An Aspergillus foetidus strain producing yellow pigment and its application

Abstract

The present invention discloses a yellow pigment-producing Aspergillus foetidus and its application. The name of the Aspergillus foetidus is Aspergillus foetidus HC32, which was deposited on January 3, 2023 at the Guangdong Microbial Culture Collection Center of the Institute of Microbiology, Guangdong Academy of Sciences, on the 5th floor, Building 59, Compound 100, Xianlie Middle Road, Guangzhou, with a deposit number of GDMCC No: 63106. The Aspergillus foetidus is a strain isolated from the natural fermentation of Xinhui tangerine peel, and a strain with high intracellular yellow pigment production is obtained by ultraviolet mutagenesis. A natural yellow pigment with a relatively clear composition can be prepared by fermentation of this strain.

Description

Technical Field

[0001] The present invention belongs to the technical field of microbial strain breeding, and particularly relates to an Aspergillus foetidus strain producing yellow pigment and its application. Background Art

[0002] Natural pigments have the characteristics of being non-toxic, highly safe, and having natural and bright colors, and are increasingly being valued and favored. The current main sources of natural pigments are plants and microorganisms. However, plant-derived pigments are limited in large-scale applications due to the long growth cycle of plants, being affected by factors such as season, climate, origin, scale, and cost, and their processing technology often leading to differences between product batches, and the pigments extracted from them being expensive. While using microbial resources to produce natural pigments by fermentation is not affected by season and site, microorganisms have a fast growth rate, low production cost, high conversion rate, and are easy to industrialize. Therefore, using microorganisms to produce natural pigments will gradually become the mainstream source of natural pigments.

[0003] The demand for natural yellow pigment is relatively large, but there is a lack of suitable strain resources for production. Currently, the only yellow pigment approved for microbial fermentation production in China is monascin, and because the content of yellow pigment in the pigments produced by Monascus is relatively low, in actual production, a chemical conversion method is used, where monascus red pigment is sulfonated with sulfide to produce monascin. Strictly speaking, the monascin formed after conversion is a non-natural pigment. Therefore, the production technology of natural yellow pigment needs to be further developed.

[0004] Aspergillus foetidus is a strain that has been applied in the fields of producing amylase, citric acid, saccharifying koji, and brewing soy sauce, wine, and vinegar. By performing ultraviolet mutagenesis on the original strain and screening out mutant strains with high yields of natural yellow pigment, it has direct practical significance and value for the production and application of natural yellow pigment. Summary of the Invention

[0005] The primary object of the present invention is to overcome the deficiencies of the prior art and provide an Aspergillus foetidus strain producing yellow pigment.

[0006] Another object of the present invention is to provide the application of the above-mentioned Aspergillus foetidus strain producing yellow pigment.

[0007] Another object of the present invention is to provide a yellow pigment produced by the above-mentioned Aspergillus foetidus strain.

[0008] The objects of the present invention are achieved by the following technical solutions:

[0009] A strain of Aspergillus foetidus that produces yellow pigment, named Aspergillus foetidus HC32, was deposited on January 3, 2023 at the Guangdong Microbial Culture Collection Center, Institute of Microbiology, Guangdong Academy of Sciences, 5th Floor, Building 59, 100 Xianlie Middle Road, Guangzhou, with the deposit number GDMCC No: 63106.

[0010] The Aspergillus foetidus HC32 has the following morphological characteristics: When cultured on a seed plate (PDA) for 7 days, a circular colony is formed. The diameter of the colony is 30 - 40 mm. The colony is yellow, short villous, without folds, the aerial hyphae are white, the substrate mycelium is yellow, and there are contents; it does not have radial grooves; the back of the colony also does not have radial grooves and is dark yellow - brown.

[0011] The application of the above - mentioned Aspergillus foetidus that produces yellow pigment in the production of yellow pigment.

