 is 380-400U / mg, and the liquefying enzyme activity of the saccharomycopsis fibuligera SF2312 is 4.5-5U / mg, which are obviously higher than those of the existing strain. The single-strain Chinese yeast is prepared and applied to brewing of food such as yellow wine, sweet fermented grains and fermented bean curd, infectious microbe pollution can be effectively avoided, enzyme activity and flavor substance content are improved, the production period is shortened, and physical and chemical indexes of the sweet fermented grains and the fermented bean curd are superior to those of the traditional method. The invention provides an efficient and stable solution for industrial production of fermented food.

Description

Technical Field

[0001] The present invention relates to the technical field of fermentation engineering, in particular to a high-yielding saccharifying enzyme and liquefying enzyme yeast strain SF2312 and its application. Background Art

[0002] Huangjiu (yellow rice wine) is one of the three oldest alcoholic beverages in the world (along with wine, beer, and yellow rice wine). It is widely popular for its high nutritional value and unique flavor. Hakka yellow rice wine is a key branch of yellow rice wine. Its brewing process primarily uses red yeast rice, yeast, and wheat koji as fermentation agents. "Koji is the backbone of wine," and the diverse microorganisms and rich enzyme systems in koji accelerate the breakdown of starch and protein in the grains, determining the wine's fundamental properties and quality.

[0003] Yeast yeast, also known as Xiaoqu or Baiyao, is a crucial leavening agent in the brewing of Hakka rice wine, performing the dual functions of saccharification and fermentation. In the traditional Hakka rice wine yeast production process, empirical production management and prolonged open fermentation environments compromise the yeast's quality stability and make it more susceptible to contamination by bacteria. Microorganisms within the yeast yeast play a key regulatory role in the fermentation process of Hakka rice wine. Research has shown that Saccharomyces cerevisiae is the dominant microorganism in the Hakka rice wine brewing process and is closely associated with the production of fermentation flavor compounds. Therefore, a strain of Saccharomyces cerevisiae that produces high levels of saccharifying and liquefying enzymes was isolated and screened, leading to the development of a yeast yeast with Saccharomyces cerevisiae as its core microorganism. This yeast yeast, which is now used in the brewing of Hakka rice wine, is of great value in improving the quality of Hakka rice wine. Summary of the Invention

[0004] The present invention aims to provide a strain of Yeast SF2312, which produces high levels of saccharifying and liquefying enzymes, and its use to address the problems of the prior art. The strain SF2312, screened and obtained in the present invention, has outstanding saccharifying and liquefying enzyme production capabilities. The yeast fermented with this strain exhibits significant advantages in the production of fermented foods such as yellow rice wine, sweet mash, and fermented bean curd.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The invention provides a Saccharomycopsis fibuligera SF2312 with high saccharification and liquefaction enzyme production, which is deposited in Guangdong Provincial Microbial Culture Collection Center with a deposit number of GDMCC No: 66046.

[0007] The present invention also provides a microbial agent containing the capsule-forming yeast SF2312 or its fermentation liquid.

[0008] The present invention also provides a single-strain yeast for wine brewing, the preparation method of which comprises the following steps:

[0009] The fermentation seed liquid of the capsule-coated yeast strain SF2312 is mixed with sterile water, and then added with a fermentation matrix and mixed to form the mixture. After fermentation and cultivation, the single-strain wine yeast is obtained.

[0010] The bacterial concentration of the fermentation seed liquid is 10 6 CFU / mL.

[0011] The preparation method of the fermentation seed liquid is as follows: the strain is streaked onto a YPD agar plate under a sterile condition and cultured at 30°C for 36-48 hours to grow a single colony, a single colony is picked and inoculated into a YPD liquid medium for activation and subculture, and the culture is carried out at 30°C in a constant temperature shaker at 170 rpm for 48 hours, and then inoculated into 50 mL YPD liquid medium at a 1% (v / v) inoculum to activate again, and cultured under the same conditions for 12 hours to prepare the seed liquid. The bacterial liquid concentration reaches 10 6 CFU / mL.

[0012] Furthermore, the fermentation temperature is 30°C.

