CN113308377A

CN113308377A - Microalgae culture medium, culture method thereof and culture water purification method

Info

Publication number: CN113308377A
Application number: CN202110668191.9A
Authority: CN
Inventors: 黄成潭; 潘军; 叶蕾; 黄敏
Original assignee: Hainan Green Algae World Biotechnology Co ltd
Current assignee: Hainan Green Algae World Biotechnology Co ltd
Priority date: 2021-06-16
Filing date: 2021-06-16
Publication date: 2021-08-27

Abstract

The invention relates to the technical field of microalgae culture, in particular to a microalgae culture medium, a culture method thereof and a purification method of aquaculture water. The microalgae culture medium comprises the following components in parts by weight: 100-500 g of sodium nitrate, 50-150 g of monopotassium phosphate, 50-150 g of EDTA-2Na, 20-80 g of ferric trichloride hexahydrate or ferric trichloride, 500-1500 g of yeast extract powder and 0.5-2.5L of polyoxyethylene polyoxypropylene pentaerythritol ether. The culture medium formula can ensure that the microalgae is amplified very quickly, the activity is enhanced, the splitting capability is enhanced, and the corrosion of harmful organisms is resisted quickly.

Description

Microalgae culture medium, culture method thereof and culture water purification method

Technical Field

The invention relates to the technical field of microalgae culture, in particular to a microalgae culture medium, a culture method thereof and a purification method of aquaculture water.

Background

Microalgae are one of the major producers of aquaculture ponds. In the aquaculture industry, there is a statement that fish farming precedes water farming. The color of the aquaculture water body before seedling placing is light green, which is expected by research and aquaculture technicians, namely the water body formed by microalgae as dominant species.

Microalgae are direct users of harmful substances in aquaculture water. As is well known, as the culture time goes on, more excrement, residual bait and animal carcasses are accumulated in water, the content of ammonia nitrogen and nitrite is directly increased, various stress reactions of cultured animals are increased and enhanced, and the possibility of large-scale outbreak of diseases is increased. However, by adopting a culture mode of directional culture of algae, the propagation of the beneficial microalgae can promote the mass growth of beneficial microorganisms and accelerate the decomposition and transformation of organic matters in the pond. The algae reduces the content of harmful substances such as ammonia nitrogen, nitrite and the like in the water body through the photosynthesis of the algae, increases the content of dissolved oxygen, and forms an environment for virtuous cycle of the substances in the aquaculture water body. Similarly, the microalgae has a powerful function of restoring water bodies, so that the microalgae can be applied to the pollution treatment of lake water bodies. Therefore, the microalgae used for developing culture products also has good market prospect.

The application of microalgae in aquaculture: fresh and alive baits for aquatic animal seedlings; the microalgae water regulating agent degrades nitrogen and phosphorus in a water body to generate dissolved oxygen, so that the dissolved oxygen in the water body is rich, harmful germ organisms are inhibited, a healthy water body environment is provided for the water body, a good water environment is provided for aquaculture animals, and healthy culture is promoted; as secondary baits, rotifers, cladocera and artemia are used as baits to form an integral food chain, so that the baits for fishes, shrimps and crabs mainly comprise rotifers, copepods, worms, cladocera and the like, and have wide application in the aspect of purifying sea cucumbers, abalones and shellfish in special culture.

The core position of microalgae in aquaculture cannot be replaced because the microalgae not only has nutrition, but also has biological activity, thereby determining the success rate of seedling culture, and improving the quality of seedling culture.

(1) The microalgae is comprehensive and rich in nutrition, is the best live bait, and is the initial bait for breeding animals such as fish, shrimps, crabs, shellfish and the like in water.

(2) And improving the stock testing rate of the seedlings.

(3) Ensuring the normal development and metamorphosis of the seedling, and providing nutrients necessary for the survival and the normal metamorphosis development of the seedling by the biological activity and the nutrition of the microalgae.

(4) Many bioactive substances of the microalgae can improve the growth speed, the body length, the body weight and other various property indexes.

(5) Microalgae improves seedling immunity.

