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CN-122012260-A - Method for preparing microbial protein by using nigre wastewater

CN122012260ACN 122012260 ACN122012260 ACN 122012260ACN-122012260-A

Abstract

The application relates to the technical field of microorganisms, in particular to a method for preparing microbial protein by using nigre wastewater, which aims to solve the problems of nigre wastewater pollution and high protein preparation cost. The method takes nigre waste water containing glycerol and sodium acetate as raw materials, realizes recycling through multistage treatment, firstly, removing toxic impurities through ferric salt sedimentation filtration, diatomite adsorption and activated carbon adsorption combination, and after pH adjustment, supplementing nitrogen sources, phosphorus sources and growth promoting factors to construct a balanced nutrition system, preparing a microorganism culture medium after sterilization, culturing and activating microorganism strains through liquid seed liquid, inoculating the microorganism strains into the culture medium for ventilation fermentation, and collecting thalli through solid-liquid separation to obtain microorganism thalli protein, wherein the separated fermentation waste liquid is recycled for nutrition allocation. The application realizes the unification of the efficient purification of nigre wastewater and the preparation of microbial protein, has the advantages of environment-friendly process, low cost and high product purity, and has remarkable economic and environmental benefits.

Inventors

  • XIA ZHILIN
  • NING SHOUJIAN

Assignees

  • 青岛碧沃德生物科技有限公司

Dates

Publication Date
20260512
Application Date
20260415

Claims (10)

  1. 1. A method for preparing microbial protein by using nigre wastewater, which is characterized by comprising the following steps: S1, adjusting pH after detoxification treatment of nigre wastewater to obtain a solution A, wherein the detoxification treatment is to firstly add ferric salt for treatment, sediment and filtration, and then sequentially carry out diatomite and activated carbon adsorption treatment on filtrate; S2, conveying the solution A to a nutrition preparation tank, and adding a nitrogen source, a phosphorus source and a growth promoting factor to obtain a solution B; S3, adjusting the pH value of the solution B, and then performing high-temperature sterilization to prepare a microorganism culture medium; s4, inoculating microorganism bacteria into a liquid seed liquid culture medium for culture to obtain microorganism seed liquid; S5, inoculating the microbial seed solution into the microbial culture medium, and carrying out aeration fermentation culture to obtain a fermentation liquor; S6, carrying out solid-liquid separation on the fermentation liquor, collecting microbial thalli to obtain microbial thalli protein, and conveying the fermentation waste liquor to a nutrition preparation tank for recycling.
  2. 2. The method for preparing microbial protein by using soapstock waste water according to claim 1, wherein in S1, the soapstock waste water comprises glycerin and sodium acetate, the pH is 4-5, the ferric salt comprises at least one of ferrous sulfate, polymeric ferric sulfate and ferric sulfate, and the mass-volume ratio of the ferric salt and the soapstock waste water is (0.5-1.0) g to 1L.
  3. 3. The method for preparing microbial protein by using nigre wastewater according to claim 1, wherein in S1, the sedimentation temperature is controlled to be 20-35 ℃ and the sedimentation time is 2-5h.
  4. 4. The method for preparing microbial protein by utilizing nigre wastewater according to claim 1, wherein in S1, the mass volume ratio of the diatomite, the activated carbon and the gleditsia sinensis wastewater is (5-15) g (3-10) g:1L, the adsorption time of the diatomite is 30-60min, and the adsorption time of the activated carbon is 60-120min.
  5. 5. The method for preparing microbial protein by utilizing nigre wastewater according to claim 1, wherein in S2, the nitrogen source comprises any one of ammonium sulfate, ammonium chloride and ammonium nitrate, the phosphorus source comprises any one of potassium hydrogen phosphate, monopotassium phosphate and monoammonium phosphate, the growth promoting factor comprises at least one of yeast extract, peptone and corn steep liquor, and the mass-volume ratio of the nitrogen source, the phosphorus source, the growth promoting factor and the solution A is (0.5-3.0) g (0.1-0.8) g (0.1-3) g:1L.
  6. 6. The method for preparing microbial protein by using nigre wastewater according to claim 1, wherein in S3, the pH value is 4-7, the high-temperature sterilization temperature is 121-132 ℃, and the sterilization time is 30-40min.
  7. 7. The method for preparing microbial protein by using nigre wastewater according to claim 1, wherein in S4, the inoculation amount of the microbial strain is 1% -5% (v/v) of the volume of the liquid seed liquid culture medium, and the microbial strain comprises one or more of yarrowia lipolytica, fusarium filiformis and oleaginous stonicus.
  8. 8. The method for preparing microbial protein by utilizing nigre wastewater according to claim 1, wherein in S4, the liquid seed liquid culture medium is potato glucose culture medium, the potato glucose culture medium comprises potato filtrate, glucose, potassium dihydrogen phosphate, magnesium sulfate, vitamin B1 and chloramphenicol, and the mass ratio of the potato filtrate to the glucose to the potassium dihydrogen phosphate to the magnesium sulfate to the vitamin B1 to the chloramphenicol is (150-250): (15-25): (2.0-4.0): (0.5-1.5): (0.05-0.15): (0.05-0.15).
  9. 9. The method for preparing microbial protein by using nigre wastewater according to claim 1, wherein in S5, sterile air or oxygen-enriched air is introduced, the ventilation is 0.8-2.0VVM, the inoculation amount of the microbial seed liquid is 1-10% (v/v) of the volume of a microbial culture medium, the fermentation temperature is 25-35 ℃, and the fermentation time is 36-96h.
  10. 10. The method for preparing microbial protein by using nigre wastewater according to claim 1, wherein in S6, the solid-liquid separation adopts sedimentation separation, and the sedimentation temperature is 25-35 ℃ and the sedimentation time is 2-8h.