[0013] Furthermore, the volume ratio of the fermentation seed liquid to the sterile water is 1:2; the volume / mass ratio of the fermentation seed liquid to the fermentation substrate is 1:5.

[0014] Furthermore, the fermentation matrix includes indica rice flour and hot polygonum tiliaceum powder; the mass ratio of the indica rice flour to the hot polygonum tiliaceum is 200:1.

[0015] The present invention also provides the use of the Hakka yellow wine single-strain yeast in the preparation of yellow wine, white wine, rice wine, soy sauce, vinegar, fermented bean curd or sweet mash.

[0016] The present invention also provides the use of the capsule-coated yeast SF2312, the microbial agent or the single-strain yeast for wine making in the preparation of fermented foods, wherein the fermented foods include alcohol products, soy products, fermented vegetables or condiments.

[0017] The present invention also provides the use of the capsule-coated yeast SF2312 or the microbial agent in improving the saccharification and liquefaction power of the yeast for wine.

[0018] The present invention discloses the following technical effects:

[0019] The present invention screened and isolated a strain of saccharomyces SF2312 from yeast for making rice wine. The yeast is a native yeast for making rice wine with good saccharifying and liquefying enzymes, and has great potential in improving the saccharifying and liquefying power of yeast for making rice wine and enhancing its flavor. The saccharifying and liquefying yeast SF2312 has outstanding saccharifying and liquefying enzyme production capabilities. The yeast for making rice wine prepared from this single strain shows significant advantages in the brewing of fermented foods such as rice wine, sweet mash, and fermented bean curd: the saccharifying power reaches 380-400U / mg, and the liquefying power is 1.8-2.0U / mg, which are higher than those of existing strains. The present invention solves the problems of contamination of traditional yeast for making rice wine with foreign bacteria and uneven quality through a single strain fermentation process, ensuring the quality uniformity and batch stability of the yeast for making rice wine. The yeast for making rice wine prepared from this single strain can increase the alcohol content and amino nitrogen content of rice wine, and the indicators such as amino acid nitrogen and total sugar of sweet mash and fermented bean curd meet industry standards. In addition, this method simplifies the process flow, achieves stable production throughout the year, and has broad prospects for industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 The starch degradation ability of different strains in liquid fermentation;

[0022] Figure 2 The starch degradation ability of different strains in solid-state fermentation;

[0023] Figure 3 This is the phylogenetic tree of the yeast SF2312 based on the complete ITS sequence. DETAILED DESCRIPTION

[0024] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0025] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0026] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0027] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0028] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0029] YPD medium formula: yeast extract 5 g, tryptone 10 g, anhydrous glucose 20 g, distilled water 1000 mL (solid medium plus agar 18 g / L), natural pH, autoclave at 121 °C for 15 min.

[0030] Liquid fermentation medium: yeast extract 5 g, peptone 10 g, soluble starch 10 g, sodium chloride 1.0 g, magnesium sulfate 0.1 g, potassium dihydrogen phosphate 0.5 g, calcium chloride 0.05 g, distilled water 1000 mL, natural pH, sterilize at 115 °C for 20 min.

[0031] Solid fermentation medium: 20 g wheat bran, 12 mL distilled water, natural pH, sterilized at 121 °C for 40 min.

[0032] Culture medium for screening amylase-producing bacteria: 5 g beef extract, 5 g NaCl, 10 g peptone, 2 g soluble starch, 20 g agar, 1000 mL distilled water; sterilization: 121°C, 15 min.

[0033] Iodine solution: Weigh 3.6 g of potassium iodide and dissolve it in 20 mL of water. Add 1.3 g of iodine and dilute to 100 mL with water after dissolution.

[0034] The saccharifying capacity and liquefying capacity are determined by the conventional iodine titration and colorimetry methods in the art, respectively.

[0035] Example 1 Isolation, screening and identification of strains

[0036] 1. Processing of yeast samples

[0037] Weigh 10 g of yeast for brewing wine (purchased from the market in Yuancheng District, Heyuan City, Guangdong Province in December 2023) and put it into a conical flask filled with 90 mL of sterile water. Shake it at 30 ° C and 170 r / min for 15 min. Draw 10 mL of dilution solution each time for gradient dilution. Draw 10 mL of dilution solution at a time. -3 ~10 -5 Spread 200 μL of the diluted solution on a YPD agar plate, with three plates in parallel for one dilution gradient. Incubate the plate at 30°C for 36-48 hours.

