Application of bakuchiol in inhibiting algae growth and algae-inhibiting preparation

Abstract

The present invention discloses the application of psoralidin in inhibiting the growth of algae and an algicidal preparation, belonging to the technical field of ecological restoration of water environment. Through a large number of experiments, the inventor has screened a natural allelochemical, psoralidin, which has wide raw material sources, is environmentally friendly, easily degradable, does not produce secondary pollution, has good ecological safety, is green and environmentally friendly, has a good effect on inhibiting the growth of algae and has a broad-spectrum algicidal performance. The algae inhibited by psoralidin include Microcystis aeruginosa, Heterosigma akashiwo, Skeletonema costatum, Phaeocystis globosa and other algae; it can be applied to the water bodies with algal blooms in inland lakes and also to the water bodies with red tide algal blooms in the ocean, and can be applied to fresh water and marine water bodies, and has broad application prospects in the field of controlling harmful algae.

Description

Technical Field

[0001] The present invention relates to the technical field of ecological restoration of water environment, and particularly to the application of psoralidin in inhibiting the growth of algae and an algae-inhibiting preparation. Background Art

[0002] Algae are important primary producers in the water ecosystem, located at the beginning of the food chain. However, their overgrowth may cause a series of environmental problems, such as water eutrophication, algal blooms, and the accumulation of toxic substances, seriously affecting water quality and ecological balance, and even threatening human health. In inland lakes or rivers, the common harmful alga is Microcystis aeruginosa; in the coastal waters of China, harmful algae such as Heterosigma akashiwo, Skeletonema costatum, Phaeocystis globosa, and Prorocentrum donghaiense are the main dominant species in outbreaks. In recent years, the ecological problems caused by algae have become increasingly serious, especially in static or slow-flowing waters such as the ocean, lakes, and rivers, where the phenomenon of algal blooms caused by the overgrowth of algae occurs frequently.

[0003] Traditional methods for controlling algae include physical, chemical, and biological means. Although these methods can alleviate the problem of algal outbreaks to a certain extent, they have many limitations. For example, physical removal has high costs and cumbersome operations, chemical agents may cause secondary pollution, and the effect of biological control is difficult to predict, and may bring ecological hazards such as the invasion of alien species. Therefore, finding new, safe, and efficient means of inhibiting algae has become a key scientific problem to be solved urgently.

[0004] In the prior art, researchers have also conducted some scientific studies based on this. For example, the Chinese patent document with the publication number CN105217801A discloses the application of environmental protection enzymes in preventing and controlling the harm of lake algal blooms, wherein the environmental protection enzymes are prepared by fermenting fruits and / or vegetables, water, and sugars in a closed container in proportion. The Chinese patent document with the publication number CN102010072A discloses a method for inhibiting the growth of bloom-forming algae by allelopathy of aquatic plants. A certain amount of Hydrodictyon reticulatum is put into the eutrophic water body containing bloom-forming algae, and the allelochemicals are released by Hydrodictyon reticulatum under the induction of bloom-forming algae, and the allelochemicals can effectively inhibit the growth of bloom-forming algae. The Chinese patent document with the publication number CN103395892A discloses the application of the dipeptide compound bacilysin in inhibiting the growth and reproduction of bloom-forming algae, which has an inhibitory effect on Microcystis aeruginosa. However, the above-mentioned inventions only target the prevention and control of freshwater bodies.

[0005] As a potential green alga inhibitor, natural allelochemicals have received extensive attention in recent research. For example, the Chinese patent document with the publication number CN109264836A discloses the application of flavonoid allelochemicals in Spartina alterniflora in inhibiting the growth of algae. Allelopathy refers to the process by which plants, microorganisms, etc. affect the growth of other organisms by releasing specific secondary metabolites. These natural allelochemicals are widely sourced, have low toxicity, have less impact on the environment, and are biodegradable, so they have important research and application value in algae control. There are a wide variety of plant secondary metabolites, including phenols, flavonoids, quinones and their derivatives, etc. Therefore, there is broad prospect in exploring new natural alga inhibitors from plant secondary metabolites. Summary of the Invention

[0006] The present invention provides the application of psoralidin in inhibiting the growth of algae and an alga-inhibiting preparation. Psoralidin can be used to prevent and control cyanobacterial blooms caused by Microcystis aeruginosa in fresh water, as well as red tides caused by Heterosigma akashiwo, Skeletonema costatum or Phaeocystis globosa in the ocean, and it can achieve excellent effect at a relatively low concentration.

