A method for controlling cyanobacterial blooms based on cytochrome b6f complex inhibitors and its application

Abstract

This invention discloses a method for controlling cyanobacterial blooms based on a cytochrome B6F complex inhibitor and its application, relating to the field of cyanobacterial bloom control technology. The method includes: chlorinating water containing cyanobacteria; adding a cytochrome B6F complex inhibitor to the water; wherein the cytochrome B6F complex inhibitor is DBMIB; by performing emergency chlorination on cyanobacterial cells followed by adding DBMIB to synergistically inhibit the activity of the cyanobacterial cytochrome B6F complex, blocking the photosynthetic electron transport chain, and inducing cyanobacteria to enter a functional inactivation state, thereby achieving long-term inhibition of their growth. This allows cyanobacteria to maintain a low density for up to two months, exhibiting high ecological safety and significant inhibition effect.

Description

Technical Field

[0001] This invention relates to the field of cyanobacterial bloom control technology, specifically to a method for controlling cyanobacterial blooms based on a cytochrome b6f complex inhibitor and its application. Background Technology

[0002] Cyanobacterial blooms are a global water environment problem, among which toxin-producing cyanobacteria such as Microcystis aeruginosa pose the most prominent threat to ecosystems and human health.

[0003] Cyanobacterial blooms can cause a chain reaction of damage to aquatic ecosystems and water resource utilization. Ecologically, the massive proliferation and death of algae leads to oxygen depletion in the water, mass mortality of organisms, and the collapse of aquatic systems due to food chain disruption. In water treatment, high-density algal cells directly interfere with coagulation processes, significantly increasing the difficulty of water treatment. Furthermore, the algal toxins and odor-causing substances released by dying cyanobacteria not only poison aquatic organisms but also accumulate in aquatic products through bioaccumulation, ultimately posing a serious threat to water supply safety and human health.

[0004] Currently, the selection of oxidants requires a trade-off between the effectiveness of inhibiting algal blooms and ecological safety. Among commonly used oxidants for algal bloom control, high-concentration chlorination can kill algal cells, but it easily leads to cell lysis and the release of intracellular toxins, causing secondary pollution. While low-concentration chlorination can delay algal cell growth, cyanobacteria can quickly regain activity within a few days, making long-term control impossible. Therefore, there is a need to develop a novel method for controlling algal blooms that is effective in the long term in inhibiting cyanobacterial growth. Summary of the Invention

[0005] The purpose of this invention is to provide a method for controlling cyanobacterial blooms based on cytochrome B6F complex inhibitors and its application, in order to solve the problem of short bloom inhibition period in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for controlling cyanobacterial blooms based on a cytochrome B6F complex inhibitor, comprising the following steps:

[0007] S1. Chloride the water containing cyanobacteria;

[0008] S2. Add cytochrome b6f complex inhibitors to the water body;

[0009] The cytochrome b6f complex inhibitor is DBMIB (2,5-dibromo-3-isopropyl-6-methyl-p-benzoquinone).

[0010] The chlorination treatment and the cytochrome b6f complex inhibitor synergistically inhibit the photosynthetic electron transport chain of cyanobacteria, thereby inhibiting cyanobacterial growth in the long term.

[0011] Furthermore, the cyanobacteria include the genus Microcystis.

[0012] Furthermore, the chlorinating agent used in the chlorination treatment is sodium hypochlorite, with a treatment concentration of 1-3 mg / L and a treatment time of 0.5-2 hours.

[0013] Furthermore, the concentration of DBMIB added is 10-20 μM.

[0014] An application of a cyanobacterial bloom control method based on cytochrome B6F complex inhibitors in controlling cyanobacterial blooms in lakes, reservoirs, or freshwater bodies.

[0015] Furthermore, the application involves adding the chlorinating agent and DBMIB at the initial stage of a cyanobacterial bloom or during an emergency treatment period.

[0016] Compared with existing technologies, this invention provides a method for controlling cyanobacterial blooms based on cytochrome B6F complex inhibitors and its application. This method involves emergency chlorination treatment of cyanobacterial cells followed by the addition of DBMIB (2,5-dibromo-3-isopropyl-6-methyl-p-benzoquinone) to synergistically inhibit the activity of the cyanobacterial cytochrome B6F complex, blocking the photosynthetic electron transport chain and inducing cyanobacteria into a functionally inactive state. This achieves long-term inhibition of cyanobacteria growth, allowing them to maintain a low-density state for up to two months. The method exhibits high ecological safety and significant inhibitory effects. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0018] Figure 1 This is a comparison diagram of Microcystis cell density provided in an embodiment of the present invention;

