A microorganism capable of absorbing boron and its application

Abstract

The present invention discloses a microorganism capable of absorbing boron, which is classified and named as Bacillus subtilis ( Bacillus subtilis ) NJ1001, the Bacillus subtilis was screened from the water of Langcuo Lake and has been deposited in the China Center for Type Culture Collection with the deposit number CCTCC NO: M 2022617. Bacillus subtilis NJ1001 has broad application prospects in boron adsorption.

Description

Technical Field

[0001] The invention relates to the field of biotechnology, in particular to a strain of Bacillus subtilis and application thereof in adsorption of non-metallic boron elements. Background Art

[0002] Boron is a chemical element, an important basic building block of life, a widely used chemical raw material mineral, and an active factor with physiological functions. At present, the boron in the earth's crust mainly includes boron ore and boron-containing aqueous solution, among which the boron in the aqueous solution is mostly distributed in salt lakes and seawater in the form of boric acid and boric acid polymers. How to safely and greenly separate and extract boron from boron-containing aqueous solution is the development trend and hot spot of the boron industry.

[0003] At present, there are two methods for extracting boron from salt lake brine: acidification and precipitation. The acidification method mostly uses corrosive strong acids such as sulfuric acid for acidification and precipitation; the precipitation method uses active magnesium oxide and lime milk for precipitation extraction. The use of strong acids and unrecoverable boric acid not only cause environmental pollution and waste of resources, but also affect subsequent mineral development. The main method for extracting boron from seawater desalination is reverse osmosis, which has high operating pressure and is prone to membrane pollution and concentrate.

[0004] There are few reports on the adsorption of boron by microorganisms. Burcu Ertit Taştan et al. isolated boron-resistant fungi from wastewater of a boron mine in Turkey and detected Penicillium chaetoceros in different culture media, namely, minimum salt medium (MSM), waste medium containing molasses (WM-1), and whey molasses (WM-2). Penicillium crustose ) and Rhodotorula Rhododendron mucilaginous ) for boron adsorption efficiency. In MSM and WM-1, both strains achieved high boron removal rates. In MSM, when the initial boron concentration was 33.95 mg / L, the maximum boron adsorption rate of Penicillium humilis was 45.68%, and at 42.76 mg / L, the maximum adsorption rate of Rhodotorula glutinosus was 38.97%, which provides an economical and feasible method for the adsorption and separation of boron from aqueous solutions. Nevertheless, there are no reports on the separation of boron by bacterial adsorption.

[0005] The Bacillus subtilis NJ1001 used in the present invention can efficiently adsorb boron in a boron-containing aqueous solution and can desorb under mild conditions, and is an effective candidate strain for boron adsorption. Summary of the invention

[0006] The first object of the present invention is to provide a microorganism capable of absorbing boron, wherein the microorganism is Bacillus subtilis ( Bacillus subtilis )NJ1001.

[0007] The second object of the present invention is to extract boron from a boron-containing aqueous solution by adsorption.

[0008] The present invention also provides Bacillus subtilis ( Bacillus subtilis ) Method for desorption of boron from NJ1001 under mild conditions.

[0009] A microorganism that absorbs boron, its classification name is: Bacillus subtilis ( Bacillus subtilis )NJ1001, has been deposited in the China Center for Type Culture Collection, address: Wuhan University, Wuhan, China, with the deposit number CCTCC NO: M 2022617 and the deposit date is May 13, 2022.

[0010] The strain is screened from the water of Langcuo Lake in Tibet Autonomous Region. The strain is Gram-positive, the cell morphology is rod-shaped, and the colony morphology is milky white, transparent, convex, and has regular edges.

[0011] The culture temperature range is 20-27 ℃, the optimum is 24 ℃, the pH range is 2.0-10.0, the optimum is 7.0, and the boron concentration range is 0-1000 ppm.

[0012] The Bacillus subtilis ( Bacillus subtilis )The culture conditions of NJ1001 are:

[0013] (1) Plate culture: Bacillus subtilis ( Bacillus subtilis ) NJ1001 was inoculated into solid culture medium and cultured at 20-27°C for 72-96h to obtain single colonies on the plate;

[0014] (2) Liquid culture: Pick a single colony from the solid plate and inoculate it into the seed culture medium. Cultivate at 20-27°C and 200 rpm for 72-96 hours to obtain seed liquid.

[0015] The solid culture medium is peptone 10-15 g / L, beef extract 3-7 g / L, sodium chloride 5-9 g / L, agar powder 20-25 g / L, pH 7-8, and the solvent is water; further preferably, the solid culture medium is: peptone 10 g / L, beef extract 3 g / L, sodium chloride 5 g / L, agar powder 20 g / L, pH 7-8, and the solvent is water;

[0016] The liquid culture medium is peptone 10-15 g / L, beef extract 3-7 g / L, sodium chloride 5-9 g / L, pH 7-8, and the solvent is water. Further preferably, the concentration composition of the liquid culture medium is: peptone 10 g / L, beef extract 3 g / L, sodium chloride 5 g / L, pH 7-8, and the solvent is water.

