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CN-121975644-A - Marine rhodotorula mucilaginosa for degrading nitrosamine and application thereof

CN121975644ACN 121975644 ACN121975644 ACN 121975644ACN-121975644-A

Abstract

The invention relates to a rhodotorula mucilaginosa strain for degrading nitrosamine and application thereof, belonging to the technical field of microorganisms. The invention provides a rhodotorula mucilaginosa SGA13 and is applied to fermented meat products, the rhodotorula mucilaginosa SGA13 can directly degrade nitrosamine in the meat products, the nitrosamine degradation capability of the rhodotorula mucilaginosa SGA13 is obviously improved compared with nitrosamine degradation capability of other yeast strains, in addition, the rhodotorula mucilaginosa SGA13 also has unique potential in the aspect of flavor substance improvement, and the rhodotorula mucilaginosa SGA13 has good application prospect as a meat product starter and can widen the application range of rhodotorula mucilaginosa.

Inventors

  • LIN XINPING
  • LI MENGYI
  • YUE YING
  • YAN XU
  • TANG YINING
  • WANG SHIMIAO
  • GUO BINGRUI
  • ZHANG SUFANG
  • JI CHAOFAN
  • CHEN YINGXI

Assignees

  • 大连工业大学

Dates

Publication Date
20260505
Application Date
20260130

Claims (10)

  1. 1. A strain of rhodotorula mucilaginosa (Rhodotorula mucilaginosa) SGA13, wherein the rhodotorula mucilaginosa SGA13 is preserved in the microorganism strain collection of Guangdong province, and the preservation number is GDMCC No:67047.
  2. 2. A microbial preparation comprising the rhodotorula mucilaginosa SGA13 of claim 1.
  3. 3. The microbial preparation according to claim 2, wherein the number of cells of the rhodotorula mucilaginosa SGA13 in the microbial preparation is not less than 1 x 10 5 CFU/g or 1 x 10 5 CFU/mL.
  4. 4. A product comprising the rhodotorula mucilaginosa SGA13 of claim 1 or the microbial preparation of claim 2 or 3, characterized in that the product comprises a food product, a pharmaceutical product or a health product.
  5. 5. The product of claim 4, wherein the food product comprises a fermented meat product.
  6. 6. A method for reducing the nitrosamine content of a fermented meat product, characterized in that the rhodotorula mucilaginosa SGA13 according to claim 1 or the microbial preparation according to claim 2 or 3 is inoculated into meat for fermentation.
  7. 7. The method of claim 6, wherein the fermented meat product comprises air-dried sausage or stinky mandarin fish.
  8. 8. The method according to claim 7, wherein the marine rhodotorula mucilaginosa SGA13 according to claim 1 is inoculated into meat at 1X 10 5 ~1×10 7 CFU/g and fermented at 10-15 ℃ for 10-12 days to obtain the air-dried sausage.
  9. 9. The method according to claim 7, wherein the marine rhodotorula mucilaginosa SGA13 according to claim 1 is inoculated into mandarin fish and fermented at 10-15 ℃ for 5-9 days to obtain the stinky mandarin fish.
  10. 10. The use of rhodotorula mucilaginosa SGA13 according to claim 1 for degrading nitrosamines.

Description

Marine rhodotorula mucilaginosa for degrading nitrosamine and application thereof Technical Field The invention relates to a rhodotorula mucilaginosa strain for degrading nitrosamine and application thereof, belonging to the technical field of microorganisms. Background Nitrite has an irreplaceable role in meat processing, including effective inhibition of botulinum growth, promotion of development of characteristic color and flavor. However, during processing or storage, nitrite can react with biogenic amines to form nitrosamines with strong carcinogenicity, wherein N-Nitrosodimethylamine (NDMA) is the most toxic and severely threatens human health. At present, biodegradation is attracting attention in the degradation method of nitrosamine because of mild reaction conditions and high safety. However, in exploring microbial degradation strategies, there is often a critical misleading area to equate nitrite removal capacity with nitrosamine degradation capacity. In fact, the degradation of nitrite and nitrosamine involves distinct biochemical mechanisms-the former relies mainly on the system of reductases in the microorganism (e.g., nitrite reductase) or facilitates its decomposition by the acidogenic environment, while the latter requires a specific enzyme system (e.g., oxygenase) to directly attack the nitrosamine molecular structure. Therefore, a microorganism capable of degrading nitrite with high efficiency does not necessarily have the ability to degrade nitrosamine. In addition, if nitrite is removed too early or excessively in the processing process of meat products, the key functions of corrosion resistance, color development and the like of the meat products can be weakened, and the quality and safety of the products are affected. In view of this, direct targeting of the end product, nitrosamine, for degradation is a more targeted and practical strategy than modulating the precursor species (nitrite). Under the background, the marine rhodotorula mucilaginosa has unique potential, and the rhodotorula mucilaginosa not only has good salt tolerance and strong oxidation resistance, but also can inhibit harmful microorganisms and promote beneficial bacteria proliferation, and has wide application prospect in the food industry. The research shows that part of marine rhodotorula mucilaginosa strains have the capability of removing nitrite in artificial sewage, but the degradation performance of the marine rhodotorula mucilaginosa strains on nitrosamine is not clear, and the safety of the marine rhodotorula mucilaginosa strains in foods is also lack of systematic evaluation. Therefore, the screening of the marine rhodotorula mucilaginosa strain with the capability of directly degrading the nitrosamine is not only beneficial to expanding the strain resources of nitrosamine biodegradation, but also can provide important technical support for developing a novel meat product starter, reducing the nitrosamine residue risk and improving the food safety level. Disclosure of Invention Based on the above research background, a first object of the present invention is to provide a rhodotorula mucilaginosa strain which exhibits excellent nitrosamine degradation ability. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: The rhodotorula mucilaginosa SGA13 has good growth state in a screening culture medium with N-dimethyl Nitrosamine (NDMA) as the only nitrogen source, and shows excellent NDMA utilization capacity. The marine rhodotorula mucilaginosa (Rhodotorula mucilaginosa) SGA13 is preserved in the Guangdong province microorganism strain preservation center, the preservation numbers are GDMCC 67047, the preservation date is 2025 years, 9 months and 28 days, and the preservation address is the Guangdong province laboratory building 5 building Guangdong province microorganism strain preservation center of No. 100 in the Xiuzhou region martyr of Guangdong province. The marine rhodotorula mucilaginosa SGA13 grows well in YPD solid plates, 30Culturing for 48h to form a colony with a round shape and a smooth surface and pink color. The invention provides a microbial preparation containing marine rhodotorula mucilaginosa SGA 13. In one embodiment of the present invention, in the microbial preparation, the number of cells of rhodotorula mucilaginosa SGA13 is not less than 1X 10 5 CFU/g or 1X 10 5 CFU/mL. The invention also provides a preparation method of the rhodotorula mucilaginosa SGA13 and the microbial preparation thereof, which comprises the following steps of inoculating single colony of the rhodotorula mucilaginosa SGA13 into YPD liquid culture medium, and culturing in 25-30C. Culturing for 36-48 hours under the condition of 180-220 rpm to obtain primary seed liquid, transferring the primary seed liquid into a fresh YPD liquid culture medium according to the inoculation amount of 1-5% of the volume ratio, continuously culturing for 36-48 hours under the same conditio