A yeast strain isolated from Chlorella symbiotic bacteria and its application in the treatment of organic waste liquid from kitchen waste.

Abstract

This invention discloses a yeast strain isolated from Chlorella symbiotic bacteria and its application in treating organic waste liquid from kitchen waste. Meyerozyma guilliermondii The strain SHS0923, with accession number CCTCCNO:M20252128, is deposited at the China Center for Type Culture Collection, Wuhan University, on September 26, 2025. This invention addresses the problems of existing strains exhibiting low adaptability to food waste, strong enzymatic dependence, difficulty in simultaneous purification, and low added value of the products. This strain achieves a carbon source utilization efficiency >80% in the unenzymatically hydrolyzed supernatant containing 70% hot pot food waste, reaches a biomass of 4 g / L after 4 days of shaking culture, and achieves COD, ammonia nitrogen, and total phosphorus removal rates of 71%, 81%, and 92%, respectively. It exhibits the highest intracellular LPC 18:1 abundance and a sedimentation efficiency >80% after 10 minutes.

Description

Technical Field

[0001] This invention relates to a yeast strain, specifically to a yeast strain isolated from Chlorella symbiotic bacteria and its application in the treatment of organic waste liquid from kitchen waste. Background Technology

[0002] The booming catering industry in Sichuan has generated a large amount of distinctive food waste that is high in salt, oil, and spicy ingredients. Traditional landfill and incineration methods easily lead to soil and air pollution. Microbial degradation technology, due to its green, low-carbon nature and high resource recovery rate, has become the core development direction in this field. The development of relevant functional strains and process optimization have become key research areas in the industry. Currently, there are two representative technical solutions, but both have significant technical shortcomings that make them difficult to adapt to the food waste in Sichuan and to meet the dual requirements of efficient degradation and high-value conversion.

[0003] The existing literature 1 (Science Popularization Times. Biotechnology turns kitchen waste into treasure [EB / OL]. (2025-01-17) [Accessed date]. China Science Popularization Network. http: / / www.kepu.gov.cn / newspaper / 2025-01 / 17 / content_287282.html) uses an artificially genetically modified "foul-eating yeast" strain as the core to construct a combined biological treatment technology. The solid and liquid components of kitchen waste are used as nutrient raw materials for integrated fermentation, realizing the conversion of starch into alcohol and lactic acid, animal protein into probiotic protein, and oil into biodiesel and bio-aviation fuel. At the same time, a demonstration production line with a processing capacity of 200 tons / day is built to simplify the sorting and pretreatment process of traditional technology and realize the multi-component resource utilization of kitchen waste. Its shortcomings are as follows: First, the strain is an artificially engineered bacterium, which is poorly adapted to the high-oil and high-spiciness food waste from Sichuan hot pot restaurants, and is prone to growth inhibition leading to a sharp drop in degradation efficiency; second, the strain is subjected to solid-liquid integrated treatment, which makes it impossible to purify the bacterial cells and collect the target high-value-added metabolites; third, the artificially modified strain has potential ecological safety risks and is not suitable for open treatment scenarios.

[0004] The technical solution of reference 2 ([1] Wang Ming, Quan Wenjie, Shang Honglei, et al. Feasibility study on solid-state anaerobic fermentation of kitchen waste to produce ethanol by inoculating yeast[J]. Environmental Science Research, 2022, 35(12):2830-2835.DOI:10.13198 / j.issn.1001-6929.2022.06.24) is to carry out solid-state anaerobic fermentation of kitchen waste by two modes: direct inoculation and inoculation with yeast after sterilization, to verify the feasibility of producing ethanol. The results show that direct inoculation can make the ethanol concentration reach 11.86~12.09g / L, and at the same time increase the starch hydrolysis rate from 19.36% to 27.90%~37.57%, realizing the directional conversion of carbohydrates in kitchen waste. Its shortcomings are as follows: First, the strain does not completely degrade starch, with starch residue still reaching 274.02-316.51 mg / g after 24 hours of fermentation. Moreover, it is only suitable for conventional kitchen waste and cannot tolerate the high salt and high oil characteristics of kitchen waste in Sichuan. Second, it relies on a strictly anaerobic environment, has a complex operation process and a single application scenario, and cannot take into account the treatment of supernatant from liquid kitchen waste. Third, it only focuses on the production of ethanol as a single product and does not achieve the synergistic removal of carbon, nitrogen, phosphorus and other pollutants. Fourth, the source of the strain is unclear and it has not undergone natural environmental adaptability screening, making it less competitive in actual complex microbial systems.

[0005] The shortcomings of the above-mentioned technical solutions are as follows: First, none of them can be adapted to the high-oil, high-salt, and spicy kitchen waste in Sichuan, and the strains have insufficient tolerance; second, the utilization rate of the large-molecule organic waste liquid of kitchen waste is low; third, it is difficult to purify and recover the high-value-added metabolites of the bacterial cells in large quantities, and there is a lack of high-value conversion ability; fourth, the simultaneous purification of nutrients such as carbon, nitrogen, and phosphorus has not been achieved. Summary of the Invention

[0006] The purpose of this invention is to provide a yeast strain isolated from Chlorella symbiotic bacteria and its application in treating organic waste liquid from kitchen waste. This invention solves the problems of low adaptability, strong enzymatic dependence, difficulty in simultaneous purification, and low added value of existing strains. This strain has a carbon source utilization efficiency of >80% in supernatant containing 70% hot pot kitchen waste without enzymatic pretreatment, and a biomass of 4 g / L after 4 days of shaking culture. The removal rates of COD, ammonia nitrogen, and total phosphorus are 71%, 81%, and 92%, respectively. The intracellular LPC 18:1 abundance is the highest, and the sedimentation efficiency is >80% after 10 minutes.

[0007] To achieve the above objectives, the present invention provides a yeast strain isolated from Chlorella symbiotic bacteria, which ( Meyerozyma guilliermondii SHS0923, with accession number CCTCCNO: M20252128, is deposited at the China Center for Type Culture Collection (CCTCC), on September 26, 2025.

[0008] This invention provides a microbial agent for treating kitchen waste containing the aforementioned yeast strain.

[0009] Preferably, the strain in the treatment agent ( Meyerozyma guilliermondii The viable count of SHS0923 is not less than 1×10⁻⁶. 9 CFU / mL.

[0010] This invention provides an application of the yeast strain as described above or the food waste treatment microbial agent as described above in the treatment of food waste.

[0011] Preferably, when using the yeast strain, the application includes the following steps: The strain ( Meyerozyma guilliermondii SHS0923 was inoculated into YPD medium and activated at 28±0.5℃ and 150 rpm. It was then inoculated into a medium containing undigested kitchen waste supernatant and cultured at 25±0.5℃ and 110 rpm with shaking.

