Application of 8-hydroxyquinoline in prevention and treatment of cyanobacterial bloom

Abstract

The invention discloses application of 8-hydroxyquinoline in prevention and treatment of cyanobacterial bloom, and belongs to the technical field of environmental protection. The method comprises the following steps: 1) dissolving 8-hydroxyquinoline in dimethyl sulfoxide to prepare a solution with the concentration of 0.8-1mM; and 2) adding the 8-hydroxyquinoline solution prepared in the step 1) into a water body with blue-green algae outbreak according to a volume ratio of 0.1% (final concentration of 0.8-1 [mu] M), wherein the algae are subjected to mass death. 8-hydroxyquinoline has a remarkable killing effect on water-blooming cyanobacteria, and the removal rate of 0.9 mu M of 8-hydroxyquinoline on severe cyanobacterial blooms (the algae density is about 5 * 10 < 8 > cells / L) reaches 100%. 8-hydroxyquinoline has a destructive effect on a photosynthetic system of blue-green algae.

Description

Technical Field

[0001] The invention relates to the field of ecological protection, and in particular to application of 8-hydroxyquinoline in preventing and controlling blue algae blooms. Background Art

[0002] In recent years, due to factors such as eutrophication of water bodies, rising CO2 levels and global climate change, cyanobacteria have frequently erupted around the world, forming cyanobacterial blooms, which have seriously affected the aquatic environment and biological health, caused serious economic losses and harm to human society, and have become a global environmental problem that needs to be urgently addressed.

[0003] The prevention and control of cyanobacteria blooms include two aspects: prevention and control. At present, the main means of prevention are nutrient control and hydrodynamic condition control; in terms of control, the methods mainly include physical control, chemical control and biological control. With the in-depth study of metabolites and allelopathic effects, natural active products have become a promising control method.

[0004] The physical treatment method is to use certain equipment or devices to separate or destroy algae cells. After the algal bloom appears, a large amount of algae floats on the water surface. The original method is to remove them by manual salvage, but it is time-consuming and labor-intensive. In recent years, some new physical algae removal methods have also been developed, such as ultrasonic technology, filtration separation, and flotation algae removal. However, these methods generally have the problems of large labor input, equipment input, and energy consumption, and there are problems such as incomplete removal and easy recurrence, which are not suitable for large-scale application.

[0005] Chemical treatment usually achieves the effect of inhibiting or killing algae by adding other chemical products or minerals to the water body of algae bloom. Common methods include adding flocculants and algaecides. There are a large number of negatively charged amines, carboxyls and hydroxyls on the surface of algae cells. Cationic flocculants can aggregate cells through electrical neutralization, thereby increasing the average particle size and sedimentation coefficient of algae to achieve the purpose of flocculation and sedimentation to inhibit algae growth. At present, commonly used flocculants include iron salts, aluminum salts and clays, etc., and biopolymers and other natural substances have also been developed as flocculants, such as chitosan. In freshwater ecosystems, some chemical agents, such as ozone, CuSO4, diuron, NaOCl, H2O2, etc., are widely used to control harmful blue algae blooms due to their significant algae inhibition effects. Although chemical algaecides can effectively remove algae cells, they have poor selectivity and will have a destructive effect on all aquatic organisms, affecting the water ecology.

[0006] Biological methods aim to establish healthy aquatic ecosystems through the competition and ingestion of harmful algae by aquatic animals, plants and microorganisms. Due to its sustainable development characteristics, this method is regarded as an important prevention and control strategy for harmful algal blooms. Among biological methods, algicidal bacteria are the most widely used. Although algicidal bacteria are environmentally friendly and have great application potential, it is a relatively difficult process to maintain a sufficient bacterial concentration in situ to effectively kill algal bloom cells due to the differences in growth conditions of bacteria and cyanobacteria.

