Method for producing single-cell protein based on co-culture of methane-oxidizing bacteria and aerobic zymophyte
Through the use of mixed gas to cultivate in mixing of methane oxide and good oxygen fermentation bacteria, the problem of non -environmental agricultural protein production methods is solved, and high -efficiency biomass and protein yields are realized, and methane maximized utilization is promoted.
Patent Information
- Application Number
- CN202411661223.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-20
- Publication Date
- 2025-01-28
AI Technical Summary
Traditional agricultural protein production methods are not environmentally friendly, resulting in greenhouse gas emissions and biodiversity impacts, and it is difficult to meet the growing global protein demand.
Based on methane oxidation bacteria and good oxygen fermentation bacteria, it is cultivated by methane and oxygen in mixed gas to convert it into single -cell protein.
It has improved biomass and protein output, promoted the maximum utilization of methane, and achieved higher protein output and more efficient methane utilization, which is suitable for large -scale industrialized production.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of gas treatment, and in particular relates to a method for producing single-cell protein based on mixed culture of methane oxidizing bacteria and aerobic fermentation bacteria. Background Art
[0002] Protein plays a vital role as an important source of human nutrition, leading to an increase in global demand for protein. However, meeting the growing demand for protein through traditional agricultural protein production methods is not environmentally friendly, and the expansion of agricultural land will lead to large amounts of greenhouse gas emissions and even affect biodiversity. Therefore, there is an urgent need to seek more efficient protein sources or production technologies to protect resources and the environment while meeting the global demand for protein.
[0003] In this context, single cell protein (SCP), i.e., microbial biomass as a source of food or feed, is considered to be a promising source of protein in the future. Microorganisms, including algae, yeast, fungi, and bacteria, are able to produce large amounts of SCP due to their fast growth rate and the large amount of protein in their chemical structure. Aerobic methanotrophic bacteria (MOB) may be a suitable bacterium, which uses CH4 as the only carbon and energy source for aerobic metabolism, which can not only fill the protein gap but also solve the solid waste problem caused by it. MOB has been successfully used in commercial production.
[0004] In addition, methanotrophs also support the growth of other bacteria, and heterotrophic bacteria such as aerobic fermenters can utilize methane-derived carbon sources (organic acids, alcohols, aldehydes, etc.). In general, co-cultivation strategies improve production performance or minimize inhibitory feedback by reducing the metabolic burden of microorganisms. In this work, the co-cultivation of MOB and aerobic fermenters was investigated to determine the optimal combination for the production of SCP. Summary of the invention
[0005] In view of the above problems, the present invention provides a method for producing single-cell protein based on the mixed culture of methanotrophic bacteria and aerobic fermentation bacteria, which not only increases the biomass and protein yields, but also facilitates the maximum utilization of methane.
[0006] The present invention is achieved through the following technical solutions: A method for producing single-cell protein based on mixed culture of methane oxidizing bacteria and aerobic fermenting bacteria, wherein methane and oxygen are mixed into a mixed gas, and the mixed gas is introduced into a culture medium of methane oxidizing bacteria and aerobic fermenting bacteria, the methane oxidizing bacteria and aerobic fermenting bacteria are cultured, and converted into protein.
[0007] Methane oxidizing bacteria use methane as a carbon source and energy source to synthesize organic matter in the body. At the same time, some intermediate products of methane oxidation such as methanol, formaldehyde, formic acid and acetic acid are discharged into the culture medium. The accumulation of metabolic by-products will inhibit the growth and metabolism of methane oxidizing bacteria. Aerobic fermentation bacteria can use these metabolic by-products as a carbon source for growth, which not only detoxifies methane oxidizing bacteria, but also provides a high-quality protein source for the growth of their own biomass, thereby achieving full conversion of the carbon source.
[0008] Furthermore, the volume ratio of methane to oxygen in the mixed gas is 1:0.5 - 1:4.