[0017] A microbial agent, the agent comprising Bacillus subtilis ( Bacillus subtilis )NJ1001.

[0018] The application of the Bacillus subtilis NJ1001 in the adsorption of boron, iron and chromium.

[0019] The microbial agent containing Bacillus subtilis NJ1001 is used in the adsorption of boron, iron and chromium.

[0020] The adsorption process is to adsorb boron, iron and chromium from a solution containing boron, iron and chromium.

[0021] The Bacillus subtilis NJ1001 or the microbial agent containing Bacillus subtilis NJ1001 has a more significant effect in boron adsorption.

[0022] Add Bacillus subtilis NJ1001 cells or culture solution containing the cells to the boron-containing solution, adsorb at 20-27°C, 100-150 rpm for 0.5-2 h, and collect the cells by centrifugation. Boron is adsorbed to Bacillus subtilis ( Bacillus subtilis ) NJ1001 surface, the adsorption rate was 33.3% in 1 h.

[0023] The application of Bacillus subtilis NJ1001 in the process of extracting boron, iron and chromium; the process of extracting boron, iron and chromium is the process of extracting boron, iron and chromium from boron, iron and chromium containing solutions, especially the application in the process of extracting boron.

[0024] The boron is boric acid.

[0025] The extraction process includes adsorbing boron from a boron-containing solution and then desorbing the boron under mild conditions to achieve the purpose of boron extraction. Specifically, it includes the following steps:

[0026] (1) Adsorption: Add Bacillus subtilis NJ1001 cells or culture solution containing the cells to the boron-containing solution at a volume ratio of 10%-30%, adsorb at 20-27°C, 100-150 rpm for 0.5-2 h, and collect the cells by centrifugation;

[0027] (2) Desorption: Add the collected bacteria into pure water at a ratio of 10%-50% (w / v), stir at 35-37°C, 100-150 rpm for 0.5 h, and collect the supernatant by centrifugation.

[0028] The centrifugal speed is 2500-4000 rpm.

[0029] The experiments of the present invention prove that the present invention has found a strain of Bacillus subtilis ( Bacillus subtilis ) NJ1001, after research, it was found that Bacillus subtilis ( Bacillus subtilis )NJ1001 can adsorb boron with high efficiency, with an adsorption rate of 33.3% in 1 hour. When the adsorption temperature is increased to above 35 ℃, boron is desorbed back into the aqueous solution.

[0030] Beneficial effects: The strain of the present invention, as a boron-adsorbing biomaterial, has a good application prospect in developing new microbial adsorbents, which not only saves resources but is also beneficial to protecting the environment and has great economic benefits. DETAILED DESCRIPTION

[0031] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0032] Example 1 Strain Screening

[0033] In May 2022, in an ultra-clean workbench, samples collected from Langcuo Lake were placed in sterile distilled water, shaken on a shaker for about 15 minutes to make a bacterial suspension, and then the mixture was centrifuged.

[0034] The bacterial suspension was diluted with sterile distilled water in a concentration gradient and then spread on a solid culture medium (peptone 15 g / L, beef extract 7 g / L, sodium chloride 9 g / L, agar powder 25 g / L, pH 7) plate and cultured at 20°C for 96 hours. After that, the colonies covered the entire plate, and the strains with different morphology, size, color, and transparency on the plate were picked up with an inoculation loop and streaked to purify the plate to obtain different single colonies. These single colonies were cultured at 20-27°C for 72-96 hours, and the single colonies were collected and inoculated into liquid culture medium (peptone 15g / L, beef extract 7 g / L, sodium chloride 9 g / L, pH 7-8). These strains were used in boron adsorption experiments, and the collected bacteria were added to pure water at a ratio of 50% (w / v), stirred at 35°C, 100 rpm for 0.5 h, and centrifuged at 2500rpm to collect the supernatant. The boron recovery rate was 58.33%. The obtained strain with strong boron adsorption ability was named Bacillus subtilis ( Bacillus subtilis )NJ1001.

[0035] The strain is gram-positive, with rod-shaped cells and milky white, transparent, convex colonies with regular edges.

[0036] The culture temperature range is 20-27 ℃, the optimum is 24 ℃, the pH range is 2.0-10.0, the optimum is 7.0, and the boron concentration range is 0-1000 ppm.

[0037] Example 2 Bacillus subtilis ( Bacillus subtilis ) NJ1001 cell preparation

[0038] The Bacillus subtilis ( Bacillus subtilis ) NJ1001 cells were prepared as follows:

[0039] (1) Plate culture: Bacillus subtilis ( Bacillus subtilis) NJ1001 was inoculated in a solid culture medium and cultured at 20°C for 96 hours to obtain a single colony on the plate. The NB solid culture medium was composed of: 10 g / L peptone, 3 g / L beef extract, 5 g / L sodium chloride, 20 g / L agar powder, pH 7-8, and the solvent was water;

[0040] (2) Liquid culture: Pick a single colony from the solid plate and inoculate it into the seed culture medium. Culture it at 20°C and 200 rpm for 96 h to obtain the seed liquid. The concentration of the seed NB culture medium is as follows: peptone 10 g / L, beef extract 3 g / L, sodium chloride 5 g / L, pH 7-8, and the solvent is water.

