Application of yeast strain QGXH1 in preparation of ethyl acetate, tectoridiol and ethyl linolenate

Abstract

The invention belongs to the technical field of food microorganisms, and particularly relates to application of a yeast strain QGXH1 in preparation of ethyl acetate, tectoridiol and ethyl linolenate, the yeast strain QGXH1 is preserved in China General Microbiological Culture Collection Center on January 29, 2024, the preservation number is CGMCC No. 29805, and the yeast strain QGXH1 is preserved in China General Microbiological Culture Collection Center on January 29805. The preservation address is Institute of Microbiology, Chinese Academy of Sciences, No.3, Yard 1, Beichen West Road, Chaoyang District, Beijing; the saccharomyces cerevisiae is classified and named as Saccharomyces cerevisiae, and the saccharomyces cerevisiae is used as a culture medium of the saccharomyces cerevisiae. The contents of ethyl acetate, ethyl palmitate, ethyl caprate, linolenic acid and ethyl 9-hexadecanoate in the plum vinegar prepared by fermentation of the yeast strain QGXH1 are obviously increased, and in addition, when the plum vinegar is prepared by co-fermentation of the yeast strain QGXH1 and green tea, tectoridiol and ethyl linolenate are added in nutritional ingredients, so that the yield of the plum vinegar is increased. The aroma components and nutrient substances of the plum vinegar are greatly enriched.

Description

Technical Field

[0001] The present invention belongs to the technical field of food microbiology, and particularly relates to the application of yeast strain QGXH1 in the preparation of ethyl acetate, iridodiol, and ethyl linolenate. Background Art

[0002] Intrahepatic cholestasis is a severe liver disease caused by disorders in bile secretion and excretion, which may be triggered by genetics, drug toxicity, or infection. Clinical manifestations include jaundice, pruritus, and abnormal liver function. Existing treatment methods mainly rely on choleretic drugs such as ursodeoxycholic acid and phenobarbital, but the efficacy of these treatments is limited, and they are often accompanied by gastrointestinal discomfort, drug resistance, or increased liver burden caused by long-term use. Therefore, the development of new, safe, and effective treatment means has become an important direction in medical research. At the same time, functional foods and beverages have attracted increasing attention due to their naturalness and multiple health benefits. Plum vinegar contains acetic acid, organic acids, amino acids, vitamins, and antioxidants, and has functions such as promoting digestion, regulating blood sugar, improving metabolism, and antioxidant effects. However, existing plum vinegar products mainly target general health needs and lack functional designs for specific liver diseases (such as intrahepatic cholestasis). For example, the traditional effects of plum vinegar mainly focus on digestion promotion and antioxidant effects, and do not directly address the problem of bile metabolism disorders. Iridoids are a class of monoterpene secondary metabolites widely present in plants and have attracted attention in recent years due to their diverse biological activities. These compounds are mainly used for pest and pathogen defense in plants and also show potential for anti-inflammatory, antioxidant, antibacterial, and metabolic regulation in the medical field. The study "Choleretic effects of alpha-iridodiolon experimentally induced intrahepatic cholestasis" published by Mizoguchi et al. (1992) in the journal Planta Medica reported the significant choleretic effect of alpha-iridodiol in an experimental intrahepatic cholestasis model. In this study, an intrahepatic cholestasis model was induced in rats by intravenous injection of a lymphokine called "cholestatic factor", resulting in a significant decrease in bile flow and bile acid excretion. After administration of alpha-iridodiol, the decrease in bile flow and bile acid excretion was significantly inhibited, and a similar choleretic effect was also observed in normal rats. Summary of the Invention

[0003] The present invention provides the application of yeast strain QGXH1 in the preparation of ethyl acetate. This strain can increase the contents of ethyl acetate, ethyl palmitate, ethyl caprate, linolenic acid, and ethyl 9-hexadecenoate in plum vinegar. When yeast strain QGXH1 is co-fermented with green tea to prepare plum vinegar, the nutritional components are increased by iridodiol, ethyl linolenate, glyoxylic acid, trans-9,12-octadecadienoic acid, β-methyllevulinic acid, 2-methoxy-3-prop-2-enylphenol, 1-butanol, ethyl octanoate, and methyl 10-oxohexadecanoate. That is, the flavor substances and nutritional components of plum vinegar are also greatly enriched.

