Kluyveromyces marxianus, method and application thereof

Abstract

The invention belongs to the technical field of resources and environmental microorganisms, and discloses Kluyveromyces marxianus, a method and application of the Kluyveromyces marxianus, the name is ART-27, the classification name is Kluyveromyces marxianus, the preservation number is CGMCC (China General Microbiological Culture Collection Center) No.39119, and the preservation date is January 7, 2026. The Kluyveromyces marxianus can flocculate macromolecular protein in dairy product water and utilize the lactose, the protein and other components to improve the utilization rate of the lactose and the protein, and the degradation rate of the Kluyveromyces marxianus to the lactose is 70.20% and is improved by 20.20% compared with the degradation rate of 50% of original bacteria; the degradation rate of whey protein is 76.20%, and is increased by 22.2% compared with the degradation rate 54% of original bacteria. The method has a good application prospect in the aspects of dairy product water treatment and resource utilization.

Description

Technical Field

[0001] This invention belongs to the field of resource and environmental microbiology technology, and in particular to a strain of Kluyveromyces martensii, its method and its application. Background Technology

[0002] In the dairy production process, the non-product water consumption for producing one ton of sterilized milk or fermented milk often reaches several tons or even more than ten tons, with cleaning water accounting for more than 80%-85%. This production model of "consuming large amounts of water for cleaning" is indispensable in ensuring food safety, but it also leads to a resource metabolism dilemma of "high input and high emissions," significantly increasing the water intake costs and wastewater treatment burden of enterprises, and bringing continuous environmental pollution risks.

[0003] Currently, the treatment of cleaning wastewater generated during dairy processing mostly employs centralized collection followed by physicochemical treatment methods, including flocculation and membrane filtration. This approach dilutes the lactose and protein-rich components in the cleaning water from equipment and pipelines by mixing with other low-concentration wastewater. The water flow generated from cleaning equipment and conveying systems contains a large amount of biodegradable organic matter, such as lactose and protein, making it ideal as a nutrient source for microorganisms. Therefore, the treatment objective of this wastewater shifts from simply degrading pollutants to resource recovery and reuse, such as microbial proteins and water. However, due to the low organic matter concentration in dairy rinsing water, existing microbial strains suffer from slow growth and low substrate conversion rates in low-concentration dairy wastewater, severely limiting their large-scale application in treating this wastewater. Therefore, selecting superior strains that efficiently utilize low-concentration dairy components is a crucial issue in solving the resource utilization of dairy wastewater, possessing significant practical and academic research value. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a strain of Kluyveromyces martensii that can efficiently flocculate large molecular proteins in dairy water and utilize components such as lactose and protein.

[0005] The technical solution adopted by this invention to solve its technical problem is: A strain of Kluyveromyces (Max Kluyveromyces) Kluyveromyces marxianus The invention is characterized in that: the name of the Kluyveromyces martensii is ART-27, the classification name is Kluyveromyces martensii, the accession number is CGMCCNo.39119, the accession date is January 7, 2026, and the depository is the China General Microbiological Culture Collection Center (CGMCC), No. 3, No. 1, Beichen West Road, Chaoyang District, Beijing.

[0006] The application of Max Kluyveromyces as described above in the treatment of dairy water.

[0007] Furthermore, the dairy water includes dairy wastewater, dairy pipeline flushing water, dairy tank flushing water, whey, etc.

[0008] The method for treating low-concentration dairy rinse water using Kluyveromyces martensii as described above includes the following steps: (1) Activation of strains and preparation of seed liquid: Kluyveromyces martensii was activated and cultured to obtain activated seed liquid; (2) Preparation of bacterial suspension: The activated seed liquid obtained in step (1) is centrifuged to collect bacterial cells, which are then washed and resuspended in physiological saline to obtain a highly active bacterial suspension. (3) Fermentation treatment: The highly active bacterial suspension obtained in step (2) is inoculated into low-concentration dairy washing water for fermentation.

[0009] Further, the activation culture in step (1) is as follows: after streaking the strain, pick a single colony, inoculate it into YPD liquid medium, and incubate at 30-42℃ for 16-24 h.

[0010] Furthermore, the low-concentration dairy product rinsing water in step (3) contains 5 g / L of lactose and 5 g / L of protein.

[0011] The application of Kluyveromyces martensii as described above in the efficient utilization of lactose and / or protein in low-concentration dairy components.

