Wickerhamomyces submembrane and application thereof

Abstract

The invention discloses submembrane Wickerhamomyces cerevisiae and application thereof, the submembrane Wickerhamomyces cerevisiae is named as SFCC-Y145 and is preserved in China Center for Type Culture Collection on August 12, 2024, and the preservation number is CCTCC NO: M 20241777. Compared with SY fermented fruit wine, the SFCC-Y145 fermented fruit wine has the advantages that the sensory score is higher, the color is better, the variety and the content of volatile substances are improved, and the content of phenolic substances generated by the SFCC-Y145 is higher, so that the SFCC-Y145 strain can effectively improve the aroma degree and the aroma richness of the fruit wine, and the SFCC-Y145 fermented fruit wine has the advantages that the fruit wine is fermented by the SFCC-Y145 strain; the sensory quality of the fruit wine is favorably improved, and a theoretical basis is provided for fermenting the fruit wine by using non-saccharomyces cerevisiae. In addition, the used raw materials are pomace byproducts generated by industrial juicing, so that the utilization value of the fruit processing byproducts is improved.

Description

Technical Field

[0001] The invention belongs to the field of biotechnology, and in particular relates to a submembrane Wickham yeast and an application thereof. Background Art

[0002] At present, in the process of fruit wine brewing, mature commercial brewing yeast is usually directly used for fermentation to ensure the stability of the wine and the consistency of quality. Although this fermentation process is easy to control, the fruit wine has a weak aroma, insufficient flavor complexity, and a single taste. Therefore, it is necessary to find new yeast strains to increase the diversity of fruit wine flavor.

[0003] Due to the defects of commercial brewing yeast in fruit wine fermentation, non-brewing yeast has gradually entered people's field of vision. However, during the fermentation process, non-brewing yeast has poor alcohol tolerance and is at a disadvantage when competing for nutrients. Brewing yeast will inhibit the growth of non-brewing yeast, thereby limiting its contribution to the formation of fruit wine flavor substances. Therefore, the screening of non-brewing yeast and the exploration of its application in fermentation technology are of great significance for the production of special fruit wine. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a submembrane Wickham yeast and an application thereof to solve the technical problem of poor fermentation effect of non-brewer's yeast.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: to provide a subpellicular Wickham yeast (Wickerhamomyces subpelliculosus), named SFCC-Y145, which was preserved in the China Center for Type Culture Collection on August 12, 2024, with a preservation address of No. 299, Bayi Road, Wuchang District, Wuhan City, Hubei Province, and a preservation number of CCTCCNO: M20241777.

[0006] The invention also discloses a biological preparation comprising the submembrane Wickham yeast SFCC-Y145.

[0007] The invention also discloses the application of submembrane Wickham yeast SFCC-Y145 or biological preparation in fruit wine fermentation.

[0008] On the basis of the above technical solution, the present invention can also be improved as follows:

[0009] Further, the application steps are:

[0010] S1. Mix the pomace and pectinase evenly, then perform enzymolysis at 40-50°C for 80-100 minutes, then adjust the sugar content of the enzymolysis solution to 18-22°, add potassium pyrosulfite, then adjust the pH of the mixed solution to 3-4, and finally sterilize in a 90-100°C water bath for 10-20 minutes to obtain a pomace treated product; the ratio of pomace, pectinase and potassium pyrosulfite is 900-1100mL: 50-100mg: 30-70mg;

[0011] S2. Inoculate the submembrane Wickham yeast SFCC-Y145 or biological agents into the pomace treated material, ferment at 25-35° C. until no bubbles are generated, filter, and obtain fruit wine.

[0012] Furthermore, the pomace is citrus pomace.

[0013] Further, the inoculation amount of the submembrane Wickham yeast SFCC-Y145 or the biological agent is 3-7wt%.