[0004] The technical solution of this application is as follows: The first object of this application is to protect the application of yeast strain QGXH1 in the preparation of ethyl acetate. The Saccharomyces cerevisiae strain QGXH1 was deposited at the General Microbiological Center of the China Committee for Culture Collection of Microorganisms on January 29, 2024, with the deposit number: CGMCC No. 29805; the deposit address: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing; the taxonomic name: Saccharomyces cerevisiae Saccharomyces cerevisiae .

[0005] According to the specific implementation manner of this application, it also includes acetic acid bacteria.

[0006] According to the specific implementation manner of this application, the yeast strain QGXH1 is added in the form of fermentation broth.

[0007] The second object of this application is to protect the application of yeast strain QGXH1 in the co-fermentation with green tea for the preparation of iridodiol.

[0008] The third object of this application is to protect the application of yeast strain QGXH1 in the co-fermentation with green tea for the preparation of ethyl linolenate.

[0009] Strain deposit information: Deposit institution: General Microbiological Center of the China Committee for Culture Collection of Microorganisms; Deposit number: CGMCC No. 29805; Deposit date: January 29, 2024; Deposit address: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing; Taxonomic name: Saccharomyces cerevisiae Saccharomyces cerevisiae .

[0010] Advantages of the present invention Plum vinegar fermented with yeast strain QGXH1 has increased contents of ethyl acetate, ethyl palmitate, ethyl caprate, linolenic acid, and ethyl 9-hexadecenoate. The content of ethyl acetate has increased by 11,815,122.2 μg / L, the content of ethyl palmitate has increased by 7,420.3 μg / L, the content of ethyl caprate has increased by 1,391.5 μg / L, the content of linolenic acid has increased by 4,558.4 μg / L, and the content of ethyl 9-hexadecenoate has increased by 1,351 μg / L.

[0011] Compared with the plum vinegar prepared by fermenting with yeast strain QGXH1 alone, the new nutrients in the plum vinegar prepared by co-fermenting yeast strain QGXH1 with green tea are iridodiol, ethyl linolenate, glyoxylic acid, trans-9,12-octadecadienoic acid, β-methyllevulinic acid, 2-methoxy-3-prop-2-enylphenol, 1-butanol, ethyl octanoate, and methyl 10-oxohexadecanoate. Among them, the content of iridodiol has increased by 170.9 μg / L, the content of ethyl linolenate has increased by 320.0 μg / L, the content of glyoxylic acid has increased by 595.8 μg / L, the content of trans-9,12-octadecadienoic acid has increased by 433.4 μg / L, the content of β-methyllevulinic acid has increased by 258.6 μg / L, the content of 2-methoxy-3-prop-2-enylphenol has increased by 78.6 μg / L, the content of 1-butanol has increased by 46.5 μg / L, the content of ethyl octanoate has increased by 39.8 μg / L, and the content of methyl 10-oxohexadecanoate has increased by 31.9 μg / L. Brief Description of the Drawings

[0012] Figure 1 Chromatograms of the products of Saccharomyces cerevisiae BY4741, yeast strain QGXH1, and the plum vinegar fermented by yeast strain QGXH1 with green tea. Detailed Embodiments

[0013] To better understand the present invention, the content of the present invention will be further clarified below in conjunction with embodiments. However, the content of the present invention is not limited to the following embodiments. The materials, reagents, etc. used in the embodiments and test examples of the present invention are all conventional products obtained from commercial channels unless otherwise specified; the methods used in the embodiments and test examples of the present invention are all conventional methods unless otherwise specified.