[0012] Preferably, the YPD culture medium is a YPD liquid culture medium and a YPD solid culture medium; wherein, the components of the YPD liquid culture medium are yeast extract, peptone and glucose; the components of the YPD solid culture medium are yeast extract, peptone, glucose and agar powder; the inoculation into the culture medium containing undigested kitchen waste supernatant is carried out at a ratio of 1:100000 between the volume of activated bacteria and the volume of undigested kitchen waste supernatant.

[0013] Preferably, the amounts of yeast extract, peptone, and glucose are 1%, 2%, and 2%, respectively; and the amounts of yeast extract, peptone, glucose, and agar powder are 1%, 2%, 2%, and 2%, respectively. Preferably, the culture medium containing the supernatant of undigested kitchen waste comprises kitchen waste, the specific component 3-O-Feruloylquinic acid, and the specific component Biotin sulfone; when the concentration of the specific component 3-O-Feruloylquinic acid is 1 μM, it can prolong the yeast growth cycle to 72 h and increase the maximum cell number by ≥11%; when the concentration of the specific component Biotin sulfone is 10 μM, it can promote yeast growth, reaching the maximum cell number in 48 h, which is ≥10% higher than the control group.

[0014] This invention provides a metabolite produced by the yeast strain described above, wherein the metabolite is LPC 18:1 (lysophosphatidylcholine 18:1), and its abundance in yeast cells is ≥3.8 × 10⁻⁶. 7 (CS30-4 sample) or ≥6.6×10 7(CH50-4 sample) can be used as a research-grade skin inflammation regulation reagent.

[0015] This invention provides the application of the metabolite as described above in the preparation of a skin inflammation regulating agent.

[0016] This invention discloses a yeast strain isolated from Chlorella symbiotic bacteria and its application in treating organic waste liquid from kitchen waste. This invention solves the problems of existing strains, such as low adaptability, strong enzymatic dependence, difficulty in simultaneous purification, and low added value of the products. It has the following advantages: The strain of the present invention ( Meyerozyma guilliermondii SHS0923 requires no enzymatic pretreatment in the treatment of kitchen waste. It has a carbon source utilization efficiency of >80% for supernatant containing 70% hot pot kitchen waste. After 4 days of shaking culture, the biomass reaches 4 g / L. The removal rates of COD, ammonia nitrogen, and total phosphorus are 71%, 81%, and 92%, respectively. It has the highest intracellular LPC 18:1 abundance and has the potential to develop a skin inflammation regulation reagent. The sedimentation efficiency of >80% in 10 minutes combines high-efficiency purification and resource utilization potential, significantly reducing the cost of industrial harvesting and providing key technical support for large-scale application. Attached Figure Description

[0017] Figure 1 This invention presents the basic component analysis results and physical images of two types of kitchen waste from Chengdu University's student canteen and Chengdu Bashuzai Hot Pot Restaurant.

[0018] Figure 2 The figure shows the observation results of the heterotrophic growth of the Chlorella symbiotic system of the present invention in the enzymatic hydrolysis and non-enzymatic hydrolysis supernatants of two types of kitchen waste.

[0019] Figure 3 This image shows the metabolomics analysis results of unenzymatically hydrolyzed supernatant from two types of kitchen waste from Chengdu University's student canteen and Chengdu Bashuzai Hot Pot Restaurant.

[0020] Figure 4 The sequence alignment results of the microorganisms cultured in the Chlorella-bacterial symbiotic system of this invention in the supernatants of two types of kitchen waste and the ITS product of isolated and purified Mg in the NCBI library.

[0021] Figure 5 The diagram shows the metagenomic analysis results of the microbial clusters cultured in the supernatant of two types of kitchen waste in the Chlorella symbiotic system of this invention, as well as the isolation, ITS, and PCR identification results of the dominant bacterial species Mg.

[0022] Figure 6 This is a graph showing the growth parameters of Mg in kitchen waste before and after enzymatic hydrolysis at different dilution ratios during static cultivation according to the present invention.

[0023] Figure 7This is a graph showing the growth parameters of Mg cultured in unenzymatically hydrolyzed kitchen waste at different dilution ratios according to the present invention.

[0024] Figure 8 The figure shows the effect of the significantly different components 3-O-Feruloylquinic acid and Biotinsulfone in the kitchen waste from hot pot on Mg growth.

[0025] Figure 9 This diagram shows the pathway enrichment results of metabolomics in Mg cells cultured from different types of undigested food waste according to the present invention.

[0026] Figure 10 This is a phylogenetic tree diagram of the ITS sequence of Mg in this invention. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] This invention focuses on the isolation, purification, culture condition optimization, verification of the degradation performance of food waste, and synthesis of high-value products of the yeast strain Meyerozyma guilliermondii (Mg). Using student canteen waste (SCW, from Chengdu University in Chengdu, Sichuan Province) and hot pot food waste (HPW, from Bashuzai Hot Pot Restaurant) as treatment targets, the invention verifies the strain's ability to degrade, purify water, and convert food waste with high value in Sichuan regional characteristics without pretreatment.

[0029] The test methods involved in the following embodiments 1. Detection of cell dry weight, biomass yield, and sedimentation efficiency. Chlorella and yeast were collected at different time points. After being freeze-dried to constant mass, the dry weight of cells per unit volume was determined by gravimetric analysis. Biomass energy production = (dry weight of cells per unit volume / total carbohydrates per unit volume in the initial culture medium) × 100%. Sedimentation efficiency: 5 mL of yeast cells cultured for 4 days were placed in a glass test tube. After standing for 0, 10, and 30 minutes, cell sap was collected at a depth of 0.5 cm from the liquid surface at different time points, and the absorbance of the cells at 600 nm was measured. Sedimentation efficiency = (OD600...) / (...) 0min -OD600 xmin ) / OD600 0min ×100%.

[0030] 2. Determination of glucose, COD, ammonia nitrogen, total nitrogen, and total phosphorus content. Food waste samples were diluted and filtered through a 0.22 μm nylon membrane (Jinteng, Tianjin). Glucose content was determined by high-performance liquid chromatography (HPLC, Agilent 1260 Infinity) using a ZORBAX Original NH2 column (Agilent, USA) and an evaporative light scattering detector (ELSD). The mobile phase was 70% acetonitrile / 30% water, the flow rate was 1 mL / min, the column temperature was 25℃, and the injection volume was 10 μL. COD, ammonia nitrogen (NH4-N), total nitrogen (TN), and total phosphorus (TP) content were determined according to the kit instructions (Henan Suijing Environmental Protection Technology Co., Ltd.).