Description

Method for preparing microbial protein by using nigre wastewater Technical Field The application relates to the technical field of microorganisms, in particular to a method for preparing microbial protein by using nigre wastewater. Background The microbial protein is also called single cell protein, is a protein resource obtained by large-scale microbial culture by taking various industrial and agricultural wastes as raw materials, and mainly comprises yeast protein, bacterial protein and algae protein. The microorganism grows and grows fast, the fermentation period is far lower than the planting period, so the production efficiency of the unit protein of the microorganism is far higher than that of the traditional agriculture. However, the production of microbial proteins is entirely dependent on the fermentation industry, wherein glucose, molasses and other conventional carbon sources derived from the plant industry are the main raw materials for producing microbial proteins, so that the cost of microbial proteins is high, which greatly limits the development and popularization of microbial proteins. Therefore, on the one hand, the conversion rate of the carbon source is further improved or the added value of the microbial protein is further improved through strain transformation and deep processing technology, and on the other hand, low-value fermentation carbon sources with wide sources, high content and low cost are developed to further reduce the production cost of the microbial protein. The soapstock waste water is formed in the process of hydrolyzing the soapstock of refined edible oil in an oil-eating factory into glycerin and fatty acid sodium through the processes of saponification, salting out, decoloration and the like when the soapstock waste water is heated together with a large amount of NaOH. The pH value of the wastewater is more than 12, and the wastewater contains a large amount of impurities such as lower fatty acid, phospholipid, protein, fat-soluble pigment and the like and salts such as NaOH, na 2CO3 and the like, so that the wastewater is extremely difficult to treat high-concentration alkaline organic industrial wastewater. In industry, acetic acid is used for neutralizing nigre waste water, and the pH value of the nigre waste water is adjusted to be neutral or weak acid and then is used as a carbon source in a denitrification link in sewage treatment. Although nigre waste water is a low-value waste water resource, the organic components in the nigre waste water are mainly glycerol, sodium acetate and the like, and the nigre waste water is a high-value component with the potential of recycling. However, the soapstock waste water with high value components has higher recycling difficulty due to the factors of purity and content. Therefore, the development of a new method for recycling high-value components in the nigre wastewater has important significance for realizing the recycling treatment of the nigre wastewater. Disclosure of Invention Aiming at the defects of the prior art, the application provides a method for preparing microbial protein by utilizing nigre wastewater, which comprises the steps of performing multi-stage detoxification treatment of ferric salt sedimentation filtration, diatomite adsorption and active carbon adsorption on the nigre wastewater containing glycerol and sodium acetate, supplementing nutrients to prepare a microbial culture medium, inoculating strains such as yarrowia lipolytica, fermenting and culturing, separating solid and liquid of fermentation liquid to collect thalli to obtain microbial thalli protein, and recycling fermentation waste liquid for nutrition allocation, thereby realizing the recycling utilization of the nigre wastewater and the efficient preparation of high-value protein. In order to achieve the above purpose, the application adopts the following technical scheme: in a first aspect, the present application provides a method for preparing microbial protein using soapstock wastewater, comprising the steps of: S1, adjusting pH after detoxification treatment of nigre wastewater to obtain a solution A, wherein the detoxification treatment is to firstly add ferric salt for treatment, sediment and filtration, and then sequentially carry out diatomite and activated carbon adsorption treatment on filtrate; S2, conveying the solution A to a nutrition preparation tank, and adding a nitrogen source, a phosphorus source and a growth promoting factor to obtain a solution B; S3, adjusting the pH value of the solution B, and then performing high-temperature sterilization to prepare a microorganism culture medium; s4, inoculating microorganism bacteria into a liquid seed liquid culture medium for culture to obtain microorganism seed liquid; S5, inoculating the microbial seed solution into the microbial culture medium, and carrying out aeration fermentation culture to obtain a fermentation liquor; S6, carrying out solid-liquid separation on the fe