[0012] The method for efficiently utilizing small molecule substances lactose and protein using Kluyveromyces martensii as described above includes the following steps: (1) Preparation of seed culture: Take out the preserved yeast strain from the -80℃ ultra-low temperature freezer and activate it by streak plate twice; pick a single colony and inoculate it into YPD liquid medium and incubate at 30-42℃ for 16 h; after centrifuging the cells at 4℃, discard the supernatant, wash 3 times with 10×PBS, and resuspend in 10×PBS of the same volume as the YPD liquid medium removed; (2) The biomass of yeast cells was diluted to OD. 600 =1.2% of the total inoculum was added to the dairy wastewater to adjust the pH to 6; (3) Ferment for 48 hours.

[0013] Furthermore, the dairy wastewater contains: 5 g / L lactose, 5 g / L protein, sulfate, and phosphate.

[0014] The advantages and positive effects of this invention are as follows: 1. This invention is based on the original strain *Kluyveromyces martensii* (…). Kluyveromyces marxianusBased on this, through ARTP mutagenesis and adaptive evolution, a strain of *Kluyveromyces martensii* CGMCC No. 39119 was screened that can efficiently flocculate large protein molecules in dairy wastewater and degrade components such as lactose and protein. Compared with the original strain, it increased biomass and achieved a higher OD500 in low-concentration wastewater. 600 The value reached 1.32, which is 42% higher than that of the original strain.

[0015] 2. The Kluyveromyces martensii CGMCC No. 39119 of this invention can rapidly degrade lactose, protein and other components of dairy water in 36-48 hours. Compared with the current aerobic or anaerobic treatment of dairy wastewater which requires 3-5 days, this invention not only meets environmental protection requirements but also reduces production costs and time, and has broad industrial application prospects.

[0016] 3. The Kluyveromyces martensii CGMCC No. 39119 of this invention produces a cell protein of up to 0.443 g / L after fermentation under the conditions of 5 g / L lactose and 5 g / L whey protein, which is 54.4% higher than that of the original strain.

[0017] 4. The *Kluyveromyces martensii* CGMCC No. 39119 of this invention exhibits a lactose degradation rate of 70.20% in dairy water, a 20.20% increase compared to the original strain's 50% degradation rate; and a whey protein degradation rate of 76.20%, a 22.2% increase compared to the original strain's 54% degradation rate. Furthermore, the bacterial protein produced by this strain during fermentation of low-concentration dairy components can reach 0.443 g / L, a 54.4% increase compared to the original strain. This method meets environmental protection requirements, reduces production costs, and is easy to cultivate on a large scale, showing broad industrial application prospects in dairy water treatment and resource utilization. Attached Figure Description

[0018] Figure 1 The Kluyveromyces martensii in this invention ( Kluyveromyces marxianus Colony morphology diagram of ART-27; Figure 2 The Kluyveromyces martensii in this invention ( Kluyveromyces marxianus Electron microscope image of ART-27; Figure 3 The OD of ART-27 and the original bacterial biomass in this invention 600 Comparison chart; Figure 4 This is a graph showing the protein consumption rates of the mutant bacterium ART-27 and the original bacterium in this invention. Figure 5 This is a graph showing the lactose consumption rates of the mutant strain ART-27 and the original strain in this invention.

[0019] A strain of *Kluyveromyces Marcius*, named ART-27, taxonomically named *Kluyveromyces Marcius* ( Kluyveromyces marxianus The accession number is CGMCC No.39119, the accession date is January 7, 2026, and the depositary institution is the China General Microbiological Culture Collection Center (CGMCC), No.3, No.1 Beichen West Road, Chaoyang District, Beijing. Detailed Implementation

[0020] The present invention will be further described below with reference to the embodiments. The following embodiments are descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0021] The various experimental operations involved in the specific embodiments are all conventional techniques in the field. For parts not specifically annotated in this document, those skilled in the art can refer to various commonly used reference books, scientific and technological documents or related instructions and manuals prior to the filing date of this invention to carry out the operations.

[0022] A strain of Kluyveromyces (Max Kluyveromyces) Kluyveromyces marxianus The invention is characterized in that: the name of the Kluyveromyces martensii is ART-27, the classification name is Kluyveromyces martensii, the accession number is CGMCCNo.39119, the accession date is January 7, 2026, and the depository is China General Microbiological Culture Collection Center, No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing.

[0023] The application of Max Kluyveromyces as described above in the treatment of dairy water.