[0041] Example 3 Bacillus subtilis ( Bacillus subtilis )NJ1001 adsorption of boron

[0042] This example investigates the Bacillus subtilis ) The adsorption of different concentrations of boron by NJ1001 (i.e., the concentration of boron in the mixed system ranges from 0 to 1000 ppm, respectively 0, 100, 200, 500, and 1000 ppm) is mainly carried out as follows: culture medium is added to the boron-containing solution at a volume ratio of 20% (the amount added is a mixture of 20 volumes of culture medium and 80 volumes of boron-containing solution), adsorbed at 20-27°C and 100-150 rpm for 1 h, and the boron adsorption rate is 27.2%-33.3% (27.21% at 100 ppm, 29.11% at 200 ppm, 33.33% at 500 ppm, and 30.15% at 1000 ppm). Adsorption rate (%) = (boron solubility in the boron solution before adsorption - boron concentration in the boron solution after adsorption) × 100% / boron concentration in the boron solution before adsorption.

[0043] Example 4 Boron Desorption

[0044] This example investigates the adsorption to Bacillus subtilis ( Bacillus subtilis ) The desorption of boron on the surface of NJ1001. The main steps are as follows: Bacillus subtilis ( Bacillus subtilis ) As for NJ1001, at an ambient temperature of 37°C, boron was desorbed from the bacterial surface. The desorption rate was 68.77% after static desorption for 1 h, and 100% at 150 rpm for 1 h.

[0045] Example 5 Bacillus subtilis ( Bacillus subtilis )Comparison of the adsorption capacity of NJ1001 for boron, iron and chromium

[0046] This example investigates the Bacillus subtilis) The adsorption of boron, iron and chromium by NJ1001 is mainly as follows: add culture medium to a mixed solution containing boron, iron and chromium at a volume ratio of 30%, where the concentration of boron, iron and chromium in the mixed system is 500 ppm, adsorb for 1 hour at 27℃ and 150 rpm, and the adsorption rates of boron, iron and chromium are 33.42%, 21.33% and 28.66% respectively. Adsorption rate (%) = (element solubility in adsorption solution - element concentration in solution after adsorption) × 100% / element concentration in solution before adsorption.

[0047] Example 6 Desorption of Boron, Iron and Chromium

[0048] This example investigates the adsorption to Bacillus subtilis ( Bacillus subtilis ) The desorption of boron, iron and chromium on the surface of NJ1001, the main steps are as follows: Bacillus subtilis ( Bacillus subtle ) NJ1001 was desorbed at 37℃ and 150rpm for 1 h, and the desorption rates of boron, iron and chromium were 100%, 77.7% and 89.2% respectively. Bacillus subtilis )NJ1001 has a certain selective adsorption and desorption ability for boron.

Claims

1. A microorganism that absorbs boron, which is classified and named as: Bacillus subtilis ( Bacillus subtilis )NJ1001, deposited in the China Center for Type Culture Collection, with the deposit number CCTCC NO: M 2022617 and the deposit date of May 13, 2022.

2. A microbial agent, comprising the Bacillus subtilis according to claim 1 ( Bacillus subtilis )NJ1001.

3. The use of the boron-adsorbing microorganism according to claim 1 in a boron extraction process, characterized in that: The boron extraction process comprises utilizing the Bacillus subtilis ( Bacillus subtilis ) The process of NJ1001 adsorbing boron from boric acid solution.

4. The use according to claim 3, characterized in that: The steps include: (1) Solid culture: Bacillus subtilis ( Bacillus subtilis ) NJ1001 was inoculated into solid culture medium and cultured at 20-27°C for 72-96 h to obtain single colonies on the plate; (2) Liquid culture: Pick a single colony from the solid plate and inoculate it into the seed culture medium. Cultivate at 20-27°C and 150-200 rpm for 72-96 h to obtain the seed solution. (3) Adsorption: Add culture medium to the boric acid solution at a volume ratio of 10%-30%, adsorb for 0.5-2 h at 20-27°C and 100-150 rpm, and collect the bacteria by centrifugation; (4) Desorption: Add the collected bacteria into pure water at a ratio of 10%-50% (w / v), stir at 35-37°C, 100-150 rpm for 0.5 h, and collect the supernatant by centrifugation.

5. The use according to claim 4, characterized in that The solid culture medium comprises 10-15 g / L of peptone, 3-7 g / L of beef extract, 5-9 g / L of sodium chloride, 20-25 g / L of agar powder, pH 7-8, and the solvent is water.

6. The use according to claim 4, characterized in that: The liquid culture medium contains 10-15 g / L of peptone, 3-7 g / L of beef extract, 5-9 g / L of sodium chloride, pH 7-8, and the solvent is water.

7. The use according to claim 4, characterized in that: The boron concentration in the boric acid solution is 10-1000 ppm.