Pseudomonas reductant and its use and method in vanadium reduction

Abstract

This invention discloses a Pseudomonas aeruginosa reducing agent and its application and method in vanadium reduction. Pseudomonas bariensis is inoculated into a vanadium-containing solution to reduce pentavalent vanadium ions. The concentration of pentavalent vanadium in the vanadium-containing solution is 0.5–10 mM. The vanadium-containing solution also includes high-salt LB medium, which is composed of: 10.0 g / L tryptone, 5.0 g / L yeast extract, and 30.0 g / L NaCl, prepared with sterile water. The pH is adjusted to 7.0 with 1 mol / L NaOH or 1 mol / L HCl, and the medium is autoclaved at 121°C for 20 min before use. The reduction reaction of the Pseudomonas aeruginosa and the vanadium-containing solution is carried out at 28°C, 150 rpm oscillation frequency, under anaerobic and dark conditions. The *Pseudomonas baralicum* provided by this invention can still grow when exposed to concentrations up to 10 mM V(V). When the vanadium concentration is 0.5, 1.0, 2.0, 5.0, and 10 mM, the reduction rate of V(V) by this *Pseudomonas baralicum* is 81.1%, 72.4%, 72.3%, 70.8%, and 60.6%, respectively, indicating that *Pseudomonas baralicum* can be used as a reducing agent to remove vanadium toxicity from vanadium-contaminated environments.

Description

Technical Field

[0001] This invention relates to the field of microbial ecological restoration technology, and more specifically, to a Pseudomonas reducing agent and its application and method in vanadium reduction. Background Technology

[0002] Vanadium is a redox-sensitive element that exists in nature in at least six oxidation states: -1, 0, +2, +3, +4, and +5, with +4 and +5 being the most common. It is generally believed that the toxicity and solubility of vanadium increase with increasing oxidation state, with V(V) being the most toxic and mobile. Therefore, reducing V(V) to V(IV) is an effective way to reduce vanadium toxicity.

[0003] Although tailings are generally considered nutrient-poor and heavy metal-rich environments, microorganisms still exist in large numbers. *Pseudomonas balearica* is a major biomarker at the species level in wet tailings. The significant enrichment of *Pseudomonas balearica* in tailings indicates its well-adaptation to the unique environment of wet tailings. *Pseudomonas balearica* is a Gram-negative, salt-tolerant, motile, non-spore-forming bacillus, short, straight, rod-shaped, 0.3–0.5 μm wide and 1.5–3.0 μm long, belonging to the denitrifying bacteria category. Studies by Kumar et al. have shown that *Pseudomonas balearica* exhibits high tolerance to the toxicity of electronic waste (mainly heavy metals and toxic pollutants such as polybrominated diphenyl ethers) and possesses efficient metal activation capabilities. The strain *Pseudomonas balearica* RAD-17, isolated from a polybutylene succinate denitrification reactor by Ruan et al., contains a series of denitrification genes under aerobic conditions, thus exhibiting good aerobic denitrification performance. Although there is evidence that Pseudomonas has a significant influence on the geochemical behavior of vanadium, there is currently no research on the reduction of vanadium by Pseudomonas microorganisms.

[0004] In view of the above, this application is hereby submitted. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a *Pseudomonas bariensis* reducing agent and its application and method in vanadium reduction. Using *Pseudomonas bariensis* as a reducing agent to reduce vanadium, it was found that *Pseudomonas bariensis* can still grow even at concentrations as high as 509 mg / L V(V) (10 mM). When the vanadium concentrations are 25.5, 50.9, 101.9, 255, and 509 mg / L (0.5, 1.0, 2.0, 5.0, and 10 mM), the reduction rates of *Pseudomonas bariensis* for V(V) are 81.1%, 72.4%, 72.3%, 70.8%, and 60.6%, respectively. This indicates that *Pseudomonas bariensis* can be used as a reducing agent to remove vanadium toxicity from vanadium-contaminated environments, providing a favorable research direction for the engineering application of vanadium bioremediation.

[0006] This invention is achieved through the following technical solution:

[0007] In a first aspect, the present invention provides an application of Pseudomonas aeruginosa, which is used for the biological reduction of vanadium ions.

[0008] In one specific implementation, it is used to reduce pentavalent vanadium ions.