[0031] 3. Determination of carbohydrate, protein, and lipid content Carbohydrate content: 5 mg of lyophilized food waste was taken, and the absorption wavelength at 483 nm was measured using the phenol-sulfuric acid method (Bio Tek Cytation, a multi-functional microplate reader). A standard curve was plotted using glucose as the standard. Remaining carbohydrate percentage = Remaining carbohydrate content / Initial carbohydrate content × 100%.

[0032] Total soluble protein: Add protein lysis buffer (Beyotime) containing 1 mM PMSF to 5 mg of lyophilized and ground food waste, vortex for 45 min, centrifuge, and collect the supernatant as the protein solution. Protein content was determined using a BCA kit (Beyotime) at a detection wavelength of 562 nm, with bovine serum albumin as the standard protein.

[0033] Total lipid content: Total lipids were extracted from 100 mg of lyophilized food waste using the methanol-chloroform method. The specific procedure was as follows: The mixture was combined with 5% NaCl (1.5 mL), methanol (2 mL), and chloroform (2 mL), shaken for 3 min, and centrifuged at 3,500 × g for 3 min. The chloroform layer was collected into a pre-weighed centrifuge tube, and the extraction was repeated with 2 mL of chloroform. The chloroform layers were combined, dried under nitrogen, and weighed to calculate the lipid content.

[0034] 4. Non-targeted metabolomics analysis of supernatant from unenzymatically hydrolyzed kitchen waste and intracellular metabolites after microbial culture LC-MS detection: Sample preparation: After slowly thawing the collected cell samples at 4°C, an appropriate amount of sample was added to a pre-cooled methanol / acetonitrile / water solution (2:2:1, v / v), vortexed, sonicated at low temperature for 30 min, allowed to stand at -20°C for 10 min, centrifuged at 14000g at 4°C for 20 min, and the supernatant was vacuum dried. For mass spectrometry analysis, 100 μL of acetonitrile-water solution (acetonitrile:water = 1:1, v / v) was added to reconstitute the sample, vortexed, and centrifuged at 14000g at 4°C for 15 min. The supernatant was then injected for analysis. Quality control (QC) samples were prepared by mixing equal volumes of the test samples. These samples were used to determine the instrument status and balance the chromatography-mass spectrometry system before injection, and also to evaluate the system stability throughout the experiment.

[0035] Chromatographic conditions: Samples were separated using an Agilent 1290 Infinity LC ultra-high performance liquid chromatography (UHPLC) system with a HILIC column; column temperature 25℃; flow rate 0.5 mL / min; injection volume 2 μL; mobile phase composition A: water + 25 mM ammonium acetate + 25 mM ammonia, B: acetonitrile; gradient elution program as follows: 0-0.5 min, 95% B; 0.5-7 min, B linearly decreasing from 95% to 65%; 7-8 min, B linearly decreasing from 65% to 40%; 8-9 min, B maintained at 40%; 9-9.1 min, B linearly decreasing from 40% to 95%; 9.1-12 min, B maintained at 95%; throughout the analysis, samples were placed in an autosampler at 4℃. To avoid the influence of instrument signal fluctuations, samples were analyzed sequentially in a random order. QC samples were inserted into the sample queue to monitor and evaluate the stability of the system and the reliability of the experimental data.

[0036] Q-TOF mass spectrometry conditions: The first and second stage spectra of the samples were acquired using an AB Triple TOF 6600 mass spectrometer. The ESI source conditions after UHPLC separation are as follows: Nebulizer gas 1 (Gas1): 60, Assisted heating gas 2 (Gas2): 60, Curtain gas (CUR): 30 psi, Ion source temperature: 600℃, Spray voltage (ISVF) ±5500V (both positive and negative modes); Primary mass-to-charge ratio detection range: 60-1000 Da, Secondary fragment ion mass-to-charge ratio detection range: 25-1000 Da, Primary mass spectrometry scan cumulative time: 0.20 s / spectra, Secondary mass spectrometry scan cumulative time: 0.05 s / spectra; Secondary mass spectrometry is obtained using data-dependent acquisition mode (IDA) and peak intensity screening mode, Declustering voltage (DP): ±60V (both positive and negative modes), Collision energy: 35±15 eV, IDA settings are as follows: Dynamic isotope exclusion, ion range 4 Da, 10 fragment spectra acquired per scan.

[0037] Chromatography-mass spectrometry analysis (Orbitrap Explorisrm 480) Chromatographic conditions: Samples were separated using a Vanquish LC ultra-high performance liquid chromatography (UHPLC) system with a HILIC column; column temperature 25℃; flow rate 0.5 mL / min; injection volume 2 μL; mobile phase composition A: water + 25 mM ammonium acetate + 25 mM ammonia, B: acetonitrile; gradient elution program as follows: 0-0.5 min, 95% B; 0.5-7 min, B linearly changes from 95% to 65%; 7-8 min, B linearly changes from 65% to 40%; 8-9 min, B maintains at 40%; 9-9.1 min, B linearly changes from 40% to 95%; 9.1-12 min, B maintains at 95%; throughout the analysis, samples were placed in an autosampler at 4℃. To avoid the influence of instrument signal fluctuations, samples were analyzed continuously in a randomized order. QC samples were inserted into the sample queue to monitor and evaluate the stability of the system and the reliability of the experimental data.

[0038] Q-TOF mass spectrometry conditions: An Orbitrap Exploris 480 mass spectrometer was used to acquire primary and secondary spectra of the samples. The ESI source conditions after UHPLC separation were as follows: Auxiliary heating gas 1 (Gas1): 50, Auxiliary heating gas 2 (Gas2): 2, ion source temperature: 350℃, spray voltage (ISVF): 3500V for positive ion mode, 2800V for negative ion mode; primary mass-to-charge ratio detection range: 70-1200 Da, resolution: 60000, cumulative scan time: 100 ms; secondary mass-to-charge ratio was acquired using a segmented acquisition method, with a scan range of 70-1200 Da, secondary resolution: 60000, cumulative scan time: 100 ms, and dynamic exclusion time: 4 s.

[0039] Data Processing: Raw data was converted to .mzML format using ProteoWizard, and then peak alignment, retention time correction, and peak area extraction were performed using the XCMS program. The XCMS software parameters were set as follows: For peak picking, centWave m / z = 10ppm, peakwidth = c(10, 60), prefilter = c(10, 100). For peak grouping, bw = 5, mzwid -0.025, and minfrac = 0.5 were used. For the data extracted by XCMS, the data integrity was first checked. Metabolites with more than 50% missing values ​​within a group were removed and not included in subsequent analysis. KNN imputation was performed for null values, and extreme values ​​were removed. Finally, the total peak area was normalized to ensure parallel comparability between samples and metabolites.

