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CN-122012311-A - Sword fungus Ensifer morelensis R-120 and application thereof

CN122012311ACN 122012311 ACN122012311 ACN 122012311ACN-122012311-A

Abstract

The invention relates to the technical field of microbiology and selenium pollution environment restoration, and provides a strain of sword bacteria Ensifer morelensis R-120 and application thereof. The strain R2-120 is a Sword fungus Ensifer morelensis capable of efficiently synthesizing volatile selenium, and the preservation number is GDMCC No:63730. The strain R2-120 has stronger tolerance to selenate and selenite, and a flat plate test shows that the strain R2-120 can tolerate at least 200 mM selenate and 60 mM selenite. The strain R2-120 can metabolize selenite to convert nano-selenium, and can convert selenite and nano-selenium to volatile selenium. The invention also establishes a method for removing selenium in the water body by utilizing R2-120 in the bioreactor, can be used for bioremediation of selenium-polluted water body and soil, and treatment and selenium recycling of selenium-containing wastewater, and has wide application prospect.

Inventors

  • GUO YANBIN
  • LIU YI
  • ZHANG YAFENG
  • YAO ZHEN
  • ZHANG SASA
  • LI KUI
  • DAI LU
  • HE LIANZHEN

Assignees

  • 中国农业大学
  • 青海省第五地质勘查院

Dates

Publication Date
20260512
Application Date
20260109

Claims (10)

  1. 1. Sword fungus Ensifer morelensis R-120, accession number GDMCC No:63730.
  2. 2. A microbial preparation comprising the Sword bacterium of claim 1.
  3. 3. The application of the sword bacteria in selenium-polluted environment restoration and nano-selenium preparation according to claim 1.
  4. 4. A method for synthesizing nano-selenium, which is characterized in that the sword bacteria of claim 1 are inoculated into a culture medium added with selenite, and after a period of culture, nano-selenium is separated and purified from the culture solution.
  5. 5. The method according to claim 4, wherein the initial selenium concentration in the selenite-added medium is 2-60 mM, preferably 2-20 mM, more preferably 2mM, 5mM, 10 mM, 20 mM, most preferably 5 mM.
  6. 6. A method for synthesizing volatile selenium, which is characterized in that the sword bacteria of claim 1 are inoculated into a culture medium added with selenite and/or nano-selenium, and after a period of culture, the generated volatile selenium is collected; The volatile selenium comprises dimethyl selenone and dimethyl diselenide.
  7. 7. The method according to claim 6, wherein the initial selenium concentration in the selenite and/or nanoselenium supplemented medium is 0.125-0.5 mM, preferably 0.125 mM, 0.25 mM, 0.5 mM, more preferably 0.5 mM.
  8. 8. Use of the method of claim 6 or 7 for the preparation of methyl selenate.
  9. 9. Use according to claim 8, wherein the volatile selenium produced according to the method of claim 6 or 7 is passed into a trapping liquid containing an oxidizing agent such that the volatile selenium is oxidized to water-soluble methyl selenate.
  10. 10. Use according to claim 9, wherein the oxidizing agent comprises nitric acid or hydrogen peroxide.

Description

Sword fungus Ensifer morelensis R-120 and application thereof Technical Field The invention relates to the technical field of microbiology and selenium pollution environment restoration, in particular to a strain of sword bacteria Ensifer morelensis R-120 and application thereof. Background Selenium (Selenium) is a trace element necessary for human and animal to maintain normal vital activities, and has important applications in the industrial fields of metallurgy, ceramic manufacturing, etc. The selenium-related industrial production can discharge high-concentration selenium-containing wastewater, and untreated wastewater can cause serious selenium pollution and waste of selenium resources. Compared with a physical and chemical restoration method, the selenium-containing wastewater treated by microorganisms is a safe, efficient and environment-friendly restoration mode. Research shows that various microorganisms have the capability of reducing selenate or selenite to synthesize nano-selenium and volatile methyl selenium. The nano selenium and volatile selenium synthesized by microorganisms are utilized, and are easy to separate and recycle from the water phase. In addition, nano selenium is a bacteriostatic agent with excellent bioactivity in the fields of medicine, feed and the like. The volatile methyl selenium can be led into nitric acid through a tail gas capturing device, and methyl selenate generated by oxidation is a novel anti-tumor drug. Sword fungus (Ensifer) belongs to rhizobiaceae (Rhizobiaceae), is a gram-negative bacterium, belongs to 24 species which are effectively published at present, and has strong biological nitrogen fixation capacity [1]. No report is made on the generation of nano-selenium or methyl-selenium by using selenate or selenite by using the sword bacteria. The research on bioconversion of the sword bacteria to selenium is beneficial to further development and utilization of new selenium repair strain resources, and large-scale production of safe and efficient nano selenium additives and methylselenate medicines with excellent anticancer performance. Disclosure of Invention The invention aims to provide a sword fungus Ensifer morelensis R-120 which can metabolize selenite to be converted into nano-selenium and can convert selenite and nano-selenium into volatile selenium and application thereof, in particular application in selenium pollution environment restoration and methyl selenate preparation. In order to achieve the purpose of the invention, in a first aspect, the invention provides a strain R2-120 which is separated and purified from Hubei Enshifu selenium soil and can efficiently synthesize volatile selenium, which is classified and named Ensifer morelensis, and is preserved in the microorganism strain preservation center (GDMCC) of Guangdong province, wherein the address is building 5 of No. 59 of 100 university in martyr of Guangzhou province, the institute of microorganisms of the university of Guangdong province, post code 510070, preservation number GDMCC No:63730, and the preservation date of 2023, 8 months and 11 days. In a second aspect, the present invention provides a microbial preparation comprising Sword R2-120. In a third aspect, the invention provides application of the sword bacteria R2-120 in selenium pollution environment restoration and nano-selenium preparation. In a fourth aspect, the invention provides a nano-selenium biosynthesis method, wherein the sword bacteria R2-120 are inoculated into a culture medium added with selenite and/or selenate, and after a period of culture, nano-selenium is separated and purified from the culture solution. The initial selenium concentration in the selenite and/or selenate-added medium is in the range of 2-60 mM, preferably 2-20 mM, more preferably 2 mM, 5mM, 10 mM, 20 mM, most preferably 5 mM. In a fifth aspect, the present invention provides a method for synthesizing volatile selenium, comprising inoculating the sword bacteria R2-120 into a culture medium added with selenite and/or nano-selenium, culturing for a period of time, and collecting the generated volatile selenium; the volatile selenium comprises dimethyl selenone (DMSeO 2) and dimethyl diselenide (DMDSe). Further, the initial selenium concentration in the selenite and/or nanoselenium added medium is 0.125-0.5 mM, preferably 0.125 mM, 0.25 mM, 0.5mM, more preferably 0.5 mM. In a sixth aspect, the present invention provides the use of the above process for the preparation of methyl selenate. The volatile selenium produced according to the method is introduced into the trapping liquid containing the oxidant, so that the volatile selenium is oxidized into water-soluble methyl selenate. The oxidizing agent includes, but is not limited to, nitric acid or hydrogen peroxide. By means of the technical scheme, the invention has at least the following advantages and beneficial effects: The Sword R2-120 has stronger tolerance to selenate and selenite, and a flat