CN112159786B

CN112159786B - Cr (VI) reducing strain C6, and culture condition and application thereof

Info

Publication number: CN112159786B
Application number: CN202011217783.0A
Authority: CN
Inventors: 谷雅文; 周磊景; 任玉文; 于鲲鹏; 周晓辉
Original assignee: Hebei University of Science and Technology
Current assignee: Hebei University of Science and Technology
Priority date: 2020-11-04
Filing date: 2020-11-04
Publication date: 2022-03-01
Anticipated expiration: 2040-11-04
Also published as: CN112159786A

Abstract

The invention relates to the technical field of microorganism application, and particularly discloses a Cr (VI) reducing strain C6, and a culture condition and application thereof. The strain preservation number of the Cr (VI) reducing strain C6 is CGMCC No.20390, and the strain can be applied to the treatment of Cr (VI) polluted wastewater and Cr (VI) polluted soil and the preparation of Cr (VI) polluted wastewater treatment agents or Cr (VI) polluted soil treatment agents. The Cr (VI) reducing strain C6 provided by the invention has the capabilities of resisting high-concentration Cr (VI) and quickly and efficiently reducing Cr (VI), and the Cr (VI) reducing strain C6 has strong environmental adaptability, good environmental safety, no pathogenicity to human bodies, low culture cost, small inoculation amount in Cr (VI) reduction, no secondary pollution and extremely high industrial popularization and application values.

Description

Cr (VI) reducing strain C6, and culture condition and application thereof

Technical Field

The invention relates to the technical field of microorganism application, in particular to a Cr (VI) reducing strain C6, and a culture condition and application thereof.

Background

Chromium (Cr) since 1797The French scientist Vauquerin finds from chrome lead ore, is widely applied to industries such as leather, electroplating, pigment, mineral separation, chemical industry, wood preservation and the like, and makes a great contribution to industrial development. Meanwhile, the mining, smelting, processing and commercial manufacturing activities of human beings for chromium and chromium salts as raw materials are increasing, and a large amount of chromium-containing waste slag and waste water are generated. Chromium exists in nine valence states under natural conditions, but the most common chromium compounds in the atmosphere, soil and water exist in the form of hexavalent chromium Cr (vi) or trivalent chromium Cr (iii). Cr (III) is a micronutrient element necessary for organisms, is relatively insoluble in water and has no carcinogenicity; and Cr (VI) is mainly Cr₂O₇ ^2-And CrO₄ ^2-Compared with Cr (III), the Cr (III) has the characteristics of high mobility, high water solubility, toxicity to all organisms and the like, and has obvious harm to human health and ecological environment. Cr (VI) is easily absorbed by organisms, can invade a human body through three ways of respiratory tract, digestive tract and skin and is accumulated in the human body, and when the physiological load of the human body is exceeded, acute and chronic diseases or long-term harm is generated, so that severe damage is caused to the skin, viscera and nervous system; the existence of Cr (VI) and the occurrence of lung cancer are proved to have significant correlation; cr (VI) is easily absorbed by plants, and destroys the ecosystem through the food chain. Therefore, Cr (VI) becomes one of three carcinogenic metal substances internationally recognized. China is a big country for producing and using chromium products, the annual chromium salt yield exceeds 16 ten thousand tons, the discharge amount of chromium slag is 35-42 ten thousand tons, and the Cr (VI) content is about 3500 tons; meanwhile, nearly hundred tons of wastewater containing Cr (VI) is discharged into the environment, so that the research on Cr (VI) pollution treatment is a long-term and difficult task.

Cr (III) is easy to form amorphous hydroxide precipitate in the environment, has small biological toxicity, and cell membranes cannot permeate free Cr (III), so that the toxicity is only one thousandth of that of Cr (VI), and therefore, the reduction of Cr (VI) into Cr (III) is a recognized effective strategy for pollution treatment. The conventional Cr (VI) repairing mode comprises methods such as chemical precipitation, chemical reduction, ion exchange, adsorption, electrochemistry and the like. These methods are expensive, consume large amounts of chemicals and are prone to secondary pollution.

