Application of Metschnikowia chrysoperla strain in wine brewing

Abstract

The invention belongs to the technical field of wine brewing, and particularly relates to application of a Metschnikowia chrysoperline strain in wine brewing, the Metschnikowia chrysoperline strain is YTM1, the preservation number is CGMCC NO.34926, and the Metschnikowia chrysoperline strain is preserved in the China General Microbiological Culture Collection Center on June 17, 2025. The invention further discloses a preparation method of the Metschnikowia chrysoperline strain. The mixed fermentation strategy of YTM1 + RC212 has positive influence on the variety and content of aroma substances, alcoholic strength, other flavor related physicochemical indexes and fermentation metabolism byproducts such as glycerol, malic acid, lactic acid and the like of the wine.

Description

Technical Field

[0001] This invention belongs to the field of winemaking technology, specifically relating to a... Metschnikowia chrysoperlae Application of strains in winemaking. Background Technology

[0002] In the winemaking process, yeast plays a central role in shaping the flavor, aroma, and quality of the wine. In traditional processes, brewing yeast (… Saccharomyces cerevisiae Due to its highly efficient alcoholic fermentation capabilities, non-brewing yeast (Non-) is widely used, but its use alone often leads to problems such as insufficient aroma complexity and a monotonous taste. In recent years, non-brewing yeast (Non-) has emerged as a growing trend. Saccharomyce s) Due to their unique metabolic characteristics, non-brewing yeasts have become a research hotspot, as they can significantly enhance the aroma complexity and sensory quality of wine through the synthesis of metabolites such as esters, terpenes, and glycerol. However, the application of non-brewing yeasts in current technologies still faces the following key bottlenecks: the limited functionality of strains leads to uneven quality improvement. Existing research focuses on the development of single functions of non-brewing yeasts, such as: 1) Enhanced aroma but unbalanced body: While some strains can produce high levels of ester compounds to enhance fruit aromas, this may be accompanied by excessive accumulation of acetic acid or acetaldehyde, resulting in excessively high acidity or prominent oxidative flavors in the wine. 2) Stable color but lack of aroma: Some strains improve the color of the wine by secreting polysaccharides or promoting anthocyanin stability, but their fermentation power is weak, requiring brewing yeast to complete the alcohol conversion, resulting in limited aroma contribution. 3) The contradiction between low alcohol content and flavor decay: Thermotolerant Kluyveromyces can reduce alcohol content and increase lactic acid content to improve the roundness of the palate, but its ability to release thiol aroma precursors is weak, limiting the diversity of aromas.

[0003] In current technologies, the application of both brewing yeast and non-brewing yeast is still limited to localized optimization of single qualities, lacking a comprehensive improvement in wine quality. Therefore, how to provide a wine that combines aromatic complexity and taste balance has become a key direction for breaking through current technological barriers. Summary of the Invention

[0004] The purpose of this invention is to provide a Metschnikowia chrysoperlae The application of strains in winemaking solves the problems existing in the current technology.

[0005] The technical solution adopted in this invention is: This invention provides Metschnikowia chrysoperlae The application of strains in winemaking, the Metschnikowia chrysoperlae The strain is YTM1, with accession number CGMCC NO.34926, and was deposited at the China General Microbiological Culture Collection Center on June 17, 2025.

[0006] Preferably, the application refers to at least one of the following: 1) Increase the variety of aroma compounds in wine; 2) Increase the content of aroma compounds in wine; 3) Reduce the alcohol content of the wine; 4) Increase the glycerol production of wine; 5) Reduce the malic acid content of wine; 6) Increase the lactic acid content of wine.

[0007] Preferably, the wine aroma substances include at least one of esters, alcohols, acids, terpenes, aromatic compounds, aldehydes and ketones, and ethers.

[0008] Preferably, the ester is at least one selected from 2-ethylhexyl lactate, ethyl 8-nonanoate, methyl decanoate, ethyl decanoate, isoamyl decanoate, and ethyl myristate; The alcohol is at least one of n-hexanol, 2-ethylhexanol, L-2,3-butanediol, n-octanol, and n-decanol; The acid mentioned is decanoic acid; The terpenes are at least one of citronellol, damascene, geraniol, and 4-isopropyl-1,6-dimethylnaphthalene; The aromatic compound is at least one of ethyl phenylacetate, phenethyl acetate and phenylethanol; The aldehydes and ketones are at least one of decanal and benzaldehyde; The ether is lauryl alcohol polyether-6.