[0019] Figure 2 The absorption spectrum of Microcystis cells provided in the embodiments of the present invention;

[0020] Figure 3 The fluorescence emission spectrum of Microcystis cells provided in the embodiments of the present invention;

[0021] Figure 4A comparison chart of chlorophyll a concentration in Microcystis aeruginosa provided in an embodiment of the present invention;

[0022] Figure 5 A comparison chart of phycocyanin concentrations from Microcystis aeruginosa provided in an embodiment of the present invention;

[0023] Figure 6 A comparison chart of the actual quantum yield of the Microcystis photosystem II provided in an embodiment of the present invention. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] Microcystis aeruginosa strain FACHB-905 was used. Microcystis cells were cultured in BG11 medium in a light-simulated incubator under natural conditions: a light-dark cycle of 12:12 hours, and parameters set to white light intensity of 30-35 μmol·m⁻¹. -2 ·s -1 The temperature is 28℃.

[0026] Example 1:

[0027] Please see Figure 1-2 Microcystis aeruginosa FACHB-905 cells cultured to the logarithmic growth phase were diluted to 1×10⁻⁶. 6 Cells / mL, a chlorination control group (treated with 2 mg / L sodium hypochlorite) and two experimental groups were set up: chlorination treatment (treated with 2 mg / L sodium hypochlorite) followed by the addition of 10 μM DBMIB inhibitor and 20 μM DBMIB inhibitor, respectively, and placed in a light incubator for continuous observation.

[0028] Chlorination was performed using sodium hypochlorite solution at a final chlorine concentration of 2 mg / L for 1 hour. The inhibitor DBMIB was prepared as a 50-100 mM stock solution using DMSO, which was then added to 1 L of cell suspension to achieve a final concentration of 10-20 μM. A DMSO concentration below 0.02% (v / v) had no effect on cell characteristics. Cells were counted using an Olympus microscope at 400x magnification, and the optical density (OD) at 750 nm was measured using a spectrophotometer. 750 (To monitor cell growth)

[0029] Figure 1 (a) Comparison of Microcystis cell density between the chlorination group (2 mg / L) (control group) and the chlorination group (2 mg / L) + 10 μM DBMIB treatment group; Figure 1(b) Comparison of Microcystis cell density between the chlorination group (2 mg / L) (control group) and the chlorination (2 mg / L) + 20 μM DBMIB treatment group. Figure 2 (a) shows the absorption spectra of Microcystis cells after low-chlorine treatment (control group) for different days; Figure 2 (b) shows the absorption spectra after low-chlorine treatment + 10 μM DBMIB for different days; Figure 2 (c) shows the absorption spectra of different days after low-chlorine treatment + 20 μM DBMIB treatment. The absorbance of each spectrum is equal at 750 nm. For clarity, the spectral positions are all shifted upward by 0.2. Among them, the 2-unchlorinated control is the spectrum of the control group that was not treated with chlorination on day 2.

[0030] Results: Cyanobacteria in the chlorination group began to recover after the third day, while those in the inhibitor group only began to recover after 27-35 days, achieving long-term inhibition of cyanobacterial growth. Within 1-44 days, the cell density inhibition rate in the chlorination (2 mg / L) + 10 μM DBMIB inhibitor group ranged from 18.94% to 99.18%, while the cell density inhibition rate in the chlorination (2 mg / L) + 20 μM DBMIB inhibitor group ranged from 25.32% to 99.63%.

[0031] Example 2:

[0032] Please see Figure 3-5 Fluorescence emission spectra (610-800 nm) of intact cells excited by chlorophyll a (440 nm) were recorded at room temperature (approximately 25 °C) using a Hitachi F-7100 fluorescence spectrophotometer (Hitachi, Tokyo, Japan) and a Hitachi F-4600 fluorescence spectrophotometer (Hitachi, Tokyo, Japan). The absorption spectra of the cell suspension (400-800 nm) were also measured using the spectrophotometers. The scan rate was 60 nm / min, the excitation and emission slit widths were 10 nm, and the step size was 0.2 nm. Chlorophyll a (Chla) and phycocyanin (PC) were detected based on the cell absorption spectra by dividing the pigment concentration by the OD of the cell suspension. 750 The value is used to calculate the pigment content of each cell.

[0033] Figure 3 (a) The fluorescence emission spectra of Microcystis cells excited at 440 nm (chlorophyll a) at different days after low chlorination treatment (control group); Figure 3 (b) Fluorescence emission spectra of chlorophyll a at 440 nm after low chlorination treatment + 10 μM DBMIB for different days; Figure 3(c) Fluorescence emission spectra of the low-chlorination treatment followed by 20 μM DBMIB treatment at different days after excitation at 440 nm (chlorophyll a). For clarity, the spectra have been normalized to their peak values ​​and shifted upward by 0.6. The 2-unchlorinated control is the spectrum of the control group that was not treated with chlorination on day 2.