Since the bacteria with Cr (VI) reducing capability are found in anaerobic environment for the first time by Romanenko and the like in the 70 th 20 th century, the bacteria-mediated Cr (VI) reduction is considered to be one of the most potential Cr (VI) pollution remediation methods due to the characteristics of mild reaction, low energy consumption and no secondary pollution. Compared with the traditional method, the method for treating the wastewater containing Cr (VI) by using the microorganisms has the advantages that: the microorganism can continuously grow and reproduce in the operation process, so that the reduced metal ions can be increased along with the increase of biomass, the reaction saturation phenomenon can not occur, a large amount of chemical agents do not need to be added, special anticorrosive equipment is not needed, the equipment is simple, and the investment is low.

Research has proved that the tolerance of the microbial strains to Cr (VI) (generally, only the microbes which can tolerate Cr (VI) with the concentration of 10.4mg/L can be called Cr (VI) tolerant microbes) and the reduction capability to Cr (VI) have no correlation, and the strains with better Cr (VI) removing capability do not necessarily have high tolerance. And it has been reported that microorganisms capable of reducing Cr (VI) often threaten human health, for example, micrococcus has pathogenicity, can cause local infection such as folliculitis, cellulitis and wound suppuration, and can also cause systemic infection such as tracheitis, pneumonia and otitis media; the conditional pathogenic bacteria in enterobacteria can cause urethritis, cystitis, appendicitis and postoperative infection on beds. And most strains can only reduce Cr (VI) under anaerobic conditions. Therefore, the microorganisms capable of reducing Cr (VI) which appear at present mostly have the defects of low Cr (VI) tolerance, large inoculation amount, high culture cost, low reduction amount, long time required for reduction, poor environment adaptability, harm to human bodies and the like, and have a certain distance from the general application of industry.

Disclosure of Invention

Aiming at the problems that most of the existing microorganisms capable of reducing Cr (VI) are low Cr (VI) tolerance, large inoculation amount, high culture cost, low reduction amount, long reduction time, poor environment adaptability and harmful to human bodies, the invention provides a Cr (VI) reducing strain C6 and culture conditions and application thereof.

In order to achieve the purpose of the invention, the embodiment of the invention adopts the following technical scheme:

a Cr (VI) reducing strain C6 with the strain preservation number of CGMCC No.20390 belongs to Bacillus sp, which is preserved in China general microbiological culture Collection center on 17.07.2020 and with the preservation address of the institute of microbiology, China academy of sciences, No. 3, West Lu No. 1 institute of China, North Jing City, Ind.

Compared with the prior art, the Cr (VI) reducing strain C6 provided by the invention has the capabilities of resisting high-concentration Cr (VI) and quickly and efficiently reducing Cr (VI). The Cr (VI) reducing strain C6 can tolerate the growth condition that the Cr (VI) concentration is 1000mg/L, and the reduction efficiency of the Cr (VI) can reach more than 85 percent within 18h under the condition of high Cr (VI) concentration; under the condition that the initial concentration of Cr (VI) is 100mg/L, the reduction efficiency of the strain to Cr (VI) can reach more than 99.9 percent within 18 hours.

Meanwhile, the Cr (VI) reducing strain C6 provided by the invention has strong environmental adaptability, good environmental safety, no pathogenicity to human body, low culture cost, small inoculation amount in Cr (VI) reduction, no secondary pollution and extremely high industrial popularization and application values.

The invention also provides application of the Cr (VI) reducing strain C6 in treatment of Cr (VI) polluted wastewater or Cr (VI) polluted soil.

The Cr (VI) reducing strain C6 provided by the invention has strong environmental adaptability, can be rapidly propagated in Cr (VI) polluted wastewater and Cr (VI) polluted soil, can be used for efficiently reducing Cr (VI) in the wastewater or the soil, and has extremely high application value.