[0014] The beneficial effects of the present invention are as follows: the SFCC-Y145 disclosed in the present invention is separated from fermented black beans, and the bacteria is identified as submembrane Wickham yeast. The present invention uses pomace as raw material, and adopts non-brewer yeast submembrane Wickham yeast SFCC-Y145 and Angel wine yeast SY to carry out a single-bacteria fermentation experiment of fruit wine. Compared with Angel wine yeast SY fermented fruit wine, the non-brewer yeast SFCC-Y145 fermented fruit wine has a higher sensory score, better color, and improved types and contents of volatile substances. In addition, the phenolic substance content produced by SFCC-Y145 is relatively high, indicating that the SFCC-Y145 strain can effectively improve the aroma degree and aroma richness of fruit wine, which is beneficial to improving the sensory quality of fruit wine, and provides a theoretical basis for the use of non-brewer yeast to ferment fruit wine. In addition, the raw materials used in the present invention are pomace by-products produced by industrial juicing, which improves the utilization value of fruit processing by-products. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 To compare the fermentation ability of different yeasts;

[0016] Figure 2 To compare the alcohol tolerance of different yeasts;

[0017] Figure 3 To compare the sugar tolerance of different yeasts;

[0018] Figure 4 Different yeasts are resistant to SO 2 Comparison of capabilities;

[0019] Figure 5 This is the colony morphology of the SFCC-Y145 strain;

[0020] Figure 6 The cell morphology of SFCC-Y145 strain;

[0021] Figure 7 This is the PCR product amplification diagram of the SFCC-Y145 strain;

[0022] Figure 8 is the phylogenetic tree of the SFCC-Y145 strain;

[0023] Fig. 9 This is a sensory diagram of citrus wine;

[0024] Fig.10 This is a comparison chart of the aroma compound content of citrus wine. DETAILED DESCRIPTION

[0025] The specific embodiments of the present invention are described below to facilitate the understanding of the present invention by those skilled in the art. If the specific conditions are not specified in the examples, the methods are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturers are not specified in the reagents or instruments used, they are all conventional products that can be purchased commercially. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention defined and determined by the attached claims, these changes are obvious, and all inventions and creations using the concept of the present invention are protected.

[0026] The composition of the culture medium used in the following experiments was:

[0027] YPD medium: Mix 10 g of peptone, 5 g of yeast extract powder, and 20 g of glucose with 1 L of water, and sterilize at 121°C for 20 min.

[0028] Example 1 Isolation and purification of non-brewery yeast

[0029] 1. Sample Collection

[0030] Douchi No. 2, red sour soup, kimchi, schisandra honey, acacia honey and honeycomb were used as separation source samples for separation and screening. Douchi No. 2 was purchased from the Huangmei County Market in Huanggang City, Hubei Province; red sour soup was homemade by Wanida Restaurant in Beibei District, Chongqing; kimchi was brewed by a resident family in Xiema Town, Beibei District, Chongqing; schisandra honey, acacia honey and honeycomb were purchased from the Xiema Town Market in Beibei District, Chongqing.

[0031] 2. Preparation of Yeast Enrichment Solution

[0032] Weigh 10 g of sample and grind it in a sterile mortar. Then, transfer the sample to a conical flask containing 90 mL of sterile saline and glass beads. Shake and culture at 30°C and 100 r / min for 20 min to ensure that the sample and saline are fully mixed. After standing for 1-2 hours, take the supernatant as yeast enrichment solution for subsequent use.

[0033] 3. Isolation and purification of yeast

[0034] 1 mL of yeast enrichment solution was taken and injected into a test tube containing 9 mL of sterile saline. After dilution and thorough mixing, 10 -1 , 10 -2 , 10 -3 , 10 -4 , 10 -5 , 10 -6 , 10 -7 , 10 -8 , 10 -9 and 10 -10 Dilutions with concentration gradients. When spreading, take 100 μL of different dilutions with concentration gradients and spread them evenly on YPD solid culture medium. Make 3 parallel groups for each gradient and culture them in a 30°C incubator for 2 to 3 days. After colonies are formed in the culture medium, analyze the colony morphology and color characteristics to select a single colony with a morphology similar to yeast. Perform streak separation and purification in YPD solid culture medium, and after purification, place it in a 30°C constant temperature incubator for 2 to 3 days. Repeat the above purification operation 3 to 4 times until a pure yeast strain is obtained.