[0038] 2. Morphological identification of strains

[0039] Multiple colonies were selected from the plate, and morphological observation of one colony revealed a fuzzy, round, white, dry, opaque colony with hyphae on the surface and edges. The colony was tightly bound to the culture medium, making it difficult to pick. The selected colony was streaked onto a YPD agar plate, and the cell morphology of the strain was examined under a light microscope. Comparison revealed that the strain was tentatively identified as Yeast of the genus Saccharomyces cerevisiae and was stored in a -80°C freezer with glycerol.

[0040] 3. Initial screening of the strain's amylase-producing transparent zone

[0041] Multiple preserved strains of Yeast were inoculated onto the culture medium for screening amylase-producing bacteria using a sterile 200 μL pipette tip. After culturing in a 30°C incubator for 1 day, the colony diameter Dc was measured. After pouring dilute iodine solution into the culture dish, the diameter of the transparent zone Dh was measured. Nine strains with a larger Dh / Dc ratio were selected for rescreening.

[0042] 4. Rescreening of solid and liquid fermentation enzyme activity of the strain

[0043] Preparation of fermentation seed liquid: The strain initially screened by the transparent circle was inoculated into YPD liquid culture medium under sterile conditions for activation and subculture. After culturing at 170 rpm at 30°C for 2 days, it was inoculated into 50 mL YPD liquid culture medium with a 1% (v / v) inoculation amount and cultured under the same conditions for 12 hours as the seed liquid.

[0044] Solid-state fermentation conditions: Inoculate 5% (v / w) seed solution into solid medium, mix thoroughly with a sterilized spatula, and incubate in an incubator at 30°C for 3 days. Shake the flasks for the first time after 12 hours, then perform a flask culture after 24 hours, and then a horizontal flask culture after 36 hours.

[0045] Liquid fermentation conditions: The seed liquid was inoculated into the liquid fermentation medium at an inoculum rate of 2% (v / v), and the culture medium was shaken at a constant temperature of 30°C at 170 rpm for 48 h.

[0046] 5. Determination of enzyme activity in rescreening

[0047] Solid-state fermentation: Weigh 1.00 g of bran, place it in a 50 mL centrifuge tube sterilized by high-pressure steam, add 18 mL of deionized water and 2 mL of acetic acid-sodium acetate buffer solution (pH 4.6), and extract in a constant temperature water bath at 40°C for 1 hour. Centrifuge the extract at 5000 r / min and 4°C for 10 minutes. The supernatant is the crude enzyme solution, and the saccharification enzyme and liquefaction enzyme activities of the enzyme-producing strains to be tested (named SF2309, SF2328, SF2322, SF2321, SF2326, SF2312, SF2313, SF2311 and SF2327) are respectively determined.

[0048] Liquid fermentation: The liquid fermentation broth was centrifuged at 5000 r / min for 10 min at 4°C, and the supernatant was used as the crude enzyme solution to be tested. The saccharification enzyme and liquefaction enzyme activities of the enzyme-producing strains to be tested (named SF2309, SF2328, SF2322, SF2321, SF2326, SF2312, SF2313, SF2311 and SF2327) were respectively determined.

[0049] The screening results of enzyme activities of each strain in solid-state fermentation and liquid fermentation are detailed in Figure 1 and Figure 2 It can be seen that the strain SF2312 has the best comprehensive activity of saccharifying enzyme and liquefying enzyme.

[0050] 6. ITS identification of strains

[0051] The template DNA of the preferred strain SF2312 (nucleotide sequence shown in SEQ ID NO. 1) was extracted using the Yeast Genomic DNA Rapid Extraction Kit of Sangon Biotech (Shanghai) Co., Ltd., and PCR amplification was performed using universal primers ITS1 (SEQ ID NO. 2) and ITS4 (SEQ ID NO. 3). The sequence of the amplified product was determined, and the result was compared with the sequence of the model strain in the NCBI database, and a phylogenetic tree was constructed (see Figure 1). Figure 3 ).