The invention also provides application of the Cr (VI) reducing strain C6 strain in preparation of a Cr (VI) polluted wastewater treatment agent or a Cr (VI) polluted soil treatment agent.

The invention also provides a culture medium for culturing the Cr (VI) reducing strain C6, wherein each liter of the culture medium comprises: 19-20g of tryptone, 4-6g of yeast powder, 5-6g of NaCl and 8-12mL of glycerol; the pH value is 7.8-8.2.

Preferably, per liter of said medium comprises: 19.8g of tryptone, 5g of yeast powder, 5.5g of NaCl and 10mL of glycerol; the pH was 8.0.

The preferable culture medium formula used by the Cr (VI) reducing strain C6 can further improve the propagation speed of the Cr (VI) reducing strain C6 and ensure that the reduction rate of Cr (VI) is close to 100 percent.

The invention also provides a culture condition of the Cr (VI) reducing strain C6, wherein the inoculation volume is 5-10%, the culture temperature is 28-32 ℃, the rotation speed is 150-250r/min, and the liquid loading volume of the culture medium is 25-35%.

Preferably, in the culture conditions, the inoculation amount is 5%, the culture temperature is 31 ℃, the rotating speed is 220r/min, and the volume of the culture medium liquid is 30%.

The preferable culture conditions for the Cr (VI) reducing strain C6 can further improve the propagation rate of the Cr (VI) reducing strain C6 and the Cr (VI) reducing efficiency.

Drawings

FIG. 1 is a graph showing the growth curve and the Cr (VI) reducing characteristics of a Cr (VI) reducing strain C6 at a Cr (VI) concentration of 100mg/L according to an embodiment of the present invention;

FIG. 2 is a colony morphology of Cr (VI) reducing strain C6 in the examples of the present invention;

FIG. 3 is a gram stain of Cr (VI) reducing strain C6 in the examples of the present invention;

FIG. 4 is a phylogenetic tree of Cr (VI) reducing strain C6 constructed in the examples of the present invention;

FIG. 5 is a graph showing the growth curve of Cr (VI) reducing strain C6 under high Cr (VI) concentration conditions and the characteristic of Cr (VI) reduction in the examples of the present invention;

FIG. 6 is a graph showing the growth of Cr (VI) reducing strain C6 in various Cr (VI) concentrations in the medium according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1

1. Materials and methods

1.1 materials

1.1.1 sources of Strain

In 2018, in Luan Shijiazhuang urban chromium salt factory, a sampling shovel is used for taking surface soil with the surface of 1.0cm seriously polluted by stone, removing impurities such as stones and the like in the soil, and putting about 200g of the soil into a sterile sampling bag. Storing at-20 deg.C for use.

1.1.2 reagents and instruments

Na₂CrO₄Tryptone, yeast powder, agar, NaCl and glycerol.

Electronic balance, double jie test instrument factory, ever-maturing city;

analytical balance, mettler-toledo (shanghai) ltd;

electronic pH meter, aohaus (shanghai) ltd;

magnetic stirrers, jintan city naborism instruments, Jiangsu province;

pipettors, dalong medical devices, ltd;

refrigerator, hel corporation;

ultra-low temperature freezing storage case, Miao national Mirabilitum;

a single-person single-side vertical purification workbench, a vertical pressure steam sterilizer and a Shanghai medical equipment factory of Bocheng industries, Ltd;

constant temperature culture shaker, shanghai zhicheng analytical instruments manufacturing ltd;

ultraviolet-visible spectrophotometer, Shanghai chromatography instruments ltd;

microscope, Motic;

shaking table.

1.1.3 culture Medium

LB medium (g/L): tryptone 10.0, yeast powder 5.0, NaCl 10.0, pH 7.0; 1X 10⁵Pa sterilizing for 30 min.