[0007] The specific technical solutions adopted are as follows:

[0008] The present invention provides the application of psoralidin in inhibiting the growth of algae. The structural formula of psoralidin is as follows:

[0009]

[0010] The algae inhibited by the said psoralidin include Microcystis aeruginosa, Heterosigma akashiwo, Skeletonema costatum or Phaeocystis globosa; it has a broad-spectrum alga-inhibiting effect.

[0011] The said psoralidin is psoralidin from natural plants. The natural plants include Psoralea corylifolia, Solidago virgaurea, etc., and it can be extracted and separated from natural plants or directly purchased according to the records of the existing technology.

[0012] The inventor has conducted a large number of experiments and screened out a natural plant allelochemical - psoralidin, which is environmentally friendly, easy to degrade, will not cause secondary pollution, has good ecological safety, and has good effect in inhibiting the growth of algae. Specifically, the functions of psoralidin include but are not limited to inhibiting the growth of microalgae or killing microalgae, etc. It can be applied to the algal bloom water bodies in inland lakes and also to the red tide algal bloom water bodies in the ocean. It can be used directly or made into an alga-inhibiting preparation for use, and has broad application prospects in the field of harmful algae control.

[0013] The present invention also provides an algal inhibitor, which includes psoralidin; when the algal inhibitor is applied, the feeding amount of psoralidin is greater than 0.125 mg / L, preferably greater than 0.25 mg / L, and most preferably 1.0 - 16 mg / L; within the above most preferred range, the cost is relatively low and efficient algal inhibition can be achieved.

[0014] Specifically, the algal inhibitor includes but is not limited to powder, granule or liquid preparation, and its components may also include auxiliaries or carriers, which play a protective role for psoralidin or are used for slow release of psoralidin to exert its long-term algal inhibition effect.

[0015] The present invention also provides a method for controlling the growth of harmful algae in water bodies, by applying the psoralidin or the algal inhibitor; specifically, the psoralidin or the algal inhibitor is put into the water body where harmful algae break out.

[0016] The water bodies where harmful algae break out include cyanobacterial blooms caused by Microcystis aeruginosa in fresh water, and red tides caused by Heterosigma akashiwo, Skeletonema costatum or Phaeocystis globosa in the ocean.

[0017] Preferably, when Microcystis aeruginosa is the dominant species in the water body where harmful algae break out, the dosage of psoralidin is maintained greater than 0.34 mg / L.

[0018] Preferably, when Heterosigma akashiwo is the dominant species in the water body where harmful algae break out, the dosage of psoralidin is maintained greater than 1.01 mg / L.

[0019] Preferably, when Skeletonema costatum is the dominant species in the water body where harmful algae break out, the dosage of psoralidin is maintained greater than 0.41 mg / L.

[0020] Preferably, when Phaeocystis globosa is the dominant species in the water body where harmful algae break out, the dosage of psoralidin is maintained greater than 0.48 mg / L.

[0021] It has been experimentally proven that within the above preferred concentration range, the algal inhibition effect of the psoralidin or the algal inhibitor is better.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] (1) The present invention discovers that the natural allelochemical psoralidin has excellent algal inhibition performance against harmful algae including Microcystis aeruginosa, Heterosigma akashiwo, Skeletonema costatum and Phaeocystis globosa.

[0024] (2) Psoralidin is derived from natural plants and can be extracted from Psoralea corylifolia and Solidago canadensis. It is environmentally friendly, easily degradable, does not produce secondary pollution, has good ecological safety, and is green and environmental protection.

[0025] (3) Psoralidin has a highly effective inhibitory effect on a variety of algae. It can not only effectively inhibit the dominant species of cyanobacteria in freshwater algal bloom water bodies, but also effectively inhibit the growth of a variety of marine red tide algae, showing broad-spectrum characteristics, and can be applied to freshwater and marine water bodies to prevent and control the outbreak of harmful algae. Description of the Drawings

[0026] Figure 1 It is a growth curve graph of psoralidin inhibiting Microcystis aeruginosa at different concentrations.

[0027] Figure 2 It is a fitting curve graph of the effective inhibitory concentration of psoralidin on Microcystis aeruginosa at 72 h.

[0028] Figure 3 It is a growth curve graph of psoralidin inhibiting Heterosigma akashiwo at different concentrations.