[0007] Algae removal by active products secreted by algae, plants and microorganisms (including chemicals, lipids, peptides and enzymes, etc.) has become an important part of algae removal research. At present, the research on the inhibition or removal of cyanobacteria by active products is mostly focused on the growth, lysis, physiological and biochemical aspects of cyanobacteria by crude or extracted mixtures, and the identification of effective components in crude mixtures, especially the identification and functional verification of single pure substances, is lacking. Summary of the invention

[0008] The present invention provides an application of a pure substance (8-hydroxyquinoline) in preventing and controlling blue algae blooms, which solves the problems of large investment in traditional physical treatment of blue algae blooms, unfriendly chemical treatment environment, and poor in-situ biological treatment. The technical solution adopted by the present invention is as follows:

[0009] The first object of the present invention is to provide application of 8-hydroxyquinoline in preventing and controlling blue algae blooms.

[0010] Preferably, the concentration of 8-hydroxyquinoline is 0.8-1 μM.

[0011] Preferably, the 8-hydroxyquinoline is dissolved in dimethyl sulfoxide.

[0012] Preferably, the cyanobacteria is Microcystis aeruginosa.

[0013] Preferably, the control is by reducing the photosynthetic efficiency of cyanobacteria or reducing the concentration of chlorophyll a.

[0014] The second object of the present invention is to provide a method for preventing and controlling cyanobacteria blooms, which uses 8-hydroxyquinoline to prevent and control cyanobacteria blooms.

[0015] Preferably, the concentration of 8-hydroxyquinoline is 0.8-1 μM, and the cyanobacteria is Microcystis aeruginosa.

[0016] Preferably, the concentration of 8-hydroxyquinoline is 0.9 μM.

[0017] Preferably, the specific steps are as follows:

[0018] A. Dissolve 8-hydroxyquinoline in dimethyl sulfoxide to prepare a solution with a concentration of 0.8-1 mM;

[0019] B. Add the 8-hydroxyquinoline solution prepared in step A into the water body with blue algae outbreak at a volume ratio of 0.1%, with a final concentration of 0.8-1 μM;

[0020] C. Physical disturbance is used to make 8-hydroxyquinoline evenly distributed in the cyanobacteria water body;

[0021] The initial algae density of cyanobacteria is about 5×10 8 cells / L (chlorophyll a concentration of 174.38μg / L), the temperature of the cyanobacteria water body is 26℃, the pH is 7-10.5, and the dissolved oxygen is 1-5mg / L. If the temperature is lower than 5℃, the concentration of 8-hydroxyquinoline should be appropriately increased.

[0022] The third object of the present invention is to provide an algae-lytic biological agent, which uses 8-hydroxyquinoline as the main algae-lytic component.

[0023] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0024] 1.8-Hydroxyquinoline has excellent killing effect on cyanobacteria. 0.9 μM 8-Hydroxyquinoline can achieve severe cyanobacterial bloom (algae density is about 5×10 8 cells / L).

[0025] 2.8-Hydroxyquinoline is more environmentally safe than chemical algaecides, and compared with biological algaecide, it overcomes the limitation of needing to provide a living environment for algae-dissolving organisms.

[0026] 3.8-Hydroxyquinoline can be biosynthesized or obtained through chemical synthesis, and has great potential for popularization of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The removal effect of different concentrations of 8-hydroxyquinoline on Microcystis aeruginosa (a, change of chlorophyll a; b, removal rate of chlorophyll a).

[0028] Figure 2 This is the fast fluorescence kinetic curve of chlorophyll in Microcystis aeruginosa.

[0029] Figure 3 It is the change of photosynthetic parameters of Microcystis aeruginosa. DETAILED DESCRIPTION

[0030] The following examples are further explanations of the present invention, but are not intended to limit the present invention. The experimental methods in the following examples are conventional experimental methods unless otherwise specified, and the experimental reagents and consumables described in the following examples are from conventional biochemical reagent companies unless otherwise specified.

[0031] Embodiment 1:

[0032] The application of 8-hydroxyquinoline to treat severe cyanobacteria blooms is as follows:

[0033] A. After the Microcystis aeruginosa was cultured in BG11 medium to the logarithmic growth phase, it was washed and inoculated into a water body with water quality close to Class V surface water, so that the number of algal cells was about 5×10 8 cells / L (chlorophyll a concentration was 174.38μg / L).