[0009] Furthermore, the methane oxidizing bacteria (MOB) include but are not limited to Methylocystis parvus , Methylotuvimicrobium buryatense , Methylococcus encapsulated , Methylosinus trichosporium , Methylomonas sp. LW13 More than one of the aerobic fermentation bacteria include but are not limited to Copper-hungry killer , Hydrogenophaga pseudoflava , Xanthobacter autotrophicus, Bacillus licheniformis, Bacillus subtilis, Saccharomyces cerevisiae、Rhodopseudomonas palustris One or more of the following.
[0010] Furthermore, the culture temperature is 25-35°C.
[0011] The beneficial effects achieved by the present invention are: The present invention mixes methanotrophic bacteria and aerobic fermentation bacteria to culture. Aerobic fermentation bacteria can utilize the potential of MOB extracellular secretions (small molecule organic acids, etc.), and are expected to obtain higher biomass and protein yields. This novel method not only promotes the growth of MOB, but also improves the utilization efficiency of methane. Compared with single MOB culture, aerobic fermentation bacteria can obtain a higher yield of biomass. This synergistic effect can effectively promote the growth of methanotrophic bacteria and improve the methane fixation efficiency, which has a demonstrative effect on industrial large-scale production. The system does not require additional material and energy input to achieve a substantial increase in biomass and protein yields. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 OD of Examples 1-4 and Comparative Examples 1-2 600 Change graph; Figure 2 The graphs of biomass and protein yield changes of Examples 1-4 and Comparative Examples 1-2 are shown; Figure 3 The results of biomass dry weight of Examples 5-8 are shown; Figure 4 is the OD of Examples 9-10600 Value change graph. DETAILED DESCRIPTION
[0013] The above contents of the present invention are further described in detail below through examples, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies implemented based on the above contents of the present invention belong to the protection scope of the present invention.
[0014] Methylocystis parvus OBBP ATCC 35066, purchased from the American Type Culture Collection; Methylotuvimicrobium buryatense 5B, VKM B-2245, purchased from BioVector NTCC Type Culture Collection; Xanthobacter autotrophicus DSM 432, purchased from China Microorganism Culture Collection Center; Copper-loving murderer H16 DSM 428 and Hydrogenophaga pseudoflava DSM 1084 were purchased from the German Collection of Microorganisms.
[0015] In the present invention, the volume ratio of methane to oxygen in the mixed gas is 1:0.5-1:4. Preferably, the volume ratio can be selected from 1:0.5, 1:1, 1:3, and 1:4.
[0016] Methane oxidizing bacteria (MOB) include but are not limited to Methylocystis small , Methylotuvimicrobium buryatense , Methylococcus capsulatus , Methylosin trichosporium , Methylomonas sp. LW13 More than one of them.
[0017] In the present invention, aerobic fermentation bacteria include but are not limited to Copper-hungry killer , Hydrogen eater pseudo-yellow , Xanthobacter autotrophicus、Bacillus licheniformis、Bacillus subtilis、Saccharomyces cerevisiae、Rhodopseudomonas palustris One or more of the following.
[0018] In the present invention, the culture temperature is 25-35°C, preferably, the temperature is selected from 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, and 35°C.
[0019] Example 1 50 mL of culture medium (the composition of the culture medium is shown in Table 1 below) was added to three 300 mL glass serum bottles, the serum bottles were sealed with butyl rubber stoppers, and sterilized at 121°C. After cooling to room temperature, the three serum bottles were inoculated in three different conditions: 1) 0.5 mL of the culture medium in the logarithmic growth phase; Methylocystis parvusOBBP, 0.5mL in logarithmic growth phase Copper-hungry killer H16; 2) 0.5mL in the logarithmic growth phase Methylocystis small OBBP, 0.5 mL in logarithmic growth phase Hydrogenophaga pseudoflava ; 3) 0.5mL in the logarithmic growth phase Methylocystis parvus OBBP, 0.5mL in logarithmic growth phase Xanthobacter autotrophicus The headspace was flushed three times with sterilized Ar2 gas, and a mixed gas of methane and oxygen (the volume percentage composition of the mixed gas was methane: oxygen = 1:2) was introduced. The culture was incubated in a shaker at 30°C and 150 rpm, and liquid / gas samples were taken every 1 or 2 days for further analysis, and the headspace gas was renewed.