[0029] Figure 4 It is a fitting curve graph of the effective inhibitory concentration of psoralidin on Heterosigma akashiwo at 72 h.

[0030] Figure 5 It is a growth curve graph of psoralidin inhibiting Skeletonema costatum at different concentrations.

[0031] Figure 6 It is a fitting curve graph of the effective inhibitory concentration of psoralidin on Skeletonema costatum at 72 h.

[0032] Figure 7 It is a growth curve graph of psoralidin inhibiting Phaeocystis globosa at different concentrations.

[0033] Figure 8 It is a fitting curve graph of the effective inhibitory concentration of psoralidin on Phaeocystis globosa at 72 h. Detailed Embodiments

[0034] To make the objectives, features, and advantages of the present invention more obvious and understandable, the following provides a detailed description through specific embodiments. Many specific details are set forth in the following description to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below. The technical features in each embodiment of the present invention can be combined correspondingly without conflict.

[0035] For the operation methods without specific conditions noted in the following examples, they are generally carried out under conventional conditions or according to the conditions recommended by the manufacturers. The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art. The experimental materials used in the following examples can be obtained from regular biochemical reagent companies without special instructions. Psoralidin can be extracted and isolated from natural plants (Psoralea corylifolia or Solidago virgaurea) or directly purchased according to the records of the prior art.

[0036] In the following examples, the inhibitory effects of psoralidin on Microcystis aeruginosa, Heterosigma akashiwo, Skeletonema costatum, and Phaeocystis globosa were studied.

[0037] Example 1: Algae inhibition activity test of psoralidin on Microcystis aeruginosa

[0038] Dissolve 16 mg of psoralidin (aladdin, >98%) in 1 mL of dimethyl sulfoxide solvent to prepare a 16 mg / mL psoralidin solution. Further, dilute it to 0.125, 0.25, 1.0, 2.0, 4.0, 8.0, 16.0 mg / mL with dimethyl sulfoxide as the working solution. Add the culture medium, Microcystis aeruginosa in the logarithmic growth phase, and 10 μL of the working solution into a 6-well plate with a culture system of 10 mL, so that the final concentrations of each experimental group are 0.125, 0.25, 1.0, 2.0, 4.0, 8.0, 16.0 mg / L. The experimental group with 10 μL of dimethyl sulfoxide added is used as the control group.

[0039] Use a microscope and a hemocytometer to count the initial algae density, and control the initial density to be 5×10 5 cells / mL. The tested algal species is Microcystis aeruginosa, and the culture medium used is BG11 medium. Use a constant temperature light incubator, and the culture conditions are 25°C, light intensity of 3000 Lux, and light-dark ratio of 12:12. After activating and inoculating twice, adjust the algal growth cycle to the logarithmic phase, count, and set aside for use.

[0040] The algal cells are cultured for 120 h. Regularly sample and count the cultured algal cells, and calculate the inhibition rate. The calculation formula of the inhibition rate is as follows:

[0041]

[0042] Among them, C sample is the algal density of the experimental group, and C control is the algal density of the control group.

[0043] The experimental results are as Figure 1 shown. It can be seen that psoralidin can significantly inhibit the growth of Microcystis aeruginosa, and with the increase of the concentration, the inhibitory effect is enhanced. Further, logistic regression analysis is used to fit the inhibition rate, and the results are as Figure 2As shown, the results showed that the half-inhibitory concentration of psoralen to Microcystis aeruginosa was 0.34 mg / L (p<0.05), which was the optimal concentration for controlling freshwater algal blooms with Microcystis aeruginosa as the dominant species.

[0044] Example 2 Test of the anti-algae activity of psoralen against Heterosigma akashiwo

[0045] The algae species tested were Heterosigma akashiwo, and the culture medium used was f / 2 culture medium. The culture was placed in a constant temperature and light incubator, and the culture conditions were 25°C, light intensity of 3000 Lux, and light-dark ratio of 12:12. After activation inoculation twice, the algae growth cycle was adjusted to the logarithmic phase, counted, and set aside. The initial density of the experiment was 5×10 4 The other experimental steps and parameters were the same as those in Example 1.

[0046] The experimental results are as follows Figure 3 As shown in the figure, it can be seen that psoralen can significantly inhibit the growth of Heterosigma akashiwo, and the inhibitory effect increases with the increase of concentration. Logistic regression analysis was further used to fit the inhibition rate, and the results are shown in the figure. Figure 4 As shown, the results showed that the half-inhibitory concentration of psoralen to Heterosigma akashiwo was 1.01 mg / L (p<0.05), which is the optimal concentration for controlling marine red tides with Heterosigma akashiwo as the dominant species.