[0009] In one specific embodiment, the Pseudomonas is Pseudomonas balearica, which was purchased from the Marine Culture Collection of China (MCCC) with accession number 1A00204.

[0010] Secondly, the present invention provides a method for applying Pseudomonas aeruginosa, wherein an appropriate amount of Pseudomonas aeruginosa is inoculated into a vanadium-containing solution to biologically reduce pentavalent vanadium ions.

[0011] In one specific embodiment, the concentration of pentavalent vanadium in the vanadium-containing solution is 0.5–10 mM.

[0012] In one specific embodiment, the concentration of pentavalent vanadium in the vanadium-containing solution is 0.5 mM.

[0013] In one specific embodiment, the inoculum amount of the Pseudomonas is 1% of the vanadium-containing solution.

[0014] In one specific embodiment, the vanadium-containing solution further includes high-salt LB medium, which is composed of: 10.0 g / L tryptone, 5.0 g / L yeast extract, and 30.0 g / L NaCl, prepared with sterile water, and the pH is adjusted to 7.0 with 1 mol / L NaOH or 1 mol / L HCl, and then used after autoclaving at 121°C for 20 min.

[0015] In one specific embodiment, the reduction reaction of the Pseudomonas bacteria and the vanadium-containing solution is carried out at 28°C, with an oscillation frequency of 150 rpm, under anaerobic and dark conditions.

[0016] Thirdly, the present invention also provides a pentavalent vanadium biological reducing agent, comprising Pseudomonas bariairis.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0018] This invention provides a Pseudomonas aeruginosa reducing agent and its application and method in vanadium reduction. Pseudomonas aeruginosa can still grow at concentrations up to 509 mg / L V(V) (10 mM). When the vanadium concentration is 25.5, 50.9, 101.9, 255, and 509 mg / L (0.5, 1.0, 2.0, 5.0, and 10 mM), the reduction rates of V(V) by this Pseudomonas aeruginosa are 81.1%, 72.4%, 72.3%, 70.8%, and 60.6%, respectively. This indicates that Pseudomonas aeruginosa can be used as a reducing agent to remove vanadium toxicity from vanadium-polluted environments, providing a favorable research direction for the engineering application of vanadium pollution bioremediation. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is an example of the growth of the strain Pseudomonas balearica under different concentrations of vanadium treatment on high-salt LB solid medium provided in Example 2 of the present invention.

[0021] Figure 2 SEM images of strain Pseudomonas balearica under different concentrations of vanadium treatment provided in Example 2 of this invention;

[0022] Figure 3 EDS scans of the strain Pseudomonas balearica under different vanadium concentration stresses provided in Example 2 of this invention;

[0023] Figure 4 This is the growth curve of strain Pseudomonas balearica under different concentrations of vanadium treatment provided in Example 2 of the present invention;

[0024] Figure 5The variation of total vanadium concentration in the culture medium under different vanadium treatments provided in Example 3 of the present invention;

[0025] Figure 6 The concentration changes of pentavalent vanadium in the culture medium under different vanadium treatments provided in Example 3 of the present invention;

[0026] Figure 7 This refers to the variation in the reduction efficiency of pentavalent vanadium under different vanadium concentrations as provided in Example 3 of the present invention.

[0027] Figure 8 The variation of TOC in the system under different vanadium concentrations provided in Example 3 of this invention;

[0028] Figure 9 The color changes of the reaction system under different vanadium concentrations provided in Example 3 of this invention;

[0029] Figure 10 XPS spectra of the reduction products of Pseudomonas balearica bioreduction V(V) provided in Example 3 of the present invention;

[0030] Figure 11 The FTIR spectrum of the reduction product of Pseudomonas balearica bioreduction V(V) provided in Example 3 of the present invention. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments. The illustrative embodiments and descriptions of this invention are only used to explain this invention and are not intended to limit this invention.

[0032] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other embodiments, well-known structures have not been specifically described in order to avoid obscuring the invention.

[0033] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "an embodiment," "an example," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination.

[0034] In the description of this invention, the terms "front," "rear," "left," "right," "upper," "lower," "vertical," "horizontal," "high," "low," "inner," and "outer," etc., indicating orientation or positional relationships, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention.