[0052] SEQ ID NO.1:

[0053] ;

[0054] SEQ ID NO.2:

[0055] 5'-TCCGTAGGTGAACCTGCGG-3';

[0056] SEQ ID NO.3:

[0057] 5'-TCCTCCGCTTATTGATATGC-3'。

[0058] The results showed that the strain belonged to Saccharomycopsis fibuligera, and was named Saccharomycopsis fibuligera SF2312. The Saccharomycopsis fibuligera SF2312 was deposited in the Guangdong Provincial Microbial Culture Collection on March 24, 2025, with the collection number GDMCC No: 66046. The collection address is the Institute of Microbiology, Guangdong Academy of Sciences, 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou.

[0059] Example 2 Preparation of single strain yeast for wine brewing using the capsule-coated yeast SF2312

[0060] A method for preparing a single-strain wine yeast:

[0061] (1) Preparation of fermentation seed liquid: Streak the yeast SF2312 from a cryopreserved tube onto a YPD agar plate and culture at 30°C for 48 h. Pick a single colony and inoculate it into 50 mL YPD liquid medium for activation and subculture. Culture it in a constant temperature shaker at 30°C and 170 rpm for 2 days. Then, inoculate it into a new 50 mL YPD liquid medium at a 1% (v / v) inoculum and culture it under the same conditions for 12 h to prepare the fermentation seed liquid.

[0062] (2) Sterilization of tap water: Sterilize sufficient tap water by moist heat at 121°C for 15 minutes;

[0063] (3) Preparation of indica rice flour: Select early indica rice, remove impurities, grind it with a grinder, pass it through a 50-mesh sieve, and cool it to room temperature for later use;

[0064] (4) Preparation of Polygonum hydropiper powder: Polygonum hydropiper was selected, impurities were removed, and then crushed with a grinder and passed through a 50-mesh sieve to prepare Polygonum hydropiper powder;

[0065] (5) Mixing powder: Mix the crushed indica rice flour and Polygonum hydropiper powder in a mass ratio of 200:1 to obtain a powder pile. Mix the powder pile thoroughly, mix clean water and fermented seed liquid in a volume ratio of 1:2, and pour it into the powder pile (the addition ratio of clean water, fermented seed liquid and powder pile is 1:2:5) to obtain a uniform mixture;

[0066] The specific method for preparing the fermentation seed liquid of the saccharomyces clavatus SF2312 is as follows: the strain is streaked onto a YPD agar plate under a sterile condition and cultured at 30°C for 36-48 hours to grow a single colony, a single colony is picked and inoculated into a YPD liquid medium for activation and subculture, and then cultured at 30°C in a constant temperature shaker at 170 rpm for 48 hours, and then inoculated into 50 mL YPD liquid medium at a 1% (v / v) inoculum for reactivation, and cultured under the same conditions for 12 hours as a seed liquid. The bacterial liquid concentration reaches 10 6 CFU / mL;

[0067] (6) Pile powder: Use heavy objects to beat the mixture to enhance the viscosity and plasticity of the mixture, making it easier to shape the wine pills;

[0068] (7) Cutting and picking yeast: Use a knife to cut the yeast into blocks with a side length of about 2 cm. Separate the cut yeast one by one and roll them into balls;

[0069] (8) Transfer the balled yeast into a 30 cm diameter round bamboo dustpan, with a spacing of at least 3 cm between the yeast balls. After placing the yeast balls, cover them with 4 layers of wet gauze. Then put the whole plate of yeast into a 40 × 40 cm fresh-keeping bag and seal it. Poke a small hole every 6 cm in the fresh-keeping bag to keep it moist and allow air to flow for the growth of the strain.

[0070] (9) Fermentation: Place the prepared yeast in a constant temperature incubator and incubate at 30°C for 3 days;

[0071] (10) Drying: After the yeast culture is completed, open the fresh-keeping bag and gauze, dry it at 30°C for 4 days, and store it at 4°C to obtain a single-strain yeast.