[0009] Preferably, using Metschnikowia chrysoperlae The method of using the strain for winemaking is as follows: preparation Metschnikowia chrysoperlae Inoculation solution; Metschnikowia chrysoperlae In the inoculation solution Metschnikowia chrysoperla The number of viable bacteria was 1×10⁻⁶. 8 cfu / mL ~1×10 9 cfu / mL; The RC212 strain was weighed out at a ratio of 0.3g:1L to grape must to prepare the inoculum for the RC212 strain. The grape must is macerated, and after maceration, the following is added first: Metschnikowia chrysoperlae The inoculum was fermented at an inoculum volume of 4% v / v; then the inoculum of RC212 strain was added to continue fermentation. After fermentation was completed, SO2 was introduced to terminate fermentation and the mixture was sealed and allowed to stand.

[0010] Preferably, Metschnikowia chrysoperlae The fermentation conditions for the inoculum were 24℃ for 72 hours.

[0011] Preferably, the end of fermentation is indicated by a grape must-liquid ratio of less than 0.993.

[0012] Preferably, the settling time is 20 to 40 days.

[0013] Preferably, the grape must is macerated at 4°C for 24 hours.

[0014] Preferably, the Metschnikowia chrysoperlae The preparation method of the inoculum solution is as follows: Pick Metschnikowia chrysoperlae Single colonies were obtained by incubating in YPD liquid medium at 28°C and 200 rpm for 36 hours. Metschnikowia chrysoperlae Seed liquid; Grape juice, YPD liquid culture medium and Metschnikowia chrysoperlae The seed culture was mixed and cultured at 28℃ and 200rpm for 36 hours to obtain... Metschnikowia chrysoperlae Inoculation solution.

[0015] The present invention relates to Metschnikowia chrysoperlae The strains are as follows: YTM1, deposited on June 17, 2025, at the China General Microbiological Culture Collection Center, with a recommended classification name. Metschnikowia chrysoperlae, The accession number is CGMCC NO.34926, and the accession address is No.3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention provides Metschnikowia chrysoperlae The application of strains in winemaking, the Metschnikowia chrysoperlae The strain is YTM1, with accession number CGMCC NO.34926, and was deposited at the China General Microbiological Culture Collection Center on June 17, 2025. The mixed-culture fermentation strategy of YTM1+RC212 used in this invention has a positive impact on the types and contents of aroma substances, alcohol content, other flavor-related physicochemical indicators, and fermentation metabolic byproducts such as glycerol, malic acid, and lactic acid in wine.

[0017] The novel yeast strain YTM1 involved in this invention can increase the content of some aroma substances when mixed with commercial brewing yeast RC212 for fermentation. Compared with the traditional fermentation method of single fermentation with commercial brewing yeast, it not only improves the aroma sensory quality, but also increases the yield of glycerol, further decomposes malic acid and produces lactic acid, and improves the fermentation efficiency of wine, thus having the advantage of comprehensively improving the overall flavor quality of wine. Attached Figure Description

[0018] Figure 1 For sensory evaluation results, 1: Example 1; 2: Comparative Example 1; 3: Comparative Example 2.

[0019] Figure 2 This is the result of the aroma evaluation.

[0020] Figure 3 The results are for evaluating physicochemical indicators. Detailed Implementation

[0021] The present invention will be further illustrated below with specific embodiments, but these embodiments do not limit the scope of the invention. Modifications or substitutions to the details and form of the technical solutions of the present invention may be made without departing from the spirit and scope of the invention, but all such modifications or substitutions fall within the protection scope of the present invention.

[0022] The inventive concept of this invention is as follows: Glycerol, a colorless and odorless byproduct of yeast sugar metabolism, has a viscous texture. Appropriate amounts of glycerol can enhance the body of wine and reduce alcohol production. Malic acid, a naturally occurring organic acid in wine, not only supports its acidity but also contributes to a green and sharp taste. This invention utilizes a mixed-culture fermentation strategy with YTM1+RC212 to convert the sharp-tasting malic acid into milder lactic acid through malolactic fermentation during winemaking, thereby improving the wine's flavor and enriching its aroma.