[0035] Example 1

[0036] Activation and Seed Culture Preparation of Pseudomonas balearica

[0037] *Pseudomonas balearica*, purchased from the Marine Culture Collection of China (MCCC), catalog number 1A00204. According to the strain instructions, bacterial activation and culture were carried out on high-salt Luria-Bertani (LB) enrichment medium. The composition of the high-salt LB medium is as follows: 10.0 g tryptone, 5.0 g yeast extract, and 30.0 g NaCl per liter, prepared with sterile water, and the pH was adjusted to 7.0 with 1 mol / L NaOH or 1 mol / L HCl. The medium was then autoclaved at 121°C for 20 min before use. The high-salt LB solid medium was prepared by adding 15.0 g agar to the pH-adjusted liquid medium.

[0038] Specific steps: On a sterile laminar flow hood, use a grinding wheel and forceps to open the ampoule. Add approximately 200–300 μL of liquid culture medium to the ampoule using a sterile pipette and mix thoroughly with the bacterial cells. Use a pipette to inoculate 200 μL of the bacterial suspension into 50 mL of liquid culture medium and incubate at 28°C and 150 rpm in a constant temperature shaking incubator until the cells reach the logarithmic growth phase, thus activating the strain. Take 1 mL of the activated bacterial suspension and inoculate it again into 100 mL of high-salt LB liquid culture medium, then incubate at 28°C and 150 rpm for 24 hours to obtain a Pseudomonas balearica culture medium.

[0039] Example 2

[0040] Verify the effect of vanadium on the growth of Pseudomonas balearica

[0041] 2.1 Growth morphology of strains under vanadium stress

[0042] Using a sterile inoculation loop, take an appropriate amount of bacterial suspension and inoculate the bacteria into high-salt LB solid medium with vanadium contents of 0, 0.5, 1.0, 2.0, 5.0 and 10 mM (provided in the form of NaVO3) using a continuous streak method. Incubate in a biochemical incubator at 28°C for a certain period of time until obvious colonies grow on the plates, and observe the growth morphology of Pseudomonas balearica under different concentrations of vanadium stress.

[0043] After inoculating *Pseudomonas balearica* into solid culture media containing different vanadium concentrations and culturing for 100 h, the growth morphology of *Pseudomonas balearica* is shown in the figure. Figure 1 .

[0044] from Figure 1 In the study, *Pseudomonas balearica* was observed to be pale yellow, semi-moist, and translucent in solid medium without added vitamin C (V), with a smooth surface and clustered growth. As the concentration of V (V) in the medium increased to 0.5, 1.0, and 2.0 mM, the colony diameter gradually decreased. In media containing 1.0 and 2.0 mM V (V), the colony count of *Pseudomonas balearica* remained relatively stable. However, at high concentrations of V (V) (5.0 and 10 mM), the colony count significantly decreased, indicating that high concentrations of V (V) had a significant inhibitory effect on the growth of *P. balearica*. Furthermore, it was observed that upon exposure to the highest concentration of V (V) (10 mM), the colony color changed from pale yellow to pale blue, due to the reduction of V (V) to V (IV) by *Pseudomonas balearica* in the solid medium.

[0045] 2.2 Cell morphology of Pseudomonas balearica under vanadium stress

[0046] Pseudomonas balearica was inoculated into 100 mL of high-salt LB liquid medium containing vanadium concentrations of 0, 0.5, 1.0, 2.0, 5.0, and 10 mM, and cultured with shaking at 28 °C until the logarithmic growth phase. The cells were collected by centrifugation at 6000 rpm for 7 min and washed twice with 0.90% NaCl solution. The collected cells were then fixed overnight at 4 °C with 2.5% glutaraldehyde solution. The fixative was removed by centrifugation (6000 rpm, 7 min) and washed twice with 0.90% NaCl solution. A second fixation was performed by adding 2.5% glutaraldehyde solution (4 °C, 30 min), followed by centrifugation (6000 rpm, 7 min) to remove the fixative and washing twice with 0.90% NaCl solution. The bacterial cells were progressively dehydrated using ethanol solutions of concentrations of 30%, 50%, 70%, 80%, 90%, and 95% (once each), with each dehydration treatment lasting 15 min. This was followed by dehydration with anhydrous ethanol for 20 min, repeated twice. The dehydrated bacterial cells were then freeze-dried, and the dried samples were ion-sprayed with gold using an ion-plating machine. The bacterial morphology was observed and photographed using SEM, and the elemental composition and content were analyzed using EDS. The cell morphology of *Pseudomonas balearica* under different vanadium concentrations of stress is shown in the figure. Figure 2 EDS scans of Pseudomonas balearica under different vanadium concentrations of stress are shown in [reference needed]. Figure 3 .

