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CN-121495724-B - Candida utilis strain for efficiently converting ethanol/acetic acid and application thereof

CN121495724BCN 121495724 BCN121495724 BCN 121495724BCN-121495724-B

Abstract

The invention discloses a candida utilis strain for efficiently converting ethanol/acetic acid and application thereof, belonging to the technical field of single cell protein production. Aiming at the technical problems of limited biomass accumulation, low carbon source conversion efficiency and low protein yield of a wild candida utilis strain when an ethanol-acetic acid mixed carbon source is utilized, the invention provides a candida utilis TU546 strain with the collection number of CGMCC No.39030, and the candida utilis TU546 strain is cultured in a mixed carbon source fermentation medium containing ethanol and acetic acid to obtain zymophyte with high protein content, thereby realizing the efficient conversion from the ethanol-acetic acid mixed carbon source to single cell protein. The strain and the method thereof are mainly used for producing single-cell protein products, can be used as feed or food additives, and have important application value in the microbial fermentation industry.

Inventors

  • LI DEMAO
  • CAO YIXIN
  • Ma Longxue
  • CHEN LIMEI
  • YANG YANG
  • CHEN WUXI

Assignees

  • 中国科学院天津工业生物技术研究所

Dates

Publication Date
20260508
Application Date
20260113

Claims (10)

  1. 1. The candida utilis strain is candida utilis TU546, and is classified and named as candida utilis Cyberlindnera jadinii, and candida utilis Cyberlindnera jadinii TU546 is preserved in China general microbiological culture collection center (CGMCC) with the preservation number of CGMCC No. 39030, the preservation time of 2025, 11 and 03 days, and the preservation unit address of North Star Xiya 1 in the Beijing area.
  2. 2. A method for producing single-cell protein, characterized in that the candida utilis strain according to claim 1 is cultivated in a fermentation medium, and fermentation thalli are obtained after the cultivation, namely the single-cell protein.
  3. 3. The method for producing single-cell proteins according to claim 2, wherein the fermentation medium comprises the following components, wherein the total concentration of the mixed carbon source is 5 g/L-50 g/L, the mixed carbon source is ethanol and acetic acid, and the mass ratio of the ethanol to the acetic acid in the mixed carbon source of the ethanol and the acetic acid is 1:1-5:1.
  4. 4. The method for producing single-cell proteins according to claim 2, wherein the ratio of ethanol to sodium acetate in the carbon source ethanol and sodium acetate mixed in the fermentation tank culture is 1:1-3:1.
  5. 5. The method for producing single cell proteins according to claim 2, wherein the cultivation is performed in a fermenter at a temperature of 25 ℃ to 37 ℃ and a pH of 5.0 to 7.0.
  6. 6. The method for producing single-cell proteins according to claim 2, wherein the fermentation medium further comprises ammonium sulfate at a concentration of 2 g/L to 10 g/L, potassium dihydrogen phosphate at a concentration of 0.5 g/L to 3.0 g/L, magnesium sulfate at a concentration of 0.2 g/L to 2.5 g/L, calcium chloride at a concentration of 0.1 g/L to 1.5 g/L, zinc sulfate heptahydrate at a concentration of 0.02 g/L to 0.2 g/L, and ferrous sulfate heptahydrate at a concentration of 5mg/L to 60 mg/L.
  7. 7. The method for producing single cell proteins according to claim 3, wherein the culturing time is 24 to 72 hours.
  8. 8. A single cell protein product produced by the method of any one of claims 2 to 7.
  9. 9. Use of a candida utilis strain as claimed in claim 1 in the preparation of a single cell protein feed or food additive.
  10. 10. Use of the candida utilis strain of claim 1 in the microbial fermentation industry using ethanol, acetic acid, sodium acetate or mixtures thereof.

