Control of large green algal blooms

Abstract

The present invention relates to the control of green macroalgal blooms. More specifically, Ulva algal blooms can be controlled by live active ingredients contained in the seawater of the Mediterranean Sea. The inventors have observed that seawater from the Mediterranean Sea collected at specific locations (e.g., latitude 43°14'N and longitude 5°21'E, or latitude 43°09'N and longitude 5°36'E) can promote the death of Ulva lactuca without releasing toxic acidic vapors, such as H2S vapor. Taken together, the inventors provide data showing that said seawater contains live microorganisms that cause the death of Ulva, particularly Ulva lactuca. More precisely, the inventors provide experimental data indicating that the microorganism promoting the death of Ulva lactuca and thus promoting the control of Ulva lactuca blooms is a virus.

Description

Technology Field

[0001] The present invention relates to the control of green macroalgae blooms. More specifically, Ulva lactuca ( Ulva lactuca ) Green algal blooms can be controlled by living microorganisms contained in seawater collected from the Mediterranean, more specifically by viruses. Background Technology

[0002] Microalgae (or algae) are classified into three main groups—brown algae, red algae, and green algae—based on pigmentation. These microalgae all contain large amounts of carbohydrates (up to 60%), medium to large amounts of protein (10% to 47%), and small amounts of lipids (1% to 3%), along with variable amounts of mineral ash (7% to 38%). As available land and freshwater resources decrease, microalgae become an attractive alternative for producing valuable biomass comparable to terrestrial crops. Cultivating microalgae under controlled and sustainable cultivation systems is likely to be the future method of choice for supplying biomass to meet market development demands.

[0003] The high-carbohydrate fraction contains various easily soluble polysaccharides such as laminarin, alginate, mannitol, or fucoidan in brown algae; starch, mannan, and sulfated galactan in red algae; and ulban in green algae. Alginate, one of the major structural polymers of brown algae, provides both stability and flexibility to specimens exposed to running water and is one of the industrially relevant carbohydrate compounds found in algal biomass, along with other hydrocolloids such as agar and carrageenan, which are commonly used as thickeners, gelling agents, or emulsifiers. Various other non-carbohydrate products obtained from algae include proteins, lipids, phenols, terpenoids, and minerals, such as iodine, potassium, and phosphorus, which are useful components for both animal and human nutrition.

[0004] Interest in microalgae in human nutrition stems from their high mineral concentrations (e.g., calcium, magnesium, and potassium) and glutamic acid, which make them useful as taste enhancers. Algae can also help address one of the biggest challenges currently facing the food industry. Indeed, because seaweed contains small amounts of sodium in contrast to table salt, it can serve as an alternative to prevent health risks associated with excessive sodium chloride intake. Microalgae are also a source of active ingredients that are being primarily explored today for the manufacture of an increasing number of pharmaceuticals. The gelling properties of sulfated polysaccharides are well known, and their therapeutic applications are under development. Microalgae polysaccharides, pigments, proteins, amino acids, and phenolic compounds are potential functional food ingredients for maintaining health and preventing chronic diseases, and they hold increasingly more potential uses in the pharmaceutical industry.

[0005] In contrast to microalgae, which are of increasing economic interest every year, macroalgae remain a risk factor, particularly to the marine environment and the health of humans and animals. Indeed, macroalgae blooms damage marine ecosystems and have a negative impact on local tourism. This is especially true in the case of the Ulva lactuca bloom.

[0006] Ulva lactuca is a phylum of green algae first described by Linnaeus in the Baltic Sea in the 18th century Chlorophyta It is a macroalgae belonging to the genus Ulva lactuca. Ulva lactuca consists of a bilayered cellular structure, and its thallus generally has a flat, blade-like appearance. It can grow either attached to rocks or free-floating. Ulva lactuca possesses the ability to reproduce in two ways: one is sexual, and the other is due to thallus fragmentation, which is rarely observed in macroalgae. These two methods provide the ability to multiply rapidly by covering the water surface, thereby reducing the biodiversity of other algal species. Ulva lactuca is a polymorphic species regarding water salinity or the degree of symbiosis with bacteria.

[0007] Ulva lactuca primarily invades beaches, and its biodegradation can generate toxic acidic vapors (mainly H2S) that induce animal deaths, possibly caused by Ulva lactuca biodegradation and humans (in 2009, a horse was reported to have died on the coast of Brittany in western France).