[0023] To enable those skilled in the art to better understand and implement the technical solutions of this invention, the invention will be further described below with reference to specific embodiments. Unless otherwise specified, all reagents used in this invention are commercially available, and all methods used are conventional techniques in the art.

[0024] The experimental materials involved in this invention are as follows: 1) YTM1, deposited on June 17, 2025 at the China General Microbiological Culture Collection Center, with a recommended classification name. Metschnikowia chrysoperlae, The accession number is CGMCC NO.34926, and the accession address is No.3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing.

[0025] 2) Commercial brewing yeast Lalvin RC212: Purchased from Laman, France, with a stated viable count of ≥1×10⁻⁶. 10 CFU / g; the recommended dosage is 0.3g / L, meaning 0.3g of Lalvin RC212 yeast should be added to every 1L of grape juice to be fermented. For ease of description, it will be referred to as RC212 below.

[0026] 3) Pectinase EX-V: Purchased from Raman Company, France, with an enzyme activity of 3479.3 U / g and an addition amount of 0.05 g / L.

[0027] 4) LEVEL2 FLAVIA: Purchased from Laman, France.

[0028] Example 1 Metschnikowia chrysoperlae The application of strains in winemaking, this embodiment utilizes Metschnikowia chrysoperlae Fermentation was carried out using strain YTM1+RC212, as detailed below: S1, Preparation Metschnikowia chrysoperla Inoculation solution.

[0029] activation Metschnikowia chrysoperla : Stored in glycerin tubes at -80°C Metschnikowia chrysoperla Streaking the medium onto YPD solid agar plates and incubating at 28°C for 36 hours.

[0030] Expand training Metschnikowia chrysoperla Single colonies were picked from YPD solid agar plates and transferred to 5 mL of YPD liquid agar. The culture was incubated at 28°C with shaking at 200 rpm for 36 h to obtain... Metschnikowia chrysoperla Seed liquid.

[0031] preparation Metschnikowia chrysoperla Inoculation solution: Crushed and pressed Cabernet Gernischt grapes were used. 150 mL of grape juice was placed in a 500 mL Erlenmeyer flask and sterilized at 80°C for 5 minutes. After the grape juice cooled to room temperature, the grape juice and YPD liquid culture medium were mixed at a volume ratio of 1:1 to obtain 300 mL of mixed culture medium. Then, the inoculum was added... Metschnikowia chrysoperla Seed liquid, making Metschnikowia chrysoperla The viable count in the mixed culture medium reached 5 × 10⁶. 6 cfu / mL; incubate at 28℃ and 200 rpm for 36 h with shaking to obtain Metschnikowia chrysoperla The inoculation solution, in the inoculation solution Metschnikowia chrysoperla The number of viable bacteria was 1×10⁻⁶. 9 cfu / mL.

[0032] S2. Prepare the inoculum for strain RC212.

[0033] Based on 7.5L of grape must, weigh 2.25g of RC212 at a dosage of 0.3g / L, add it while stirring into 10% wt sugar water at 37℃, and wait for the yeast to start fermenting to obtain the seed liquid for later use.

[0034] S3, the production of Cabernet Sauvignon dry red wine.

[0035] Select mature Cabernet Gernischt grapes and destem and crush them. Then, take 7.5L of grape must and put it into a 10L fermentation tank. Add 30mg / L SO2 to the fermentation tank. After 30min, add 0.375g of pectinase EX-V. Place the fermentation tank at 4℃ for cold soaking for 24h.

[0036] After cold maceration, the grape must is warmed to above 12°C, and the mixture prepared by S1 is added. Metschnikowia chrysoperla The inoculum was prepared at a rate of 4% v / v and fermented at 24°C. The fermentation temperature and specific gravity of the mash were measured every 6 hours, and the mash was capped.