[0012] A method for producing yellow pigment, comprising the following steps:

[0013] (1) Inoculate the seed liquid of the above - mentioned Aspergillus foetidus that produces yellow pigment into a fermentation medium for fermentation culture to obtain a fermentation broth;

[0014] (2) Perform solid - liquid separation on the fermentation broth obtained in step (1) and take the thalli;

[0015] (3) Oscillate and extract the intracellular contents of the thalli obtained in step (2) with an organic solvent, and the obtained extract is the intracellular yellow pigment solution.

[0016] The seed liquid of Aspergillus foetidus in step (1) is Aspergillus foetidus in the logarithmic growth phase; preferably, it is prepared through the following steps: Activate the preserved strain of Aspergillus foetidus and inoculate it into a seed medium for shake - flask culture to obtain Aspergillus foetidus in the logarithmic growth phase.

[0017] The preferred activation steps are as follows: Streak the preserved strain of Aspergillus foetidus on a PDA medium plate and culture it at 25 - 30 °C for 4 - 7 days for activation.

[0018] The inoculation amount for the inoculation is two plate colonies with a diameter of 0.5 - 1 cm per 50 mL of seed medium.

[0019] The seed medium is preferably PDB liquid medium.

[0020] The preferred conditions for the shake - flask culture are culturing at 25 - 35 °C, 100 - 200 rpm for 24 - 48 h; more preferably, culturing at 28 - 30 °C, 180 - 200 rpm for 48 h.

[0021] The inoculation amount of the Aspergillus foetidus seed liquid described in step (1) is 5-15% by volume; more preferably 10% by volume.

[0022] The composition of the fermentation medium described in step (1) is preferably as follows: carbon source 20-80 g / L, nitrogen source 4-60 g / L, KH2PO4 0-1 g / L, MgSO4·7H2O 0-0.5 g / L, KCl 0-0.5 g / L, and FeSO4·7H2O 0-0.01 g / L, made up to 1000 mL with distilled water, and the pH value is natural.

[0023] The carbon source is at least one of glucose, fructose, sucrose, brown sugar, maltose, rice flour, soluble starch, lactose, sodium gluconate, and potato starch; preferably glucose.

[0024] The concentration of the glucose in the fermentation medium is preferably 50-80 g / L; more preferably 55-65 g / L.

[0025] The nitrogen source is at least one of soy peptone, bacteriological peptone, fish peptone, tryptone, yeast extract, beef extract, yeast powder, soybean powder, sodium glutamate, ammonium chloride, and ammonium sulfate; preferably soy peptone.

[0026] The concentration of the soy peptone in the fermentation medium is preferably 5-20 g / L; more preferably 10-15 g / L.

[0027] The composition of the fermentation medium is preferably as follows: K2HPO4 1 g / L, MgSO4 0.5 g / L, KCl 0.5 g / L, FeSO4 0.01 g / L, glucose 50-80 g / L, soy peptone 5-20 g / L, pH natural; more preferably as follows: K2HPO4 1 g / L, MgSO4 0.5 g / L, KCl 0.5 g / L, FeSO4 0.01 g / L, glucose 55-65 g / L, soy peptone 10-15 g / L, pH natural.

[0028] The conditions for the fermentation culture described in step (1) are preferably as follows: culture at 25 - 35 °C and 100 - 200 rpm for 4 - 12 days; more preferably as follows: culture at 25 - 30 °C and 150 - 200 rpm for 5 - 10 days; most preferably as follows: culture at 28 - 30 °C and 150 - 200 rpm for 6 - 7 days. The inventors of the present invention have found that the culture time of the strain is not the longer the better, but there are fluctuations. The mutant Aspergillus foetidus HC32 of the present invention has a significantly shorter fermentation period than the original strain, and it can achieve a large production of yellow pigment within a short time after the start of fermentation. Therefore, the culture time of the mutant Aspergillus foetidus HC32 of the present invention can be 4 - 12 days, preferably 5 - 10 days, more preferably 6 - 7 days.

[0029] The methods of solid-liquid separation described in step (2) include filtration with filter paper, suction filtration, and centrifugation; preferably filtration with filter paper.