[0008] The first Ulva lactuca outbreak to be described occurred in Belfast (Northern Ireland) in the late 19th century. Ulva lactuca outbreaks have been well studied in the Laguna of Venice since the 1930s, and an unexplained decline has been observed since the 1990s. Since the 1980s, Ulva lactuca outbreaks have been observed globally, ranging from Galicia (Spain) to Tokyo Bay (Japan), and including the coasts of the Americas and Australia. However, the largest global event to date remains the algal bloom observed in the Yellow Sea for 10 consecutive years starting in 2007, covering 10% of its surface. In Europe, the largest Ulva lactuca outbreak is located on the northern coast of Brittany. Today, Ulva lactuca outbreaks are acknowledged to be primarily the result of human activity, particularly due to the increase in trace amounts of nitrogen and phosphorus in seawater. Furthermore, the algal blooms observed in the waters around Belfast and Venice have been correlated with an increase in the rejection of human waste.

[0009] It has been reported that changing the water temperature can affect the proliferation of algae, as in document KR20040037467. Others have also reported that microorganisms, particularly bacteria, can be used to kill proliferating algae in lakes and rivers (see, e.g., KR20180119021). Finally, JPH1171203 disclosed that β-cyano-alanine can be proven effective as an algaecide to promote the control of cyanobacteria in marine environments.

[0010] So far, collecting green algae from seawater or coastlines, for example, beaches, is the only solution to deal with Ulva lactuca outbreaks.

[0011] Therefore, on coastal land contaminated with seawater or Ulva, the Ulva genus Ulva ) birds, especially the Ulva lactuka species Ulva lactuca It is necessary to provide means to control and / or eradicate the mass outbreak of ).

[0012] In addition, there is a need to control Ulva outbreaks in a safe manner, particularly without the release of toxic acid vapors such as H2S vapor, for example. The problem to be solved

[0013] One aspect of the present invention relates to a method for controlling and / or preventing an algal bloom of the genus Ulva in a marine environment requiring this, comprising the step of contacting seawater collected in the Mediterranean Sea with said marine environment. In certain embodiments, the algae of the genus Ulva are algae of the species Ulva lactuca. In some embodiments, the seawater is collected at latitude 43°14'N and longitude 5°21'E, latitude 43°09'N and longitude 5°36'E, latitude 43°18'N and longitude 5°17'E, latitude 43°14'N and longitude 5°17'E, or latitude 43°15'N and longitude 5°19'E. In one embodiment, the seawater is collected at latitude 43°14'N and longitude 5°21'E or latitude 43°09'N and longitude 5°36'E. In certain embodiments, the seawater contains living microorganisms capable of promoting the death of algae of the genus Ulva. In some embodiments, the living microorganisms are viruses. means of solving the problem

[0014] In another aspect, the present invention also relates to a method for controlling and / or preventing an outbreak of algae of the genus Ulva in a marine environment requiring this, comprising the step of contacting the marine environment with one or more living microorganism(s) derived from seawater collected in the Mediterranean Sea. In some embodiments, the algae of the genus Ulva are algae of the species Ulva lactuca. In certain embodiments, the seawater is collected at latitude 43°14'N and longitude 5°21'E, latitude 43°09'N and longitude 5°36'E, latitude 43°18'N and longitude 5°17'E, latitude 43°14'N and longitude 5°17'E, or latitude 43°15'N and longitude 5°19'E. In one embodiment, the seawater is collected at latitude 43°14'N and longitude 5°21'E or latitude 43°09'N and longitude 5°36'E. In some embodiments, the living microorganism is a virus.

[0015] Another aspect of the present invention relates to the use of one or more living microorganism(s) derived from seawater collected in the Mediterranean Sea for controlling and / or preventing an outbreak of algae of the genus Ulva in a marine environment. In certain embodiments, the algae of the genus Ulva are algae of the species Ulva lactuca. In some embodiments, the seawater is collected at latitude 43°14'N and longitude 5°21'E, latitude 43°09'N and longitude 5°36'E, latitude 43°18'N and longitude 5°17'E, latitude 43°14'N and longitude 5°17'E, or latitude 43°15'N and longitude 5°19'E. In one embodiment, the seawater is collected at latitude 43°14'N and longitude 5°21'E or latitude 43°09'N and longitude 5°36'E. In a specific embodiment, the living microorganism is a virus.

[0016] 정의

[0017] In the present invention, the following terms have the following meanings:

[0018] - Preceding the number " 약"It includes plus or minus 10% or less of the above numerical value. It should be understood that the value referred to by the term "about" is specifically, preferably disclosed itself.