[0037] 72 hours after fermentation started, the inoculum of strain RC212 prepared by S2 was completely inoculated, and the fermentation temperature and specific gravity of the mash were continuously monitored, with continuous capping treatment. When the specific gravity dropped below 0.993, the alcoholic fermentation was considered complete. The wine was pressed and separated from the pomace, and 40 mg / L SO2 was added to the wine to terminate fermentation. The wine was then sealed in full tanks and stored. After standing for 1 month, the precipitate was separated, and the corresponding indicators were measured. After racking 3 times, the wine was bottled and stored in a storage area at 15°C.

[0038] Comparative Example 1 Metschnikowiapulcherrima The applications of bacterial strains in winemaking are as follows: This comparative example uses species from a different species within the same genus as YTM1. Metschnikowiapulcherrima It is fermented in combination with RC212, that is, LEVEL2 FLAVIA + RC212 co-fermentation.

[0039] In this comparative example, LEVEL2 FLAVIA was used to replace YTM1 in Example 1, and the other experimental steps were exactly the same as in Example 1.

[0040] Comparative Example 2 The application of RC212 in winemaking: This comparative example uses RC212 in winemaking, as detailed below: S1. Prepare the inoculum for strain RC212.

[0041] Based on 7.5L of grape must, weigh 2.25g of RC212 at a dosage of 0.3g / L, add it while stirring into 10% wt sugar water at 37℃, and wait for the yeast to start fermenting to obtain the seed liquid for later use.

[0042] S2, the production of Cabernet Sauvignon dry red wine.

[0043] Select mature Cabernet Gernischt grapes and destem and crush them. Then, take 7.5L of grape must and put it into a 10L fermentation tank. Add 30mg / L SO2 to the fermentation tank. After 30min, add 0.375g of pectinase EX-V. Place the fermentation tank at 4℃ for cold soaking for 24h.

[0044] After cold maceration, the grape must was warmed to above 15°C, and the inoculum of strain RC212 prepared by S1 was completely inoculated. Fermentation was carried out at 24°C, with fermentation temperature and specific gravity measured every 6 hours, and capping was performed. Alcoholic fermentation was considered complete when the specific gravity dropped below 0.993. The wine was then pressed to separate the pomace, and 40 mg / L SO2 was added to terminate fermentation. The wine was then sealed in full tanks and stored. After standing for one month, the sediment was separated, and relevant indicators were measured. After racking three times, the wine was bottled and stored in a 15°C storage area.

[0045] The wines prepared in Example 1, Comparative Example 1, and Comparative Example 2 were analyzed and evaluated, including sensory evaluation, detection of volatile components, determination of glycerol content, and determination of organic acid content.

[0046] 1. Sensory evaluation of wine.

[0047] The wine sensory evaluation panel consisted of 30 professional sommeliers who conducted tastings in a standard tasting room using standard tasting glasses. They performed sensory analysis and evaluation of the wine samples. After tasting the wine samples, panel members selected descriptive terms from an aroma descriptor list corresponding to the aroma characteristics they tasted. These descriptors were then scored according to intensity, ranging from 1 to 11 points. The intensity scoring criteria are shown in Table 1.

[0048] Table 1 Intensity Level Scoring Criteria 2. Detection of volatile components.

[0049] 2.1 Sample pretreatment.

[0050] Wine sample pretreatment: According to the formula: the number of milliliters of original wine to be taken = A certain amount of the original wine sample was transferred to a 50mL volumetric flask and diluted to volume with ultrapure water to complete the dilution, requiring an alcohol content <10%. 10mL of the diluted sample was then transferred to a 20mL headspace vial, along with 3g of sodium chloride and 20µL of 500mg / L 3-octanol. A stir bar was added, and the vial was capped. The vial was then placed in a constant temperature water bath with a magnetic stirrer and equilibrated for 15 minutes at 50℃ and 500rpm.

[0051] 2.2 Gas Chromatography-Mass Spectrometry Analysis Conditions A 30m × 0.25mm × 0.25µm DB-Wax column was used.

[0052] Gas chromatography conditions: injection inlet temperature 250℃; injection time 5 min; initial temperature 50℃, reaction time 2 min. Then, the temperature was increased at 6℃ / min to 100℃, then at 5℃ / min to 200℃, and finally at 10℃ / min to 240℃, held for 6 min. Helium was used as the carrier gas, with a split ratio of 5:1.

