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CN-122012296-A - Bacillus subtilis 20P3 LZT, fermentation broth and application thereof in microbial oil recovery

CN122012296ACN 122012296 ACN122012296 ACN 122012296ACN-122012296-A

Abstract

The invention relates to the technical field of microbial oil extraction, in particular to bacillus subtilis 20P3 LZT, fermentation broth and application thereof in microbial oil extraction, wherein the bacillus subtilis 20P3 LZT is preserved in China general microbiological culture collection center (CGMCC) No.30366. The invention discovers that the bacillus subtilis 20P3 LZT can generate surfactant lipopeptid for the first time, can grow on the basis of taking molasses or corn steep liquor dry powder as a carbon source, has good emulsifying and viscosity reducing properties on crude oil, can achieve 70% of emulsifying and viscosity reducing rate on thick oil, can reduce the viscosity of crude oil, enhance the fluidity of crude oil, on one hand, reduces the oil-water fluidity ratio, on the other hand, the emulsified crude oil plays the roles of profile control and liquid flow diversion, indirectly improves the recovery rate of crude oil, and provides new strains and materials for the microbial oil recovery technology.

Inventors

  • WANG HONGBO
  • LIAN ZETE
  • LIU XIAOLI
  • DAI XUECHENG
  • BAI LEI
  • MA YANQING
  • NIE XIAOBIN
  • LUAN HEXIN

Assignees

  • 中国石油天然气股份有限公司

Dates

Publication Date
20260512
Application Date
20241105

Claims (10)

  1. 1. The bacillus subtilis 20P3 LZT is characterized in that the strain is preserved in China general microbiological culture Collection center (CGMCC) with the preservation number of CGMCC No.30366.
  2. 2. A fermentation broth comprising bacillus subtilis 20p3 LZT according to claim 1.
  3. 3. The fermentation broth containing bacillus subtilis 20p3 LZT according to claim 2, characterized in that it is obtained by the following method: inoculating bacillus subtilis 20P3 LZT into a seed culture medium for culturing to obtain seed liquid; and secondly, inoculating seed liquid with the inoculation volume of 4-6% into a fermentation medium containing a carbon source for culturing to obtain fermentation liquor containing bacillus subtilis 20P3 LZT.
  4. 4. The fermentation broth containing bacillus subtilis 20p3 LZT according to claim 3, wherein in the first step, the seed culture broth is LB liquid medium.
  5. 5. The fermentation broth containing bacillus subtilis 20p3 LZT according to claim 3 or 4, characterized in that in the first step, the culture is specifically shaking culture in a shaking table at a culture temperature of 35 ℃ to 37 ℃ for 36h to 40h and at a shaking speed of 120r/min to 150r/min.
  6. 6. The fermentation broth containing 20P3 LZT of claim 3, 4 or 5, characterized in that in the second step, the formulation of the fermentation medium containing carbon source is 30g/L to 50g/L of carbon source, 3g/L to 5g/L of sodium citrate, 0.5g/L to 1.0g/L of ammonium sulfate, 0.2g/L to 0.5g/L of dipotassium hydrogen phosphate, 0.2g/L to 0.5g/L of potassium dihydrogen phosphate, 0.5g/L to 1.5g/L of sodium chloride, 0.2g/L to 0.5g/L of magnesium sulfate heptahydrate and 0.001g/L to 0.002g/L of ferrous sulfate heptahydrate, and the pH value of the fermentation medium containing carbon source is 7.2.
  7. 7. The fermentation broth containing bacillus subtilis 20P3 LZT according to claim 6, characterized in that in the second step, the formulation of the fermentation medium containing carbon source is 40g/L of carbon source, 3g/L of sodium citrate, 0.5g/L of ammonium sulfate, 0.2g/L of dipotassium hydrogen phosphate, 0.2g/L of potassium dihydrogen phosphate, 1.0g/L of sodium chloride, 0.2g/L of magnesium sulfate heptahydrate, 0.001g/L of ferrous sulfate heptahydrate, and the pH value of the fermentation medium containing carbon source is 7.2.
  8. 8. Fermentation broth containing bacillus subtilis 20p3 LZT according to any of claims 3 to 7, characterized in that in the second step the carbon source is one of molasses and corn steep liquor dry powder.
  9. 9. The fermentation broth containing 20P3 LZT of any of the claims 3 to 8, characterized in that in the second step the culture is specifically shaking culture in a shaking table at a shaking speed of 100rpm to 150rpm, at a temperature of 30 ℃ to 40 ℃ and for a time of 30h to 40h, or/and in that in the second step the concentration of 20P3 LZT of the fermentation broth containing 20P3 LZT is 1X 10 8 to 1X 10 10 /mL.
  10. 10. Use of a fermentation broth comprising bacillus subtilis 20p3 LZT according to any of claims 3 to 8 in microbial oil recovery.