[0040] 5. Metagenomic analysis of microbial clusters cultured in the supernatant of two types of kitchen waste in a Chlorella-bacterial symbiotic system. High-quality genomic DNA was extracted from biological samples using a modified CTAB method. Sequencing libraries were then constructed using the MGI DNA Library Universal Kit (Novizan, Nanjing), and quality checks were performed after library construction. Qualified libraries were then subjected to high-throughput sequencing on the MGI-SEQ 2000 sequencing platform. The raw sequencing data were first quality-assessed using FastQC, and adapter sequences and low-quality reads were removed using Trimmomatic. Subsequently, Bowtie2 was used to align the sequences to a reference genome to remove host-derived sequences. High-quality sequencing reads were assembled into contigs using MEGAHIT, and the taxonomic composition and functional characteristics of the microbial community were analyzed using Kraken2 in conjunction with a functional annotation database. Statistical analysis of community structure, including diversity index calculation and differential abundance analysis, was performed in the R language environment.

[0041] All experiments were performed in triplicate, and results are expressed as mean ± SD. Data were analyzed using GraphPad Prism 9.3.1. Differences between groups were analyzed using ANOVA, and post-hoc comparisons were performed using Tukey's multiple comparison method. A p-value < 0.05 was considered statistically significant.

[0042] YPD liquid medium consists of 1% yeast extract, 2% peptone, and 2% Dextrose (glucose). YPD solid medium consists of 1% yeast extract, 2% peptone, 2% Dextrose (glucose), and 2% agar powder.

[0043] Example 1: Extraction, isolation and identification of Meyerozyma guilliermondii strain The student cafeteria waste (SCW) selected in this invention comes from Chengdu University in Chengdu, Sichuan Province, and the hot pot kitchen waste (HPW) comes from Bashuzai Hot Pot Restaurant, such as... Figure 1 The values ​​are shown in D and Table 1. Irrelevant parts (such as bones, plastic packaging, paper towels, and other non-food components) from the food waste were manually removed, thoroughly mixed, and stored at -20°C. 20g samples were taken from each group and freeze-dried under vacuum until constant mass was achieved, at which point the moisture content was determined. The resulting freeze-dried samples were used for subsequent component analysis.

[0044] Table 1. Moisture content and pH changes before and after enzymatic hydrolysis for two types of kitchen waste. S: Student canteen waste; H: Hot pot restaurant waste.

[0045] like Figure 1 As shown, this invention presents the basic component analysis results and physical images of two types of kitchen waste from Chengdu University's student canteen and Chengdu Bashuzai Hot Pot Restaurant. A represents the ratio analysis of carbohydrates, proteins, and lipids; B represents the change in glucose content during the enzymatic hydrolysis of kitchen waste; C represents the mixed liquid after enzymatic hydrolysis of kitchen waste; D represents the collected kitchen waste sample; SCW represents student canteen waste; and HPW represents hot pot kitchen waste.

[0046] Depend on Figure 1 As shown in Table 1, the overall moisture content of food waste from hot pot restaurants is higher than that of food waste from student canteens. The main component analysis results indicate that food waste from student canteens has the highest carbohydrate content, exceeding 50% of its dry weight, while food waste from hot pot restaurants has the highest lipid content, reaching over 47%. Figure 1 (A) This may be because student cafeteria waste contains a lot of rice, resulting in a high starch content, while hot pot is heavy on oil and spice, leading to a high fat content. Adding a certain proportion of water to the food waste solids and blending them, while simultaneously adding protease, amylase, cellulase, and lipase for enzymatic hydrolysis (…) Figure 1 (C), it was found that the initial glucose content of the two types of food waste was almost 0, but the glucose content increased significantly after enzymatic hydrolysis, and tended to stabilize after 2 hours of enzymatic hydrolysis. Figure 1 (B), pH decreased with increasing enzymatic hydrolysis time, and was generally acidic (Table 1).

[0047] The unenzymatic treatment of kitchen waste in this invention: Take 100g of wet kitchen waste, mix it with tap water (pH 7.0±0.1) at a solid-liquid ratio of 1:2 (w / v), and homogenize it with a household blender (JUJIKE, LM-861). Centrifuge at 8000×g for 20min at room temperature to separate the supernatant, precipitate it, and obtain the unenzymatic supernatant. The precipitate is freeze-dried and used for further component testing.

[0048] The enzymatic hydrolysis treatment of kitchen waste in this invention is as follows: 100g of wet kitchen waste is mixed with tap water (pH 7.0±0.1) at a solid-liquid ratio of 1:2 (w / v) and homogenized using a household high-speed blender (JUJIKE, LM-861). The mixture is then subjected to magnetic stirring in a 50℃ water bath for 6 hours without pH adjustment. Samples are taken at 0 min, 9 min, 35 min, 1 h, 2 h, and 6 h, and centrifuged at 8,000×g for 3 min at room temperature. The supernatant is collected for subsequent analysis. The pH of the supernatant is measured using a portable pH meter (PHB-3, Shanghai). After enzymatic hydrolysis, the mixture is centrifuged at 8,000×g for 20 min at room temperature, and the supernatant is collected as the kitchen waste hydrolysate (i.e., the enzymatic hydrolysis supernatant). The precipitate is freeze-dried for further component testing. The enzymes used included glucoamylase (260,000 U / mL), protease (50,000 U / g), cellulase (200 U / g), and lipase (100,000 U / g) (all purchased from Ningxia Xiasheng Industrial Group Co., Ltd.). The amount of glucoamylase added was 1% (v / w) of the mass of kitchen waste, and the amounts of protease, cellulase, and lipase added were all 1% (w / w) of the mass of kitchen waste.

[0049] The resulting enzymatically hydrolyzed and un-enzymatically hydrolyzed supernatants were sterilized by filtration through a 0.22 μm stainless steel cylindrical filter (YG-1000, Shaoxing), and then diluted with deionized water at concentrations of 10%, 20%, 30%, 40%, 50%, and 70%, respectively, before being used for microalgae culture. *Chlorella proteoglycans* Chlorella pyrenoidosa (Provided by Professor Li Hongye's research group at Jinan University) It was stored in a 250mL Erlenmeyer flask (in 100mL of sterile BG11 medium) and the main components were as follows: sodium nitrate (1.5g / L, as the main nitrogen source), dipotassium hydrogen phosphate (40mg / L), magnesium sulfate (75mg / L), calcium chloride (36mg / L), citric acid (6mg / L), ferric ammonium citrate (6mg / L), sodium carbonate (20mg / L) and a small amount of EDTA-Na2 (1mg / L), and a 1 mL / L A5 trace element solution was also prepared. The A5 trace element composition contains boric acid (2.86 mg / L), manganese chloride tetrahydrate (1.86 mg / L), zinc sulfate heptahydrate (0.22 mg / L), sodium molybdate dihydrate (0.39 mg / L), copper sulfate pentahydrate (0.08 mg / L), and cobalt nitrate hexahydrate (0.05 mg / L). It was cultured in an artificial climate chamber (RXZ-436D, Ningbo Jiangnan Instrument Factory) at a temperature of 25 ± 0.5℃, a light / dark cycle of 12 h / 12 ​​h, and a light intensity of 120 μmol photons·m⁻¹. -2 ·s -1 .