[0053] Mass spectrometry conditions: ion source temperature 200℃, interface temperature 250℃, solvent delay 3.5 min, transfer line temperature 280℃, acquisition mode is scan, scan rate is 1250, initial 30 m / z, final 500 m / z.

[0054] 2.3 Qualitative and quantitative analysis methods.

[0055] Qualitative analysis: The spectra were analyzed using the NIST17 standard database and relevant literature to identify the aroma components of various compounds.

[0056] Quantitative analysis: Using 3-octanol as an internal standard, the relative contents of each compound were calculated using the semi-quantitative internal standard method according to the following formula.

[0057] .

[0058] A 1 —Peak area of ​​the target substance; C 0 —Internal standard concentration, mg / L; V 0 —Internal standard volume, 20µL; A 0 —Peak area of ​​internal standard; V 1 —Sample volume, 10 mL B —Relative content of various compounds.

[0059] 3. Glycerol content determination.

[0060] The analysis was performed using an E2695 Waters high-performance liquid chromatograph, equipped with a Waters 2414 differential detector. The chromatographic column was a Waters-specific sugar column, and the column temperature was set to 85℃. The sample was diluted 10 times and filtered through a 0.45μm filter membrane before being analyzed.

[0061] 4. Determination of organic acid content.

[0062] The determination of malic acid and lactic acid was carried out in accordance with the national standard GB / T 15038-2006, "General Analytical Methods for Wine and Fruit Wine".

[0063] 5. Evaluation results.

[0064] 5.1 Sensory evaluation.

[0065] Compared to the wine obtained from the mixed fermentation of Comparative Example 1, the wine from the mixed fermentation of Example 1 exhibits a stronger aroma intensity, with more pronounced cherry, cranberry, and strawberry flavors, and a lower level of undesirable flavors such as nail polish. Compared to the single-strain fermentation of Comparative Example 2, the wine from the mixed fermentation of Example 1 demonstrates greater complexity and layering, with stronger aromas of strawberry, redcurrant, blueberry, almond, ginger, and dried plum, and a lower level of undesirable flavors such as raw, grassy tastes. See the results below. Figure 1 .

[0066] 5.2 Aroma.

[0067] Compared to Comparative Example 1, the mixed fermentation in Example 1 produced a richer variety of aromas, totaling 73, while Comparative Example 1 only produced 66 aromas. Furthermore, the mixed fermentation in Example 1 yielded higher aromas, including higher yields of esters, acids, terpenes, aromatic compounds, aldehydes, ketones, and ethers. Compared to the single-strain fermentation in Comparative Example 2, the mixed fermentation in Example 1 produced a richer variety of aroma compounds, while Comparative Example 2 only produced 65 aromas. Compared to the single-strain fermentation in Comparative Example 2, the mixed fermentation in Example 1 also yielded higher yields of terpenes, aromatic compounds, and aldehydes, ketones. These results are shown in Table 2 and... Figure 2 As shown.

[0068] Table 2. Fermentation aroma content (mg / L) of Example 1, Comparative Example 1, and Comparative Example 2 Note: "ND" in Table 2 indicates that this substance was not detected.

[0069] 5.3 Physicochemical Indicators.

[0070] The alcohol content of the wine fermented by mixed culture in Example 1 was 11.62% v / v, significantly lower than the 12.01% v / v of the wine fermented by single RC212 strain in Comparative Example 2. p <0.05; and lower than the alcohol content of 11.90% v / v in the mixed fermentation of Comparative Example 1. p <0.05, which meets the current pursuit of low-alcohol fermentation in winemaking.

[0071] In Example 1, the glycerol yield from mixed fermentation was 7.17 g / L, while in Comparative Example 2, the glycerol yield from single-strain fermentation using RC212 was 6.43 g / L. p <0.05; the glycerol yield of the mixed fermentation in Comparative Example 1 was 6.57 g / L. p<0.05, therefore this invention relates to strains that produce high levels of glycerol to enhance the body and flavor of wine.

