Emericella turuncata
By screening and optimizing Aspergillus cristatus Ec-520 and its preparations, the problems of long fermentation time and low yield of Fu brick tea have been solved, thus improving the quality of Fu brick tea.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- INST OF ANIMAL HUSBANDRY & VETERINARY FUJIAN ACADEMY OF AGRI SCI
- Filing Date
- 2024-06-20
- Publication Date
- 2026-07-03
AI Technical Summary
Traditional Fu brick tea has problems with poor quality, long processing time, and small quantity of fermentation during the fermentation process. Loose tea is difficult to ferment, making it hard to meet product quality requirements.
A highly efficient proliferating strain of Aspergillus cristatus Ec-520 was provided, and corresponding microbial preparations and Fu brick tea were prepared. The conditions for flower development were optimized, including temperature and humidity control, and the inoculum volume was increased.
Shorten the fermentation time, increase the quantity and effect of fermentation, and improve the quality and taste of Fu brick tea.
Smart Images
Figure CN118879502B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of microbiology, and more particularly to a strain of *Aspergillus cristatus* that proliferates rapidly. Background Technology
[0002] *Eurotium cristatum*, also known as *Aspergillus cristatus*, commonly called "golden flower fungus," is the dominant fungus growing on Fu brick tea, directly affecting its quality. It obtains nutrients from the tea leaves and, through its own metabolism, produces various enzymes that catalyze the transformation of various substances in the tea, resulting in the unique color, aroma, and flavor of Fu brick tea. Studies have found that *Eurotium cristatum* is non-toxic, and its metabolites can effectively regulate human metabolism, exhibiting strong lipid-lowering, blood pressure-lowering, anti-tumor, and carbohydrate metabolism-regulating effects, thus improving and optimizing the taste and other characteristics of the tea.
[0003] "Golden flowers" are a key technology in the production of Fu brick tea. During the "golden flowers" process, *Aspergillus cristatus* multiplies in large quantities and uses its secondary metabolites and its own biological enzymes to transform the nutrients in Fu brick tea into other beneficial functional components, giving Fu brick tea its unique color, aroma and flavor. The number of *Aspergillus cristatus* directly determines the quantity and quality of "golden flowers" in the finished tea, and is an important factor in determining the quality of Fu brick tea.
[0004] Traditional fermentation methods rely on natural blooming, but this process has drawbacks such as poor bloom quality, long fermentation time, and low bloom quantity. Furthermore, brick tea is cumbersome to use. To shorten fermentation time and facilitate convenient drinking, loose tea is used for blooming, resulting in small golden spots on the surface, creating the convenient "golden flower" black tea. However, natural blooming of loose tea is more difficult than that of brick tea. Therefore, this study investigates the growth of *Aspergillus cristatus* in loose tea during blooming to meet product quality requirements. Summary of the Invention
[0005] The technical problem to be solved by this invention is to provide a strain of *Eurotium cristatum* that proliferates efficiently, thereby further shortening the flowering time and increasing the number of flowers.
[0006] This invention is implemented as follows:
[0007] This invention provides a highly efficient proliferating strain of *Aspergillus cristatus*, Ec-520, which was deposited on December 27, 2023, at the Guangdong Provincial Microbial Culture Collection Center (GDMCC), located at 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, with accession number GDMCCNo. 64205.
[0008] The present invention also provides a microbial preparation comprising the aforementioned *Aurotriarcha*.
[0009] The present invention also provides a Fu tea containing the aforementioned *Eurotium cristatum*.
[0010] The present invention has the following advantages: The present invention screened a strain of *Eurotium cristatum* that proliferates efficiently, which further shortens the flowering time, increases the number of flowers, and achieves a better flowering effect. Attached Figure Description
[0011] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0012] Figure 1 This shows the final state of the strain after it stopped growing on PDA medium (left: BNCC146563, right: Ec-520).
[0013] Figure 2 The image shows the blooming of the bacterial strain on a small white tea cake (left: BNCC146563, right: Ec-520).