[0019] - " 대발생 " refers to a rapid and excessive increase in population. Expanded, " 조류 대 발생 " refers to the rapid and excessive growth of algae in a specific marine environment. In practice, an algal bloom refers to the green coloring of seawater caused by the presence of excessive concentrations of algae in a specific surrounding area." 녹조 It can be a cause of. As used in this document, " 조류 대발생 Contaminated water, particularly seawater and coastal areas, especially coasts and beaches, is considered a pollutant because the toxic vapors released during the decomposition of algae can threaten the lives of both animals and humans.

[0020] - " 해양 환경 "It refers to an ecosystem of seawater that includes the open sea (or deep sea), coasts, estuaries, and coastlines. In practice, a coastline includes any land or surface in direct contact with the sea, such as rocks and beaches."

[0021] - " 제어하는"Iran refers to both steps including a preventive or preventive step undertaken to prevent or delay (mitigate) a specific harmful phenomenon. Environments requiring such steps include environments already experiencing the specific harmful phenomenon, environments prone to experiencing the specific harmful phenomenon, or environments where the specific harmful phenomenon must be prevented. The specific harmful phenomenon is successfully "controlled" when, after receiving an efficient amount of seawater collected from the Mediterranean Sea according to the present invention, the environment exhibits one or more parameters related to the specific harmful phenomenon; an observable and / or measurable reduction in the environment at or in the absence of a better quality of environment. The parameters for evaluating successful control and improvement in the environment can be easily measured by routine procedures familiar to those skilled in the art. In one embodiment, the specific harmful phenomenon is a macroalgae bloom, particularly an Ulva lactuca bloom.

[0022] - " 방지하는 "It refers to preventing at least one parameter of a specific harmful phenomenon from occurring and / or reducing the likelihood of its occurrence."

[0023] - " 살아있는 미생물 " refers to a microorganism capable of performing division under appropriate conditions, e.g., a protozoan, bacteria, or a virus. In one embodiment, the living microorganism is a virus.

[0024] - " 사망을 촉진하는 " refers to the ability to eliminate targets. By extension, " 조류의 사망을 촉진하는 " is intended to refer to the death or decomposition of algae. In practice, dead algae can no longer grow, spread, or promote green algae. In one embodiment, the death of algae may be preceded by the whitening or bleaching of algal tissue.

[0025] As used herein, the expressions "Ulba birds" and "Ulba genus birds" refer to the same subject and are interchangeable.

[0026] 상세한 설명

[0027] The inventors have observed that major Ulva lactuca outbreaks do not occur in the Mediterranean Sea, as observed in the Yellow Sea or Brittany. However, considering the presence of Ulva lactuca, significant tidal deficiency (water stagnation), and the presence of abundant nitrogen and phosphorus sources, Ulva lactuca outbreaks should be expected in the Mediterranean Sea. Surprisingly, the inventors demonstrate that controlling Ulva lactuca outbreaks in Brittany may be feasible by using seawater from one or more selected points in the Mediterranean Sea. More specifically, the inventors provide herein experimental data showing that the seawater contains microorganisms that promote the death of Ulva lactuca and thus facilitate the control of Ulva lactuca outbreaks, and that these microorganisms are viruses.

[0028] One aspect of the present invention relates to a method for controlling and / or preventing an outbreak of Ulva algae in a marine environment requiring this, comprising the step of bringing seawater collected from the Mediterranean Sea into contact with said marine environment.

[0029] In another aspect, the present invention also relates to the use of seawater collected from the Mediterranean Sea for controlling and / or preventing the mass bloom of Ulva algae in marine environments where this is required.

[0030] Another aspect of the present invention relates to a method for controlling and / or preventing an outbreak of Ulva algae in a marine environment, comprising the step of bringing seawater collected from the Mediterranean Sea into contact with the marine environment.

[0031] In another aspect, the present invention also relates to the use of seawater collected from the Mediterranean Sea for controlling and / or preventing the mass bloom of Ulva algae in a marine environment.