[0047] Example 3 Test of the anti-algae activity of psoralea corylifolia against Skeletonema costatum

[0048] The algae species was Skeletonema costatum, and the culture medium used was f / 2+Si culture medium. The algae were placed in a constant temperature and light incubator with the culture conditions of 25°C, 3000 Lux of light intensity, and 12:12 light-dark ratio. After activation inoculation twice, the algae growth cycle was adjusted to the logarithmic phase, counted, and set aside. The initial density of the experiment was 5×10 4 The other experimental steps and parameters were the same as those in Example 1.

[0049] The experimental results are as follows Figure 5 As shown in the figure, it can be seen that psoralen can significantly inhibit the growth of Skeletonema costatum, and the inhibitory effect increases with the increase of concentration. Logistic regression analysis was further used to fit the inhibition rate, and the results are shown in the figure. Figure 6 As shown, the results showed that the half-inhibitory concentration of psoralen to Skeletonema costatum was 0.41 mg / L (p<0.05), which is the optimal concentration for controlling marine red tides with Skeletonema costatum as the dominant species.

[0050] Example 4 Test of the anti-algae activity of psoralen against Psoralea sphericalensis

[0051] The spherical brown cyst was used as the test algae species, and the culture medium used was f / 2 culture medium. The culture was placed in a constant temperature and light incubator, and the culture conditions were 25°C, light intensity of 3000Lux, and light-dark ratio of 12:12. After activation inoculation twice, the algae growth cycle was adjusted to the logarithmic phase, counted, and set aside. The initial density of the experiment was 5×10 5 The other experimental steps and parameters were the same as those in Example 1.

[0052] The experimental results are as follows Figure 7 As shown in the figure, it can be seen that psoralen can significantly inhibit the growth of Psora sphericalensis, and the inhibitory effect increases with the increase of concentration. Logistic regression analysis was further used to fit the inhibition rate, and the results are shown in the figure. Figure 8 As shown, the results showed that the half-inhibitory concentration of psoralen to Skeletonema costatum was 0.48 mg / L (p<0.05), which is the optimal concentration for controlling marine red tides with Phaeocystis sphericalensis as the dominant species.

[0053] The embodiments described above provide a detailed description of the technical solutions of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements or similar substitutions made within the scope of the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. The use of psoralen in inhibiting the growth of algae, characterized in that: The structural formula of Psoralea corylifolia is shown below: ； The algae inhibited by psoralen include Microcystis aeruginosa, Heterosigma akashiwo, Skeletonema costatum or Phaeocystis sphericalensis; When Microcystis aeruginosa is the dominant species in a water body with an outbreak of harmful algae, the dosage of psoralen should be kept above 0.34 mg / L; When Heterosigma akashiwo is the dominant species in a water body with an outbreak of harmful algae, the dosage of psoralen should be kept above 1.01 mg / L; When Skeletonema costatum is the dominant species in the water body where harmful algae bloom, the dosage of psoralen should be kept above 0.41 mg / L; When harmful algae blooms and Psoralea spherica is the dominant species in the water body, the dosage of Psoralea corylifolia should be kept greater than 0.48 mg / L.

2. The use of psoralen in inhibiting algae growth according to claim 1, characterized in that: The psoralen is derived from natural plants, and the natural plants include psoralen or Solidago canadensis.

3. A method for controlling the growth of harmful algae in a water body, characterized in that: Using psoralen, the psoralen is added into a water body where harmful algae have erupted; the algae inhibited by the psoralen include Microcystis aeruginosa, Heterosigma akashiwo, Skeletonema costatum or Phaeocystis sphericalensis; When Microcystis aeruginosa is the dominant species in a water body with an outbreak of harmful algae, the dosage of psoralen should be kept above 0.34 mg / L; When Heterosigma akashiwo is the dominant species in a water body with an outbreak of harmful algae, the dosage of psoralen should be kept above 1.01 mg / L; When Skeletonema costatum is the dominant species in the water body where harmful algae bloom, the dosage of psoralen should be kept above 0.41 mg / L; When harmful algae blooms and Psoralea spherica is the dominant species in the water body, the dosage of Psoralea corylifolia should be kept greater than 0.48 mg / L.

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