[0035] A total of 399 yeast strains were isolated and purified from the collected fermented foods using the above method, of which 76 strains had potential fermentation ability. The isolation source information is shown in Table 1.

[0036] Table 1 Isolation source information of yeast strains with potential fermentation ability

[0037] source Strain name number Schisandra Honey SFCC Y69-71, SFCC Y74-78, SFCC Y81-82, SFCC Y102-113 22 Acacia honey SFCC Y84-89, SFCC Y91-95, SFCC Y97-99 14 honeycomb SFCC Y117-119 3 Fermented black beans No.2 SFCC Y145 1 Red sour soup SFCC Y198-211 14 Pickle SFCC Y214-219, SFCC Y222-226, SFCC Y228-238 22

[0038] Example 2 Screening of non-brewery yeast

[0039] In order to preliminarily identify the non-brewery yeasts with excellent performance from the 76 yeast strains isolated in the example, the fermentation capacity, alcohol tolerance, sugar tolerance and SO 2 Tolerance test to determine non-Saccharomyces yeasts suitable for fruit wine brewing.

[0040] 1. Analysis of yeast fermentation capacity

[0041] 200 mL of sweet orange pomace produced in the juice processing workshop of the Citrus Research Institute of Southwest University was taken and placed in a 250 mL sterilized conical flask. 80 mg / L of pectinase was added to the pomace, and enzymolysis was performed in a water bath at 45°C for 90 minutes. Sucrose was added to adjust the sugar content to 20°, and 50 mg / L of potassium pyrosulfite was added. Then, citric acid was used to adjust the pH of the solution to 3.6, and then pasteurized in a 95°C water bath for 15 minutes. Finally, the activated yeast sample liquid was inoculated into the pretreated sweet orange pomace at a 5% inoculation rate, and then placed in a 30°C constant temperature incubator for fermentation. The fermentation liquid was manually shaken twice a day and weighed every 24 hours. The weight lost by the fermentation liquid (i.e., CO2) was calculated by the carbon dioxide weight loss method using commercial brewer's yeast as a control. 2 The fermentation rate change curve was constructed with the weight lost by the fermentation liquid (g) as the vertical axis and the fermentation time (h) as the horizontal axis ( Figure 1 ) and analyzed the fermentation performance of different strains.

[0042] 2. Determination of alcohol tolerance

[0043] Anhydrous ethanol was added to each 10 mL of YPD medium to make the initial alcohol concentrations in the fermentation broth 2%, 4%, 6%, 8%, 10% and 12%, respectively. The same yeast strain was then inoculated into the medium with different alcohol concentrations at an inoculation density of 10 6 CFU / mL. After inoculation, the culture medium was placed in a constant temperature environment at 28°C and cultured for 48 hours. After the culture was completed, the optical density (OD 600 ) value in order to further analyze the growth of yeast under different alcohol concentrations. Each sample was processed three times in parallel, and finally a curve reflecting the alcohol tolerance of yeast was drawn with the change of alcohol concentration as the horizontal axis and the corresponding absorbance value as the vertical axis ( Figure 2 ).

[0044] 3. Determination of glucose tolerance

[0045] Glucose was added to each 10 mL of YPD medium to make the initial sugar concentrations in the fermentation broth 100 g / L, 140 g / L, 180 g / L, 220 g / L, and 260 g / L, respectively. The same yeast strain was then inoculated into the medium with different sugar concentrations at an inoculation density of 10 6 CFU / mL. After inoculation, the culture medium was placed in a constant temperature environment at 28°C and cultured for 48 hours. After the culture was completed, the optical density (OD 600 ) value. Each sample was processed in parallel 3 times, and finally the sugar tolerance curve of yeast was drawn with sugar concentration as the horizontal axis and absorbance as the vertical axis ( Figure 3 ).