LB solid medium: and adding 10g of agar into the LB culture medium to obtain the LB solid culture medium.

Cr (VI) reducing strain C6 optimized culture medium (g/L): tryptone 19.8, yeast powder 5.0, NaCl 5.5, glycerol 10mL,pH 8.0；1×10⁵pa sterilizing for 30 min.

Cr (VI) reducing strain C6 solid optimization culture medium: and adding agar 10g into the optimized culture medium of the Cr (VI) reducing strain C6 to obtain the solid culture medium of the Cr (VI) reducing strain C6.

1.2 methods

1.2.1 isolation and purification of the Strain

And (3) adding 10g of the soil sample collected in 1.1.1 into a 100mL sterile water triangular flask filled with glass beads, manually oscillating and smashing for 10min, standing for a moment, taking out 1mL of liquid, adding the liquid into an LB culture medium triangular flask filled with 100mg/L Cr (VI), and culturing for 24h at 160r/min in an incubator at 28 ℃ to obtain an enriched bacterial liquid. Diluting and coating the enriched bacterial liquid by a flat plate method with 10 percent^-3、10^-4、10^-5、10^-6The four dilution concentration gradients are coated on an LB solid medium plate with the Cr (VI) content of 100mg/L, and the primary screening is carried out by inverted culture at 30 ℃. Colonies were purified (3-4 replicates streaks) and stored after single colonies were obtained.

6 monoclonal strains which have good growth condition and large bacterial colony and can grow in a culture medium containing 100mg/L Cr (VI) are obtained through primary screening culture and are respectively named as C1 to C6.

1.2.2 Strain growth Curve and Cr (VI) reduction Properties

Inoculating the selected 6 monoclonal bacteria into LB culture medium, culturing at 160r/min and 28 deg.C to OD₆₀₀The nm value was 1.0, 1.5mL, 2.5mL, 3.5mL and 5mL of the culture broth were added to 50mL (20% liquid content) of LB medium in an inoculation volume of 3%, 5%, 7% and 10%, respectively, and Na was added₂CrO₄0.3115, the initial Cr (VI) concentration was set at 100mg/L, the culture was carried out at 160r/min28 ℃, and the OD of the medium was measured periodically₆₀₀And nm and the Cr (VI) content in the strain, and drawing a thallus growth curve and a Cr (VI) content curve to verify the reduction capability of different strains on the Cr (VI).

As a result, the optimal inoculation amounts of 6 strains of bacteria are respectively 5%, 3%, 7% and 5%; the best inoculation amount of each strain is used for respective transfer culture, the growth conditions of the strains C2 and C6 are the best, and the growth and reproduction speed of C6 is the fastest. The C6 strain with high propagation speed and high Cr (VI) reduction rate is stored in an ultra-low temperature refrigerator at minus 80 ℃ for standby.

And culturing the same batch of fermentation medium under the same condition with the inoculated bacteria, wherein the Cr (VI) content in the non-inoculated culture medium is a blank control group, and the Cr (VI) reduction rate is calculated as the percentage of the Cr (VI) content of the blank control group minus the residual Cr (VI) content of the experimental group to the Cr (VI) content of the blank control group. The results showed that the C6 strain of the 6 strains had the best ability to reduce Cr (VI).

Inoculating the selected C6 monoclonal bacteria into LB culture medium with initial Cr (VI) concentration of 100mg/L, culturing at 160r/min and 28 deg.C to OD₆₀₀The nm value is 1.0, the inoculum size is 5%, 2.5mL of bacterial liquid is absorbed and added into 50mL (liquid loading is 20%) of LB culture medium, the culture is carried out at 160r/min and 28 ℃, and the OD of the culture medium is measured every 2h₆₀₀nm and the Cr (VI) content in the strain, and drawing a thallus growth curve and a Cr (VI) content curve, as shown in figure 1. The result shows that when the inoculation culture is carried out for 18 hours, the thalli are propagated to enter a stable phase; the thallus reproduction and the reduction of Cr (VI) are synchronously carried out; when the thalli are propagated into a stable period, the reduction amount of Cr (VI) is basically stable, and the reduction amount of the strain to Cr (VI) is not greatly improved after 18 hours. Therefore, when the initial Cr (VI) concentration is 100mg/L, the reduction rate of the C6 strain to Cr (VI) can reach more than 99% after 18h of culture.