Description

Bacillus subtilis 20P3 LZT, fermentation broth and application thereof in microbial oil recovery Technical Field The invention relates to the technical field of microbial oil extraction, in particular to bacillus subtilis 20P3 LZT, fermentation broth and application thereof in microbial oil extraction. Background In the petroleum recovery process, after primary oil recovery by utilizing natural energy and secondary oil recovery by water injection exploitation, a large amount of crude oil still remains in stratum, and tertiary oil recovery by utilizing physical, chemical and biological methods to develop the crude oil is currently an important technical means for improving the recovery ratio in China. Among them, the technology of improving oil recovery rate (Microbial Enhanced Oil Recovery, MEOR) by using microorganisms is one of tertiary oil recovery technologies with great development potential. Microorganisms used at present mainly take bacteria, and can utilize the propagation of bacteria in stratum and the interaction of surface active substances produced by bacteria and crude oil, so as to improve the recovery ratio of crude oil. The basic principle of the method is that surface active substances, organic solvents, organic acids, biopolymers or biogas and the like generated by ① bacteria act on residual oil in an oil reservoir to change the fluidity of crude oil, ② directly changes the properties of crude oil in the metabolic process of microorganisms, such as degrading partial components of crude oil to cause the property change of crude oil, so that crude oil is easy to flow to improve the oil washing efficiency of the residual oil, thereby improving the recovery ratio, and the biopolymers generated by ③ bacteria metabolism can play a role in regulating and plugging large pore channels of a stratum, improve the seepage rule of the stratum and enlarge the water flooding wave and volume. Compared with other tertiary oil recovery technologies, MEOR has the advantages of high efficiency, economy, no secondary pollution, no damage to oil layers and the like, and is the most potential technology for improving the crude oil recovery rate. The strain used for microbial oil displacement reported at present is concentrated in pseudomonas aeruginosa, and most of the produced surfactant is rhamnolipid. The strain type reserve for microbial oil displacement is insufficient, the types of microbial oil extraction strains and produced biosurfactants still need to be widened continuously, and various microbial functional bacteria with surfactant production, emulsification and chemotaxis are developed, so that new strains and materials are provided for the microbial oil extraction technology. Disclosure of Invention The invention provides bacillus subtilis 20P3 LZT, fermentation broth and application thereof in microbial oil extraction, overcomes the defects of the prior art, and firstly discloses bacillus subtilis 20P3 LZT which can produce surfactant lipopeptid, has good emulsifying and viscosity reducing properties, and can achieve 70% of emulsifying and viscosity reducing rate of thick oil. One of the technical schemes of the invention is realized by the following measures that the bacillus subtilis 20P3 LZT is classified and named as bacillus subtilis Bacillus subtilis, and the strain is preserved in China general microbiological culture Collection center (CGMCC) No.30366, and the preservation address is the institute of microorganisms, national academy of sciences 3, north Star Xiyu 1 in the Korean region of Beijing, and the preservation date is 2024, 04 and 17. The second technical scheme of the invention is realized by the following measures that the fermentation liquor contains the bacillus subtilis 20P3 LZT. The following is a further optimization and/or improvement of the second technical scheme of the invention: The fermentation liquor containing the bacillus subtilis 20P3 LZT is obtained by the following steps: inoculating bacillus subtilis 20P3 LZT into a seed culture medium for culturing to obtain seed liquid; and secondly, inoculating seed liquid with the inoculation volume of 4-6% into a fermentation medium containing a carbon source for culturing to obtain fermentation liquor containing bacillus subtilis 20P3 LZT. In the first step, the seed culture solution is LB liquid culture medium. In the first step, the culture is specifically shaking culture in a shaking table, the culture temperature is 35-37 ℃, the culture time is 36-40 h, and the shaking rotation speed is 120-150 r/min. In the second step, the formulation of the fermentation medium containing the carbon source comprises 30g/L to 50g/L of the carbon source, 3g/L to 5g/L of sodium citrate, 0.5g/L to 1.0g/L of ammonium sulfate, 0.2g/L to 0.5g/L of dipotassium hydrogen phosphate, 0.2g/L to 0.5g/L of potassium dihydrogen phosphate, 0.5g/L to 1.5g/L of sodium chloride, 0.2g/L to 0.5g/L of magnesium sulfate heptahydrate and 0.001g/L to 0.002g/L o