[0072] In the conversion of malic acid to lactic acid, the malic acid content in the mixed fermentation of Example 1 was 0, the malic acid content in the mixed fermentation of Comparative Example 1 was 0.56 g / L, and the malic acid content in the single-strain fermentation of Comparative Example 2 was 1.89 g / L. The malic acid content in the wine prepared in Example 1 was significantly lower than that in Comparative Example 1 and Comparative Example 2. p <0.05. The lactic acid content of the mixed fermentation in Example 1 was 5.76 g / L, the lactic acid content of the mixed fermentation in Comparative Example 1 was 4.18 g / L, and the lactic acid content of the single-strain fermentation in Comparative Example 2 was 0.25 g / L. The lactic acid content of the wine prepared in Example 1 was significantly higher than that in Comparative Example 1 and Comparative Example 2. p <0.05. The results are shown in Table 3 and... Figure 3 These results illustrate the findings described in Example 1. Metschnikowia chrysoperlae The yeast strain exhibits excellent malic acid-lactic acid conversion ability during co-fermentation with RC212, which can greatly improve fermentation efficiency.

[0073] Table 3. Statistics of Physicochemical Indicators The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0074] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. Metschnikowia chrysoperlae The application of strains in winemaking is characterized by, The Metschnikowia chrysoperlae The strain is YTM1, with accession number CGMCC NO.34926, and was deposited at the China General Microbiological Culture Collection Center on June 17, 2025.

2. The application as described in claim 1, characterized in that, The application refers to at least one of the following: 1) Increase the variety of aroma compounds in wine; 2) Increase the content of aroma compounds in wine; 3) Reduce the alcohol content of the wine; 4) Increase the glycerol production of wine; 5) Reduce the malic acid content of wine; 6) Increase the lactic acid content of wine.

3. The application as described in claim 2, characterized in that, The aroma compounds of the wine include at least one of esters, alcohols, acids, terpenes, aromatic compounds, aldehydes and ketones, and ethers.

4. The application as described in claim 3, characterized in that, The ester is at least one of 2-ethylhexyl lactate, ethyl 8-nonanoate, methyl decanoate, ethyl decanoate, isoamyl decanoate, and ethyl myristate; The alcohol is at least one of n-hexanol, 2-ethylhexanol, L-2,3-butanediol, n-octanol, and n-decanol; The acid mentioned is decanoic acid; The terpenes are at least one of citronellol, damascene, geraniol, and 4-isopropyl-1,6-dimethylnaphthalene; The aromatic compound is at least one of ethyl phenylacetate, phenethyl acetate and phenylethanol; The aldehydes and ketones are at least one of decanal and benzaldehyde; The ether is lauryl alcohol polyether-6.

5. The application as described in claim 1, characterized in that, use Metschnikowia chrysoperlae The method of using the strain for winemaking is as follows: preparation Metschnikowia chrysoperlae Inoculation solution; Metschnikowia chrysoperlae In the inoculation solution Metschnikowia chrysoperla The number of viable bacteria was 1×10⁻⁶. 8 cfu / mL ~1×10 9 cfu / mL; The RC212 strain was weighed out at a ratio of 0.3g:1L to grape must to prepare the inoculum for the RC212 strain. The grape must is macerated, and after maceration, the following is added first: Metschnikowia chrysoperlae The inoculum was fermented at an inoculum volume of 4% v / v; then the inoculum of RC212 strain was added to continue fermentation. After fermentation was completed, SO2 was introduced to terminate fermentation and the mixture was sealed and allowed to stand.

6. The application as described in claim 5, characterized in that, Metschnikowia chrysoperlae The fermentation conditions for the inoculum were 24℃ for 72 hours.

7. The application as described in claim 5, characterized in that, The end of fermentation is indicated by a grape must-liquid ratio of less than 0.

993.

8. The application as described in claim 5, characterized in that, The settling time is 20 to 40 days.

9. The application as described in claim 5, characterized in that, The grape must was macerated at 4°C for 24 hours.

10. The application as described in claim 5, characterized in that, The Metschnikowia chrysoperlae The preparation method of the inoculum solution is as follows: Pick Metschnikowia chrysoperlae Single colonies were obtained by incubating in YPD liquid medium at 28°C and 200 rpm for 36 hours. Metschnikowia chrysoperlae Seed liquid; Grape juice, YPD liquid culture medium and Metschnikowia chrysoperlae The seed culture was mixed and cultured at 28℃ and 200rpm for 36 hours to obtain... Metschnikowia chrysoperlae Inoculation solution.

Images