CN-121991875-A - Coupling fermentation method for synthesizing single-cell protein by using methane and carbon dioxide

CN121991875ACN 121991875 ACN121991875 ACN 121991875ACN-121991875-A

Abstract

The invention belongs to the technical field of synthetic biology and fermentation engineering, and particularly relates to a coupling fermentation method for synthesizing single-cell protein by using methane and carbon dioxide. The method comprises the steps of domesticating methanotrophic bacteria and domesticated microalgae, inoculating the domesticated methanotrophic bacteria and the domesticated microalgae into a special culture medium, mixing, vacuumizing, introducing first mixed gas, performing light fermentation to obtain fermentation liquor, and sequentially performing centrifugal separation and vacuum drying on the fermentation liquor to obtain single-cell protein. According to the invention, the domesticated methanotrophic bacteria and microalgae are inoculated into a special culture medium together for fermentation, and then are subjected to centrifugal separation and vacuum drying, so that the single-cell protein yield is improved.

Inventors

WANG YUJIE
CHANG YUFENG
KONG YAJING
Lei Lanyue
SUN JIAHUI
CHEN YUTONG

Assignees

陕西德量源生物科技有限公司

Dates

Publication Date: 20260508
Application Date: 20260202

Claims (10)

1. A coupled fermentation method for synthesizing single-cell protein by using methane and carbon dioxide, which is characterized by comprising the following steps: the domesticated methanotrophic bacteria and the domesticated microalgae are inoculated into a special culture medium together for mixing, then vacuumizing is carried out, and then a first mixed gas is introduced and subjected to illumination fermentation to obtain fermentation liquor; and sequentially carrying out centrifugal separation and vacuum drying on the fermentation liquor to obtain single-cell protein.
2. The coupled fermentation method for synthesizing single-cell proteins by using methane and carbon dioxide according to claim 1, wherein the preparation method for domesticated methanotrophic bacteria comprises the following steps: Mixing the methanogen and a culture medium for domestication according to the weight part ratio of 1:9-10, then introducing a second mixed gas, and performing domestication culture in a temperature environment of 26-28 ℃ to obtain the domesticated methanogen; the preparation method of the culture medium for domestication comprises the following steps: Mixing the basic nutrient solution, the iron-containing nutrient enrichment solution, the trace element mixed solution and the nitrogen source solution according to the volume ratio of 10-12:2-4:2-4:1, adding deionized water to fix the volume to 1L, and then performing high-pressure sterilization treatment at 121 ℃ for 20min to obtain the culture medium for domestication.
3. The coupled fermentation method for synthesizing single-cell protein by using methane and carbon dioxide according to claim 2, wherein the basic nutrient solution is obtained by mixing magnesium sulfate monohydrate and calcium chloride in a weight ratio of 14-15:2-3 and fixing the volume to 1L.
4. The coupled fermentation method for synthesizing single-cell protein by using methane and carbon dioxide according to claim 2, wherein the iron-containing nutrient enrichment liquid is an ethylenediamine tetraacetic acid iron sodium solution with a mass concentration of 4 g/L-4.5 g/L.
5. The coupling fermentation method for synthesizing single-cell protein by using methane and carbon dioxide according to claim 2, wherein the trace element mixed solution is obtained by mixing boric acid, zinc sulfate monohydrate, copper sulfate pentahydrate and manganese chloride tetrahydrate according to the weight ratio of 0.2-0.3:0.09-0.1:0.01-0.011:0.03-0.04 and constant volume to 1L.
6. The coupled fermentation method for synthesizing single-cell protein by using methane and carbon dioxide according to claim 2, wherein the nitrogen source solution is a sodium nitrate aqueous solution with a mass concentration of 190-195 g/L.
7. The coupled fermentation method for synthesizing single-cell protein by using methane and carbon dioxide according to claim 1, wherein the preparation method of domesticated microalgae comprises the following steps: Mixing microalgae and SE culture medium according to the weight ratio of 1:15-16, performing light treatment for 10h and shading treatment for 14h in a temperature environment of 25 ℃ to serve as a domestication period, performing domestication treatment for 1-2 days in the light intensity of 1000Lux, performing domestication treatment for 1-2 days in the light intensity of 1300Lux, and performing domestication treatment for 1-2 days in the light intensity of 1500Lux to obtain the domesticated microalgae.
8. The coupled fermentation method for synthesizing single-cell protein by using methane and carbon dioxide according to claim 1, wherein the preparation method of the special culture medium comprises the following steps: 4-4.6 g of ammonium chloride, 4.4-5.0 g of dipotassium hydrogen phosphate, 2.1-2.9 g of monopotassium phosphate, 9.4-9.7 g of potassium nitrate, 2.6-2.7 g of sodium chloride, 6.5-6.6 g of disodium hydrogen phosphate, 0.2-0.22 g of calcium chloride, 4.1-4.3 g of magnesium sulfate heptahydrate, 0.021-0.023 g of ferric chloride, 0.03g-0.031 g of ferric sulfate heptahydrate and 0.08-0.09 g of ethylenediamine tetraacetic acid are added with water, mixed and stirred, and the volume is fixed to 1L to obtain a first mixed solution; adding 0.1-0.2 g of manganese sulfate monohydrate, 0.4-0.41 g of zinc sulfate heptahydrate, 0.01-0.02 g of copper sulfate pentahydrate and 0.08-0.1 g of sodium molybdate dihydrate into water, mixing, stirring and fixing the volume to 1L to obtain a second mixed solution; Sucking 80-90 mL of the first mixed solution and 10mL of the second mixed solution, mixing, fixing the volume to 1L, and performing high-pressure sterilization at 121 ℃ for 20min to obtain the special culture medium.
9. The coupling fermentation method for synthesizing single-cell proteins by using methane and carbon dioxide according to claim 1, wherein the weight ratio of the domesticated methanotrophic bacteria to the domesticated microalgae to the special culture medium is 1:1:10-12.
10. The coupled fermentation method for synthesizing single-cell protein by using methane and carbon dioxide according to claim 1, wherein the condition of illumination fermentation comprises a fermentation temperature of 30 ℃, an illumination intensity of 2000Lux and a fermentation time of 7 days.