[0046] 4. Resistant to SO 2 Ability test

[0047] Potassium metabisulfite was added to each 10 mL of YPD medium to make SO 2 The concentrations are 40mg / L, 60mg / L, 80mg / L, 100mg / L, 120mg / L and 140mg / L, with a 10 6 CFU / mL inoculation density, the same yeast was inoculated into different SO 2 After inoculation, the culture medium was placed in a constant temperature environment at 28°C and incubated for 48 hours. After the incubation, the optical density (OD 600 ) value. Each sample was processed 3 times in parallel. 2 The concentration is plotted on the horizontal axis, and the absorbance value is plotted on the vertical axis to plot the SO 2 Tolerance curve ( Figure 4 ).

[0048] The results are as follows Figure 1-Figure 4 As shown, in non-Saccharomyces cerevisiae, the CO produced by strain SFCC-Y145 on the second day 2 The fermentation capacity of SFCC-Y145 at each stage was significantly higher than that of other strains, that is, the fermentation efficiency was the highest; SO 2 The tolerance is poor but meets the production requirements; SFCC-Y145 has strong alcohol tolerance and can still grow when the alcohol volume fraction is 6%; SFCC-Y145 also has strong sugar tolerance, but the biomass decreases significantly at a sugar concentration of 180g / L.

[0049] In summary, SFCC-Y145 was selected as further experimental material.

[0050] Example 3 Identification of SFCC-Y145 strain

[0051] 1. Morphological observation

[0052] (1) Colony morphology observation: Using the naked eye method, the key indicators such as colony size, shape, color, transparency, wetness, edge condition and protrusion degree were carefully evaluated. Figure 5 As shown, the SFCC-Y145 colonies were round, cream-colored, had neat edges, high moisture content, and were easy to pick up.

[0053] (2) Observation of cell morphology: Add sterile saline to the slide, pick up the bacteria in the YPD medium with an inoculation loop and mix them evenly with the saline. Then cover the bacterial solution with a coverslip and let it stand for 3 minutes. Then observe the morphology of the yeast under a microscope. Figure 6As shown, the cell morphology of SFCC-Y145 is oval.

[0054] 2. Molecular identification

[0055] After SFCC-Y145 was inoculated in YPD liquid medium at 30°C for a certain period of time, 1.5 mL of bacterial solution was centrifuged and the bacterial precipitate was washed 2 to 3 times with sterile saline. The yeast DNA was used as a template and the yeast 26S rDNA region sequence was PCR amplified using primers NL1 and NL4. The PCR amplification program was: first denaturation at 94°C for 10 minutes, followed by denaturation at 94°C for 30 seconds, annealing at 55°C for 30 seconds, and extension at 72°C for 1 minute, and 35 cycles, and finally extension at 72°C for 10 minutes.

[0056] PCR amplification reaction system: 12.5 μL 2× Taq PCR Mix, 1.5 μL yeast genomic DNA, 1 μL upstream and downstream primers, 1 μL each, 9 μL sterile double distilled water. The amplified product was detected by 1% agarose gel electrophoresis. The amplification results are as follows: Figure 7 The amplified fragment is about 550 bp, which is a typical characteristic band of yeast. The band is single and bright, consistent with the expected size, and can be used for the next step of sequencing analysis.

[0057] The amplified products were sequenced by Bioengineering Technology Co., Ltd., and the sequencing results were compared by BLAST on the NCBI website. The sequences with high homology were downloaded according to the BLAST results, and the phylogenetic tree was constructed using the bootstrap method (multiplicity of 1000) using MEGA11 software ( Figure 8 ).

[0058] The gene sequence of the SFCC-Y145 strain (SEQ ID NO. 1) is as follows: ACTCAGGCTTGCCTCAGTACG.

[0059] Combining the morphological characteristics with the molecular identification results, it was shown that strain SFCC-Y145 and Wickerhamomyces subpelliculosa were clustered in one branch and had the closest relationship.

[0060] Embodiment 4 wine making process

[0061] The isolated submembrane Wickham yeast is represented by SFCC-Y145, and the Angel fruit wine yeast SY is represented by SY. Citrus is used as an example for fruit wine preparation, and the blank control group is not inoculated with yeast strains.