(6) Microalgae can purify a water body of seedlings to reduce the number of harmful microorganisms, a seedling raising workshop in which industrial culture and seedling raising are not in contact with the outside is adopted, the water body needs to be purified actually, physical and chemical methods are generally adopted to be more effective than biological methods, but a water adjusting agent is required to be ensured, bait algae are fresh and healthy, otherwise, the bait is unhealthy, so that breeding of bacteria or generation of diseases can also cause harm to the seedlings.

(7) Microalgae can be used to enhance the nutrition of animal baits, for example, the nutrition of microalgae can be transferred to young animals for eating by secondary bait organisms such as rotifers.

Microalgae are rich in biochemical components, and proteins, carbohydrates, fats and chlorophyll are the most main components of pigments and are very powerful in function. Chlorella has the functions of expelling toxin, particularly discharging heavy metals, and is realized through chlorophyll metabolites, so that more green vegetables and chlorella can be consumed, and particularly heavy metals, environmental toxins (pesticide residues, medicine residues, animal residues, dioxin) and the like can be consumed. Different microalgae have more varieties and different nutrient content, and certain types of microalgae have different nutrient content. The fatty acid moiety of diatoms is a relatively highly effective component. Haematococcus pluvialis accumulates astaxanthin, which is the main functional ingredient. The microalgae used as bait is preferably capable of being compounded, that is, when bait is fed, one kind of microalgae is not fed, for example, only one kind of chlorella is fed, which causes malnutrition, and the chlorella contains protein, has the longest chain of fatty acid to 18 carbon, and has little EPA, arachidonic acid and the like in the future, which is determined genetically, so that other microalgae, such as diatom, protein and fatty acid of golden algae and other pigments are matched. Even if high-grade ornamental fish can be used, astaxanthin, algal slurry, etc. are acceptable. Therefore, the nutrients required in the metamorphosis growth and development process of the breeding breed and the animal are used as the reference for compound use and compound feeding to improve the quality of the offspring seeds.

The polyunsaturated fatty acid has the main functions of increasing the concentration of PUFA in a seedling body, ensuring normal development and promoting growth. Fatty acids are necessary in the shelling of animals such as prawns. The low temperature resistance of cold water fish is necessary for polyunsaturated fatty acid, Japanese likes to eat sashimi, and people usually eat more sashimi and cold water fish related to their diets when walking on snow in winter, so that the body has more polyunsaturated fatty acid, and the fish resists cold and freeze. Such as Skeletonema, pavlova, chrysophyceae, Chaetoceros and the like all have different polyunsaturated fatty acids and different concentrations, and the content of some fatty acids is more specific types, such as high-energy EPA of nannochloropsis, and no DHA, so the microalgae is the best algae for producing high-purity EPA. Schizochytrium has a high content of DHA. According to the nutritional requirements of different animals, microalgae varieties are used in a matching way, and the microalgae is very important for healthy cultivation and normal metamorphosis development of the animals. In addition, the microalgae culture medium is rich in vitamins, the types and the content of the vitamins are very important for the growth and development of seedlings, and different microalgae culture mediums have different vitamin contents and have different requirements on the vitamins in different culture periods for different cultured animals. Vitamins are added into the compound formula feed, if microalgae can be added, vitamins, mineral substances, biological activity and the like are available, artificial pellet feed cannot be eaten in offspring seeds, so that microalgae mostly dominates, the content of the vitamins is sufficient, astaxanthin is also necessary like cold water fish, astaxanthin is also necessary, astaxanthin developed by shelling of shrimps and crabs is also necessary, the source of vitamin H for crustaceans is the microalgae in the nature, but the content of different microalgae is different, so that artificially synthesized pigments are basically added into the artificial feed, but more and more countries, such as Europe, have banned the use of the chemically synthesized pigments, and China has no complete ban but has no advocated the use. The pigment is colored but has no biological function, and the pigment such as all natural astaxanthin is claimed to have biological function and biological activity.