[0014] The construction process of the genetic engineering bacterium of yeast strain QGXH1 can be found in Chinese Patent CN118006476A.

[0015] YPD solid medium: Weigh 2 g of glucose, 2 g of peptone, 1 g of yeast extract powder, and 2 g of agar powder and dissolve them in 100 mL of distilled water.

[0016] YPD liquid medium: Weigh 2 g of glucose, 2 g of peptone, and 1 g of yeast extract powder and dissolve them in 100 mL of distilled water.

[0017] YPG galactose liquid medium: weigh 2 g galactose, 2 g peptone, and 1 g yeast extract powder and dissolve them in 100 mL of distilled water.

[0018] Example 1 The method for preparing the fermentation broth of yeast strain QGXH1 comprises the following steps: The yeast strain QGXH1 was streaked onto a YPD solid culture medium plate. After a single colony grew on the plate, a single colony was picked and inoculated into a test tube containing 3 mL of YPD liquid culture medium. The tube was placed in a constant temperature shaker and cultured (30°C, 220 r / min) until the OD600 value was about 0.5, and the first activation was completed. The tube was then transferred to a triangular flask containing 100 mL of YPG galactose liquid culture medium according to a 1% inoculation amount for secondary activation culture. The fermentation broth was prepared when the OD600 value was about 1.5 (30°C, 220 r / min).

[0019] Experimental Example 2 Yeast strain QGXH1 is used for liquid fermentation of plum vinegar, comprising the following steps: (1) Select 1 kg of fresh plums and squeeze them into juice. Add 1 g of pectinase (from Shanghai MacLean Biological Reagent Co., Ltd.) and filter the juice with gauze at 55°C for 2 h. Adjust the sugar content to 20 with white sugar and divide the juice into experimental group and control group. (2) 40 mL of the fermentation liquid of the yeast strain QGXH1 prepared in Example 1 was added to the experimental group, and 40 mL of the activated Saccharomyces cerevisiae BY4741 (from Beijing Coolaibo Technology Co., Ltd.) was added to the control group, and alcohol fermentation was carried out at 17°C; after fermentation for 7 days, plum wine was obtained; The activation method of brewer's yeast BY4741 is as follows: streak brewer's yeast BY4741 onto a YPD solid culture medium plate, pick a single colony after a single colony grows on the plate, inoculate it into a test tube containing 100 mL of YPD liquid culture medium, and culture it in a constant temperature shaker (30°C, 220 r / min) until the OD600 value is about 0.5, and the activation is completed.

[0020] (3) The alcohol content of the experimental group and the control group was adjusted to 7%, and 1 g of Acetobacter acutilobacillin Huniang 1.01 bacterial powder (from Beijing Baozang Biotechnology Co., Ltd.) was inoculated into the plum wine prepared in step (2) for acetic acid fermentation; (4) After the control group and the experimental group were acidified in a shaker at 30°C and 190 r / min for 7 days, samples were collected for GC-MS and high performance gas chromatography-mass spectrometry. Figure 1 ,from Figure 1It can be seen that compared with the plum vinegar fermented by yeast strain BY4741, the content of flavor substances in the plum vinegar fermented by yeast strain QGXH1 has increased significantly.

[0021] Experimental Example 3 Yeast strain QGXH1 and green tea are jointly used for liquid fermentation of plum vinegar, including the following steps: (1) Weigh 10 g of fresh green tea leaves and remove the excess moisture in an 80 °C oven until the tea leaves are in a semi-dry state. Stir-fry in a brand-new iron pot (not contaminated with oil) for 5 h, paying attention to rubbing while stir-frying; then dry in the oven. Soak the tea leaves in 100 mL of 90 °C hot water for 1 h, concentrate to 80 mL, and filter to obtain the tea soup.

[0022] (2) Select 1 kg of fresh plums, squeeze them into juice, add 1 g of pectinase (from Shanghai Macklin Biochemical Co., Ltd.), and carry out a water bath at 55 °C for 2 h. Filter with gauze to obtain plum juice, and adjust the sugar content of the obtained plum juice to 20 with granulated sugar.