[0062] Use a sterile inoculation loop to pick a single yeast colony, inoculate it into 20 mL YPD liquid medium for activation, and culture it at 30°C until the bacterial density reaches 10 7 ~10 8 cfu / mL, and used as seed solution.

[0063] 200 mL of citrus pomace was placed in a 250 mL sterilized conical flask, 80 mg / L of pectinase was added to the citrus pomace, enzymolysis was performed in a water bath at 45°C for 90 min, sucrose was added to adjust the sugar content to 20°, 50 mg / L of potassium pyrosulfite was added, and the pH of the solution was adjusted to 3.6 using citric acid, followed by pasteurization in a 95°C water bath for 15 min, and finally the expanded cultured strain was inoculated into the prepared citrus pomace at a 5% inoculation rate, and fermented in a constant temperature incubator at a temperature of 30°C, manually shaken twice a day, and weighed every 24 hours until no bubbles were generated. After the fermentation was completed, the supernatant was taken and the fruit wine sample (experimental group: SFCC-Y145; control group: SY) was obtained.

[0064] Example 5 Fruit Wine Evaluation

[0065] 1. Sensory evaluation

[0066] A sensory evaluation of citrus wine was conducted. Ten professionally trained students were selected to form a review panel. The evaluation was mainly based on four aspects: color, aroma, taste, and style. The full score was 100 points. The specific standards are shown in Table 2.

[0067] Table 2 Sensory scoring standards

[0068]

[0069]

[0070] Evaluation results such as Fig. 9 As shown. The sensory score of fruit wine fermented by non-Saccharomyces SFCC-Y145 was 75.8, and the sensory score of fruit wine fermented by Angel Wine Yeast SY was 74.7. From the perspective of aroma, SFCC-Y145 scored the highest at 23.9, which is due to the highest content of aroma compounds, while Angel Wine Yeast SY scored 22. This shows that the fermentation of non-Saccharomyces cerevisiae has a certain effect on the aroma of fruit wine compared with the fermentation of Angel Wine Yeast SY.

[0071] 2. Chroma detection

[0072] Color is not only a key factor that consumers consider when choosing products, but also an indispensable indicator for evaluating food quality. It reflects the relationship between L*, a*, b* and the total color difference. Therefore, the chromaticity of citrus wine was tested. A colorimeter was used to measure the color index of the citrus wine prepared by the method of Example 4. The colorimeter was calibrated according to the steps in the manual and preheated for 30 minutes, and then the samples were measured. Each sample was measured three times, and ΔE was calculated:

[0073] ΔE=[(LL 0 )×2+(aa 0)×2+(bb 0 )×2] / 2;

[0074] Where, ΔE is the CIELab color difference; L, a and b represent the Hunter parameters of the fermented citrus wine, L 0 、a 0 and b 0 Indicates Hunter parameters before fermentation.

[0075] The effects of non-brew yeast SFCC-Y145 and Angel wine yeast SY on L*, a* and b* of citrus wine after fermentation are shown in Table 3.

[0076] Table 3 Differences in ΔE values ​​of citrus wines

[0077] Fermentation strains L* a* b* △E SFCC-Y145 <![CDATA[98.1±0.21 a ]]> <![CDATA[-1.97±0.07 cd ]]> <![CDATA[10.74±0.73 c ]]> <![CDATA[22.74±0.74 a ]]> Angel Wine Yeast SY <![CDATA[97.31±0.38 ab ]]> <![CDATA[-1.8±0.16 bc ]]> <![CDATA[14.67±0.6 a ]]> <![CDATA[18.91±0.71 c ]]> Blank control <![CDATA[97.01±0.73 ab ]]> <![CDATA[-2.04±0.21 d ]]> <![CDATA[13.5±2.29 ab ]]> <![CDATA[19.8±2.33 bc ]]>

[0078] Note: Different letters (ad) in the same column indicate significant differences (p<0.05).