[0024] Furthermore, the dairy water includes dairy wastewater, dairy pipeline flushing water, dairy tank flushing water, whey, etc.

[0025] The method for treating low-concentration dairy rinse water using Kluyveromyces martensii as described above includes the following steps: (1) Activation of strains and preparation of seed liquid: Kluyveromyces martensii was activated and cultured to obtain activated seed liquid; (2) Preparation of bacterial suspension: The activated seed liquid obtained in step (1) is centrifuged to collect bacterial cells, which are then washed and resuspended in physiological saline to obtain a highly active bacterial suspension. (3) Fermentation treatment: The highly active bacterial suspension obtained in step (2) is inoculated into low-concentration dairy washing water for fermentation.

[0026] Further, the activation culture in step (1) is as follows: after streaking the strain, pick a single colony, inoculate it into YPD liquid medium, and incubate at 30-32℃ for 16-24 h.

[0027] Furthermore, the low-concentration dairy product rinsing water in step (3) contains 5 g / L lactose and 5 g / L protein.

[0028] The application of Kluyveromyces martensii as described above in the efficient utilization of lactose and / or protein in low-concentration dairy components.

[0029] The method for efficiently utilizing small molecule substances lactose and protein using Kluyveromyces martensii as described above includes the following steps: (1) Preparation of seed culture: The yeast strain was taken out from the -80℃ ultra-low temperature freezer and activated by streak plate twice; a single colony was picked and inoculated into YPD liquid medium and cultured at 30℃ for 16 h; the supernatant was discarded by centrifugation at 4℃ and 6000 r / min for 5 min, washed 3 times with 10×PBS, and resuspended with 10×PBS of the same volume as the YPD liquid medium removed; (2) The biomass of yeast cells was diluted to OD. 600 =1.2% of the total inoculum was added to the dairy wastewater to adjust the pH to 6; (3) Ferment for 48 hours.

[0030] Furthermore, the dairy wastewater contains: 5 g / L lactose, 5 g / L protein, sulfate, and phosphate.

[0031] Specifically, the relevant preparation and testing methods are as follows: Example 1: Mutagenesis and selection of high-efficiency strains 1. ARTP mutagenesis (1) Activation of the starting strain: Kluyveromyces macrocarpa KM-6 preserved in the laboratory was inoculated into YPD medium in Erlenmeyer flasks and cultured at 30℃ for 24-30 h as the starting strain for ARTP mutagenesis; (2) Preparation of starting bacterial suspension: Take 1 mL of seed liquid from step (1), centrifuge at 12000 r / min for 2 min, discard the supernatant and collect the bacterial cells, wash the bacterial cells 2-3 times with 0.9% physiological saline, resuspend and dilute 100 times to prepare a bacterial suspension with uniform cell dispersion, which will be used as the starting bacterial suspension for subsequent ARTP treatment; (3) ARTP mutagenesis treatment: Take 5-10 μL of the starting bacterial suspension prepared in step (2) and spread it evenly on a sterilized metal slide. Place it in an ARTP mutagenesis breeding instrument for mutagenesis treatment. The ARTP treatment parameters are set as follows: working gas is high-purity helium, radio frequency power is 70-120 W, gas flow rate is 8-12 slm, treatment time is 30-100 s, and irradiation distance is 2-4 mm. (4) Post-mutation culture: Wash off the mutagenized cells with 990 μL of 0.9% sterile physiological saline, dilute appropriately, and spread on a low-concentration carbon and nitrogen source (lactose, protein) solid culture medium plate (lactose 5 g / L, protein 5 g / L, manganese sulfate 0.02 g / L, magnesium sulfate 0.5 g / L, dipotassium hydrogen phosphate 2 g / L, agar 2 g / L, solvent is water), and incubate upside down at 28-34℃ for 2-3 days.

[0032] 2. Preservation of highly effective mutagenic bacteria (1) Observe the colonies obtained in step 1 on solid culture medium, pick a single colony from the plate and inoculate it into YPD medium and incubate at 30℃ for 16 h, and store it in a 60% glycerol tube at -80℃. (2) The mutant strain and the original strain obtained in step (1) were streaked in a “z” shape onto the YPD slant medium and cultured at 30℃ for 2-3 days.