[0050] The control group (WT) of the heterotrophic culture medium for Chlorella was BG11 medium supplemented with 10 g / L, at a ratio of 10:10. ^6 Cells / mL were inoculated into supernatants of either enzymatically digested or undigested kitchen waste at different dilution ratios and incubated in the dark at 25±0.5℃. The symbiotic cell population of Chlorella bacteria cultured in 20mL of undigested 30% student canteen waste and 50% hot pot kitchen waste supernatants was collected, washed once with PBS, and stored at -80℃ for subsequent metagenomic analysis.

[0051] The symbiotic cell clusters were streaked onto YPD solid medium (10 g / L yeast extract, 20 g / L peptone, 20 g / L glucose, and 15 g / L agar) and incubated at 28°C until single colonies appeared. Single colonies were picked and inoculated into YPD liquid medium and incubated at 28±0.5°C and 150 rpm for 16 h. One mL of culture was collected, washed once with ultrapure water (UP water), and the cells were resuspended in 50 μL LUP water. 3 μL of this culture was used as a template for ITS sequence PCR amplification using Taq polymerase (Vazyme). The primer sequences were: ITS1: 5'-TCCGTAGGTGAACCTGCGG-3', ITS4: 5'-TCCTCCGCTTATTGATATGC-3'. Sequencing of the PCR products followed by BLAST analysis confirmed the isolated strain as *Meyerozyma guilliermondii* (abbreviated as Mg).

[0052] The specific nucleotide sequence for ITS verification of Mg is as follows: .

[0053] The strain's genbank accession number is as follows: SUB15860032 seq1 PX720640.

[0054] like Figure 10 The diagram shown is a phylogenetic tree of the ITS sequence of Mg in this invention. Figure 10 Phylogenetic analysis of the ITS sequence of strain Mg SHS0923 revealed that this strain is related to... Meyerozyma guilliermondii strain GS-12 is the most closely related, with a similarity of 99%.

[0055] This strain ( Meyerozyma guilliermondii SHS0923 (hereinafter referred to as: Meyerozyma guilliermondii The specimen (Mg) with accession number CCTCCNO: M20252128 is deposited at the China Center for Type Culture Collection, located at the Collection Center of Wuhan University, on September 26, 2025.

[0056] A yeast strain (Meyerozyma guilliermondii) that exhibits dominant growth in the supernatant of kitchen waste was isolated and purified from Chlorella symbiotic bacteria. Microalgae, as single-celled photosynthetic microorganisms, can utilize both carbon dioxide and organic carbon sources, exhibiting autotrophic, heterotrophic, and polytrophic capabilities, enabling the rapid production of high-value-added bioactive products. Chlorella, in particular, is renowned for its high protein and unsaturated fatty acid content. Furthermore, Chlorella possesses exceptional environmental adaptability, growing rapidly even in environments containing heavy metals and toxic substances, thus making it commonly used for the biological treatment and resource utilization of solid and liquid waste. While food waste contains abundant organic nutrients such as starch, protein, and lipids, and related literature indicates that Chlorella can stably grow in hydrolysate and remove organic pollutants, Sichuan food waste exhibits significant local characteristics, such as high salt, high oil, and pungent flavors, which may affect the normal growth and metabolism of Chlorella.

[0057] Microalgae typically cannot directly utilize organic macromolecules such as starch and protein in food waste and require enzymatic pretreatment with enzymes such as amylase, lipase, and protease for normal growth. Therefore, to investigate the tolerance and biotransformation capacity of Chlorella to different types of Sichuan kitchen waste, Chlorella was inoculated into kitchen waste with different dilution ratios of either enzymatically or non-enzymatically digested waste for heterotrophic culture.

[0058] like Figure 2 The figure shows the observation results of the heterotrophic growth of the Chlorella symbiotic system of the present invention in the supernatants of two types of kitchen waste enzymatically hydrolyzed and unenzymatically hydrolyzed waste. SCW represents student canteen waste; HPW represents hot pot kitchen waste; WT represents the control group; SCW10%, SCW20%, SCW30%, and SCW40% represent the concentrations of the student canteen supernatant diluted with deionized water to 10%, 20%, 30%, and 40%, respectively; HPW50% and HPW70% represent the concentrations of the hot pot kitchen waste supernatant diluted with deionized water to 50% and 70%, respectively. Figure 2 The results showed that Chlorella was not the dominant species in either type of food waste under heterotrophic conditions, regardless of whether it was enzymatically or non-enzymatically hydrolyzed. Chlorella easily breeds many symbiotic bacteria during cultivation. The growth of these bacteria is usually inhibited in the conventional organic carbon-free phototrophic medium BG11 (WT) for Chlorella, thus forming a long-term symbiotic system between Chlorella and other bacteria. However, Sichuan food waste not only contains a large amount of organic carbon sources but also other complex components, which seems unfavorable for the heterotrophic growth of Chlorella, and instead leads to the rapid growth of other bacteria within the Chlorella.

[0059] The supernatant of undigested kitchen waste was further analyzed using metabolomics.

[0060] like Figure 3The figure shows the metabolomics analysis results of the unenzymatic supernatant of kitchen waste from Chengdu University's student canteen and Chengdu Bashuzai Hot Pot Restaurant. A represents the component differences in the supernatant of student canteen waste and hot pot restaurant food waste; B represents the changes in components in the supernatant of hot pot restaurant food waste before and after 4 days of algae-bacterial symbiotic system cultivation; S30 represents 30% student canteen waste; H50 represents 50% hot pot restaurant kitchen waste; FW0 and FW4 represent the supernatant of hot pot restaurant kitchen waste after 0 or 4 days of algae-bacterial symbiotic system cultivation, respectively. Figure 3 As shown in A, the compositional differences between the two types of food waste are very significant. Figure 3 The B metabolomics results showed that after culturing this algae-bacterial symbiotic system in the kitchen waste of hot pot restaurants for 4 days, the content of most components in the supernatant of the kitchen waste was significantly reduced, indicating that the miscellaneous bacteria in Chlorella have the potential to rapidly degrade and purify kitchen waste in Sichuan.