After the culture is finished, the total chromium content in the culture medium is basically unchanged compared with the initial stage, and the Cr (VI) content is continuously reduced. Three approaches for microbial Cr (VI) reduction have been reported: one is that the cell utilizes Cr (vi) as the final electron acceptor of the respiratory chain (but under anaerobic conditions); secondly, soluble enzyme in the microorganism directly reduces Cr (VI) into Cr (III); thirdly, the reduction of Cr (vi) is caused by metabolites of certain microorganisms. The strain C6 can reduce Cr (VI) in large quantity under aerobic condition, and the reduction of Cr (VI) and the growth and reproduction of Cr (VI) are synchronously carried out without delay, so the Cr (VI) is not caused by metabolites of Cr (VI). It is assumed that the reduction of Cr (VI) by the strain C6 is that the soluble enzyme in vivo directly reduces Cr (VI) to Cr (III). The larger the growth and reproduction amount of the cells, the stronger the reduction capability to Cr (VI).

1.2.3 morphological and physiological and biochemical identification of cells

The isolated and purified monoclonal strain C6 was formed into irregular smooth colonies with white round, slightly transparent edges on LB solid medium, as shown in FIG. 2, and was easily picked up. The gram stain results are shown in figure 2. The results showed that strain C6 was a gram-positive bacterium. Physiological and biochemical tests were carried out according to the manual for identifying common bacteria systems, and the results of the physiological and biochemical tests of the obtained strain C6 are shown in Table 1.

TABLE 1 physiological and biochemical Properties of Strain C6

1.2.4 extraction and identification of bacterial 16S rRNA

Inoculating the monoclonal strain C6 into LB culture medium, culturing at 28 deg.C and 160r/min overnight, placing 1mL culture solution into a centrifuge tube, centrifuging at 12000r/min for 2min, removing supernatant, collecting thallus, rinsing with sterile water, and extracting DNA with bacterial genome kit.

And performing PCR amplification on the 16S rRNA gene of the bacteria by taking the extracted DNA as a template, wherein the general amplification primer is 27F: 5'-AGAGTTTGATCCTGGCTCAG-3' (SEQ ID NO:1) and 1492R: 5'-GGTTACCTTGTTACGACTT-3' (SEQ ID NO:2), the PCR reaction system is shown in Table 2, and the PCR reaction conditions are shown in Table 3.

TABLE 2 PCR reaction System

TABLE 3 PCR reaction conditions

After the PCR product was detected by 1.5% agarose gel electrophoresis, 16S rRNA gene sequence of the strain C6 was subjected to two-way sequencing by the Token Biotech engineering (Shanghai) Co., Ltd. After splicing the sequenced 16S r RNA gene sequences, the 16S rRNA gene sequence of the strain C6 is shown as SEQ ID NO:3, and BLASTn (www.ncbi.nlm.nih.gov/BLAST) similarity alignment is carried out on the 16S rRNA gene sequence. The BLAST alignment is downloaded for the strain sequences with higher sequence similarity, the MEGA 5.05 software is used to calculate the sequence similarity, meanwhile, the adjacency-joining method is used to construct the phylogenetic tree of the strain, the phylogenetic status of the species is determined, and the constructed phylogenetic tree is shown in fig. 4.

1.2.5 Strain C6 Medium optimization

Through medium composition investigation experiments, the optimal carbon source, nitrogen source and inorganic salt species of the cultured strain C6 are respectively determined. Determined optimal fermentation medium-Cr (VI) reducing strain C6 optimal medium (g/L): tryptone 19.8, yeast powder 5.0, NaCl 5.5, glycerol 10mL, pH 8.0.