In the culture pond, the microalgae is not only the water body purification mastery which naturally exists in the water body, is most effective, is the cheapest and is most convenient to operate, but also the purified metabolite of the microalgae, namely the live algae, is a water body purification process which is not toxic but can provide nutrients in general. Almost all microalgae in the pond are in NH form₄ ⁺、NO₃ ^-、NO₂ ^-Is a nitrogen nutrient source for the propagation and increment of algae. The microalgae in the culture pond are obtained by absorbing water containing NH₄ ⁺、NO₃ ^-、NO₂ ^-The inorganic matters in the pond reduce NH in the water body while completing the propagation and increment processes of microalgae in the pond₄ ⁺、NO₃ ^-、NO₂ ^-The content of the water keeps the stability of various indexes of the water quality of the pond water body. Organic matters which can not be directly utilized and absorbed by the microalgae in the water body can be converted into NH through the decomposition of bacteria₄ ⁺、NO₃ ^-、NO₂ ^-The inorganic nitrogen nutrient salt in the water is utilized by the microalgae, thereby playing a continuous role in supplying the microalgae for growth and simultaneously completing the purification process of the water quality.

Most aquatic seedling raising enterprises in China have microalgae culture facilities for self-production of various baits in the seedling raising production. However, general seedling farms generally lack corresponding professional technical strength, can only utilize respective algae ponds and natural water bodies for extensive culture, and are respectively in different aspects of bait microalgae germplasm, production technology and application method, so that the microalgae germplasm is disordered, unstable in supply, unbalanced in nutrient content, low in bait titer, and lack of multi-variety intensive production application technology; meanwhile, the method is limited by the limitations of microalgae high-density culture, harvesting technology and concentrated solution preservation technology, and domestic uniform and specialized bait microalgae quality standards and centralized supply points are almost not available. Therefore, the algae seeds need to be supplemented in time for industrial seedling raising, and the initial feeding is very important.

Like other organisms, algae are also infested with external pests during their growth. The main pests of microalgae are viruses, bacteria, fungi and protists. These diseases may seriously affect the growth of algae, especially impact the economic algae production, and increase the production cost.

In the long-term evolution process of the nature, different bacteria live in the growth environment of algae, and the two groups have complex and unique interaction, so that the method is very critical to the circulating process of substances and energy in the water environment. The relationship between algae and bacteria may be symbiotic, inhibitory, or not significant. Some bacteria may be pathogenic species of algae, which can inhibit or lyse algal bodies.

The causes of algal diseases by bacteria are mainly classified into five main groups:

(1) killing the algae by releasing algicidal components into the environment;

(2) directly contacting the algal body, digesting cell walls of algal cells by releasing enzymes for dissolving cellulose, and cracking the algal cells;

(3) bacteria compete with algae for nutrients such as C, N, P, K and the like to inhibit the growth of algae cells;

(4) forming a bacterial film on the static water surface to obstruct gas exchange and light transmission and kill the algae;

(5) the bacteria enter the algae cells to kill the algae. The direct contact of bacteria to kill algae cells results in a decrease in chlorophyll a.

Commercial large-scale production of microalgae has been hampered by biological contaminants. In large scale culture systems, various contaminants inevitably enter the microalgae culture from water, air or bioreactors. Contaminants in microalgae cultures include mainly zooplankton, bacteria, viruses and other algae. Different biological contaminants have different mechanisms of growth that damage microalgae. Zooplankton is the primary predator in farming systems. The bacteria secrete extracellular compounds with the ability to have lytic activity on algal cells to inhibit algal growth; the virus infects algal cells, causing the culture to "crash"; and competition with the target invading algae for resources of microalgae for limiting nutrient elements, e.g., nitrogen, phosphorus, potassium, magnesium, calcium. For microalgae, different types of contaminants can cause the microalgae culture to be damaged to varying degrees.