[0033] A strain of *Kluyveromyces martensii* capable of efficiently utilizing low concentrations of lactose and protein for growth was obtained. The name of this *Kluyveromyces martensii* strain is ART-27, and its taxonomic name is *Kluyveromyces martensii*. Kluyveromyces marxianus The accession number is CGMCC No.39119, the accession date is January 7, 2026, and the depositary institution is the China General Microbiological Culture Collection Center, No.3, No.1 Beichen West Road, Chaoyang District, Beijing.

[0034] The Max Kluyveromyces ( Kluyveromyces marxianus The physicochemical properties of ART-27 are as follows: Gram-positive bacteria; colonies on solid culture media are spherical, moist, and milky white in color. Figure 1 , Figure 2 As shown in the figure, the optimal growth pH is 4-5 and the optimal growth temperature is 28-34℃.

[0035] The Max Kluyveromyces ( Kluyveromyces marxianus Application of ART-27 in fermentation and degradation of dairy wastewater; Furthermore, the dairy components include, but are not limited to: lactose (2-15 g / L), protein (2-15 g / L), sulfate, phosphate, etc. Furthermore, Max Kluyveromycin ( Kluyveromyces marxianus ART-27 is a method for efficiently utilizing small molecules such as lactose and protein.

[0036] (1) Preparation of seed culture: The preserved yeast strain was taken out from the -80℃ ultra-low temperature freezer and activated by streak plating twice. Single colonies were picked and inoculated into 5 mL of YPD liquid medium and cultured at 30℃ for 16 h. The supernatant was discarded after centrifugation at 4℃ and 6000 r / min for 5 min. The culture was washed 3 times with 10×PBS to remove residual nutrients in the YPD liquid medium and resuspended in an equal volume of 10×PBS.

[0037] (2) The biomass of yeast cells was diluted to OD. 600 Add approximately 1.2% of the total inoculum to 50 mL of dairy wastewater and adjust the pH to 6.

[0038] (3) The number of viable bacteria of the original bacteria and the number of viable bacteria of the mutant bacteria were determined at 12-48 h, and their biomass and consumption rates of lactose and protein were determined.

[0039] Example 2: Growth of Kluyveromyces martensii ART-27 under low concentration of dairy components 1. Biomass determination (1) Strain activation: Yeast ( Kluyveromyces marxianus ART-27 was cultured statically at 30°C for 12-16 hours in YPD medium to obtain a seed culture. (2) The activated bacterial strain was washed with 0.9% physiological saline. The washed bacterial solution was inoculated into 50 ml of simulated wastewater (lactose 5 g / L, protein 5 g / L, manganese sulfate 0.02 g / L, magnesium sulfate 0.5 g / L, dipotassium hydrogen phosphate 2 g / L, solvent: water) at an inoculation rate of 2%. A sample was taken as the 0 h sample, and samples were taken at 12, 24, 36, and 48 h to measure the OD. 600 The result is as follows Figure 3 As shown, after 36 hours, the biomass of the mutagenized strain in low-concentration wastewater reached 1.32, while the OD of the original strain was... 600 The value was 0.81, which was 35%-42% higher than that of the original strain.

[0040] Example 3: Genetic stability of Kluyveromyces Marcius ART-27 The *Kluyveromyces martensii* ART-27 strain obtained in Example 1 was passaged six times. Each generation was inoculated into 5 mL YPD medium and cultured. Each generation was stored at -4°C by streak plating. The results showed that after six passages, the viable cell count of the ART-27 mutant strain remained at approximately 5.5 g / L, and the residual lactose and protein content during fermentation were 1.5-1.7 g / L and 1.3-1.21 g / L, respectively, indicating good genetic stability.

[0041] Example 4: Residual lactose concentration in fermentation wastewater (1) Standard curve plotting: The anthrone colorimetric method is based on the principle that the hexose present in the lactose molecule can react with anthrone, and the solution after the reaction turns blue-green with maximum light absorption at 620 nm. The residual sugar is determined based on this principle. Samples were taken every 12 h during fermentation to determine the residual sugar in the fermentation broth. Five test tubes were selected, and 0.2, 0.4, 0.6, 0.8 and 1 mL of 0.1 mg / mL standard lactose solution were added to each tube respectively. Distilled water was then added to each tube to a final volume of 1 mL. Another test tube was used as a blank tube with 1 mL of distilled water added. 4 mL of 0.2% anthrone solution was added to each of the above six test tubes, mixed well, boiled in a water bath for 10 min, removed, cooled to room temperature, and the OD of each tube was measured. 620 The data was subjected to regression analysis, resulting in a linear regression equation: Y = 0.8306X + 0.1297, R0. 2 =0.9993 (where Y is the concentration of lactose, X is the OD value) 620 value).