1.2.6 optimization of culture conditions for Strain C6

The monoclonal strain C6 was inoculated in LB medium and cultured at 28 ℃ at 160r/min to an OD600nm value of 1.0 as a seed solution. The influence on the growth and the propagation of the strain C6 after culturing for 18h under different temperatures, pH, rotating speed, inoculum size and liquid loading amount is researched, and the optimal culture conditions of the strain C6 are determined as follows: the inoculation amount is 5 percent, the culture temperature is 31 ℃, the rotating speed is 220r/min, the volume of the culture medium is 30 percent, and Ph8.0.

1.2.7 Cr (VI) concentration tolerance analysis of Strain C6 in optimal Medium and culture conditions

The Na2CrO4 in the optimized culture medium is respectively adjusted to be 0.623g/L, 0.935g/L, 1.25g/L, 1.56g/L and 3.12g/L, so that the Cr (VI) concentration in the optimized culture medium is respectively 200mg/L, 300mg/L, 400mg/L, 500mg/L and 1000 mg/L.

Inoculating C6 monoclonal strain into initial Cr (VI) concentrationCulturing at 31 deg.C to OD at 220r/min in optimized culture medium of 100mg/L₆₀₀The nm value is 1.0, 2.5mL of bacterial liquid is respectively sucked according to the inoculation amount of 5 percent, added into 75mL (the liquid loading amount is 30 percent) of 5 kinds of Cr (VI) culture media with different Cr (VI) concentrations of 200mg/L, 300mg/L, 400mg/L, 500mg/L and 1000mg/L respectively, and cultured at 220r/min and 31 ℃ for 18h to determine the content of Cr (VI) in the media, thereby verifying the tolerance and the reducing capability of the C6 strain to high-concentration Cr (VI). And culturing the same batch of fermentation medium under the same condition with the inoculated bacteria, wherein the Cr (VI) content in the non-inoculated culture medium is a blank control group, and the Cr (VI) reduction rate is calculated as the percentage of the Cr (VI) content of the blank control group minus the residual Cr (VI) content of the experimental group to the Cr (VI) content of the blank control group.

The result of detecting the reduction rate of the C6 strain on Cr (VI) is shown in figure 5, when the concentration of Cr (VI) is 200mg/L, the reduction rate of Cr (VI) can reach 98.9 percent after culturing for 18 hours, and the thallus reproduction reaches the maximum value; when the concentration of Cr (VI) is more than 300mg/L, the reproduction of thalli is inhibited, but the reduction capability of Cr (VI) is still more than 95 percent; when the Cr (VI) concentration reaches 1000mg/L, the Cr (VI) reduction rate can still reach more than 85 percent.

The presence of Cr (VI) in the medium favours the activation of the chromium reductase of strain C6. As shown in figure 5, when the strain C6 is cultured under the initial condition of 100mg/L Cr (VI) for the first time and then is transferred to a Cr (VI) culture medium with higher concentration, the reduction efficiency of the strain to Cr (VI) is obviously improved, about 90% can be achieved after 9 hours, and the basic principle of reducing Cr (VI) by the strain C6 is the substrate induced reductase generated by the strain.

The growth of the C6 strain in the blank control group and 5 media with Cr (VI) concentrations of 200mg/L, 500mg/L, 800mg/L and 1000mg/L respectively is shown in FIG. 6, and it can be seen that the C6 strain can continue to grow even when the Cr (VI) concentration is 1000 mg/L. It is considered that a microorganism capable of tolerating Cr (VI) at a concentration of 10.4mg/L is referred to as a Cr (VI) -resistant microorganism. Obviously, the strain C6 is a Cr (VI) resistant microorganism, and the tolerance of Cr (VI) reaches more than 1000 mg/L.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents or improvements made within the spirit and principle of the present invention should be included in the scope of the present invention.