[0032] In a specific embodiment, the genus Ulva is Ulva acanthophora ( Ulva acanthophora ), Ulba Anandii( Ulva anandii ) , Ulba Arasakii( Ulva arasakii ), Ulva Armoricana( Ulva armoricana ), Ulva Atroviridis( Ulva atroviridis ), Ulva Baytensis( Ulva beytensis ), Ulva Bifrons( Ulva bibrows ), Ulva Brevistifita( Ulva brevistipita ), Ulba Burmanica( Ulva burmanica ), Ulva California ( Ulva californica ), Ulba cetomorphoides( Ulva chaetomorphoides ), Ulvaclate( Ulva clathrate ), Ulva Compressor( Ulva including ), Ulva conglobata( Ulva conglobata ), Ulba Cornuta( Ulva horny ), Ulva covelongensis( Ulva covelongensis ), Ulva Krasa( Ulva fat ), Ulva Krasimembrana( Ulva crossmembrane ), Ulba Kurbata( Ulva curved ), Ulva Denticulate( Ulva denticulate ), Ulva Diafana( Ulva diaphana ), Ulba Elegance( Ulva elegance), Ulba Enteromorpha( Ulva enteromorpha ), Ulba Erecta( Ulva erecta ), Ulva Xpansa( Ulva expansa ), Ulba Fasciata( Ulva fascia ), Ulva Flexuosa( Ulva flexible ), Ulba Geminoidea( Ulva geminoidea ), Ulba Gigantea( Ulva gigantic ), Ulva Grandis( Ulva grow up ), Ulva Hukkeriana( Ulva hookeriana ), Ulba Hopkirkiy ( Ulva hop church ), Ulva habensis( Ulva howensis ), Ulva Indica( Ulva indica ), Ulva intestinalis( Ulva intestinalis ), Ulba intestinaloides( Ulva intestinaloides ), Ulva Javanika( Ulva javanica ), Ulba Kilini ( Ulva kylinii ), Ulva Raktuka( Ulva lactuca ), Ulba Letevirens( Ulva laevirens ), Ulba Reingii( Ulva others ), Ulva Linearis( Ulva linear ), Ulva Linza( Ulva lens ), Ulba Rippie ( Ulva lippii ), Ulva Litoralis ( Ulva littoralis ), Ulba Litorea( Ulva littorea ), Ulva Robate( Ulva iron ), Ulba Marginata( Ulva marginata ), Ulva Micrococa ( Ulva micrococca ), Ulba Mutabilis( Ulva mutabilis ), Ulva Neapolitana( Ulva Neapolitan ), Ulba Nematoidea( Ulva nematoidea ), Ulba Onoi( Ulva ohnoi ), Ulba Olivasins( Ulva olivascens ), Ulva Pacifica( Ulva peaceful ), Ulva Papenpusi ( Ulva papenfussii ), Ulba Parva( Ulva parva ), Ulva Paschima( Ulva Easter ), Ulva Patengensis ( Ulva patenensis ), Ulba Percursa( Ulva persecutor ), Ulva Pertusa( Ulva percussionist ), Ulva Philosa( Ulva phyllosa ), Ulva polyclada, Ulva poppenguinensis( Ulva popenguinensis ), Ulva Polyfolia( Ulva porrifolia ), Ulva Procera( Ulva procera ), Ulva propunda( Ulva deep ), Ulva prolifera( Ulva prolifera ), Ulva Shudokurvata( Ulva pseudocurvata ), Ulba Shudolinza( Ulva pseudolinza ), Ulba Pulchira( Ulva pulchra ), Ulva quilonensis ( Ulva quilonensis ), Ulva Radiata( Ulva radiata ), Ulba Ralphsi ( Ulva ralfsii ), Ulva Ranunculata( Ulva ranunculata ), Ulva Reticulata( Ulva reticulata ), Ulba Lacodes( Ulva rhacodes ), Ulba Rigida( Ulva rigida ), Ulva Rotundata( Ulva rotundata ), Ulba Saifullahi ( Ulva saifullahii ), Ulva Scandinavica( Ulva scandinavica ), Ulva Serrata( Ulva serrata ), Ulva Simplex( Ulva simplex ), Ulva Sorrenzeni( Ulva sorensenii ), Ulva spinulosa( Ulva spinulosa ), Ulva Stenophila ( Ulva stenophylla ), Ulva Subritoralis( Ulva sublittoralis ), Ulba Seobulata( Ulva subulata ), Ulba Taniata( Ulva taeniata ), Ulva Tanneri( Ulva tanneri ), Ulva Tenera( Ulva tenera ), Ulba Torta( Ulva torta ), Ulva Tuberosa( Ulva tuberosa ), Ulva uncialis, Ulva uncinate, Ulva uncinate( Ulva uncinate ), Ulba Usneoides( Ulva usneoides ), Ulva Utricularis( Ulva utricularis ), Ulva Utriculosa( Ulva utriculosa ), Ulba Uboides( Ulva uvoides ) and Ulva Ventricosa( Ulva ventricosa It is selected from a group including ) species of birds.

[0033] In some embodiments, birds of the genus Ulva are selected from the group including birds of the species Ulva armoricana and Ulva lactuca. In one embodiment, birds of the genus Ulva are birds of the species Ulva lactuca.

[0034] Within the scope of the present invention, birds of the Ulva lactuca species may also refer to Enteromorpha birds.

[0035] Within the scope of the present invention, "marine environment requiring this" refers to a marine ecosystem that is experiencing or is likely to experience an Ulva outbreak.