[0030] The organic solvent described in step (3) is preferably an ethanol aqueous solution with a pH value of 1.5 - 2.5 and a concentration of 60 - 80% by volume; more preferably an ethanol aqueous solution with a pH value of 2.0 and a concentration of 70% by volume.

[0031] The pH is preferably adjusted with hydrochloric acid.

[0032] The extract described in step (3) can be further concentrated and dried to obtain the yellow pigment.

[0033] A yellow pigment obtained by the above production method; its main components are 4 components with molecular weights of 472.30, 574.42, 486.31, and 412.37 respectively.

[0034] After appropriate processing, purification, and detoxification treatment, the yellow pigment can be used as a pigment additive.

[0035] The yellow pigment is a natural yellow pigment and can be applied to products that require color enhancement treatment, such as medicine, cosmetics, food, feed, and industrial products.

[0036] The present invention has the following advantages and effects compared with the prior art:

[0037] (1) The existing Monascus purpureus used for producing microbial natural pigments can produce 111 identified Monascus pigments, mainly including three categories: red pigments, orange pigments, and yellow pigments. Since the proportion of yellow pigments in the produced pigments is relatively low, in actual production, yellow pigments are made by sulfonating Monascus red pigments with sulfides to form Monascus yellow pigments. Strictly speaking, it is obtained by a chemical conversion method, and the formed Monascus yellow pigments are non-natural pigments. However, the yellow pigments produced by the Aspergillus foetidus strain HC32 selected in this invention mainly consist of four components, and it is easy to prepare products with clear components without chemical conversion.

[0038] (2) The high-yield intracellular yellow pigment Aspergillus foetidus strain provided by this invention can achieve high production of intracellular yellow pigments under the conditions of selecting conventional carbon sources (glucose) and nitrogen sources (soy peptone).

[0039] (3) The breeding method provided by this invention is simple, the fermentation conditions are mild, the investment is small, and it is easy to master. Description of the Drawings

[0040] Figure 1 It is the phylogenetic tree diagram of the original strain Aspergillus foetidus HC16.

[0041] Figure 2 It is the spectrogram of the intracellular yellow pigment produced by Aspergillus foetidus HC32.

[0042] Figure 3 It is the colony and cell morphology diagram of Aspergillus foetidus HC32; among them, a is the front view of the colony, b is the back view of the colony, c is the hypha diagram under an optical microscope magnified 400 times, and d is the hypha diagram under an optical microscope magnified 100 times.

[0043] Figure 4 It is the graph of the color value and mycelial biomass of the intracellular yellow pigment produced by the original strain and Aspergillus foetidus HC32 in the basic fermentation medium.

[0044] Figure 5 It is the graph of the color value and mycelial biomass of the intracellular yellow pigment produced by the original strain and Aspergillus foetidus HC32 in the improved fermentation medium.

[0045] Figure 6 It is the ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) analysis spectrogram of the 4 main components of the intracellular yellow pigment produced by Aspergillus foetidus HC32; among them, a is the mass spectrogram of the sample, b is the molecular weight detection result of component A, c is the molecular weight detection result of component B, d is the molecular weight detection result of component C, and e is the molecular weight detection result of component D. Detailed Embodiments

[0046] The following further describes the present invention in detail in combination with the embodiments and the drawings, but the embodiments of the present invention are not limited thereto.

[0047] Potato Dextrose Agar Medium (PDA Solid Medium): 20 g of glucose, 4 g of potato powder, 20 g of agar, made up to 1000 mL with distilled water, pH natural.

[0048] Potato Dextrose Broth Medium (PDB Liquid Medium): 20 g of glucose, 4 g of potato powder, made up to 1000 mL with distilled water, pH natural.

[0049] Basic fermentation broth: 1 g / L of K2HPO4, 0.5 g / L of MgSO4, 0.5 g / L of KCl, 0.01 g / L of FeSO4, 20 g / L of glucose, 5 g / L of fish peptone, pH natural.