Meanwhile, the culture in an outer pond has complex hydrological environment. The traditional external pond culture mode is extensive, and harmful ammonia nitrogen and sub-salt in the water body are increased due to the continuous increase of pollutants such as residual bait, excrement, dead algae and the like in the culture water body. On the other hand, the excessive discharge of human domestic sewage, various industrial wastewater, agricultural wastewater and the like pollutes the water source of aquaculture water, causes the reduction of aquaculture water quality and the deterioration of aquaculture environment. Pathogenic microorganism species are increased, the propagation speed is accelerated, the occurrence of aquaculture biological diseases is getting more and more serious, and serious loss is caused to the aquaculture industry. According to incomplete statistics, the area of the breeding diseases which occur in China more than a medium degree accounts for more than 20% of the total breeding area each year, and the annual loss yield exceeds 146 million tons. Especially in mariculture and breeding with high intensification degree. With the continuous expansion of aquaculture scale and the continuous improvement of intensive aquaculture degree, the eutrophication degree of the aquaculture pond is higher and higher. The large amount of organic matters is thrown to ensure that eutrophic factors such as residual baits, excrements of fishes and shrimps and the like coexist in a water body, and the self-purification and regulation capability of the pond and the pond is added to reduce the Chemical Oxygen Demand (COD), the Biological Oxygen Demand (BOD), ammonia nitrogen, nitrate, nitrite, sulfide and the like in the culture water body. The indexes seriously exceed the standard, the water quality of the pond is deteriorated, and the frequent occurrence of organic pollution, ammonia nitrogen and nitrite nitrogen accumulation of fish and shrimp diseases is the main inducement of the deterioration of the culture water body of the pond, the occurrence of fish and shrimp diseases and the quality reduction. Therefore, it is necessary to develop a culture medium capable of rapidly amplifying microalgae so as to ensure the cleanness and health of the culture water in the external pond.

Disclosure of Invention

In view of the above, the invention provides a microalgae culture medium, a culture method thereof and a purification method of aquaculture water. The culture medium formula can ensure that the microalgae can be amplified very quickly, the activity is enhanced, the splitting capability is enhanced, and the corrosion of harmful organisms can be resisted quickly.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a microalgae culture medium, which consists of the following components in percentage by weight:

100-500 g of sodium nitrate, 50-150 g of monopotassium phosphate, 50-150 g of EDTA-2Na, 20-80 g of ferric trichloride hexahydrate or ferric trichloride, 500-1500 g of yeast extract powder and 0.5-2.5L of polyoxyethylene polyoxypropylene pentaerythritol ether.

Preferably, the microalgae culture medium consists of the following components in percentage by weight:

400-450 g of sodium nitrate, 80-100 g of monopotassium phosphate, 80-100 g of EDTA-2Na, 40-50 g of ferric trichloride hexahydrate or ferric trichloride, 1000-1200 g of yeast extract powder and 1-1.5L of polyoxyethylene polyoxypropylene pentaerythritol ether.

400 g of sodium nitrate, 100 g of monopotassium phosphate, 80 g of EDTA-2Na, 45 g of ferric trichloride hexahydrate or ferric trichloride, 1000 g of yeast extract powder and 1.2L of polyoxyethylene polyoxypropylene pentaerythritol ether.

The invention also provides a culture method of the microalgae, which comprises the following steps:

step 1) introducing seawater into an outer pond, and sterilizing and aerating a water body; adding a microalgae culture medium into the seawater of the external pond; the microalgae culture medium comprises the following components in parts by weight: 100-500 g of sodium nitrate, 50-150 g of monopotassium phosphate, 50-150 g of EDTA-2Na, 20-80 g of ferric trichloride hexahydrate or ferric trichloride, 500-1500 g of yeast extract powder and 0.5-2.5L of polyoxyethylene polyoxypropylene pentaerythritol ether;

step 2), inoculating microalgae seeds into a recovery culture medium for recovery culture;

step 3) adding the microalgae subjected to recovery culture into the seawater of the outer pond for amplification culture; and adding the microalgae culture medium every other day when the density of the microalgae in the seawater of the outer pond exceeds 200 ten thousand per milliliter.

Wherein, the step 1) and the step 2) are not limited in sequence.