[0079] High-quality fruit wines often have bright and clear colors without impurities or sediments. The L* value indicates brightness. The larger the L* value, the brighter the sample. As shown in Table 3, compared with the blank control, the brightness of SFCC-Y145 and Angel Fruit Wine Yeast SY increased after fermentation, and the citrus wine fermented by SFCC-Y145 had the highest brightness, which was 98.1±0.21.

[0080] The a* value is used to indicate the red-green bias of the color, where a positive value means the sample is biased towards red, and the larger the value, the more biased towards red; while a negative value means the sample is biased towards green, and the larger the negative value, the more biased towards green. As can be seen from Table 3, the redness of the wine produced by all yeasts decreased after the fermentation, which may be due to the degradation of pigments during the fermentation process.

[0081] The b* value is used to describe the yellow-blue bias of the color. When the b* value is positive, it means that the sample is biased towards yellow, and as the value increases, the yellow tone becomes more obvious. On the contrary, if the b* value is negative, it means that the sample is biased towards blue, and the larger the negative value, the more obvious the blue tone. As can be seen from Table 3, the b* value of Angel Fruit Wine Yeast SY shows an upward trend after the fermentation is completed, and the yellow is more obvious. The b* value of SFCC-Y145 shows a downward trend after the fermentation is completed, and the yellow is lighter.

[0082] As shown in Table 3, the color difference value ΔE of the fruit wine obtained after fermentation with Angel fruit wine yeast SY is smaller than that of the blank control, while the color difference values ​​of the fruit wine obtained after fermentation with SFCC-Y145 are greater than those of the blank control, indicating that the fermentation with non-brewer's yeast has a significant effect on the color of the fruit wine.

[0083] 3. Detection of aroma substances in citrus wine

[0084] The volatile aroma compounds of citrus wine were detected. The specific steps were as follows: 5 mL of citrus wine was taken into a 20 mL headspace bottle, 1.5 g of sodium chloride and 2.5 μL of internal standard cyclohexanone (mass concentration was 0.95 mg / mL) were added, sealed with a polytetrafluoroethylene septum and placed on a 40 ° C magnetic stirrer for equilibration for 20 min, the SPME extraction head was inserted into the headspace bottle through the septum for adsorption for 20 min, then the extraction head was retracted and immediately inserted into the GC injection port for desorption for 5 min. The mass spectrum of the detected sample was preliminarily compared with the spectral library NIST14s for identification, and cyclohexanone was used as the internal standard for semi-quantification. The percentage of aroma substances was calculated by the relative peak area method, and the experimental results were presented in the form of mean ± standard deviation. The test results are shown in Table 4.

[0085] Table 4 Types and contents of aroma substances in citrus wine

[0086]

[0087]

[0088]

[0089] As shown in Table 4, there are differences in the types and contents of volatile substances in citrus wine. The wines made by Angel wine yeast SY and non-brewer's yeast SFCC-Y145 contain 35 and 39 volatile substances, respectively. Compared with Angel wine yeast SY, non-brewer's yeast SFCC-Y145 produces 7 unique substances, namely (±)-6-methyl-5-heptenyl-2-ol, 2-heptanol, isopentanol, n-heptanol, isobutyl acetate, isobutyric acid and γ-terpinene, and the types of volatile substances in the wine samples fermented by SFCC-Y145 are the most. As an important volatile substance in fruit wine, alcohol, the content of alcohol substances in the wine samples fermented by SFCC-Y145 is significantly higher than that of Angel wine yeast SY. The content of alcohol substances in the fruit wine fermented by Angel wine yeast SY is 9.48ug / L, while the content of alcohol substances in the fruit wine fermented by SFCC-Y145 is 42.51ug / L. 2-Heptanol was only detected in the fruit wine fermented by SFCC-Y145. 2-Heptanol can emit fresh lemon and grass-herbal aromas, with slight ether and oil aromas. It can be used as an important intermediate for spices within a specific concentration range.