[0050] Example 1: Isolation, Identification and Mutation of a High-Yield Intracellular Yellow Pigment-Producing Aspergillus foetidus Strain

[0051] Aspergillus foetidus HC16 used in this invention was isolated from Xinhui dried tangerine peel. The specific isolation steps are as follows: Place Xinhui dried tangerine peel in a 250 mL conical flask containing 100 mL of sterile water, shake on a shaker at 180 rpm for 30 min, then pipette 100 μL of the liquid and spread it on the PDA medium. After culturing in a constant temperature incubator at 28 °C for 3 days, pick colonies with different morphological characteristics and perform streak plate isolation on the PDA medium. Culture at 28 °C until single colonies with a single morphology appear on a single plate. Then inoculate the obtained single colonies into the PDB medium, and a yellow bacterial liquid is found in one bottle. Extract the total DNA of this bacterium, use the fungal ITS rRNA PCR amplification universal primers ITS4 and ITS5 for PCR amplification, and send it to Genewiz for sequencing. The sequencing results are as follows:

[0052]

[0053] Compare the obtained sequence with the known sequences in the GenBank database, and use MEGA6.0 software to construct a phylogenetic tree. As Figure 1 shown, it can be seen that the homology of this strain (named HC16) with Aspergillus foetidus CBS128.28 is 99.17%, and it is determined that this bacterium is Aspergillus foetidus. Use Aspergillus foetidus HC16 as the original strain for mutation. After fermenting the mutated Aspergillus foetidus HC32 in the PDB liquid medium, then use 70% ethanol solution to extract the intracellular substances. After spectral scanning with an ultraviolet spectrophotometer, as Figure 2 shown, a maximum absorption peak is found at 422 nm. The specific steps of the mutation are as follows:

[0054] (Ⅰ) Preparation of mold spore suspension: The original strain HC16 was inoculated on a PDA solid medium and cultured at 28 °C for 15 days. When spores grew on the mycelium on the plate, the surface of the mycelium was rinsed with sterile normal saline, dispersed with sterilized glass beads, filtered through 8 layers of sterile gauze, and the number of spores was counted using a hemocytometer under a microscope. After appropriate dilution, a suspension with a spore count of 1×10 5 cells / mL was prepared.

[0055] (Ⅱ) UV mutagenesis: 20 mL of the spore-containing suspension obtained in step (Ⅰ) was pipetted into a 90-mm-diameter petri dish and placed 30 cm away from a 19-W UV lamp. While stirring magnetically, it was irradiated for 6 minutes for UV mutagenesis.

[0056] (Ⅲ) Plate isolation and screening: The mutagenized suspension in step (Ⅱ) was diluted and spread on a PDA solid medium plate. It was cultured at 28 °C in the dark in an inverted position. After colonies grew, strains with changed colony morphology compared to the original strain (including the depth of yellow pigment color, radius size, and hyphal radius size) were selected, and single colony streak isolation was performed. After repeated isolation and purification, relatively pure mutagenized strains were obtained and stored at 4 °C.

[0057] (Ⅳ) Fermentation and breeding: The mutagenized strains isolated and purified in step (Ⅲ) were subjected to a fermentation experiment. That is, the mutagenized strains isolated and purified in step (Ⅲ) were inoculated into 50 mL of sterilized PDB liquid medium for culture and proliferation. One 2-mm × 2-mm-sized fungal block was inoculated into each 50 mL of PDB liquid medium, and it was cultured at 180 rpm for 48 hours to make Aspergillus foetidus in the logarithmic growth phase to obtain a seed liquid; the seed liquid was inoculated into 50 mL of PDB liquid medium at a ratio of 10% (V / V) and cultured at 180 rpm for 7 days. The fermented fermentation broth was subjected to solid-liquid separation, the mycelium was taken, and the intracellular content of the mycelium was extracted with 70% ethanol aqueous solution (the pH value was adjusted to 2.00 with dilute hydrochloric acid), and the color value and components of intracellular yellow pigment in the extract were detected to obtain a high-yield intracellular yellow pigment-producing Aspergillus foetidus strain.