[0034] Figure 4 (a) Comparison of chlorophyll a concentration in Microcystis aeruginosa after treatment with chlorination (2 mg / L) (control group) and chlorination (2 mg / L) + 10 μM DBMIB; Figure 4 (b) is a comparison of the concentration of chlorophyll a in Microcystis aeruginosa after treatment with chlorination (2 mg / L) (control group) and chlorination (2 mg / L) + 20 μM DBMIB. Figure 5 (a) Comparison of phycocyanin concentration in Microcystis aeruginosa after treatment with chlorination (2 mg / L) (control group) and chlorination (2 mg / L) + 10 μM DBMIB; Figure 5 (b) is a comparison of the concentration of phycocyanin in Microcystis aeruginosa after treatment with chlorination (2 mg / L) (control group) and chlorination (2 mg / L) + 20 μM DBMIB.

[0035] Results: Within 0-41 days, the inhibition rates of chlorophyll a (Chla) in the chloride (2 mg / L) + 10 μM DBMIB inhibitor group were 13.79%-98.29% and the inhibition rates of phycocyanin (PC) were 9.98%-97.28%, while the inhibition rates of chlorophyll a (Chla) in the chloride (2 mg / L) + 20 μM DBMIB inhibitor group were 15.63%-99.73% and the inhibition rates of phycocyanin (PC) were 11.72%-99.19%.

[0036] Example 3:

[0037] Please see Figure 6 A full suite of photosynthetic parameters characterizing photosystem II (PSII) and photosystem I (PSI) was measured using a Dual-PAM 100 (Walz GmbH, Germany). The light-induced state transitions of cells in the control and treatment groups were monitored. Measurements were performed on cells (20 μg Chla) deposited on a filter membrane between two microscope slides, with each photocycle lasting 11 min. Furthermore, induction curves and rapid light curves were measured using a special program within the Dual-PAM software, including a specific pool size determination procedure. Cells that were severely inhibited, had extremely low Chla concentrations, and could not be measured on the Dual-PAM 100 were monitored using Phyto-PAM (Walz GmbH, Germany), and all photosynthetic parameters and PSII rapid light curves were measured.

[0038] Figure 6 (a) Comparison of the actual quantum yield of Microcystis photosystem II after treatment with chlorination (2 mg / L) (control group) and chlorination (2 mg / L) + 10 μM DBMIB; Figure 6 (b) is a comparison of the actual quantum yield of Microcystis photosystem II after treatment with chlorination (2 mg / L) (control group) and chlorination (2 mg / L) + 20 μM DBMIB.

[0039] Results: The actual quantum yield inhibition rate of photosystem II in the group with chloride (2 mg / L) + 10 μM DBMIB inhibitor was 82.56%-100% from day 1 to day 41, while the actual quantum yield inhibition rate of photosystem II in the group with chloride (2 mg / L) + 20 μM DBMIB inhibitor was 100% from day 1 to day 35.

[0040] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A method for controlling cyanobacterial blooms based on cytochrome b6f complex inhibitors, characterized in that, Includes the following steps: S1. Chloride the water containing cyanobacteria; S2. Add cytochrome b6f complex inhibitors to the water body; The cytochrome b6f complex inhibitor is DBMIB; The chlorination treatment and the cytochrome b6f complex inhibitor synergistically inhibit the photosynthetic electron transport chain of cyanobacteria, thereby inhibiting cyanobacterial growth in the long term.

2. The method for controlling cyanobacterial blooms based on a cytochrome b6f complex inhibitor according to claim 1, characterized in that, The cyanobacteria include the genus Microcystis.

3. The method for controlling cyanobacterial blooms based on a cytochrome b6f complex inhibitor according to claim 1, characterized in that, The chlorinating agent used in the chlorination treatment is sodium hypochlorite, with a treatment concentration of 1-3 mg / L and a treatment time of 0.5-2 hours.

4. The method for controlling cyanobacterial blooms based on a cytochrome b6f complex inhibitor according to claim 1, characterized in that, The concentration of DBMIB added is 10-20 μM.

5. The application of the method according to any one of claims 1-4 in controlling cyanobacterial blooms in lakes, reservoirs or freshwater bodies.

6. The application according to claim 5, characterized in that, The application involves adding the chlorinating agent and DBMIB at the initial stage of a cyanobacterial bloom or during an emergency treatment period.

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