[0090] In addition, alcohol substances also include higher alcohols. In the production of fruit wine, yeast plays a major role in the formation of higher alcohols. Phenylethanol exudes an elegant and delicate rose and honey aroma, while isoamyl alcohol has a unique aroma of whiskey, malt and burnt, and isobutanol exudes a fresh fragrance. These components have a positive effect on the formation of the aroma of fruit wine. Combined with Table 4, it can be seen that the isoamyl alcohol content in the fruit wine fermented by SFCC-Y145 is the highest, which is 17.83ug / L. The content of phenylethanol and isobutanol produced by it is higher than that of Angel Fruit Wine Yeast SY. In fruit wine, these higher alcohol substances coexist in different proportions and cooperate with each other to create a variety of unique flavors of fruit wine, enriching the aroma and taste experience of fruit wine. In addition, SFCC-Y145 also produces some alcohol substances with characteristic flavors, such as linalool, pinolene, etc., whose content is higher than that of citrus wine fermented by Angel Fruit Wine Yeast SY. It can be seen that SFCC-Y145 helps to enrich the flavor of fruit wine. Esters play a vital role in fruit wine. As the main contributors to aroma, they add unique wine and fruity aroma to fruit wine directly or through synergistic effects.

[0091] The total content of ester substances in the citrus wine fermented by SFCC-Y145 is higher than that in Angel Wine Yeast SY. Among them, only the fruit wine fermented by SFCC-Y145 contains ethyl propionate. Ethyl propionate has a pineapple aroma and can be used as a wine flavor. This characteristic can be used as a research point for subsequent exploration of the influence of non-brewing yeast on the aroma components of fruit wine. In addition, SFCC-Y145 also produces higher levels of ethyl hexanoate and isoamyl acetate than Angel Wine Yeast SY. Ethyl hexanoate has the aroma of pineapple fruit, giving people a sweet and refreshing feeling. The aroma of isoamyl acetate is described as similar to the aroma of apple, so it is often used as a flavoring ingredient in food, beverages and perfumes. Acid compounds are mainly volatile acids, which are also the main flavor substances in fruit wine. By Fig.10 It can be seen that the total amount of acid substances produced by non-brewery yeast SFCC-Y145 is greater than that produced by Angel fruit wine yeast SY.

[0092] The types, molecular structures and contents of phenolic substances in fruit wine are closely related to the color depth, taste richness, aroma level and complexity of fruit wine. It is also an important active ingredient in fruit wine, with strong antioxidant activity. The phenolic substance content produced by SFCC-Y145 is relatively high, indicating that the SFCC-Y145 strain can effectively increase the content of volatile aroma compounds in fruit wine, which is beneficial to improve the sensory quality of fruit wine and has certain economic value.

Claims

1. A subpellicular Wickerhamomyces yeast (Wickerhamomyces subpelliculosus), named SFCC-Y145, was deposited in the China Center for Type Culture Collection on August 12, 2024, with the deposit address being No. 299, Bayi Road, Wuchang District, Wuhan City, Hubei Province, and the deposit number being CCTCC NO: M 20241777.

2. A biological agent, characterized in that: The invention comprises the submembrane Wickham yeast SFCC-Y145 as described in claim 1.

3. Use of the submembrane Wickham yeast SFCC-Y145 according to claim 1 or the biological preparation according to claim 2 in fruit wine fermentation.

4. The use according to claim 3, characterized in that: The application steps are: S1, mixing the pomace and pectinase evenly, then performing enzymolysis at 40-50°C for 80-100 minutes, adjusting the sugar content of the enzymolysis solution to 18-22°, adding potassium pyrosulfite, then adjusting the pH of the mixed solution to 3-4, and finally sterilizing in a 90-100°C water bath for 10-20 minutes to obtain a pomace treated product; the ratio of the pomace, pectinase and potassium pyrosulfite is 900-1100mL:50-100mg:30-70mg; S2. Inoculate the submembrane Wickham yeast SFCC-Y145 described in claim 1 or the biological agent described in claim 2 into the pomace treated material, ferment at 25-35° C. until no bubbles are generated, filter, and obtain fruit wine.

5. The use according to claim 4, characterized in that: The pomace is citrus pomace.

6. The use according to claim 4, characterized in that: The inoculation amount of the submembrane Wickham yeast SFCC-Y145 or the biological agent is 3-7wt%.

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