[0058] After breeding, a high-yield intracellular yellow pigment-producing Aspergillus foetidus strain was obtained, which had the following characteristics: It grew well on a potato dextrose agar medium, formed round colonies, and did not have radial grooves; as Figure 3 shown in a, the colony was yellow, with a velvety texture, and a marginal zone was formed around the mycelium. The hyphae in the marginal zone were sparse and extended in all directions. After culturing for 6 - 7 days, the diameter could reach 30 - 40 mm. As Figure 3 shown in b, the back of the colony also did not have radial grooves and was dark yellow-brown; as Figure 3As shown in c and d, the mycelium is yellowish green and has contents. It was named Aspergillus foetidus HC32 and was deposited on January 3, 2023 at the Guangdong Microbial Culture Collection Center, Institute of Microbiology, Guangdong Academy of Sciences, 5th Floor, Building 59, 100 Xianlie Middle Road, Guangzhou, with the deposit number GDMCC No: 63106.

[0059] Example 2 Preparation of yellow pigment using a high-yield intracellular yellow pigment-producing Aspergillus foetidus strain by a conventional method

[0060] (1) Preparation of seed liquid: The original strain (HC16) and mutant strain (HC32) plate seeds streaked on PDA plates were respectively inoculated into sterilized 50 mL PDB liquid medium for culture and proliferation. The inoculation amount was 2 fungal blocks with a diameter of 0.5 cm, and they were cultured on a shaker at 180 rpm for 48 h to obtain the seed liquid.

[0061] (2) Fermentation culture: The seed liquid was inoculated into 50 mL of basic fermentation medium at an inoculation amount of 10% (V / V), and fermented and cultured on a shaker at 180 rpm and 30 °C for 7 days. The fermented fermentation broth was filtered and separated, and the mycelium was taken. 50 mL of 70% ethanol aqueous solution (pH value adjusted to 2.00 with dilute hydrochloric acid) was added, and it was oscillated in a shaker at 180 rpm for 3 h to extract the mycelium contents. After filtration with filter paper, the color value of the filtrate and the dry weight of the mycelium were measured.

[0062] (3) Method for measuring color value: The intracellular pigment extract was diluted to a suitable concentration, and a spectrophotometer was used to detect the color value of the yellow pigment in the filtrate obtained after filtration (i.e., the absorbance value at a wavelength of 422 nm). The results are as Figure 4 shown. The absorbance of the intracellular pigment extract fermented by the mutant strain measured at 422 nm with an ultraviolet spectrophotometer was 14.05 AU / mL; the absorbances of the intracellular extracts fermented by the original strain measured at 422 nm with an ultraviolet spectrophotometer were 8.25 AU / mL. It can be seen that the color value of the intracellular yellow pigment of the mutant strain is 1.703 times that of the original strain.

[0063] (4) Method for measuring the dry weight of mycelium: The mycelium was filtered onto filter paper with a pre-weighed mass, and repeatedly rinsed with deionized water until the filtrate became colorless; the filter paper was removed, placed in an oven and dried at 120 °C for 2 h, then placed in a desiccator until room temperature, and the total weight of the filter paper and the mycelium was weighed using a precision analytical balance, and finally the dry weight of the mycelium was obtained. The results are as Figure 4 shown. The dry weight of the mycelium after fermentation of the mutant strain was 4.45 g / L; the dry weight of the mycelium fermented by the original strain was 2.66 g / L. It can be seen that the dry weight of the mycelium of the mutant strain is 1.71 times that of the original strain.

[0064] Example 3 Preparation of intracellular yellow pigment using an Aspergillus foetidus strain with high intracellular yellow pigment production and optimized carbon and nitrogen sources