[0034] B. Set up 9 experimental groups and 1 control group (adding dimethyl sulfoxide). Dissolve 8-hydroxyquinoline in dimethyl sulfoxide to prepare 8-hydroxyquinoline solutions with concentrations of 0.1mM, 0.2mM, 0.4mM, 0.5mM, 0.6mM, 0.7mM, 0.8mM, 0.9mM, and 1mM, respectively, and add the above 8-hydroxyquinoline solutions to the experimental groups at a volume ratio of 0.1% to make their final concentrations 0.1μM, 0.2μM, 0.4μM, 0.5μM, 0.6μM, 0.7μM, 0.8μM, 0.9μM, and 1μM, respectively. Add dimethyl sulfoxide to the experimental group at a volume ratio of 0.1%, and the frequency of addition is 1 time, so that 8-hydroxyquinoline is evenly distributed by physical disturbance. Then test the changes in chlorophyll a in the water body every day to reflect the growth of algae. The temperature of the cyanobacteria water body is: 26℃; pH range is: 7-10.5; dissolved oxygen: 1-5mg / L. If the temperature is lower than 5℃, the concentration of 8-hydroxyquinoline should be appropriately increased.

[0035] C. The 1 μM addition group was sampled at 0 h and 24 h for chlorophyll fluorescence test analysis. After the samples were subjected to a 20-min dark reaction, a handheld chlorophyll fluorescence meter (AquapenAP110 / C, Czech Republic) was used to perform a rapid chlorophyll fluorescence kinetic test, and relevant photosynthetic system parameters were obtained, including the maximum light quantum yield Fv / Fm, the electron transfer light quantum flux ratio ψ0 in the captured light quantum, and the electron transfer light quantum yield Energy dissipation light quantum yield

[0036] The results showed that after adding 8-hydroxyquinoline, the growth of algae was inhibited to varying degrees. Figure 1 It can be seen that after treatment with 0.9 μM 8-hydroxyquinoline, the chlorophyll a concentration in the system dropped to 0 μg / L on the 5th day, and the removal rate reached 100%. Figure 2 It shows that after treatment with 1 μM 8-hydroxyquinoline, the algae chlorophyll fluorescence kinetic curve loses its curve characteristics. Figure 3 The results showed that the photosynthetic efficiency of algae decreased after treatment with 1 μM 8-hydroxyquinoline. Figure 2 and Figure 3This indicates that 8-hydroxyquinoline can have a strong destructive effect on the photosynthetic system of algae and reduce photosynthetic efficiency. Figure 1 , Figure 2 and Figure 3 The results showed that 8-hydroxyquinoline has a significant effect on the removal of cyanobacteria.

Claims

1. Application of 8-hydroxyquinoline in preventing and controlling cyanobacterial blooms.

2. The use according to claim 1, characterized in that: The concentration of the 8-hydroxyquinoline is 0.8-1 μM.

3. The use according to claim 1 or 2, characterized in that: The 8-hydroxyquinoline is dissolved in dimethyl sulfoxide.

4. The use according to claim 1, characterized in that: The cyanobacteria is Microcystis aeruginosa.

5. The use according to claim 1, characterized in that: The control is carried out by reducing the photosynthetic efficiency of cyanobacteria or reducing the concentration of chlorophyll a.

6. A method for preventing and controlling cyanobacterial blooms, characterized in that: Use 8-hydroxyquinoline to control algae blooms.

7. The method according to claim 6, characterized in that The concentration of the 8-hydroxyquinoline is 0.8-1 μM, and the cyanobacteria is Microcystis aeruginosa.

8. The method according to claim 6 or 7, characterized in that: The concentration of 8-hydroxyquinoline is 0.9 μM.

9. The method according to claim 6, characterized in that The specific steps are as follows: A. Dissolve 8-hydroxyquinoline in dimethyl sulfoxide to prepare a solution with a concentration of 0.8-1 mM; B. Add the 8-hydroxyquinoline solution prepared in step A into the water body with blue algae outbreak at a volume ratio of 0.1%, with a final concentration of 0.8-1 μM; C. Physical disturbance is used to make 8-hydroxyquinoline evenly distributed in the cyanobacteria water body; The initial algae density of cyanobacteria is 5×10 8 cells / L, the temperature of the cyanobacteria water body is 26℃, the pH is 7-10.5, and the dissolved oxygen is 1-5mg / L.

10. An algicidal biological agent, characterized in that: 8-Hydroxyquinoline is the main algae-dissolving component.

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