CN-121495776-B - Selenium-resistant pantoea agglomerans and application thereof

Abstract

The invention provides a pantoea agglomerans and application thereof, belonging to the technical field of microorganisms, wherein the strain is preserved in the China general microbiological culture Collection center (CGMCC No. 36122), has high selenium tolerance and conversion capability, and can convert inorganic selenium (such as Se (IV)) with higher toxicity into organic selenium (such as selenomethionine and selenocysteine) with low toxicity and zero-valent nano selenium (Se 0 ) in a culture medium containing sodium selenite. The pantoea agglomerans obtained by the invention has selenium-rich microbial characteristics, and can have potential application value in biological conversion of selenium, microbial synthesis of nano-selenium and growth promotion of crops and selenium enrichment. The pantoea agglomerans can promote plant growth, and the highest organic selenium conversion rate can reach 92.5% and the nanometer selenium synthesis efficiency can reach 88.3% by utilizing the liquid fermentation technology developed by the strain. Has good help for the development of organic selenium agricultural products.

Inventors

• ZHANG JUN
• HE BO
• XIA ZENGRUN
• Feng zhongjiang

Assignees

• 安康市富硒产品研发中心

Dates

Publication Date

20260508

Application Date

20251128

Claims (4)

1. 1. The Pantoea agglomerans AKFX-001 is characterized in that Latin name of Pantoea agglomerans AKFX-001 is Pantoea agglomerans, and the Latin is preserved in China general microbiological culture Collection center with the preservation number of CGMCC No.36122.
2. 2. The use of pantoea agglomerans AKFX-001 according to claim 1, wherein pantoea agglomerans AKFX-001 is used for converting inorganic sodium selenite into organic selenomethionine in 2-100 mM sodium selenite culture medium.
3. 3. The use of pantoea agglomerans AKFX-001 according to claim 1, wherein pantoea agglomerans AKFX-001 is used for converting inorganic sodium selenite into amorphous nano-selenium in 2-100 mM sodium selenite culture medium.
4. 4. The use of Pantoea agglomerans AKFX-001 according to claim 1, wherein Pantoea agglomerans AKFX-001 is used for producing indoleacetic acid, phosphorus and siderophores.

Description

Selenium-resistant pantoea agglomerans and application thereof Technical Field The invention belongs to the technical field of microorganisms, and particularly relates to selenium-resistant pantoea agglomerans and application thereof in promoting plant growth and enriching selenium. Background The pantoea agglomerans (Pantoea agglomerans) is gram-negative rod-shaped bacteria, the cell size is 0.5-1.0x1-3 microns, the pantoea agglomerans has the characteristics of periphyton flagellum and yellow pigment production, most strains are facultative anaerobic energy heterotrophic bacteria, the cell walls of the pantoea agglomerans are thin because of being gram-negative rod-shaped bacteria, the pantoea agglomerans can synthesize nano-selenium, but the maximum selenium-resistant concentration of the pantoea agglomerans can grow is 2mM according to the previous experiments of the inventor, the selenium conversion rate of the pantoea agglomerans is larger than that of other microorganisms, and only a small amount of selenium can be converted into organic selenium or nano-selenium at a lower concentration. Selenium (Selenium, se) is used as a trace nutrient element necessary for human and animal organisms, and plays a vital physiological function in the aspects of antioxidation, immunoregulation, thyroid hormone metabolism, cancer prevention and anticancer, etc. The selenium deficiency of human body can directly cause various diseases such as keshan disease, large bone joint disease and the like, and maintaining proper selenium intake level is the key for guaranteeing health. Selenium in nature exists mainly in two forms, inorganic selenium (such as selenate Se (VI) and selenite Se (IV)) and organic selenium (such as selenoamino acid, selenoprotein and selenoglycose). Among them, inorganic selenium, particularly selenite, has not only low bioavailability but also strong toxicity, and its narrow safety window severely limits its direct application in the nutritional field, in contrast, organic selenium and zero-valent nano selenium (Se 0) exhibit higher bioavailability and significantly reduced cytotoxicity, and thus are widely considered as ideal and safe dietary selenium supplement forms. At present, the technical approaches for obtaining the organic selenium and the nano-selenium mainly comprise a chemical synthesis method, a plant transformation method and a microbial transformation method. Chemical synthesis methods generally adopt strong reducing agents (such as hydrazine and sodium borohydride) for reducing to prepare nano-selenium, or generate selenoamino acid through organic synthesis reaction. Although the method can realize batch production, the method inevitably has a plurality of defects that the chemical reduction process possibly brings environmental and safety risks, the synthesized nano selenium particles are easy to agglomerate and have uneven size distribution to influence the biological activity, the organic synthesis route has complex steps and high cost, and harmful organic solvents possibly remain, so that the method is difficult to meet the strict requirements of food and medicine fields on the safety. The plant transformation method (namely the plant selenium-rich technology) utilizes high-polymer selenium crops such as edible fungi or grains to transform inorganic selenium into organic selenium by applying selenium fertilizer. Although the method has more natural properties, the method has the inherent defects of long conversion period, restriction by geographical environment and season climate, large fluctuation of selenium content in plants, low organic selenium proportion and the like, and is difficult to realize the standardization and large-scale production of products. The microbial transformation method utilizes the metabolic functions of microorganisms such as saccharomycetes, lactobacillus, fungi and the like to reduce inorganic selenium into nano selenium or assimilate the nano selenium into organic selenium, and has become a hot spot of current research because of the advantages of mild reaction conditions, environmental friendliness, good biocompatibility of products, easy process regulation and the like. For example, there are patents disclosing lactobacillus acidophilus for the synthesis of nano-selenium, or candida utilis for the production of selenium enriched yeasts. However, the existing microbial technology still faces a series of serious challenges, namely the primary bottleneck is that a plurality of strains are limited in tolerance concentration to selenium, growth is obviously inhibited under high selenium pressure, conversion efficiency is greatly reduced, for example, growth of partial lactobacillus is severely inhibited when sodium selenite concentration exceeds 2mM, the existing strains tend to be single in function and only good at synthesizing nano-selenium or accumulating organic selenium, directional high-efficiency synthesis of two products is difficult to reali