Preferably, the disinfectant used for killing is a mixture of sodium hypochlorite, zinc oxide, permethrin, copper sulfate/copper sulfate pentahydrate and sodium dichloroisocyanurate, and the dosage of each component is as follows: 1000-1200 g/mu of sodium hypochlorite, 500-600 g/mu of zinc oxide, 100-150 g/mu of permethrin, 300-320 g/mu of copper sulfate/blue copperas and 300-350 g/mu of sodium dichloroisocyanurate;

preferably, the aeration is oxygen aeration, and the aeration time is 20-30 h.

Preferably, the aeration time is 24 h.

Preferably, in step 1) or step 3), the usage amount of the microalgae culture medium is as follows: 100-500 g/mu of sodium nitrate, 50-150 g/mu of monopotassium phosphate, 50-150 g/mu of EDTA-2Na, 20-80 g/mu of ferric trichloride hexahydrate or ferric trichloride, 500-1500 g/mu of yeast extract powder and 0.5-2.5L/mu of polyoxyethylene polyoxypropylene pentaerythritol ether.

Preferably, in step 1) or step 3), the amount of the microalgae culture medium is: 400-450 g/mu of sodium nitrate, 80-100 g/mu of monopotassium phosphate, 80-100 g/mu of EDTA-2Na, 40-50 g/mu of ferric trichloride hexahydrate or ferric trichloride, 1000-1200 g/mu of yeast extract powder and 1-1.5L/mu of polyoxyethylene polyoxypropylene pentaerythritol ether.

More preferably, in step 1) or step 3), the amount of the microalgae culture medium is: 400 g/mu of sodium nitrate, 100 g/mu of monopotassium phosphate, 80 g/mu of EDTA-2Na, 45 g/mu of ferric trichloride hexahydrate or ferric trichloride, 1000 g/mu of yeast extract powder and 1.2L/mu of polyoxyethylene polyoxypropylene pentaerythritol ether.

Preferably, the prescription of the resuscitation culture medium is as follows: 400-600 g of sodium nitrate, 50-150 g of monopotassium phosphate, 50-150 g of EDTA-2Na, 20-80 g of ferric trichloride hexahydrate or ferric trichloride, and the balance of seawater to 50L.

Preferably, the formulation of the resuscitation medium is: 500 g of sodium nitrate, 100 g of monopotassium phosphate, 100 g of EDTA-2Na, 50 g of ferric trichloride hexahydrate or ferric trichloride, and the balance of seawater to 50L.

Preferably, the inoculation amount of the recovery culture medium is 5% -15%, and the recovery culture time is 20-30 h.

Preferably, the inoculation amount of the recovery culture medium is 10%, and the recovery culture time is 24 h.

In the present invention, the conditions of amplification culture are natural light and natural water temperature.

The invention also provides a purification method of the aquaculture water body, which comprises the following steps:

step 3) adding the microalgae subjected to recovery culture into the seawater of the outer pond for amplification culture; adding a microalgae culture medium every other day when the density of microalgae in seawater in the outer pond exceeds 200 ten thousand per milliliter;

and 4) when the density of the microalgae in the seawater of the outer pond reaches 50 ten thousand per milliliter or more than 50 ten thousand per milliliter, taking the algae liquid every day and introducing the algae liquid into the culture pond for water body purification.

Preferably, the volume of the algae liquid introduced every day is 5-15% of the volume of the culture pond.

Preferably, the volume of algal solution introduced daily is 10% of the volume of the culture pond.

Preferably, the introduction mode is as follows: discharging part of culture water in the culture pond, introducing an equivalent amount of algae liquid, and sprinkling 50-150 g/mu of ammonium bicarbonate and 20-80L/mu of ortho-hydroxybenzoic acid in the culture pond.

Preferably, 100 g/mu of ammonium bicarbonate and 50L/mu of o-hydroxybenzoic acid are splashed in the culture pond.