[0065] The Aspergillus foetidus strain HC32 with high intracellular yellow pigment production and the original strain HC16 were used for seed activation of the mycelium according to the method of Example 2. Different from Example 2, in the fermentation medium (i.e., the basic fermentation broth), the carbon source was changed to glucose and the concentration of glucose was increased to 60 g / L, and the nitrogen source was changed to soy peptone with a concentration changed to 15 g / L. After 7 days of fermentation, the color value of the intracellular pigment extract and the dry weight of the mycelium were measured according to the method of Example 2. The results are as follows Figure 5 shown. The absorbance of the intracellular fluid of the mutant strain at 422 nm measured by an ultraviolet spectrophotometer was 99.42 AU / mL, and the absorbance of the intracellular pigment extract of the original strain at 422 nm measured by an ultraviolet spectrophotometer was 37.68 AU / mL. It can be seen that under the optimized fermentation medium conditions, the color value of the intracellular yellow pigment of the mutant strain is 2.64 times that of the original strain. The dry weight of the mycelium of the mutant strain after fermentation was 11.04 g / L, and the dry weight of the mycelium of the original strain after fermentation was 4.32 g / L. It can be seen that under the optimized fermentation medium conditions, the dry weight of the mycelium of the mutant strain is 2.55 times that of the original strain.

[0066] Example 4 Detection of the components and molecular weights of the yellow pigment prepared from an Aspergillus foetidus strain with high intracellular yellow pigment production using optimized carbon and nitrogen sources

[0067] The Aspergillus foetidus strain HC32 with high intracellular yellow pigment production was used for seed activation of the mycelium according to the method of Example 2, and then fermented and cultured according to the fermentation medium formula in Example 3. After 7 days of fermentation, the intracellular pigment extract was separated according to the method of Example 2, and the extract was detected using ultra-high performance liquid chromatography-mass spectrometry.

[0068] Ultra-high performance liquid chromatography-mass spectrometry detection method: The intracellular pigment extract was filtered through a 0.22 μm organic membrane, and an experiment was carried out using a Thermo Fisher Scientific Ultimate 3000 ultra-high performance liquid chromatography system in combination with an LTQ Orbitrap Elite mass spectrometer. At a mobile phase flow rate of 0.3 mL min -1Chromatographic separation was carried out on an ACQUITY UPLC HSS T3 chromatographic column (inner diameter 100 mm × 2.1 mm, particle size 1.8 μm). The mobile phase consisted of (A) water containing 0.1% formic acid and (B) acetonitrile. The gradient elution program was as follows: maintained at 20% to 80% B for 0 - 13 minutes, maintained at 80% B for 13 - 18 minutes, and maintained at 20% B for 18 - 30 minutes. The injection volume was 1 μL. The column and sample temperatures were maintained at 40 and 10 °C, respectively. The parameters set for the mass spectrometer were as follows: electrospray ionization source, detection in positive ion mode, negative and positive capillary voltages were 2.50 KV and 3.20 KV, respectively, source vaporizer temperature 250 °C, capillary temperature 275 °C, sheath gas 35 arb, auxiliary gas 10 arb, carrier gas was helium, and the MS spectrum was recorded in the m / z range of 100–1000. The data was processed using Thermo Fisher Scientific Xcalibur software, and relevant molecular weight and other information were obtained based on the mass spectrum.

[0069] The results are as Figure 6 shown in a of Figure 6 below. The intracellular extract produced by the fermentation of Aspergillus foetidus HC32 after mutation mainly contains 4 components (A - D) at 422 nm. Further detection of the molecular weight information of each component shows that the results are as

[0070] shown in b - e below, and their molecular weights are A: 472.30, B: 574.42, C: 486.31, D: 412.37.

[0071] Furthermore, the Aspergillus foetidus HC32 strain with high - yield yellow pigment of the present invention can be used as the original strain, and further improved by means such as laboratory domestication, genetic breeding, and molecular genetic manipulation to obtain derivative strains with higher yields or more optimized enzyme systems. Taking the Aspergillus foetidus HC16 strain of the present invention as the original strain, the strains obtained by further screening and optimization through these artificial operation means should also be included within the overall scope of the present invention.