[0036] In some embodiments, the marine environment may be limited to seawater, particularly deep sea, coasts, estuaries, etc.

[0037] In fact, assessing whether the marine environment needs to control and / or prevent a mass bloom of Ulva algae can be performed by measuring one or more of the following parameters, including average seawater salinity, average seawater surface temperature, and the average concentration of Ulva in said environment.

[0038] For example, the measurement of average seawater salinity, i.e., the concentration of salt (g) per kilogram of seawater, may be performed by any method known in the art. Non-limiting examples of methods suitable for measuring seawater salinity include the measurement of electrical conductivity (EC) and the measurement of total dissolved solids (TDS). In some embodiments, a marine environment where it is necessary to control and / or prevent an outbreak of Ulva algae may have an average salinity consisting of about 30 g to about 40 g of salt per kilogram of seawater. Within the scope of the invention, the expression “about 30 g to about 40 g of salt per kilogram of seawater” includes 30 g, 31 g, 32 g, 33 g, 34 g, 35 g, 36 g, 37 g, 38 g, 39 g, and 40 g of salt per kilogram of seawater.

[0039] For example, the measurement of the average sea surface temperature may be performed by any method known in the art. Non-limiting examples of methods suitable for measuring the average sea surface temperature include satellite microwave radiometers, infrared (IR) radiometers, and field buoys. In some embodiments, the marine environment where it is necessary to control and / or prevent a mass bloom of Ulva algae may have an average surface temperature consisting of about 12°C to about 25°C, preferably about 14°C to about 20°C. Within the scope of the invention, the expression “about 12°C to about 25°C” includes 12°C, 13°C, 14°C, 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C, and 25°C.

[0040] For example, the measurement of the average concentration of algae of the genus Ulva may be performed by any method known in the art. In practice, the biomass of algae in seawater may be evaluated by any of the sufficiently established methods, for example, the method disclosed in the literature (cf. Hambrook Berkman, JA and Canova, MG (2007, Algal biomass indicators (ver. 1.0): US Geological Survey Techniques of Water-Resources Investigations, book 9, chap. A7, section 7.4). Non-limiting examples of methods suitable for measuring the biomass of algae include the measurement of carbon biomass as ash-free dry mass, the measurement of particulate organic carbon (POC), or the quantification of chlorophyll a in seawater samples.

[0041] In some embodiments, Ulva algal blooms can be controlled in seawater before becoming stranded, particularly on coastlines, especially on rocks or beaches.

[0042] In some other embodiments, Ulva algal blooms can be controlled on any land or surface in direct contact with the sea, for example, on a coastline including rocks and beaches.

[0043] In practice, seawater according to the present invention may come into contact with algae of the genus Ulva on a coastline. In some embodiments, the Ulva algae are killed before their natural biodegradation. In practice, natural biodegradation begins when a significant amount of toxic acidic vapor, particularly H2S vapor, is released. For example, once killed, the green algae can be safely removed and / or stored before final destruction.

[0044] In certain embodiments, seawater promotes the death of algae of the genus Ulva. In some embodiments, the death of algae of the genus Ulva is achieved without the release of acid vapor, in particular without the release of H2S vapor.

[0045] In some embodiments, the seawater is collected at latitude 43°14'N and longitude 5°21'E, latitude 43°09'N and longitude 5°36'E, latitude 43°18'N and longitude 5°17'E, latitude 43°14'N and longitude 5°17'E, or latitude 43°15'N and longitude 5°19'E.

[0046] In one embodiment, seawater is collected at latitude 43°14'N and longitude 5°21'E, or latitude 43°09'N and longitude 5°36'E.

[0047] In one embodiment, seawater is collected at latitude 43°14'N and longitude 5°21'E. In one embodiment, seawater is collected at latitude 43°09'N and longitude 5°36'E. In one embodiment, seawater is collected at latitude 43°18'N and longitude 5°17'E. In one embodiment, seawater is collected at latitude 43°14'N and longitude 5°17'E. In one embodiment, seawater is collected at latitude 43°15'N and longitude 5°19'E.

[0048] In fact, seawater can be collected from the surface to a depth of up to 30m. Within the scope of the present invention, the expression "maximum 30m" refers to 1cm, 5cm, 10cm, 15cm, 20cm, 30cm, 40cm, 50cm, 60cm, 70cm, 80cm, 90cm, 1m, 1.5m, 2m, 2.5m, 3m, 3.5m, 4m, 4.5m, 5m, 5.5m, 6m, 6.5m, 7m, 7.5m, 8m, 9m, 10m, 11m, 12m, 13m, 14m, 15m, 16m, 17m, 18m, 19m, 20m, 21m, 22m, 23m, 24m, 25m, 26m, 27m, 28m, It includes 29m and 30m.