[0014] Figure 3 The flowering of the strain on black tea (left: BNCC146563, right: Ec-520). Detailed Implementation
[0015] 1. Isolation and culture of *Eurotium cristatum*
[0016] Under aseptic conditions, golden cleistothecia were directly picked from Fu brick tea and inoculated onto PDA medium. The mixture was incubated at 28°C. When the colonies turned yellow, a suitable amount of bacteria was picked up with a sterile inoculation loop and streaked onto a plate. This streaking was repeated until the strain was initially purified. Golden yellow single colonies were picked from the plate and inoculated onto PDA plates. Incubation continued until the colonies turned yellow. Colony morphology was observed daily, and the best-growing strain was selected as the target strain. A suitable amount of yellow cleistothecia was picked up with an inoculation loop and placed in sterile physiological saline. The mixture was shaken thoroughly, and hemocytocytes were counted to achieve a spore suspension concentration of 10⁻⁶. 8 CFU / mL yields the spore suspension used in liquid fermentation.
[0017] 2. Identification of *Eurotium cristatum*
[0018] The spore suspension was inoculated into PDB medium at a rate of 3%, and incubated at 27.5°C and a rotation speed of 160 rpm. -1 After culturing for 24 hours, total DNA was extracted using a fungal DNA extraction kit. The purified total DNA was then stored at -20°C.
[0019] PCR amplification was performed using universal references ITS1 and TS4. The reaction mixture consisted of: 25 μL 2×Mix; 2 μL ITS1 (10 μmol / L); 2 μL ITS4 (10 μmol / L); 8 μL DNA template; and ddH2O added to a final volume of 50 μL. The amplification conditions were: pre-denaturation at 95°C for 5 min; denaturation at 95°C for 30 s; and annealing at 56°C.
[0020] C / 30s; extension 72℃ / 1min, repeat the denaturation, annealing and extension steps 40 times; extension 72°C / 10min. Detect by 2% agarose gel electrophoresis.
[0021] Results: A target band of 500 bp was detected. The PCR product was then sequenced by Shanghai Platinum Biotechnology Co., Ltd. After comparing and analyzing the 16S rRNA sequence of the strain on the NCBI website (https: / / www.ncbi.nlm.nih.gov / ), and considering the ecological characteristics of the strain, it was confirmed that the strain belongs to *Aspergillus cristatus* taxonomically and was named *Aspergillus cristatus* Ec-520.
[0022] 3. Growth of *Eurotium cristatum*
[0023] A comparative experiment was conducted between the *Aureobasidium tricuspidata* strain BNCC146563 purchased from Beina Chuanglian Biotechnology Co., Ltd. and the strain Ec-520 isolated in this invention. The specific results are as follows:
[0024] Table 1. Growth of *Eurotium cristatum* on PDA medium
[0025]
[0026] The isolated *Aspergillus cristatus* Ec-520 was inoculated onto PDA agar medium and incubated at 28°C. After approximately 36 hours, *Aspergillus cristatus* began to grow, initially producing white mycelia extending outwards, with the colony center gradually changing from white to light yellow. After 3 days of growth, yellow cleistothecia formed throughout the colony area, reaching a diameter of 8–12 mm and appearing pale yellow. By day 5, the colony edges were pale yellow, with a raised center; the color gradually deepened towards the center, becoming yellow and then dark yellow, with the center reaching a dark olive-brown or dark brown. Growth ceased on day 18, with a colony diameter of 55–60 mm. At this point, a dry, raised, wrinkled appearance was clearly visible in the colony center, and the entire colony turned brown, with the secreted pigment turning the entire culture medium dark brown. Figure 1 As shown.
[0027] The growth of the strain on PDB medium is shown in Table 2. It can be seen that the strain Ec-520 of this invention exhibits a high mycelial yield.
[0028] Table 2. Growth of *Eurotium cristatum* on PDB medium.
[0029]
[0030] As shown in Table 3 and Figure 2 , Figure 3 As shown, the strain Ec-520 of the present invention further shortens the flowering time, increases the number of flowers, and achieves a better flowering effect.
[0031] Table 3. Flowering phenomenon of *Eurotium cristatum* on tea leaves.
[0032]
[0033] 4. Conditions for the flowering of *Eurotium cristatum*
[0034] Temperature: 27-30℃, pH: natural, tea moisture content: 10%-30%, inoculum volume (ml of inoculum / g of tea): 10%-30%.
[0035] The best results for flower development were achieved at 28.6℃, with a tea moisture content of 15% and an inoculum concentration of 15%.
[0036] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope of protection of the claims of the present invention.
Claims
1. A strain of *Aspergillus cristatus*, characterized by: for Aspergillus cristatus Ec-520 was deposited at the Guangdong Provincial Microbial Culture Collection Center (GDMCC) on December 27, 2023, at 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, with accession number GDMCCNo.64205.