[0072] The saccharification power, liquefaction and protease activity of the single-strain yeast for wine brewing prepared above were measured and counted multiple times. The results showed that the saccharification power of the single-strain yeast for wine brewing obtained was 380-400 (U / mg), the liquefaction was 4.5-5 (U / mg), and the protease activity was 3-3.5 (U / mg). In addition, the enzyme activity of this strain was higher than that of the currently reported saccharomyces cerevisiae C-3 (see patent CN116515651A for details) and saccharomyces cerevisiae ZLCY-93 (see patent CN117264790A for details). This shows that the saccharomyces cerevisiae SF2312 obtained by screening and separation of the present invention has a rich enzyme system and high enzyme activity. It has a good degradation ability for some macromolecular food matrices and can provide a good nutrient source for the growth of other microorganisms.

[0073] Example 3 Application of the capsule-coated yeast SF2312 in yellow rice wine brewing

[0074] The single strain yeast prepared in Example 2 was used for yellow rice wine brewing:

[0075] (1) Soaking rice: soak glutinous rice overnight;

[0076] (2) Steaming: Steam the soaked glutinous rice until it is transparent and plump and the grains are intact and not broken;

[0077] (3) Spread the rice: Spread the steamed glutinous rice on a clean gauze and let it cool to room temperature;

[0078] (4) Mixing the yeast: Weigh 900 g of cooked rice and 750 g of water (the control group was inoculated with 5% of the commercial Angel yeast, and the experimental group was inoculated with 5% of the single-strain yeast prepared in Example 2);

[0079] (5) Fermentation: The pre-fermentation stage is fermented at 30°C for 5 days, then the temperature is lowered to 15°C for a 15-day post-fermentation stage. The rice wine brewing is completed after a total of 20 days of fermentation.

[0080] After fermentation, the alcohol content of the rice wine was determined according to GB 5009.225-2023. The total acid and amino nitrogen contents were determined according to GB13662-2018, and the reducing sugar content was determined by the 3,5-dinitrosalicylic acid method. The results of the physical and chemical indexes of the rice wine obtained by fermentation in the control group and the experimental group are shown in Table 1.

[0081] Table 1 Determination of physical and chemical indicators of rice wine obtained by fermentation in the control group and experimental group

[0082]

[0083] As can be seen from Table 1, the single-strain yeast prepared by screening and separating the capsule-coated yeast SF2312 of the present invention is used in rice wine brewing, which can show good results: the fermentation effect is better than that of the commercially available Angel Yeast, and the alcohol content and amino nitrogen content meet the requirements of commercially available rice wine. The koji making cycle can be significantly shortened. At the same time, the aseptic environment control of the production process also avoids contamination by miscellaneous bacteria, overcomes the limitations of weather factors, and can achieve uninterrupted production throughout the year.

[0084] Example 4 Application of Capsule-coated Yeast SF2312 in Sweet Grains Brewing

[0085] The single strain yeast prepared in Example 2 was used for brewing sweet mash:

[0086] (1) Shelling and cleaning

[0087] The wheat needs to be rubbed to remove the skin and impurities.

[0088] (2) Cooked

[0089] Cook the wheat kernels until they are 80% cooked (the surface opens), drain and cool them to obtain the basic material.

[0090] (3) Mixing koji

[0091] Mix the basic material and distiller's yeast (the preparation of distiller's yeast is: mix the single-strain yeast prepared in Example 2 and the distiller's yeast from Angel Yeast in a mass ratio of 1:10); the addition ratio of the basic material and distiller's yeast is 100:1.

[0092] (4) Fermentation

[0093] The mixed basic materials and distiller's yeast are placed in a sealed porcelain basin, kept at a constant temperature (about 15° C.), and fermented for 5 days to obtain the finished sweet mash.

[0094] After fermentation, the finished sweet mash has a fragrant wine flavor, a sweet taste, and naturally leached wine. Testing of the physical and chemical indicators of the sweet mash revealed the following: alcohol content 3% (vol%), total acid 4.5 (g / kg), and total sugar 13 (g / 100g). These indicators indicate that the sweet mash fermented with a single-strain yeast prepared using the screened yeast SF2312 meets the standard requirements (Q / LXTZ0001S-2021).