[0020] Table 1 Methylocystis parvus OBBP culture medium composition Example 2 50 mL of culture medium (the composition of the culture medium is shown in Table 2 below) was added to three 300 mL glass serum bottles, the serum bottles were sealed with butyl rubber stoppers, and sterilized at 121°C. After cooling to room temperature, the three serum bottles were inoculated in three different conditions: 1) 0.5 mL of the culture medium in the logarithmic growth phase; Methylotuvimicrobium buryatense 5B, 0.5mL in logarithmic growth phase Copper-hungry killer H16; 2) 0.5mL in the logarithmic growth phase Methylotuvimicrobium buryatense 5B, 0.5mL in logarithmic growth phase Hydrogen eater pseudo-yellow ; 3) 0.5mL in the logarithmic growth phase Methylotuvimicrobium buryatense 5B, 0.5mL in logarithmic growth phase Xanthobacter autotrophicus The headspace was flushed three times with sterilized Ar2 gas, and a mixed gas of methane and oxygen (the volume percentage composition of the mixed gas was methane: oxygen = 1:2) was introduced. The culture was incubated in a shaker at 30°C and 150 rpm, and liquid / gas samples were taken every 1 or 2 days for further analysis, and the headspace gas was renewed.
[0021] Table 2 Methylotuvimicrobium buryatense 5GB1C medium composition Example 3 50 mL of culture medium (as shown in Table 1) was added to three 300 mL glass serum bottles, the serum bottles were sealed with butyl rubber stoppers, and sterilized at 121 °C. After cooling to room temperature, the three serum bottles were inoculated in three different conditions: 1) 0.5 mL of the culture medium in the logarithmic growth phase; 2) 0.5 mL of the culture medium in the logarithmic growth phase; 3) 0.5 mL of the culture medium in the logarithmic growth phase; 4) 0.5 mL of the culture medium in the logarithmic growth phase; 5) 0.5 mL of the culture medium in the logarithmic growth phase; 6) 0.5 mL of the culture medium in the logarithmic growth phase; 7) 0.5 mL of the culture medium in the logarithmic growth phase; 8) 0.5 mL of the culture medium in the logarithmic growth phase; 9) 0.5 mL of the culture medium in the logarith Methylocystis parvusOBBP, 0.5 mL in logarithmic growth phase Copper-hungry killer H16, 0.5mL in logarithmic growth phase Hydrogenophaga pseudoflava ; 2) 0.5mL in the logarithmic growth phase Methylocystis parvus OBBP, 0.5 mL in logarithmic growth phase Copper-hungry killer H16, 0.5mL in logarithmic growth phase Xanthobacter autotrophicus ; 3) 0.5mL in the logarithmic growth phase Methylocystis parvus OBBP, 0.5 mL in logarithmic growth phase Hydrogen eater pseudo-yellow , 0.5mL is in the logarithmic growth phase Xanthobacter autotrophicus The headspace was flushed three times with sterilized Ar gas, and a mixed gas of methane and oxygen (the volume percentage composition of the mixed gas was methane: oxygen = 1:2) was introduced. The culture was incubated in a shaker at 30°C and 150 rpm, and liquid / gas samples were taken every 1 or 2 days for further analysis, and the headspace gas was renewed.