[0061] Metagenomic analysis was conducted to further identify the types and proportions of mixed microorganisms growing in the supernatants of the two types of kitchen waste.

[0062] like Figure 4 The image shows the sequence alignment results of the Chlorella algae-bacterial symbiotic system of this invention, cultured in the supernatants of two types of kitchen waste, and the ITS product of purified Mg, in the NCBI database. S30 and H50 represent the algae-bacterial symbiotic systems cultured in 30% student canteen waste and 50% hot pot waste, respectively. The results indicate that the dominant bacterial groups cultured in both types of kitchen waste are... Meyerozyma guilliermondii In addition, such as Figure 5 The diagram shows the metagenomic analysis results of the microbial clusters cultured in the Chlorella-microbe symbiotic system of this invention in two types of kitchen waste supernatants, as well as the isolation, ITS, and PCR identification results of the dominant microbial species Mg. A represents the species-level metagenomic analysis; B represents the isolated and purified microbial clusters cultured in student canteen waste. Meyerozyma guilliermondii C represents the ITS PCR identification of the isolated Mg yeast strain. The results indicate that the two most abundant microbial species growing in the supernatants of the two types of food waste were... Meyerozyma guilliermondii and Meyerozymasp. JA9 all belong to the genus Meyerozyma ( Figure 5 A), and Meyerozyma guilliermondii Growth has an absolute advantage. According to literature reports... Meyerozyma guilliermondii This yeast strain is highly adaptable to various environments, has a wide range of carbon source utilization capabilities, and possesses lipid accumulation capabilities, making it suitable for multiple applications including enzyme production, bio-oil manufacturing, food fermentation, and bioremediation. To further investigate the degradation and biotransformation capabilities of this yeast strain for food waste, it was isolated and purified using streak plating. The appearance and ITS identification results of the isolated yeast are as follows: Figure 5 As shown in B and C of Figure 5, the isolated strain was identified by sequencing. Meyerozyma guilliermondii (Abbreviated as Mg) Figure 4 ).

[0063] Example 2: Static culture of the above-mentioned Mg yeast in kitchen waste before and after enzymatic hydrolysis Hot pot kitchen waste (HPW) and student canteen waste were processed according to the methods described in Example 1: un-enzymatic treatment of kitchen waste, enzymatic treatment of kitchen waste, and un-enzymatic treatment of kitchen waste, respectively, to obtain the supernatant of un-enzymatically hydrolyzed hot pot kitchen waste, the supernatant of enzymatically hydrolyzed hot pot kitchen waste, the supernatant of un-enzymatically hydrolyzed hot pot kitchen waste, and the supernatant of enzymatically hydrolyzed student canteen waste. These supernatants were diluted with deionized water at concentrations of 10% (v / v), 20%, 30%, 40%, 50%, and 70%, respectively, and then filtered and sterilized through a 0.22 μm stainless steel cylindrical filter.

[0064] Mg yeast activated for 16 h was inoculated at a ratio of 1:100,000 (v / v) into food waste supernatants before and after enzymatic hydrolysis at different dilution ratios (where S10, S20, S30, and S40 represent dilutions of student canteen waste supernatant to 10%, 20%, 30%, and 40% with deionized water, respectively; H50 and H70 represent dilutions of hot pot kitchen waste supernatant to 50% and 70% with deionized water, respectively). The cells were incubated statically at 25±0.5℃ in the dark. On day 10, cell dry weight was measured using the vacuum freeze-drying method, and the biomass accumulation reached 2.5 g / L. During the culture process, the initial glucose content of the supernatant was low, then showed a trend of first increasing and then decreasing, and was almost completely depleted by day 10. After the culture was completed, the carbohydrate utilization efficiency reached over 80%.

[0065] like Figure 6As shown, the growth parameters of Mg in kitchen waste before and after enzymatic hydrolysis at different dilution ratios are plotted in the figure. A is the biomass accumulation curve of Mg in kitchen waste without enzymatic hydrolysis at different ratios; B is the glucose content change curve in the supernatant of kitchen waste without enzymatic hydrolysis at different ratios after culturing Mg; C is the biomass accumulation curve of Mg in kitchen waste after enzymatic hydrolysis at different ratios; D is the glucose content change curve in the supernatant of kitchen waste after enzymatic hydrolysis at different ratios after culturing Mg; E is the initial carbohydrate content in the supernatant of kitchen waste without enzymatic hydrolysis and the proportion of residual carbohydrates in the supernatant after culturing Mg; S10-40 represents student canteen waste diluted 10%~40%; H50-70 represents hot pot restaurant food waste diluted 50% and 70%; YPD is YPD liquid culture medium used as a control for conventional yeast culture medium. All experiments are expressed as the mean ± standard deviation of three biological replicates. The results showed that Mg growth was significantly better in both enzymatically hydrolyzed and non-enzymatically hydrolyzed hot pot food waste than in student canteen waste. Furthermore, the highest biomass accumulation of 2.5 g / L was achieved in 70% diluted, non-enzymatically hydrolyzed hot pot waste on day 10, which was higher than that in 70% diluted, enzymatically hydrolyzed hot pot waste (approximately 2 g / L). Figure 6 (A and C of 6). However, the food waste after enzymatic hydrolysis uses glucose as the main organic carbon source, which is conducive to the rapid growth of Mg in the early stages. The rate of glucose consumption can be seen, especially in the enzymatically hydrolyzed hot pot waste, where glucose is almost completely consumed by day 7, consistent with the growth curve. Figure 6 (D). It is noteworthy that the initial glucose content of undigested food waste is extremely low, but during the culture process, the glucose content in the food waste supernatant first increases and then decreases. Figure 6 The result (B) indicates that Mg can degrade macromolecular organic carbon sources into monosaccharides such as glucose for use as organic carbon sources, achieving the utilization of kitchen waste without pretreatment. Furthermore, the carbon source utilization efficiency shows that although the initial carbohydrate content of 40% diluted canteen waste and 70% diluted hot pot waste is similar, the utilization efficiency of yeast for hot pot food waste reaches over 80%, far exceeding the utilization efficiency of student canteen waste (approximately 54%). Figure 6 E).