[0072] Methods well-known to those skilled in the art can be used to further mutagenize the living strains of the present invention, resulting in genetic coding changes, enzyme activity characteristics, and morphological changes in living cells. These methods include physical methods such as using radiation, particles, lasers, etc., and chemical mutagenesis methods such as using alkylating agents, base analogs, hydroxylamine, acridine dyes, etc. The mutagenesis can be multi-generation mutagenesis using one or more of the above methods and is not limited to these methods. Based on the strains provided by the present invention, breeding can be further carried out by physical and chemical means, or new yellow pigment regulatory genes and other related regulatory genes can be introduced. The enzyme production performance of the obtained mutants and transformants can be further improved. The breeding methods described above are one or a combination of more than one of the above.

[0073] Methods well-known to those skilled in the art can be used to construct expression constructs (vectors) and further modify the strains of the present invention. For example, further improvement can be made to the signal pathways, signal transduction pathways, and proteins involved therein that have been discovered or newly discovered in the strains and are related to yellow pigment production. Transformation of host cells with recombinant DNA can be carried out using conventional techniques well-known to those skilled in the art. The steps used are well-known in the art.

[0074] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A strain of Aspergillus foetidus producing yellow pigment, characterized in that: The name of the Aspergillus foetidus strain producing yellow pigment is Aspergillus foetidus ( Aspergillus foetidus ) HC32, which was deposited on January 3, 2023 at the Guangdong Provincial Microbial Culture Collection Center, Institute of Microbiology, Guangdong Academy of Sciences, 5th Floor, Building 59, 100 Xianlie Middle Road, Guangzhou, with the deposit number GDMCC No: 63106.

2. Use of Aspergillus foetidus producing yellow pigment according to claim 1 in the production of yellow pigment.

3. A method for producing a yellow pigment, characterized in that It includes the following steps: (1) Inoculate the seed liquid of Aspergillus foetidus producing yellow pigment according to claim 1 into a fermentation medium for fermentation culture to obtain a fermentation broth; (2) Perform solid-liquid separation on the fermentation broth obtained in step (1), and take the thallus; (3) Oscillate and extract the intracellular content of the thallus obtained in step (2) with an organic solvent, and the obtained extract is the intracellular yellow pigment solution; The composition of the fermentation medium described in step (1) is as follows: K2HPO4 1 g / L, MgSO4 0.5 g / L, KCl 0.5 g / L, FeSO4 0.01 g / L, glucose 50 - 80 g / L, soy peptone 5 - 20 g / L, pH natural; or K2HPO4 1 g / L, MgSO4 0.5 g / L, KCl 0.5 g / L, FeSO4 0.01 g / L, glucose 20 g / L, fish peptone 5 g / L, pH natural.

4. The production method of yellow pigment according to claim 3, characterized in that: The seed liquid of Aspergillus foetidus described in step (1) is prepared through the following steps: Activate the preserved strain of Aspergillus foetidus and inoculate it into a seed medium for shake flask culture to obtain Aspergillus foetidus in the logarithmic growth phase; The activation steps are as follows: Streak the preserved strain of Aspergillus foetidus on a PDA medium plate, culture it at 25 - 30 °C for 4 - 7 days for activation to obtain plate seeds; During the preparation process of the seed liquid of Aspergillus foetidus: The inoculation amount for the inoculation is two plate colonies with a diameter of 0.5 - 1 cm per 50 mL of seed medium; the seed medium is a PDB liquid medium; the conditions for the shake flask culture are to culture at 25 - 35 °C, 100 - 200 rpm for 24 - 48 h.

5. The production method of yellow pigment according to claim 3, characterized in that: The inoculation amount of the seed liquid of Aspergillus foetidus described in step (1) is 5 - 15% by volume percentage; The conditions for the fermentation culture described in step (1) are as follows: Culture at 25 - 35 °C, 100 - 200 rpm for 4 - 12 days.

6. The production method of yellow pigment according to claim 3, characterized in that: The method of solid-liquid separation described in step (2) is filter paper filtration, suction filtration or centrifugation; The organic solvent described in step (3) is an ethanol aqueous solution with a pH value of 1.5 - 2.5 and a volume percentage of 60 - 80%.

7. The production method of yellow pigment according to claim 3, characterized in that: The extract described in step (3) is further concentrated and dried to obtain yellow pigment.

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