[0022] Example 4 50 mL of culture medium (as shown in Table 2) was added to three 300 mL glass serum bottles, the serum bottles were sealed with butyl rubber stoppers, and sterilized at 121 °C. After cooling to room temperature, the three serum bottles were inoculated in three different conditions: 1) 0.5 mL of the culture medium in the logarithmic growth phase; 2) 0.5 mL of the culture medium in the logarithmic growth phase; 3) 0.5 mL of the culture medium in the logarithmic growth phase; 4) 0.5 mL of the culture medium in the logarithmic growth phase; 5) 0.5 mL of the culture medium in the logarithmic growth phase; 6) 0.5 mL of the culture medium in the logarithmic growth phase; 7) 0.5 mL of the culture medium in the logarithmic growth phase; 8) 0.5 mL of the culture medium in the logarithmic growth phase; 9) 0.5 mL of the culture medium in the logarith Methylotuvimicrobium buryatense 5B, 0.5mL in logarithmic growth phase Copper-hungry killer H16, 0.5mL in logarithmic growth phase Hydrogenophaga pseudoflava ; 2) 0.5mL in the logarithmic growth phase Methylotuvimicrobium buryatense 5B, 0.5mL in logarithmic growth phase Copper-hungry killer H16, 0.5mL in logarithmic growth phase Xanthobacter autotrophicus ; 3) 0.5mL in the logarithmic growth phase Methylotuvimicrobium buryatense 5B, 0.5mL in logarithmic growth phase Hydrogenophaga pseudoflava , 0.5mL is in the logarithmic growth phase Xanthobacter autotrophicus The headspace was flushed three times with sterilized Ar gas, and a mixed gas of methane and oxygen (the volume percentage composition of the mixed gas was methane: oxygen = 1:2) was introduced. The culture was incubated in a shaker at 30°C and 150 rpm, and liquid / gas samples were taken every 1 or 2 days for further analysis, and the headspace gas was renewed.
[0023] Example 5 Add 50 mL of culture medium to three 300 mL glass serum bottles, seal the serum bottles with butyl rubber stoppers, and sterilize them at 121°C. After cooling to room temperature, inoculate 0.5 mL of the logarithmic growth phase of the three serum bottles. Methylotuvimicrobium buryatense5B, 0.75 mL in logarithmic growth phase Copper-loving murderer H16, 0.25mL in logarithmic growth phase Hydrogenophaga pseudoflava The headspace was flushed three times with sterilized Ar gas, and a mixed gas of methane and oxygen (the volume percentage of the mixed gas was methane: oxygen = 1:2) was introduced. The culture was incubated in a shaker at 30°C and 150 rpm, and liquid / gas samples were taken every 1 or 2 days for further analysis, and the headspace gas was renewed.
[0024] Example 6 Add 50 mL of culture medium to three 300 mL glass serum bottles, seal the serum bottles with butyl rubber stoppers, and sterilize them at 121°C. After cooling to room temperature, inoculate 0.5 mL of the logarithmic growth phase of the three serum bottles. Methylotuvimicrobium buryatense 5B, 0.25mL in logarithmic growth phase Copper-loving murderer H16, 0.75mL in logarithmic growth phase Hydrogenophaga pseudoflava The headspace was flushed three times with sterilized Ar gas, and a mixed gas of methane and oxygen (the volume percentage of the mixed gas was methane: oxygen = 1:2) was introduced. The culture was incubated in a shaker at 30°C and 150 rpm, and liquid / gas samples were taken every 1 or 2 days for further analysis, and the headspace gas was renewed.
[0025] Example 7 Add 50 mL of culture medium to three 300 mL glass serum bottles, seal the serum bottles with butyl rubber stoppers, and sterilize them at 121°C. After cooling to room temperature, inoculate 0.5 mL of the logarithmic growth phase of the three serum bottles. Methylotuvimicrobium buryatense 5B, 2.5mL in logarithmic growth phase Copper-loving murderer H16, 2.5mL in logarithmic growth phase Hydrogenophaga pseudoflava The headspace was flushed three times with sterilized Ar gas, and a mixed gas of methane and oxygen (the volume percentage of the mixed gas was methane: oxygen = 1:2) was introduced. The culture was incubated in a shaker at 30°C and 150 rpm, and liquid / gas samples were taken every 1 or 2 days for further analysis, and the headspace gas was renewed.