[0049] In a specific embodiment, seawater is collected at a depth of about 10 cm to about 10 m, preferably about 50 cm to about 2 m.

[0050] In some embodiments, seawater is collected during the spring, particularly from March 20 to June 21, more specifically from May 20 to June 20.

[0051] In some embodiments, the collected seawater samples are preserved at a temperature of about 4°C to about 30°C, preferably about 10°C to about 20°C, more preferably about 20°C. Within the scope of the invention, the expression “about 4°C to about 30°C” includes 4°C, 5°C, 6°C, 7°C, 8°C, 9°C, 10°C, 11°C, 12°C, 13°C, 14°C, 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, and 30°C.

[0052] In fact, before use to promote the death of Ulva algae, the collected seawater samples can be preserved for up to 50 days, preferably up to 30 days, more preferably up to 10 days. Within the scope of the present invention, the expression “up to 50 days” includes 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 days, and 1 day.

[0053] In a specific embodiment, the seawater contains living microorganisms capable of promoting the death of algae of the genus Ulva.

[0054] In some embodiments, the death of the genus Ulva algae may be evaluated by decolorizing the green tissue of the algae into white tissue. As used herein, the decolorization of the green tissue of the algae into white tissue may also be referred to as "bleaching" of the green tissue of the algae. In practice, the observation of dead (necrotic) white tissue may be evaluated visually or by light microscopy. In certain embodiments, white tissue may be observed for about 1 day to about 15 days after contacting the Ulva algae with seawater according to the present invention, preferably during the day and / or at a temperature of about 20°C to about 30°C. Within the scope of the present invention, the expression "about 1 day to about 15 days" includes 1 day, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, and 15 days. Within the scope of the present invention, the expression “about 20°C to about 30°C” includes 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, and 30°C.

[0055] In fact, the above-mentioned living microorganisms are selected from a group consisting of protozoa, bacteria, and viruses.

[0056] In some embodiments, microorganisms according to the present invention may be concentrated, isolated, and / or characterized.

[0057] In some embodiments, the microorganism according to the present invention may be purified from seawater according to the present invention. As used herein, the term "purified" refers to a step that allows the isolation of the microorganism according to the present invention as an active ingredient from other living organisms in seawater according to the present invention. Other living organisms may include algae, phytoplankton, etc.

[0058] The concentration, isolation, and characterization of microorganisms can be performed by any suitable technique of the latest technology.

[0059] In some embodiments, microorganisms may be filtered from a collected seawater sample using, for example, a membrane filter, a Seitz filter, a sintered glass filter, and / or a candle filter. In practice, the filter may have a pore size in the range of about 0.01 µm to about 10 µm. Within the scope of the invention, the expression “about 0.01 µm to about 10 µm” includes 0.01 µm, 0.02 µm, 0.03 µm, 0.04 µm, 0.05 µm, 0.06 µm, 0.07 µm, 0.08 µm, 0.09 µm, 0.1 µm, 0.2 µm, 0.3 µm, 0.4 µm, 0.5 µm, 0.6 µm, 0.7 µm, 0.8 µm, 0.9 µm, 1 µm, 2 µm, 3 µm, 4 µm, 6 µm, 7 µm, 8 µm, 9 µm, and 10 µm.

[0060] In some embodiments, amoebas may be filtered using a filter having a pore size in the range of about 1 µm to about 10 µm. In some embodiments, bacteria may be filtered using a filter having a pore size in the range of about 0.05 µm to about 10 µm, preferably about 0.1 µm to about 8 µm. In some embodiments, viruses may be filtered using a filter having a pore size in the range of about 0.01 µm to about 1.5 µm, preferably about 0.1 µm to about 1 µm.

[0061] In certain embodiments, the microorganisms may optionally be centrifuged by differential centrifugation after polyethylene glycol (PEG) precipitation. Reference may be made to the protocol disclosed in the literature (see: Lawrence and Steward (Purification of viruses by centrifugation. 2010; Manual of aquatic viral ecology; Chapter 17, 166-181)).

[0062] Characterization of microorganisms can be performed by any suitable technique known from the latest technology. For example, next-generation sequencing (NGS) of the entire genome of a microorganism can be performed after nucleic acids are extracted from the microorganism. In practice, viral nucleic acids can be extracted using, for example, the QIAamp Viral RNA Mini Kit (QIAGEN®) or the Pure Link® Viral RNA / DNA Mini Kit (Invitrogen®). Genomic bacterial nucleic acids can be extracted using, for example, the Illustra Bacterial Genome Prep Mini Spin Kit (GE Health Life Sciences®) or the NEBNext® Microbiome DNA Concentration Kit (New England Biolabs®).