[0047] from Figure 2 As can be seen, when grown in high-salt LB liquid medium without V(V), Pseudomonas balearica cells maintain intact morphology, have smooth surfaces, and exhibit a rod-like structure. Under V(V) stress, some cells show significant shortening, cell aggregation, and marked cell morphology with indentation and distortion. Furthermore, a large amount of extracellular secretions or vanadium-containing compounds were observed adhering to the bacterial surface. With increasing V(V) concentration, the degree of cell deformation worsens, but a few cells still maintain their intact morphology, indicating that despite the high toxicity of V(V) to cells, Pseudomonas balearica still exhibits good tolerance to V(V).

[0048] like Figure 3As shown in the EDS spectra, the main elemental composition of the cells includes C, O, N, P, and Na. Characteristic peaks of V were detected in the EDS spectra of the Pseudomonas balearica cell surface at 5.0 and 10 mM V(V), indicating that some vanadium was adsorbed by the cells. Furthermore, an increase in the atomic percentages of P and O in the cells was noted under high concentration V(V) treatment, suggesting that the V adsorbed on the cells may be related to PO4. 3- and OH - In the process of reducing V(V), a green precipitate composed of V and P is produced.

[0049] 2.2 Growth curves of Pseudomonas balearica under vanadium stress

[0050] *Pseudomonas balearica* was inoculated at a 1% inoculum into serum bottles on high-salt LB medium. Initial vanadium concentrations were set at 0, 0.5, 1.0, 2.0, 5.0, and 10 mM (provided as NaVO3). All serum bottles were sealed to maintain an anaerobic environment and then incubated in a constant-temperature shaking incubator (28°C, 150 rpm) in the dark. Samples were taken using a sterile syringe at 2, 4, 8, 12, 24, and 48 h of culture to determine the growth curves of the strain. The growth curves of *Pseudomonas balearica* under different vanadium concentration stresses are shown in [Figure number missing]. Figure 4 .

[0051] The results showed that the strain could still grow even when exposed to the highest V(V) concentration (10 mM). Under different V(V) concentrations, *Pseudomonas balearica* reached a stable growth phase after 24 h of culture, similar to the control treatment. Under 0.5 mM and 1.0 mM V(V) treatments, the growth trend of *Pseudomonas balearica* was comparable to the control group without added V(V), indicating that *Pseudomonas balearica* possesses a resistance mechanism to V(V) stress under these conditions. However, when the V(V) concentration was between 2.0 and 10 mM, a significant inhibitory effect of V(V) on bacterial growth was observed. Specifically, in the V(V) treatment groups with concentrations of 5.0 mM and 10 mM, the highest OD after 48 h was... 600 The value was approximately half that of the control group without V (V), which is consistent with the finding that high concentrations of V (V) significantly inhibited the growth of Pseudomonas balearica on solid culture medium.

[0052] Example 3

[0053] 3.1 Verify the ability of Pseudomonas balearica to reduce vanadium

[0054] Pseudomonas balearica was inoculated at a 1% inoculum into serum bottles on high-salt LB medium, with initial vanadium concentrations of 0, 0.5, 1.0, 2.0, 5.0, and 10 mM (provided as NaVO3). All serum bottles were sealed to maintain an anaerobic environment and then incubated in a constant-temperature shaking incubator (28°C, 150 rpm) in the dark. Samples were taken using a sterile syringe at 2, 4, 8, 12, 24, and 48 h of incubation to measure changes in total vanadium, pentavalent vanadium, and TOC, and the reduction efficiency of Pseudomonas balearica to pentavalent vanadium was calculated. Each experiment was performed in triplicate, and the average results were recorded.

[0055] The changes in total vanadium concentration in the culture medium under different vanadium treatments are shown in the figure. Figure 5 The results showed that the total vanadium concentration in the culture medium decreased in all treatment groups during the 48-hour incubation period, especially at the highest V(V) concentration (10 mM). This is likely due to the adsorption or absorption of V by *Pseudomonas balearica*. Studies have shown that *P. putida*, *Bacillus cereus*, and *P. peudoalkaligenes* enhance vanadium absorption and growth at a vanadium concentration of 40 mg / L, and these strains can accumulate approximately 10%–12% vanadium.