The invention provides a microalgae culture medium, a culture method thereof and a purification method of aquaculture water. The microalgae culture medium comprises the following components in parts by weight: 100-500 g of sodium nitrate, 50-150 g of monopotassium phosphate, 50-150 g of EDTA-2Na, 20-80 g of ferric trichloride hexahydrate or ferric trichloride, 500-1500 g of yeast extract powder and 0.5-2.5L of polyoxyethylene polyoxypropylene pentaerythritol ether. The invention has the technical effects that:

the culture medium formula can ensure that the microalgae is amplified very quickly, the activity is enhanced, the splitting capability is enhanced, and the corrosion of harmful organisms is resisted quickly;

the method effectively reduces water pollutants by combining the compatibility of the microalgae and various microecological reagents, so that the culture water quality is clean and healthy, and the culture survival rate of the groupers in the external pond is effectively improved.

Detailed Description

The invention discloses a microalgae culture medium, a culture method thereof and a purification method of a culture water body, and can be realized by appropriately improving process parameters by taking the contents of the culture medium as reference by a person skilled in the art. It is expressly intended that all such similar substitutes and modifications which would be obvious to one skilled in the art are deemed to be included in the invention. While the methods and applications of this invention have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations and modifications in the methods and applications described herein, as well as other suitable variations and combinations, may be made to implement and use the techniques of this invention without departing from the spirit and scope of the invention.

The reagents or apparatus used in the present invention are commercially available.

The invention is further illustrated by the following examples:

example 1

First, culture of algae pond

1) Before cultivation, cleaning an outer pond to be cultivated. Clean seawater is introduced.

2) Splashing the following materials in the whole pond for water body disinfection: sodium hypochlorite 1000 g/mu: 600 g/mu of zinc oxide, 100 g/mu of permethrin, 300 g/mu of copper sulfate pentahydrate, and sodium dichloroisocyanurate: 300 g/mu;

3) and starting the oxygen machine, and aerating for 24 hours.

4) Adding a microalgae culture medium: 400 g/mu of sodium nitrate, 100 g/mu of monopotassium phosphate, EDTA-2 Na: 80 g/mu, 45 g/mu ferric chloride hexahydrate, yeast extract powder: 1000 g/mu, 1.2L/mu of polyoxyethylene polyoxypropylene pentaerythritol ether.

5) Inoculating 5L microalgae seeds into a 50L white barrel filled with clean seawater, and adding an algae seed recovery culture medium: 500 g of sodium nitrate, 100 g of monopotassium phosphate, EDTA-2 Na: 100 g of ferric chloride hexahydrate and 50 g of ferric chloride hexahydrate.

6) And (3) recovering and expanding the microalgae in the vat for 24 hours, and then pouring the microalgae into the pond for natural illumination and natural water temperature.

7) And (3) detecting the microalgae density in the pond every day, if the density exceeds 200 ten thousand per milliliter, adding the following culture media every other day:

400 g/mu of sodium nitrate, 100 g/mu of monopotassium phosphate, EDTA-2 Na: 80 g/mu, 45 g/mu ferric chloride hexahydrate, yeast extract powder: 1000 g/mu, 1.2L/mu of polyoxyethylene polyoxypropylene pentaerythritol ether.

Second, the purified water for external pond cultivation

When the density of the microalgae in the algae pond reaches 50 ten thousand per milliliter, introducing the algae water in the algae culture pond into the culture pond according to the following introduction proportion: 10%/(V/V algal solution volume to pond volume) daily. The introduction mode is as follows:

1) discharging 10% of culture water in the culture pond.

2) Introducing microalgae solution in an equal amount of the algae pond.

3) 100 g/mu of ammonium bicarbonate and 50L/mu of o-hydroxybenzoic acid are sprinkled in the whole culture pond.

4) And continuously adding fresh seawater into the residual algae liquid in the algae pond, and continuously culturing for later use.