[0026] Example 8 Add 50 mL of culture medium to three 300 mL glass serum bottles, seal the serum bottles with butyl rubber stoppers, and sterilize them at 121°C. After cooling to room temperature, inoculate 0.5 mL of the logarithmic growth phase of the three serum bottles. Methylotuvimicrobium buryatense 5B, 5mL in logarithmic growth phase Copper-loving murdererH16, 5mL in logarithmic growth phase Hydrogenophaga pseudoflava The headspace was flushed three times with sterilized Ar gas, and a mixed gas of methane and oxygen (the volume percentage of the mixed gas was methane: oxygen = 1:2) was introduced. The culture was incubated in a shaker at 30°C and 150 rpm, and liquid / gas samples were taken every 1 or 2 days for further analysis, and the headspace gas was renewed.
[0027] Example 9 Add 50 mL of culture medium to three 300 mL glass serum bottles, seal the serum bottles with butyl rubber stoppers, and sterilize them at 121°C. After cooling to room temperature, inoculate 0.5 mL of the logarithmic growth phase of the three serum bottles. Methylotuvimicrobium buryatense 5B, 0.5mL in logarithmic growth phase Copper-loving murderer H16, 0.5mL in logarithmic growth phase Hydrogenophaga pseudoflava The headspace was flushed three times with sterilized Ar gas, and a mixed gas of methane and oxygen (the volume percentage of the mixed gas was methane: oxygen = 1:1) was introduced. The culture was incubated in a shaker at 30°C and 150 rpm, and liquid / gas samples were taken every 1 or 2 days for further analysis, and the headspace gas was renewed.
[0028] Example 10 Add 50 mL of culture medium to three 300 mL glass serum bottles, seal the serum bottles with butyl rubber stoppers, and sterilize them at 121°C. After cooling to room temperature, inoculate 0.5 mL of the logarithmic growth phase of the three serum bottles. Methylotuvimicrobium buryatense 5B, 0.5mL in logarithmic growth phase Copper-loving murderer H16, 0.5mL in logarithmic growth phase Hydrogenophaga pseudoflava The headspace was flushed three times with sterilized Ar gas, and a mixed gas of methane and oxygen (the volume percentage composition of the mixed gas was methane: oxygen = 1:3) was introduced. The culture was incubated in a shaker at 30°C and 150 rpm, and liquid / gas samples were taken every 1 or 2 days for further analysis, and the headspace gas was renewed.
[0029] Comparative Example 1 Add 50 mL of culture medium (as shown in Table 1) to a 300 mL glass serum bottle, seal the serum bottle with a butyl rubber stopper, and sterilize it at 121°C. After cooling to room temperature, inoculate 0.5 mL of a culture medium in the logarithmic growth phase into the serum bottle. Methylocystis parvusOBBP, the headspace was flushed three times with sterilized Ar gas, and a mixed gas composed of methane and oxygen (the volume percentage composition of the mixed gas was methane: oxygen = 1:2) was introduced. The culture was incubated in a shaker at 30°C and 150 rpm, and liquid / gas samples were taken every 1 or 2 days for further analysis, and the headspace gas was renewed.
[0030] Comparative Example 2 Add 50 mL of culture medium (as shown in Table 2) to a 300 mL glass serum bottle, seal the serum bottle with a butyl rubber stopper, and sterilize it at 121°C. After cooling to room temperature, inoculate 0.5 mL of a culture medium in the logarithmic growth phase into the serum bottle. Methylotuvimicrobium buryatense The headspace of 5B was flushed three times with sterilized Ar gas, and a mixed gas of methane and oxygen (the volume percentage composition of the mixed gas was methane: oxygen = 1:2) was introduced. The culture was incubated in a shaker at 30°C and 150 rpm, and liquid / gas samples were taken every 1 or 2 days for further analysis, and the headspace gas was renewed.