[0056] The changes in the concentration of pentavalent vanadium in the culture medium under different vanadium treatments are shown in the figure. Figure 6 The results show that the reduction in V(V) was significantly greater than the reduction in total vanadium in all treatments as the reaction proceeded, indicating that most of the V(V) in the reaction system was reduced rather than adsorbed or absorbed by *Pseudomonas balearica*. Furthermore, the amount of V(V) reduced by reduction during the reaction increased with increasing V(V) treatment concentration in the culture medium. When the V(V) treatment concentration was 10 mM, the V(V) concentration in the system decreased from 6.82 mM at 2 h to 3.5 mM at 48 h.

[0057] The changes in the reduction efficiency of pentavalent vanadium under different vanadium concentrations are shown in the figure. Figure 7The results show that during the first 12 hours of cultivation, the V(V) reduction efficiency of all treatment groups increased rapidly, ranging from 46.5% to 73.7%. Subsequently, the reduction efficiency increased slowly, reaching a peak of 60.6% to 81.1% at 48 hours. At 48 hours, when the initial vanadium concentration was 0.5 mM, *Pseudomonas balearica* exhibited the highest vanadium reduction efficiency, exceeding 80%. With increasing V(V) addition, the V(V) reduction efficiency of *Pseudomonas balearica* significantly decreased; the V(V) reduction efficiency under the 10 mM V(V) treatment (60.6%) was only 74.7% of that under the 0.5 mM V(V) treatment (81.1%).

[0058] The changes in TOC in the system under different vanadium concentrations are shown in the figure. Figure 8 The results show that during the 48-hour culture period, the TOC in the reaction system gradually decreased, indicating that the carbon source provided by the yeast extract in the culture medium provided electrons for the bioreduction of V(V) and provided nutrients for the growth of Pseudomonas balearica.

[0059] The color changes of the reaction system under different vanadium concentrations are shown in the figure. Figure 9 The results show that after 24 hours of cultivation, the Pseudomonas balearica cultures treated with 5.0 mM and 10 mM V(V) changed from light yellow to light blue. This phenomenon was more pronounced at 48 hours, where the culture medium treated with high V(V) (5.0 mM and 10 mM) clearly showed a deep blue color, confirming that V(IV) exists in the system as vanadium-based ions.

[0060] The concentration of vanadium in the wastewater of my country's mainstream vanadium industry is between 10 and 200 mg / L, while my country's "Vanadium Industry Pollutant Emission Standard" (GB 26452-2011) stipulates that the emission limit of vanadium in water pollutants from newly built enterprises is 1.0 mg / L.

[0061] The *Pseudomonas balearica* strain used in this invention exhibits growth inhibition with increasing V(V) concentration. However, even when exposed to a V(V) concentration of 10 mM (509 mg / L), the *Pseudomonas balearica* strain survives, achieving a reduction rate of 60.6% for pentavalent vanadium at the end of the reaction. These data demonstrate the high tolerance of *Pseudomonas balearica* to vanadium and prove its effectiveness in reducing V(V), indicating its potential for removing vanadium from various vanadium-containing environments and promising application prospects in treating practical vanadium-containing wastewater.

[0062] Although tailings are generally considered to be nutrient-poor and heavy metal-rich environments, microorganisms still exist in large numbers. There is current evidence of Pseudomonas enrichment in vanadium-titanium magnetite tailings; therefore, this invention provides the possibility of using in-situ microorganisms *Pseudomonas balearica* grown in tailings for bioremediation of vanadium-contaminated sites.

[0063] 3.2 Characterization of reduction products of bioreduction of V (V) by Pseudomonas balearica

[0064] Pseudomonas balearica was inoculated at a rate of 1% into serum bottles containing 100 mL of high-salt LB medium. Initial V(V) concentrations were set at 1.0 and 10 mM (provided as NaVO3), with a control group containing no V(V). The culture was carried out at 28 °C with shaking at 150 rpm for 10 days. The corresponding reduction precipitates and cell precipitates were collected by centrifugation (6000 rpm, 10 min) and then freeze-dried. The morphology and composition of the reduction products were identified using FTIR and XPS.