[0023] (3) Divide the plum juice into an experimental group and a control group; mix the experimental group with the tea soup in step (1), and do not treat the control group. (4) Add 40 mL of the fermentation broth of yeast strain QGXH1 to the experimental group and the control group for alcoholic fermentation for 7 days to obtain plum wine; adjust the alcohol content to 7%, weigh 1 g of Acetobacter pasteurianus Huniang 1.01 bacterial powder (from Beijing Baocang Biotechnology Co., Ltd.), and add it to the plum wine for acetic acid fermentation.

[0024] (4) The control group and the experimental group are acidified in a shaker at 30 °C and 190 r / min for 7 days, and then samples are taken for GC-MS and high-performance gas mass spectrometry detection. The results are shown in Figure 1 , from Figure 1 It can be seen that compared with the plum vinegar fermented by Saccharomyces cerevisiae BY4741, the content of flavor substances in the plum vinegar fermented by yeast strain QGXH1 has increased significantly. The combined action of yeast strain QGXH1 and green tea can further increase the types of flavor substances in plum vinegar.

[0025] Example of implementation effect Analysis of the component detection results of the plum vinegar obtained in Effect Example 1, Examples 2 and 3.

[0026] Table 1 GC-MS detection results of the plum vinegar obtained in Examples 2 and 3

[0027] It was detected that the difference between the experimental group and the control group lies in: In the experimental group of Example 2 compared with the control group, the content of ethyl acetate in the experimental group increased to 11815122.21 μg / L, the content of ethyl palmitate increased to 7420.3 μg / L, the content of linoleic acid increased to 4561.4 μg / L, the content of ethyl 9-hexadecenoate increased to 1351 μg / L, and the content of ethyl decanoate increased to 1391.5 μg / L.

[0028] In the experimental group of Example 3 compared with the control group, although the contents of flavor substances such as ethyl acetate, ethyl palmitate, linoleic acid, ethyl 9-hexadecenoate, and ethyl decanoate in the experimental group decreased, the types of flavor substances and the types of nutrients in the experimental group increased. The added substances were iridodiol, ethyl linolenate, glyoxylic acid, trans-9,12-octadecadienoic acid, β-methyllevulinic acid, 2-methoxy-3-prop-2-enylphenol, 1-butanol, ethyl octanoate, methyl 10-oxohexadecanoate, and so on.

[0029] The data of the experimental group and the control group in Example 2 prove that the yeast strain QGXH1 can significantly increase the content of flavor substances in plum vinegar compared with Saccharomyces cerevisiae BY4741. The data of the experimental group and the control group in Example 3 prove that the combined action of the yeast strain QGXH1 and green tea can further increase the types of flavor substances and nutrients in plum vinegar.

[0030] Ethyl linolenate is a plant-derived ω-3 fatty acid. Ethyl linolenate is commonly used as a dietary supplement, which helps to improve blood lipid and support cardiovascular health. In some food processing, ethyl linolenate may be used as a flavor enhancer or a component to enhance flavor.

Claims

1. Application of yeast strain QGXH1 in the preparation of ethyl acetate, characterized in that: The yeast strain QGXH1 was deposited in the General Microbiology Center of the China Microbiological Culture Collection Administration on January 29, 2024, with the deposit number: CGMCC No. 29805; the deposit address is: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing; classification name: Saccharomyces cerevisiae Saccharomyces cerevisiae .

2. The use according to claim 1, characterized in that: Also included is Acetobacter.

3. The use according to claim 1 or 2, characterized in that: The yeast strain QGXH1 is added in the form of fermentation broth.

4. Application of yeast strain QGXH1 in the preparation of irisdiol by green tea fermentation.

5. Application of yeast strain QGXH1 in the preparation of ethyl linolenate by green tea fermentation.

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