Description

Coupling fermentation method for synthesizing single-cell protein by using methane and carbon dioxide Technical Field The invention belongs to the technical field of synthetic biology and fermentation engineering, and particularly relates to a coupling fermentation method for synthesizing single-cell protein by using methane and carbon dioxide. Background Greenhouse gases refer to gases capable of absorbing and emitting infrared radiation, and include primarily carbon dioxide, methane, nitrous oxide, water vapor, and the like. The main sources of greenhouse gases can be classified into natural sources including volcanic eruption, organic decomposition of soil and ocean, etc., and artificial sources mainly from combustion of fossil fuels, industrial production, agricultural activities, land use changes, etc. Of these, combustion of fossil fuels is the largest source of carbon dioxide, while agriculture is an important source of methane and nitrous oxide. The increase of greenhouse gases causes global climate changes, which bring about frequent extreme weather phenomena such as heat waves, drought, floods, etc., which seriously affect the production and life of humans. In addition, global warming also causes glaciers to melt and sea level to rise, thereby threatening the safety of coastal areas. Furthermore, an imbalance in the ecosystem also exposes many species to extinction risks, and biodiversity is severely compromised. Therefore, reduction of greenhouse gas emissions and low carbon development have become an important consensus. With the innovative breakthrough of modern biotechnology and the popularization of energy conservation and emission reduction concepts, greenhouse gas has become an important carbon source capable of being utilized by microorganisms. Single Cell Proteins (SCPs) are produced by fermentation processes based on microorganisms such as bacteria, yeasts, fungi and the like. The single cell protein is rich in protein, amino acid, vitamin and mineral, has high nutritive value, and is widely used in feed and food industry. With the increasing global demand for proteins, single cell proteins are becoming increasingly important as an emerging protein source. Single cell protein production mainly includes three stages of culture, fermentation and harvest. First, a suitable microorganism strain is selected and cultured to increase its growth rate and protein synthesis ability. Secondly, fermentation technology is adopted, greenhouse gas is used as a carbon source, and a series of biochemical reactions are carried out to promote the growth of microorganisms and accumulate protein. Finally, single cell proteins are harvested by centrifugation, drying, and the like. The greenhouse gas is used as a carbon source, and the microorganism is utilized for fermentation, so that the pollution problem caused by the emission of the greenhouse gas can be effectively solved, the single-cell protein with high economic value can be created, and the method has important development prospect. Because the solubility of CH 4 and CO 2 gases in water is lower than that of glycosyl carbon sources, the gas-liquid mass transfer rate severely limits the conversion of microorganisms to the carbon source gases, and further affects the production of single-cell proteins. Therefore, how to utilize methane and carbon dioxide to prepare single-cell proteins with high yield by fermentation is of great significance. Disclosure of Invention According to the defects of the prior art, the method comprises the steps of inoculating the domesticated methanotrophic bacteria and the domesticated microalgae into a special culture medium for fermentation, and obtaining single-cell proteins through centrifugal separation and vacuum drying, so that the technical problems in the background art are solved. Specifically, the technical scheme of the invention comprises the following steps: a coupled fermentation method for synthesizing single-cell protein by using methane and carbon dioxide, comprising the following steps: Inoculating the domesticated methanotrophic bacteria and the domesticated microalgae into a special culture medium, mixing, vacuumizing, introducing a first mixed gas, and carrying out illumination fermentation to obtain a fermentation broth; and sequentially carrying out centrifugal separation and vacuum drying on the fermentation liquor to obtain single-cell protein. Further, the preparation method of the domesticated methanotrophic bacteria comprises the following steps: Mixing the methanogen and a culture medium for domestication according to the weight part ratio of 1:9-10, then introducing a second mixed gas, and performing domestication culture in a temperature environment of 26-28 ℃ to obtain the domesticated methanogen; the preparation method of the culture medium for domestication comprises the following steps: Mixing the basic nutrient solution, the iron-containing nutrient enrichment solution, the trace element