[0063] In one embodiment, the living microorganism is a protozoan, specifically an amoeba.

[0064] As used herein, the term "protozoa" includes actinopods such as radiolarians, heliozoans, and Acantaria; foraminifera such as monothalames and polyphthalames; and marine protozoa including amoebas, e.g., Gymnamoebians and Thecamoebians. Within the scope of the present invention, the expression "marine protozoa" includes marine amoebas.

[0065] Non-limiting examples of marine amoebas include the genus Clidodonella. Clydonella ); genus Lingulamoeba Lingulamoeba ), for example, L. Reyes( L. leei Mayorella genus Mayorella ), for example, M. Gemmifera( M. gemmifera ); genus Neoparamoeba Neoparamoeba ), for example, N. branch pillar( N. branchiphila ); Vanella genus Vannella ), for example, V. Aberdonica( V. aberdonica ), V. Miroidesu( V. miroides ); Vermistella genus Vermistella ), for example, V. Antarstica( V. Antarctica ); genus Vexylifera Vexillifera ), for example, V. Minutissima( V. minutissima ), V. Tasmaniana( V. tasmaniana Includes ) amoebas.

[0066] In one embodiment, the living microorganism is bacteria, particularly marine bacteria. Non-limiting examples of marine bacteria are the genus Bacillus Bacillus ), for example, B. Megatherium( B. megaterium ), B. turingiensis( B. thuringiensis ); Flavobacterium genus Flavobacterium ), for example, Formosa agaripila ( Formosa agariphila ); Halomonas genus Halomonas ), for example, H. Propundus( H. profundus ), H. Hydrothermalis ( H. hydrothermalis ); genus Pseudomonas Pseudomonas ), for example, P. Gezennei( P. guezennei ); genus Saccharophus Saccharophagus ), for example, S. degradans; Vibrio genus Vibrio ), for example, V. Azureus( V. azureus ), V. Proteoliticus( V. proteolyticus Includes bacteria of ).

[0067] In one embodiment, the living microorganism is a virus. In a specific embodiment, the virus is of the family of microviral ( MimiviridaeIt belongs to ). In some embodiments, viruses belonging to the family Mimiviridae are cafeteriavirus genus (genus Cafeteriavirus ), genus of Klosnoivirus Klosneuvirus ), genus Mimivirus ), genus Tupanvirus ...etc. In some embodiments, the microorganism is a virus.

[0068] In some embodiments, viruses from seawater collected from the Mediterranean Sea according to the present invention are filtered through a filter with a pore size of about 0.2 μm. That is, viruses pass through a filter with a pore size of about 0.2 μm and are understood not to be retained by said filter.

[0069] In a specific embodiment, according to the present invention, the presence of viruses in seawater collected from the Mediterranean is advantageously stained with aromatic compounds, in particular SYBR Gold dye (N',N'-dimethyl-N-[4-[(E)-(3-methyl-1,3-benzothiazole-2-ylidene)methyl]-1-phenylquinoline-1-ium-2-yl]-N-propylpropane-1,3-diamine). SYBR Gold dye binds preferentially to DNA. This dye is widely used in virology to stain and visualize virus-like particles (VLPs) present in seawater and other aquatic samples.

[0070] In some embodiments, the amount of virus in seawater collected from the Mediterranean Sea according to the present invention is about 10 5 to about 10 9 PFU / ml, especially about 10 6 to about 10 8 It is the range of PFU / ml.

[0071] As used herein, "about 10 5 to about 10 9 The expression "PFU / ml" is 10 5 , 5×10 5 , 10 6 , 5×10 6 , 10 7 , 5×107 , 10 8 , 5×10 8 and 10 9 It contains PFU / ml.

[0072] As used herein, PFU stands for "Plaque Forming Unit" and refers to the number of virus particles capable of forming a plaque in a cell monolayer.

[0073] Another aspect of the present invention relates to a method for controlling and / or preventing an outbreak of Ulva algae in a marine environment requiring this, comprising the step of bringing one or more living microorganism(s) derived from seawater collected in the Mediterranean Sea into contact with said marine environment.

[0074] A further aspect of the present invention also relates to the use of one or more living microorganism(s) derived from seawater collected in the Mediterranean Sea for controlling and / or preventing outbreaks of Ulva algae in marine environments where such are required.

[0075] In another aspect, the present invention also relates to the use of one or more living microorganism(s) derived from seawater collected in the Mediterranean Sea for controlling and / or preventing outbreaks of Ulva algae in a marine environment.