[0095] Example 5 Application of capsule-coated yeast SF2312 in fermented bean curd brewing

[0096] The single strain yeast for brewing wine prepared in Example 2 was used for fermented bean curd brewing:

[0097] (1) Raw material selection and processing

[0098] In winter, high-protein (≥35%), mold-free soybeans are soaked in water at 23°C for 6 hours, with a soybean-to-water ratio of 1:2.5. After soaking, the soybeans are ground to a fineness of 100 mesh and a water-to-water ratio of 1:7.

[0099] (2) Blanking

[0100] Slurrying: add coagulant (gypsum), control the temperature at 80°C and pH 6.8; pressing molding: pressure 0.3MPa, time 35 minutes, and control the moisture content of the tofu blank at 70%.

[0101] (3) Pre-fermentation inoculation: 0.2% Angel fermented bean curd koji powder inoculation, 0.1% single-strain yeast prepared in Example 2, temperature 23°C. Cultivation time: 60 hours, until mycelium covers the surface of the green body (white fuzz); Hair rolling: After fermentation, hair rolling ("reverse hair") is performed to allow the mycelium to wrap around the green body.

[0102] (4) Late fermentation and salting: add salt in layers (ratio of raw material to salt is 1:0.2), marinate for 7 days, and control the sodium chloride content at 13%; add ingredients into jars: add brine (rice wine with 10% alcohol content, red yeast rice, and spices; the ratio of rice wine, red yeast rice, and spices is 1:1:0.1), seal and ferment; post-ripening: temperature 30°C, time 5 months.

[0103] (5) Index detection

[0104] The amino acid content, water-soluble protein content, and total acid content of the fermented bean curd obtained by the above fermentation were measured. The results showed that the amino acid nitrogen content was 0.5 (g / 100g), the water-soluble protein content was 6 (g / 100g), and the total acid content was 1.5 (g / 100g). The results showed that after adding the single-strain yeast for wine brewing prepared in Example 2 of the present invention, the amino nitrogen content of the fermented bean curd obtained was higher than that of ordinary fermentation. The specific method of ordinary fermentation and its measurement data were 0.3 (g / 100g), 4.5 (g / 100g) of water-soluble protein, and 1.4 (g / 100g) of total acid.

[0105] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A strain of Saccharomycopsis fibuligera SF2312 that produces high levels of saccharifying and liquefying enzymes, characterized in that: It is deposited in Guangdong Provincial Microbiological Culture Collection with the deposit number GDMCC No: 66046.

2. A microbial agent, characterized in that: Contains the capsule-coated yeast SF2312 according to claim 1 or its fermentation liquid.

3. A single-strain yeast for wine brewing, characterized in that: The preparation method comprises the following steps: The fermentation seed liquid of the capsule-coated yeast SF2312 according to claim 1 is mixed with sterile water, and the mixture is mixed and formed after adding a fermentation matrix. The single-strain wine yeast is obtained after fermentation and cultivation.

4. The single-strain yeast for wine brewing according to claim 3, characterized in that: The bacterial concentration of the fermentation seed liquid is 10 6 CFU / mL.

5. The single-strain yeast for wine brewing according to claim 3, characterized in that: The fermentation temperature was 30°C.

6. The single-strain yeast for wine brewing according to claim 3, characterized in that: The volume ratio of the fermentation seed liquid to the sterile water is 1:2; the volume / mass ratio of the fermentation seed liquid to the fermentation substrate is 1:

5.

7. The single-strain yeast for wine brewing according to claim 3, characterized in that: The fermentation matrix includes indica rice flour and hot polygonum tiliaceum powder; the mass ratio of the indica rice flour to the hot polygonum tiliaceum is 200:

1.

8. Use of the single-strain yeast for brewing wine according to any one of claims 3 to 7 in the preparation of yellow rice wine, white wine, rice wine, soy sauce, vinegar, fermented bean curd or sweet mash.

9. The use of the capsule-coated yeast SF2312 according to claim 1, the microbial agent according to claim 2, or the single-strain yeast for wine brewing according to any one of claims 3 to 7 in the preparation of fermented foods, characterized in that: The fermented food includes alcohol products, soy products, fermented vegetables or condiments.

10. Use of the capsule-coated yeast SF2312 according to claim 1 or the microbial agent according to claim 2 in improving the saccharification and liquefaction capacity of the single-strain yeast for wine according to any one of claims 3 to 7.

Images