[0042] (2) Sample processing and determination: The original strain and the mutant strain were inoculated into YPD medium and cultured statically at 30℃ for 16-18 h. The resulting seed culture was inoculated into a lactose-containing simulated dairy rinse water medium (lactose 5 g / L, protein 5 g / L, manganese sulfate 0.02 g / L, magnesium sulfate 0.5 g / L, dipotassium hydrogen phosphate 2 g / L, solvent: water) and fermented statically at 30–34℃ and pH 5–7 for 48 h. From the start of fermentation, samples were taken every 12 hours, centrifuged (8000 × g, 10 min, 4℃) to remove the bacterial cells, and the supernatant was appropriately diluted and subjected to anthrone colorimetric reaction according to the above standard curve plotting method. The OD was then measured. 620 value.

[0043] (3) Calculation and analysis of results: The results are as follows Figure 4 As shown, *Kluyveromyces martensii* CGMCC No. 39119 achieved a lactose degradation rate of 70.20% after 48 hours, which is 20.20% higher than the original strain's degradation rate of 50%. Since lactose is a major component of dairy wastewater, the increased removal rate indicates that the mutagen has enhanced lactose utilization capabilities.

[0044] Example 5: Residual protein concentration in fermentation wastewater (1) Preparation of standard curve: The protein standard curve was prepared by serially diluting the 5.0 mg / mL BCA standard provided in the kit with the same dilution buffer (such as PBS) as the test sample to prepare a series of standards with concentrations of 0, 0.05, 0.1, 0.15, 0.2, and 0.3 mg / mL. 25 μL of each concentration of standard (3 replicates), the test protein sample (2-3 replicates), and the buffer blank control were added to each well of a 96-well plate. Then, 200 μL of freshly prepared BCA working solution was quickly added to each well, gently vortexed for 30 seconds, and the plate was capped and incubated at 37°C in the dark for 30 min. After incubation, the microplate was cooled to room temperature, and the absorbance of each well was measured at 562 nm using a microplate reader. The data were subjected to regression analysis, resulting in a linear regression equation Y = 1.1103x + 0.1411, R0 2 =0.9993 (where Y is the protein concentration and X is the OD). 562 The samples collected at 12, 24, 36, and 48 hours were diluted tenfold, added to a 96-well plate, and BCA working solution was added. The plates were incubated at 37°C in the dark for 30 minutes, and the OD values ​​were measured. 562 Substitute this into the linear regression equation.

[0045] (2) Sample processing and determination: The original strain and the mutant strain were inoculated into YPD medium and cultured statically at 30℃ for 16-18 h. The resulting seed culture was inoculated into a lactose-containing simulated dairy rinse water medium (lactose 5 g / L, protein 5 g / L, manganese sulfate 0.02 g / L, magnesium sulfate 0.5 g / L, dipotassium hydrogen phosphate 2 g / L, solvent: water) and fermented statically at 30–34℃ and pH 5–7 for 48 h. From the start of fermentation, samples were taken every 12 hours, centrifuged (8000 × g, 10 min, 4℃) to remove the bacterial cells, and the supernatant was appropriately diluted and determined according to the standard curve plotting method described above.

[0046] (3) Calculation and analysis of results: The results are as follows Figure 5 As shown, *Kluyveromyces martensii* CGMCC No. 39119 achieved a whey protein degradation rate of 76.20% after 48 hours, a 22.2% increase compared to the original strain's 54%. Whey protein is a major component of dairy wastewater, and the increased removal rate indicates that the mutagenized bacteria have enhanced protein utilization capabilities. Compared to methanogens and some microalgae that cannot utilize protein, the mutagenized *Kluyveromyces martensii* can utilize protein as a nitrogen source for growth, removing most of the whey protein.

[0047] Example 6 (1) Activation of strains: The original strain KM-6 and the mutant strain ART-27 were inoculated into YPD medium and cultured at 30℃ for 16-18 h to obtain seed liquid.