SEQUENCE LISTING

<110> university of Hebei science and technology

<120> Cr (VI) reducing strain C6, and culture condition and application thereof

<130> 2020

<160> 3

<170> PatentIn version 3.5

<210> 1

<211> 20

<212> DNA

<213> 27F

<400> 1

agagtttgat cctggctcag 20

<210> 2

<211> 19

<212> DNA

<213> 1492R

<400> 2

ggttaccttg ttacgactt 19

<210> 3

<211> 1468

<212> DNA

<213> 16S rRNA

<400> 3

tcaggatgaa cgctggcggc gtgcctaata catgcaagtc gagcgaatgg attaagagct 60

tgctcttatg aagttagcgg cggacgggtg agtaacacgt gggtaacctg cccataagac 120

tgggataact ccgggaaacc ggggctaata ccggataaca ttttgaaccg catggttcga 180

aattgaaagg cggcttcggc tgtcacttat ggatggaccc gcgtcgcata gctagttggt 240

gaggtaacgg ctcaccaagg caacgatgcg tagccgactg agagggtgat cggccacact 300

gggactgaga cacggcccca gactcctacg ggaggcagca gtagggaatc ttccgcaatg 360

gacgaaagtc tgacggagca acgccgcgtg agtgatgaag gctttcgggt cgtaaaactc 420

tgttgttagg gaagaacaag tgctagttga ataagctggc accttgacgg tacctaacca 480

gaaagccacg gctaactacg tgccagcagc cgcggtaata cgtaggtggc aagcgttatc 540

cggaattatt gggcgtaaag cgcgcgcagg tggtttctta agtctgatgt gaaagcccac 600

ggctcaaccg tggagggtca ttggaaactg ggagacttga gtgcagaaga ggaaagtgga 660

attccatgtg tagcggtgaa atgcgtagag atatggagga acaccagtgg cgaaggcgac 720

tttctggtct gtaactgaca ctgaggcgcg aaagcgtggg gagcaaacag gattagatac 780

cctggtagtc cacgccgtaa acgatgagtg ctaagtgtta gagggtttcc gccctttagt 840

gctgaagtta acgcattaag cactccgcct ggggagtacg gccgcaaggc tgaaactcaa 900

aggaattgac gggggcccgc acaagcggtg gagcatgtgg tttaattcga agcaacgcga 960

agaaccttac caggtcttga catcctctga caaccctaga gatagggctt ctccttcggg 1020

agcagagtga caggtggtgc atggttgtcg tcagctcgtg tcgtgagatg ttgggttaag 1080

tcccgcaacg agcgcaaccc ttgatcttag ttgccatcat ttagttgggc actctaaggt 1140

gactgccggt gacaaaccgg aggaaggtgg ggatgacgtc aaatcatcat gccccttatg 1200

acctgggcta cacacgtgct acaatggacg gtacaaagag ctgcaagacc gcgaggtgga 1260

gctaatctca taaaaccgtt ctcagttcgg attgtaggct gcaactcgcc tacatgaagc 1320

tggaatcgct agtaatcgcg gatcagcatg ccgcggtgaa tacgttcccg ggccttgtac 1380

acaccgcccg tcacaccacg agagtttgta acacccgaag tcggtggggt aacctttttg 1440

gagccagccg cctaaggtgg gacagatg 1468

Claims

1. A Cr (VI) reducing strain C6, which is characterized in that: the strain belongs to Bacillus (Bacillus sp.) and the preservation number of the strain is CGMCC No. 20390.

2. The use of the Cr (vi) reducing strain C6 according to claim 1 in the treatment of Cr (vi) contaminated wastewater or Cr (vi) contaminated soil.

3. The use of the Cr (vi) reducing strain C6 according to claim 1 in the preparation of a Cr (vi) contaminated wastewater treatment agent or a Cr (vi) contaminated soil treatment agent.