[0065] XPS analysis was used to analyze the reduced precipitate of cells in the culture. For example... Figure 10 As shown, XPS spectroscopy confirmed that the main elements in the precipitate were C, N, O, Na, P, and Cl. Figure 10 a) Unlike the control group without added V(V), the characteristic peaks of vanadium appeared in the reduced precipitate treated with 10 mM V(V). The V 2p spectrum shows that the characteristic peaks are located at 523.9 eV and 516.5 eV (a). Figure 10 b), attributed to the binding energies of V 2p1 / 2 and V 2p3 / 2 respectively, indicates the presence of V(IV). Regarding the C1s spectrum, the binding energies of the control group at 284.8, 286.5, and 288.1 eV represent CC / CH / CC, CO, and OCO / C OH, respectively. Figure 10c). Compared with the C1s spectrum of the control group, the peak area of ​​CC / CH / CC in the precipitate produced by V(V) treatment decreased from 73.08% to 70.19%, while the peak area of ​​OCO / C OH increased from 13.90% to 16.79%. Figure 10 d). The change in peak area is due to the reduction of V(V) by Pseudomonas. Microbial cell walls, mainly composed of polysaccharides, lipids, and proteins, provide many functional groups that can bind to heavy metal ions, including carboxyl, hydroxyl, amino, and phosphate groups. Therefore, the reduction product V(IV) may bind to functional groups on the bacterial cell wall.

[0066] The properties of the reduction products were further characterized using FTIR. For example... Figure 11 As shown, compared with the control without V(V), the intensity of each absorption band increased significantly under V(V) stress, indicating that functional groups play a crucial role in the bioreduction of V(V) in *Pseudomonas balearica*. The strain treated with 1.0 mM V(V) showed increased absorption band intensity at 1085 cm⁻¹. -1 A characteristic peak appears at [value missing], corresponding to the vibrations of PO and PO from phosphate groups. This peak weakens upon the addition of 10 mM V(V), indicating that phosphate-containing groups on the cell surface are involved in the interaction with V(V). This is consistent with the results of EDS. Furthermore, bacterial cells exposed to 1.0 mM V(V) [value missing] at 1241 cm⁻¹ [value missing]. -1 The peak observed at [value missing], representing the vibration of CO in the carboxyl group (COOH), shifted to 1243 cm⁻¹ when treated with 10 mM V(V). -1 The displacement and decreased transmittance confirm the interaction between V(V) and carboxyl groups on the bacterial cell surface.

[0067] In summary, combining Figure 9 Color changes in the culture and Figure 10 XPS spectroscopy of the reduction product indicated that the reduction product of V(V) in the bioreduction of V(V) by Pseudomonas balearica was V(IV). FTIR spectroscopy of the reduction product also indicated that the phosphorus and carboxyl groups on the cell surface of Pseudomonas balearica facilitated the binding and reduction of V(V).

[0068] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An application of a Pseudomonas aeruginosa, characterized in that, Pseudomonas barialis was used for the bioreduction of vanadium ions.

2. The application of Pseudomonas according to claim 1, characterized in that, Used to reduce pentavalent vanadium ions.

3. A method for applying Pseudomonas aeruginosa, characterized in that, An appropriate amount of *Pseudomonas bariensis* was inoculated into a vanadium-containing solution to bioreduced pentavalent vanadium ions.

4. The method for applying Pseudomonas aeruginosa according to claim 3, characterized in that, The concentration of pentavalent vanadium in the vanadium-containing solution is 0.5~10 mM.

5. The method for applying Pseudomonas aeruginosa according to claim 3, characterized in that, The inoculation amount of *Pseudomonas bariensis* was 1% of the vanadium-containing solution.

6. The method for applying Pseudomonas aeruginosa according to claim 3, characterized in that, The vanadium-containing solution also includes high-salt LB medium, which is composed of: 10.0 g / L tryptone, 5.0 g / L yeast extract, and 30.0 g / L NaCl. It is prepared with sterile water, and the pH is adjusted to 7.

0. It is then sterilized by autoclaving at 121°C for 20 min before use.

7. The method for applying Pseudomonas aeruginosa according to claim 3, characterized in that, The reduction reaction of *Pseudomonas bariensis* and vanadium-containing solution was carried out at 28°C, with an oscillation frequency of 150 rpm, under anaerobic and dark conditions.

8. A pentavalent vanadium bioreducing agent, characterized in that, Including Pseudomonas bariairis.

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