[0066] Example 3: Shaking culture of the above-mentioned Mg yeast in unenzymatically hydrolyzed hot pot kitchen waste 70% HPW supernatant was prepared using the same method as in Example 2. After filtration and sterilization, it was inoculated with Mg yeast activated for 16 h at an inoculation ratio of 1:100,000 (v / v). The inoculated culture system was placed in an incubator at 25±0.5℃ and cultured with shaking at 110 rpm / min. By day 4, the biomass reached a plateau, with a cell dry weight of 4 g / L, an increase of 60% compared to static culture. Due to the increased dissolved oxygen from shaking, large carbohydrate molecules were rapidly utilized once degraded into monosaccharides by extracellular enzymes, and no glucose accumulation was observed in the supernatant. After the culture ended, the carbohydrate utilization efficiency remained above 80%, and the biomass production per unit volume of carbohydrates reached 45%, significantly higher than the 28% of the YPD control group (20 g / L glucose). 5 mL of yeast cells cultured to day 4 were placed in a glass test tube, and after standing for 10 min, the sedimentation efficiency was above 80%.

[0067] Based on the above culture results, in order to increase the aeration rate, Mg was inoculated into 30% undigested canteen waste, 50% and 70% hot pot waste (where S30 represents 30% of the total volume of student canteen waste after dilution with deionized water; H50 and H70 represent 50% and 70% of the total volume of hot pot kitchen waste after dilution with deionized water, respectively) and cultured with shaking.

[0068] like Figure 7 As shown, the growth parameters of Mg in unenzymatically hydrolyzed kitchen waste at different dilution ratios are plotted in the diagram. A represents the biomass accumulation curve of Mg in unenzymatically hydrolyzed kitchen waste at different dilution ratios; B represents the change curve of glucose content in the supernatant of kitchen waste after Mg cultivation; C represents the biomass yield of carbohydrates per unit volume; D represents the initial carbohydrate content in the supernatant of unenzymatically hydrolyzed kitchen waste and the proportion of remaining carbohydrates in the supernatant after Mg cultivation; E and F represent the sedimentation efficiency of Mg after cultivation in kitchen waste at the same dilution ratio; YPD represents the control group, expressed as the mean ± standard deviation of three biological replicates. The results show that increasing the aeration rate significantly increased the growth rate of Mg, reaching a plateau around day 4. At a 70% dilution, the yeast biomass in the hot pot waste increased from 2.5 g / L (10 days) under static conditions to 4 g / L (4 days). Figure 7 (A) Due to the rapid growth of biomass, the macromolecular organic carbon source is degraded into glucose and used almost immediately for yeast growth, thus avoiding the phenomenon of initial rise followed by decline seen in static culture. Figure 7 (B). After increasing the aeration rate, the carbohydrate utilization efficiency of food waste before and after yeast culture remained at over 80% compared to the final utilization efficiency during settling (see details). Figure 6 (E and D of 7). This indicates that increasing aeration does not affect carbon source utilization efficiency, but it can affect the conversion efficiency of carbon source to total biomass. Furthermore, as... Figure 7 The C results show that although the organic carbon source content in the control group (YPD conventional medium, containing 20 g / L glucose) was much higher than the initial organic carbon source content in the hot pot restaurant food waste (approximately 7-10 g / L), Figure 7 The biomass production capacity per unit volume of carbon source converted to biomass in YPD (28%) was lower than that in 70% of hot pot restaurant food waste (45%). Settling efficiency affects the collection time and cost of microorganisms in industrial production. This invention found that the settling efficiency of yeast cultured from 70% of hot pot food waste was significantly improved compared to the control group, with a settling efficiency of over 80% in about 10 minutes. Although the biomass of this group was lower than that of YPD (D), Figure 7 The results of E and F indicate that the yeast cultured from high-concentration hot pot waste has greater potential for large-scale collection in industrial production.

[0069] Related studies have shown that Mg strain is a yeast with strong environmental adaptability, wide carbon source utilization, and lipid accumulation ability. It also shows excellent performance in wastewater treatment and bioremediation. The data in Table 2 are expressed as the average of three biological replicates.

[0070] Table 2. Purification efficiency of yeast on supernatant of two types of unenzymatically hydrolyzed kitchen waste. S30: 30% canteen waste; H50 and H70: 50% and 70% hot pot restaurant waste, respectively.

[0071] The results in Table 2 show that Mg culture achieved the highest removal efficiency of 71% COD, 81% ammonia nitrogen, and 92% total phosphorus in the supernatant from 70% unenzymatically hydrolyzed hot pot restaurant food waste.

[0072] Example 4: Comparison of the cultivation performance of the above-mentioned Mg yeast in two types of unenzymatically hydrolyzed kitchen waste. Supernatant from student canteen waste (SCW) was prepared using the same method as in Example 2 and diluted to a concentration of 30%. Activated Mg yeast was inoculated and subjected to both static and shaking cultures (25±0.5℃, 110 rmp / min). Under static culture conditions, yeast biomass accumulation was significantly lower than that of the 50% dilution of hot pot waste (HPW) with equivalent carbohydrate content, with a carbon source utilization efficiency of only 59%. Under shaking culture conditions, yeast growth rate increased, but the maximum biomass was still lower than that of the 50% HPW group with equivalent carbohydrate content. Metabolomics analysis showed that the abundance of components such as 3-O-Feruloylquinic acid, Deoxyinosine, and Biotin sulfone in the HPW supernatant was significantly higher than that in the SCW group, and these components decreased significantly after Mg culture. Even with increased aeration during shaking culture, the yeast utilization efficiency of hot pot food waste still reached over 80%, far exceeding the utilization efficiency of student canteen waste (approximately 54%).

[0073] Example 5: Metabolomics analysis of the effects of differentially expressed components on the growth of the above-mentioned Mg yeast. Based on LC-MS non-targeted metabolomics analysis, as shown in Table 3, the abundance of 3-O-Feruloylquinic acid, deoxyinosine, and biotin sulfone in the HPW supernatant was significantly higher than that in SCW. YPD medium (10 g / L yeast extract, 20 g / L peptone, 20 g / L glucose) was used as the basal medium, with 1 μM, 5 μM, and 10 μM of 3-O-Feruloylquinic acid and biotin sulfone added, respectively. Mg yeast activated for 16 h was inoculated at a ratio of 1:3000 (v / v) and cultured at 28±0.5℃ and 150 rmp / min. OD600 was measured to plot growth curves.

[0074] Table 3. Changes in components of yeast cultured in supernatant of unenzymatically hydrolyzed kitchen waste. Note: SFW0: Canteen waste before culture; HFW0 and HFW4 represent hot pot waste before culture and after 4 days of culture, respectively.

[0075] As shown in Table 3, the abundance of 3-O-Feruloylquinic acid, Deoxyinosine, and Biotin sulfone in hot pot restaurant food waste was significantly higher than that in student canteen waste, and these components decreased significantly after yeast culture.