[0048] (2) The seed culture was inoculated into a simulated aqueous culture medium (lactose 5 g / L, protein 5 g / L, manganese sulfate 0.02 g / L, magnesium sulfate 0.5 g / L, dipotassium hydrogen phosphate 2 g / L, solvent: water) and fermented for 48 h. Samples were taken to determine the OD. 600 The fermentation broth was collected and transferred to a 200 mL centrifuge cup. It was centrifuged at 5000 r / min for 10 min, and the precipitate was recovered. The precipitate was dried in a 60℃ oven to constant weight, and its dry weight was measured. After collecting the lyophilized cells to constant weight, 0.5 g of the constant-dry sample was weighed, and 2 tablets of Kjeltabs Cu3, 5, 2 tablets of defoamer, and 12 mL of concentrated sulfuric acid were added to the digestion tube. The cells were digested in a graphite digester at 240℃ for 30 min, then at 420℃ for 1 h. After cooling, the digestion tube was placed in an automated Kjeldahl nitrogen analyzer to measure the protein content (%). The protein yield was calculated using the formula: Protein yield (g / L) = Dry weight of cells (g / L) × Protein content (%).

[0049] (2) The bacterial protein content of the strain is shown in Table 1.

[0050] Table 1

[0051] As shown in Table 3, the *Kluyveromyces martensii* CGMCC No. 39119 provided by this invention significantly improves cell protein yield compared to the original *Kluyveromyces martensii* strain. The original strain's cell protein yield was only 0.202 g / L, while *Kluyveromyces martensii* CGMCC No. 39119 achieved a cell protein yield of 0.443 g / L, representing a 54.4% increase. Dairy wastewater rich in lactose, protein, and other organic matter serves as a raw material for cultivating microorganisms to produce cell protein, transforming wastewater treatment from a simple degradation process into a process that both treats wastewater and generates valuable products. In practical applications, it can treat large quantities of dairy wastewater with considerable cell protein yield.

[0052] Although embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations, and modifications are possible without departing from the spirit and scope of the invention and the appended claims. Therefore, the scope of the invention is not limited to the contents disclosed in the embodiments.

Claims

1. A strain of Kluyveromyces martensii ( Kluyveromyces marxianus ), characterized by: The name of the Kluyveromyces martensii strain is ART-27, the taxonomic name is Kluyveromyces martensii, the accession number is CGMCCNo.39119, the accession date is January 7, 2026, and the depository is the China General Microbiological Culture Collection Center (CGMCC), No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing.

2. The application of Kluyveromyces martensii as described in claim 1 in the treatment of dairy water.

3. The application according to claim 2, characterized in that: The dairy water includes dairy wastewater, dairy pipeline flushing water, dairy tank flushing water, and whey.

4. A method for treating low-concentration dairy product rinse water using Kluyveromyces martensii as described in claim 1, characterized in that: Includes the following steps: (1) Activation of strains and preparation of seed liquid: Kluyveromyces martensii was activated and cultured to obtain activated seed liquid; (2) Preparation of bacterial suspension: The activated seed liquid obtained in step (1) is centrifuged to collect bacterial cells, which are then washed and resuspended in physiological saline to obtain a highly active bacterial suspension. (3) Fermentation treatment: The highly active bacterial suspension obtained in step (2) is inoculated into low-concentration dairy washing water for fermentation.

5. The method according to claim 4, characterized in that: In step (1), the activation culture is as follows: after streaking the strain, pick a single colony, inoculate it into YPD liquid medium, and incubate at 30-42℃ for 16-24 h.

6. The method according to claim 4 or 5, characterized in that: In step (3), the low-concentration dairy product rinsing water contains 5 g / L lactose and 5 g / L protein.

7. The use of Kluyveromyces martensii as described in claim 1 in the efficient utilization of lactose and / or protein in low-concentration dairy components.

8. A method for efficiently utilizing small molecule substances lactose and protein using Kluyveromyces martensii as described in claim 1, characterized in that: Includes the following steps: (1) Preparation of seed culture: The yeast strain was taken out from the -80℃ ultra-low temperature freezer and activated by streak plate twice; single colonies were picked and inoculated into YPD liquid medium and cultured at 30-42℃ for 16 h; after centrifugation, the cells were washed three times with 10×PBS and resuspended with 10×PBS of the same volume as the YPD liquid medium removed. (2) The biomass of yeast cells was diluted to OD. 600 =1.2% of the total inoculum was added to the dairy wastewater to adjust the pH to 6; (3) Ferment for 48 hours.

9. The method according to claim 8, characterized in that: The dairy wastewater contains: 5 g / L lactose, 5 g / L protein, sulfate, and phosphate.

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