Test example 1:

1) comparing the culture medium of the culture pond with the culture medium in the market in the embodiment 1 of the invention for water culture, the algae seeds used in the experiment are all marine chlorella, and the water culture method and the water purification mode of the culture pond are the same as the embodiment 1 except that the culture medium formula of each experimental group is different, and the concrete steps are as follows:

TABLE 1

2) Detection index and detection mode

TABLE 2

3) The purified water quality data is as follows:

TABLE 3 Pond 1

TABLE 4 Pond 2

TABLE 5 Pond 3

TABLE 6 Pond 4

As can be seen from the above data: the culture medium disclosed by the embodiment 1 of the invention has obvious effect in the culture of groupers and prawns, and compared with a control group, the culture in 39 days can realize that indexes of harmful substances such as ammonia nitrogen and sub-salt in a water body can be controlled at a lower level, the conductivity and the turbidity are not changed too much, the water purification effect is obvious, and the final conductivity of the control group is 2 times that of an experimental group, the turbidity is 2.5 times that of the experimental group, and the ammonia nitrogen and the sub-salt are more than 10 times that of the experimental group. The water quality deterioration is obvious.

Test example 2

The chlorella is taken as the algal species, and the result of verifying the algal species amplification rate by comparing the example 1 with the common culture medium on the market is as follows:

TABLE 7

The results are as follows (results are algal cell density in units of ten thousand/ml):

TABLE 8

Incubation time	Experimental group	Control group 1	Control group 2	Control group3
					0h	2.6	2.3	1.9	1.75
12h	5.8	3.8	4.8	2.55
					24h	10.95	7.35	5.5	4.25
36h	15.5	5.9	6.6	5.5
					48h	23.8	10.15	5.25	4.6
60h	27.55	8.5	9.2	4.35
					72h	36.05	10.1	9.6	3.73

Experiments show that the growth rate of microalgae cultured by the culture medium is more than 3 times that of a control group, and the cell density is higher.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A microalgae culture medium is characterized by comprising the following components in parts by weight:

2. The microalgae culture medium of claim 1, which is composed of the following components in proportion:

3. A culture method of microalgae is characterized by comprising the following steps:

4. The culture method according to claim 3, wherein the disinfectant is a mixture of sodium hypochlorite, zinc oxide, permethrin, copper sulfate/copper sulfate pentahydrate, and sodium dichloroisocyanurate, and the dosage of each component is as follows: 1000-1200 g/mu of sodium hypochlorite, 500-600 g/mu of zinc oxide, 100-150 g/mu of permethrin, 300-320 g/mu of copper sulfate/blue copperas and 300-350 g/mu of sodium dichloroisocyanurate;

the aeration is oxygen aeration, and the aeration time is 20-30 h.

5. The culture method according to claim 3, wherein the microalgae culture medium used in step 1) or step 3) is: 100-500 g/mu of sodium nitrate, 50-150 g/mu of monopotassium phosphate, 50-150 g/mu of EDTA-2Na, 20-80 g/mu of ferric trichloride hexahydrate or ferric trichloride, 500-1500 g/mu of yeast extract powder and 0.5-2.5L/mu of polyoxyethylene polyoxypropylene pentaerythritol ether.

6. The culture method according to claim 3, wherein the resuscitation medium is formulated as: 400-600 g of sodium nitrate, 50-150 g of monopotassium phosphate, 50-150 g of EDTA-2Na, 20-80 g of ferric trichloride hexahydrate or ferric trichloride, and the balance of seawater to 50L.

7. The culture method according to any one of claims 3 to 6, wherein the inoculation amount of the recovery culture medium is 5 to 15%, and the recovery culture time is 20 to 30 hours.

8. A purification method of a culture water body is characterized by comprising the following steps:

step 3) adding the microalgae subjected to recovery culture into the seawater of the outer pond for amplification culture; adding the microalgae culture medium every other day when the density of the microalgae in the seawater of the external pond exceeds 200 ten thousand per milliliter;

9. The purification method according to claim 8, wherein the volume of the algae solution introduced daily is 5-15% of the volume of the culture pond.

10. The purification method according to claim 8 or 9, wherein the introduction is: discharging part of culture water in the culture pond, introducing an equivalent amount of algae liquid, and sprinkling 50-150 g/mu of ammonium bicarbonate and 20-80L/mu of ortho-hydroxybenzoic acid in the culture pond.