[0076] like Figure 8 As shown in the figure, the effects of the significantly differentiating components 3-O-Feruloylquinic acid and biotin sulfone in hot pot kitchen waste on Mg growth are illustrated. A and C represent the effects of different concentrations of 3-O-Feruloylquinic acid and biotin sulfone on the Mg growth curves; B and D represent the maximum Mg biomass at the plateau phase under different concentrations of 3-O-Feruloylquinic acid and biotin sulfone treatments. Data are expressed as the mean ± standard deviation of three biological replicates, and significance analysis was performed using Tukey's multiple comparison test. An asterisk indicates a significant difference between groups (P < 0.05). Figure 8 It can be seen that in YPD medium, 1 μM 3-O-Feruloylquinic acid can prolong the yeast growth cycle, reaching maximum biomass at 72 h. Figure 8(A and B of 8); 1 μM Biotin sulfone inhibited yeast growth, while a 10 μM concentration showed a promoting effect, achieving maximum biomass at 48 h. Figure 8 (C and D of 8).

[0077] Example 6: Verification of the accumulation of the high-value-added intracellular product LPC 18:1 in the above-mentioned Mg yeast Mg cells cultured for 4 days in undigested 30% SCW and 50% HPW supernatants with shaking were collected and slowly thawed at 4°C. Each sample was mixed with pre-cooled methanol / acetonitrile / water solution (2:2:1, v / v), vortexed, sonicated at low temperature for 30 min, incubated at -20°C for 10 min, centrifuged at 14000 g at 4°C for 20 min, and the supernatant was vacuum dried. After reconstitution, LC-MS analysis was performed using an Agilent 1290 Infinity LC ultra-high performance liquid chromatography system with a HILIC column, column temperature 25°C, flow rate 0.5 mL / min, and injection volume 2 μL. Mass spectrometry was performed using an AB Triple TOF 6600 mass spectrometer in positive and negative ion modes. Data processing showed that LPC 18:1 was the most abundant metabolite accumulated in yeast cells cultured for 4 days in both SCW and HPW. The accumulation in HPW cells was significantly higher than in the SCW group, increasing by more than 73%, indicating its potential for developing research-grade skin inflammation regulation reagents. The most abundant metabolite accumulated in both types of food waste was LPC 18:1 (Table 4), and high-purity LPC18:1 can be developed into research-grade skin inflammation regulation reagents.

[0078] Table 4. Ranking of intracellular metabolite abundance in yeast after 4 days of culturing yeast in supernatant of unenzymatically hydrolyzed kitchen waste. Note: CS30-4: 30% of student canteen waste cultured for 4 days; CH50-4: 50% of hot pot waste cultured for 4 days; LPC 18:1: lysophosphatidylcholine 18:1, the most abundant metabolite in both samples.

[0079] Further enrichment of the KEGG pathway in yeast cells was carried out using metabolomics.

[0080] like Figure 9 As shown in the figure, this invention presents the pathway enrichment results of intracellular metabolomics in Mg cells cultured in different types of undigested food waste. A represents the KEGG enrichment pathway of intracellular metabolites in Mg cells after 4 days of culture in two types of food waste; B represents the KEGG enrichment pathway of intracellular metabolites in Mg cells after 4 and 10 days of culture in hot pot food waste. Figure 9The results showed that food waste from two different sources mainly affected the expression of protein pathways in yeast, while food waste from hot pot, after being cultured for 4 and 10 days, mainly affected the unsaturated fatty acid synthesis pathway in yeast.

[0081] Example 7: Adaptability verification of the above-mentioned Mg yeast to undiluted kitchen waste at different dilution ratios Undigested HPW supernatant (diluted to 50%, 70%) and SCW supernatant (diluted to 10%, 20%, 30%, 40%) were prepared using the same method as in Example 2. After filtration and sterilization, Mg yeast was inoculated at an inoculation ratio of 1:100000 (v / v) and cultured statically at 25±0.5℃.

[0082] The results showed that in both 50% and 70% HPW (high-oil, high-volume) waste, yeast biomass increased with increasing dilution ratio, reaching 2.5 g / L in the 70% group on day 10. However, in the SCW (steam-cooked waste) group, even after the dilution ratio was reduced to 40%, the carbohydrate content was comparable to that in the 70% hot pot waste group, but the yeast biomass was still significantly lower than that in the HPW group, with a carbon source utilization efficiency of only 54%. Therefore, Mg yeast exhibits stronger adaptability and degradation and transformation capabilities for hot pot waste with high oil and high organic matter concentrations.

[0083] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A yeast strain isolated from Chlorella symbiotic bacteria, characterized in that, This strain ( Meyerozyma guilliermondii SHS0923, with accession number CCTCCNO: M20252128, is deposited at the China Center for Type Culture Collection, located at the Collection Center of Wuhan University, on September 26, 2025.

2. A food waste treatment microbial agent containing the yeast strain as described in claim 1.

3. The food waste treatment microbial agent according to claim 2, characterized in that, The strain described in the treatment agent ( Meyerozyma guilliermondii The viable count of SHS0923 is not less than 1×10⁻⁶. 9 CFU / mL.

4. The application of a yeast strain as described in claim 1 or a food waste treatment microbial agent as described in claim 2 in the treatment of organic waste liquid from food waste.

5. The application according to claim 4, characterized in that, When using the yeast strain as described in claim 1, the application includes the following steps: The strain ( Meyerozyma guilliermondii SHS0923 was inoculated into YPD medium and activated at 28±0.5℃ and 150 rpm. It was then inoculated into a medium containing undigested kitchen waste supernatant and cultured at 25±0.5℃ and 110 rpm with shaking.

6. The cultivation method according to claim 5, characterized in that, The YPD culture medium includes YPD liquid culture medium and YPD solid culture medium; wherein, the components of YPD liquid culture medium are yeast extract, peptone and glucose; the components of YPD solid culture medium are yeast extract, peptone, glucose and agar powder; the inoculation into the culture medium containing undigested kitchen waste supernatant is carried out at a ratio of 1:100000 between the volume of activated bacteria and the volume of undigested kitchen waste supernatant.

7. The cultivation method according to claim 6, characterized in that, The amounts of yeast extract, peptone, and glucose are 1%, 2%, and 2%, respectively; the amounts of yeast extract, peptone, glucose, and agar powder are 1%, 2%, 2%, and 2%, respectively.

8. The cultivation method according to claim 5, characterized in that, The culture medium containing undigested kitchen waste supernatant comprises kitchen waste, the specific component 3-O-Feruloylquinic acid, and the specific component Biotin sulfone.

9. A metabolite produced by the yeast strain as described in claim 1.

10. The use of the metabolite as described in claim 9 in the preparation of a skin inflammation regulating agent.

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