[0031] OD of Example 1 and Comparative Example 1 600 Changes such as Figure 1 (a) shows the OD of Example 3 and Comparative Example 1. 600 Changes such as Figure 1 As shown in (c), the results show that Cupriavidus necator H16, Hydrogenophaga pseudoflava , Xanthobacter autotrophicus Single or combined bacterial communities Methylocystis parvus The growth effects of OBBP are different. 600 Changes such as Figure 1 (b) shows the OD of Example 4 and Comparative Example 2. 600 Changes such as Figure 1 As shown in (d), the results show that Cupriavidus necator H16, Hydrogenophaga pseudoflava for Methylotuvimicrobium buryatense 5B growth impact is basically the same, but Xanthobacter autotrophicus Single or combined bacterial communities Methylotuvimicrobium buryatense The growth impacts of 5B vary.
[0032] The changes in biomass and protein yields between Example 1 and Comparative Example 1 are as follows: Figure 2 As shown in (a), the changes in biomass and protein yields of Example 3 and Comparative Example 1 are as follows Figure 2 (c) As shown in Comparative Example 1 Methylocystis parvus The biomass yield of OBBP was 1.556 g / L and the protein yield was 0.713 g / L. Methylocystis parvus OBBP+ Cupriavidus necator H16, Methylocystis parvus OBBP+ Hydrogenophaga pseudoflava , Methylocystis parvus OBBP + Xanthobacter autotrophicus The biomass yields were 1.408 g / L, 0.966 g / L, and 1.284 g / L, and the protein yields were 0.753 g / L, 0.634 g / L, and 0.717 g / L, respectively. Methylocystis parvus OBBP+ Cupriavidus necator H16+ Hydrogenophaga pseudoflava, Methylocystis parvus OBBP+ Cupriavidus necator H16+ Xanthobacter autotrophicus, Methylocystis parvus OBBP+ Hydrogenophaga pseudoflava + Xanthobacter autotrophicus The biomass yields were 2.282 g / L, 1.648 g / L, and 2.863 g / L, and the protein yields were 1.334 g / L, 0.900 g / L, and 1.789 g / L, respectively. Methylocystis parvus OBBP+ Hydrogenophaga pseudoflava + Xanthobacter autotrophicus Compared with the control example 1 Methylocystis parvus The biomass yield of pure culture of OBBP increased by 83.98%, and the protein yield increased by 148.82%.
[0033] The changes in biomass and protein yields between Example 2 and Comparative Example 2 are as follows: Figure 2 (b) shows that the changes in biomass and protein yields of Example 4 and Comparative Example 2 are as follows: Figure 2 (d) As shown in Comparative Example 2 Methylotuvimicrobium buryatense The biomass yield of 5B was 3.042 g / L and the protein yield was 1.785 g / L. Methylotuvimicrobium buryatense 5B+ Cupriavidus necator H16, Methylotuvimicrobium buryatense 5B + Hydrogenophaga pseudoflava , Methylotuvimicrobium buryatense 5B + Xanthobacter autotrophicus The biomass yields were 2.822 g / L, 2.66 g / L, and 3.036 g / L, and the protein yields were 1.781 g / L, 1.540 g / L, and 1.742 g / L, respectively. Methylotuvimicrobium buryatense 5B+ Cupriavidus necator H16+ Hydrogenophaga pseudoflava, Methylotuvimicrobium buryatense 5B+ Cupriavidus Necator H16+ Xanthobacter autotrophicus, Methylotuvimicrobium buryatense 5B+ Hydrogenophaga pseudoflava + Xanthobacter autotrophicusThe biomass yields were 4.957 g / L, 3.213 g / L, and 3.020 g / L, and the protein yields were 2.620 g / L, 1.908 g / L, and 1.920 g / L, respectively. Methylotuvimicrobium buryatense 5B+ Cupriavidus necator H16+ Hydrogenophaga pseudoflava Compared with the control example 2 Methylotuvimicrobium buryatense The biomass yield of pure culture of 5B increased by 62.95%, and the protein yield increased by 46.78%.