Description

Candida utilis strain for efficiently converting ethanol/acetic acid and application thereof Technical Field The invention belongs to the technical field of single-cell protein production, and relates to a candida utilis strain for efficiently converting ethanol/acetic acid and application thereof. Background Proteins are increasingly demanded in the fields of food industry, feed production, medical care, etc. as core constituent substances of organisms. However, global protein resources are facing a dual pressure of "demand surge" and "traditional supply limitation". The traditional livestock and poultry and aquaculture modes are difficult to meet the requirement of sustainable development due to the problems of high resource consumption, high environmental load and the like. In this context, microbial proteins, in particular single cell proteins, are considered to be a very potential sustainable protein source. Among them, candida utilis (also called Cyberlindnerajadinii) is a recognized and safe industrial microorganism, and has great application potential in single cell protein production due to its high protein content, balanced amino acid composition and ability to utilize various inexpensive carbon sources. Of particular interest is the conversion of synthesis gas, based on carbon monoxide, carbon dioxide and hydrogen, to a mixture of ethanol and acetic acid via Clostridium (Clostridium spp) fermentation. This route provides a non-food, low-carbon raw material path for the production of single cell proteins. The candida utilis can cooperatively utilize the ethanol/acetic acid mixed solution as a carbon source, so that the candida utilis becomes an ideal downstream consumer of an upstream synthetic gas fermentation solution, and an innovative biological manufacturing route of 'gas-liquid-protein' can be constructed. However, the industrial development of the technical route still has a core bottleneck that firstly, the wild candida utilis strain has the problems of limited biomass accumulation and low carbon source conversion efficiency, so that the final protein yield is not high, and the economic feasibility of the candida utilis strain is restricted. Secondly, when carbon sources such as ethanol are utilized, toxic intermediates such as acetaldehyde can be accumulated in the metabolic process of the thalli, feedback inhibition is generated on cell growth, and biomass is further limited. In addition, for a high efficiency fermentation process using a specific mixed carbon source of ethanol/acetic acid, particularly a control strategy suitable for mass production, intensive research and optimization are still required. Therefore, there is an urgent need in the art for a candida utilis strain capable of efficiently utilizing ethanol/acetic acid mixed carbon sources, having high biomass and high protein yield, and a high-efficiency fermentation process matched with the candida utilis strain, so as to break through the current technical bottleneck and realize efficient conversion from non-grain carbon sources to high-value single-cell proteins. Disclosure of Invention It is an object of the present invention to address at least the above problems and/or disadvantages and to provide at least the advantages described below. For this purpose, the technical scheme provided by the invention is as follows: A candida utilis strain for efficiently converting ethanol/acetic acid is a candida utilis TU546, the classification name of the candida utilis TU546 strain is candida utilis Cyberlindnerajadinii, the candida utilis CyberlindnerajadiniiTU546 strain is preserved in China general microbiological culture collection center (CGMCC), the preservation number is CGMCC No. 39030, the preservation time is 2025, 11 and 03 days, and the preservation unit address is North Star West-way No. 1, 3 of the Korean region North Star in Beijing city. A method for producing single cell protein comprises culturing the candida utilis strain in a fermentation medium to obtain fermentation thalli after culturing, namely the single cell protein. Preferably, in the method for producing the single-cell protein, the fermentation medium comprises the following components of mixed carbon source total concentration of 5 g/L-50 g/L, mixed carbon source of ethanol and acetic acid, and mass ratio of ethanol to acetic acid in the mixed carbon source of ethanol and acetic acid of 1:1-5:1. Preferably, in the method for producing single-cell protein, the ratio of ethanol to sodium acetate in the carbon source mixed with ethanol and sodium acetate in the fermentation tank culture is 1:1-3:1. Preferably, in the method for producing single-cell protein, the culture is performed in a fermentation tank, the culture temperature is 25-37 ℃, and the pH is 5.0-7.0. Preferably, in the method for producing the single cell protein, the fermentation medium further comprises ammonium sulfate with the concentration of 2 g/L-10 g/L, monopotassium phosphate with