[0034] The biomass dry weight results of Examples 5-8 are as follows Figure 3 As shown, by Embodiments 5 and 6 and Embodiment 4 ( Figure 2 d) It is relatively clear that Methylotuvimicrobium buryatense 5B+ Cupriavidus necator H16+ Hydrogenophaga pseudoflava When the inoculation ratio is 0.5:0.5:0.5, 0.5:0.25:0.75, and 0.5:0.75:0.25, the biomass yield is 4.975, 3.880, and 3.784 g / L, respectively, indicating that the relative composition of the aerobic fermentation bacteria itself has a certain influence on the biomass yield. When the inoculation ratio is 0.5:0.5:0.5, the biomass yield of the constructed bacterial community is the largest. Figure 2 d) It is relatively clear that Methylotuvimicrobium buryatense 5B+ Cupriavidus necator H16+ Hydrogenophaga pseudoflava When the inoculation ratio was 0.5:0.5:0.5, 0.5:2.5:2.5, and 0.5:5:5, the biomass was 4.957, 4.100, and 4.080 g / L, respectively, indicating that when the inoculation ratio of methanotrophic bacteria to fermentation bacteria was 1:2-1:20, the biomass yield could reach more than 4 g / L, indicating that the overall inoculation ratio of fermentation bacteria to methanotrophic bacteria had a certain influence on the production of the mixed system, and the optimal result occurred when the inoculation ratio was 0.5:0.5:0.5.
[0035] OD of Examples 9-10 600 The value changes as Figure 4 As shown, compared with Example 4 ( Figure 1 d) It can be seen from the comparison that as the proportion of oxygen in the reaction system increases, Methylotuvimicrobium buryatense 5B+ Cupriavidus necator H16+ Hydrogenophaga pseudoflava system OD 600 The value increases accordingly, and when methane: oxygen = 1:1, the OD at the end of logarithmic growth 600 The value is the largest, which is about 23.3% higher than that when methane: oxygen = 1:3, indicating that the methane: oxygen ratio has a greater impact on the system.
Claims
1. A method for producing single-cell protein based on mixed culture of methanotrophic bacteria and aerobic fermentation bacteria, characterized in that: Methane and oxygen are mixed into a mixed gas, which is introduced into a culture medium of methane oxidizing bacteria and aerobic fermenting bacteria to culture the methane oxidizing bacteria and aerobic fermenting bacteria and convert them into proteins.
2. The method for producing single-cell protein based on mixed culture of methanotrophic bacteria and aerobic fermentation bacteria according to claim 1, characterized in that: The volume ratio of methane to oxygen in the mixed gas is 1:0.5-1:
4.
3. The method for producing single-cell protein based on mixed culture of methanotrophic bacteria and aerobic fermentation bacteria according to claim 1, characterized in that: The methane oxidizing bacteria are Methylocystis parvus , Methylotuvimicrobium buryatense , Methylococcus capsulatus , Methylosinus trichosporium , Methylomonas sp. LW13 One or more of the following: Cupriavidus necator , Hydrogenophaga pseudoflava , Alcaligenes hydrogenophilus , Pelomonas saccharophila , Xanthobacter autotrophicus, Bacillus licheniformis, Bacillus subtilis, Saccharomyces cerevisiae, Rhodopseudomonas palustris One or more of the following.
4. The method for producing single-cell protein based on mixed culture of methanotrophic bacteria and aerobic fermentation bacteria according to claim 1, characterized in that: The inoculation volume ratio between methane oxidizing bacteria and aerobic fermenting bacteria is between 1:2 and 1:
20.
5. The method for producing single-cell protein based on mixed culture of methanotrophic bacteria and aerobic fermentation bacteria according to claim 1, characterized in that: The culture temperature is 25°C-35°C.