[0076] In another aspect, the present invention relates to the use of one or more living microorganism(s) derived from seawater collected in the Mediterranean Sea in a method for controlling and / or preventing an outbreak of Ulva algae in a marine environment where this is additionally required.

[0077] Another aspect of the present invention relates to the use of one or more living microorganism(s) derived from seawater collected in the Mediterranean Sea in a method for further controlling and / or preventing an outbreak of algae of the genus Ulva in a marine environment.

[0078] In some embodiments, the effective dose of the virus for controlling and / or preventing an outbreak of Ulva algae is approximately 1 × 10⁻⁶ of the marine environment being treated. 1 to about 1×10 12 PFU / m 2 It is within the range of. In a specific embodiment, the effective dose is approximately 1 × 10⁻⁶ of the marine environment being treated. 2 Up to 1×10 8 , preferably about 1×10 2 to about 1×10 8 PFU / m 2 It is the range of.

[0079] Within the scope of the present invention, "about 1x10 of the marine environment being treated 1 to about 1x10 12 PFU / m 2 The term "1x10 of the marine environment being treated" 1 , 1x10 2 , 1x10 3 , 1x10 4 , 1x10 5 , 1x10 6 , 1x10 7 , 1x10 8 , 1x10 9 , 1x10 10 , 1x10 11 and 1x10 12 PFU / m 2 Includes Brief explanation of the drawing

[0080] Fig. 1a-1c is enteromorpha( Enteromorpha It is a photo of a bird. do 1a : Green ornamental algae formerly named Enteromorpha, collected in November 2018 following an outbreak in the Trieufjord (TR) on the northern coast of Brittany (48°46'N, 3°06'W). do 1b : The tubular shape disappears after incubation with seawater collected in June 2018 from the Bay of Marseille (43°18'N 5°16'E or spot X(RS) in Fig. 2) for one month at 20°C and sun exposure. do 1c "Enteromorpha" became a typical Ulva lactuca after 3 months of exposure to 20°C and sunlight. Fig. 2 Figure [] is a diagram showing the statistical analysis of in vitro proliferation of *British Ulva lactuca* using unique seawater samples from the Bay of Marseille. Seawater samples were collected from three different locations in the Bay of Marseille in June 2018. X(RN) was 43°18'N, 5°16'E; Y(RS) was 43°15'N, 5°19'E; and Z(PR) was 43°14'N, 5°21'E. The seawater samples were divided into three tube groups (n=36). *British Ulva lactuca* collected from Breguet (north coast of Brittany, 48°43'N, 2°06'W) in June 2018 was 1 cm 2 The specimens were cut into pieces and placed in three groups of tubes corresponding to points X, Y, and Z in the Bay of Marseille, collected one day prior to sampling (D1). Ulva lactuca proliferation was carried out at 25°C using seawater in 50 ml tape-sealed tubes to induce anoxia. Proliferation was observed in 25 tubes out of 36 (69%) at point X, which corresponds to the open sea, while it was observed in 14 tubes out of 36 (39%) at point Y and only in 1 tube out of 36 (2.7%) at point Z, which is closest to the shore (see inset graph). In the tubes where Ulva lactuca proliferated, confluence was reached after one week, and acidity was detected. In the tubes where Ulva lactuca did not grow, no acidity was observed, and the Ulva lactuca turned white after five days. Seawater from point Z was stored from D30 to D180 before being recultured with British Ulva lactuca, and proliferation was observed in 12 tubes / 36 (33%) for D30 and 36 tubes / 36 (100%) for D180 (see inset graph). Figs. 3a-3d This is a photograph showing a comparison with optical microscopy of Ulva lactuca in three different conditions. do 3a: Ulva lactuca turned white after 5 days when cultured with seawater from point Z of the Bay of Marseille at 20°C and exposed to sunlight. do 3b : Optical microscopic examination of white Ulva lactuca (10X). Ulva lactuca tissue remains unaffected by the regular tissue of Ulva cells. do 3c : Optical microscopic examination (10X) of a healthy Ulva lactuca. Fig. 3d : Optical microscope (10X) of Ulva lactuca after acidic biodegradation. Ulva lactuca tissue is destroyed by the release of chlorophyll that remains green despite anoxia. Photographed with a Nikon D3100 camera connected to a Nikon Eclipse Ti L100 microscope (Nikon, Tokyo, Japan). Figs. 4a-4d This is a photograph and graph showing fluorescence microscopy after SYBR staining. do 4a-c Mediterranean seawater that causes bleaching was cultured without Ulva (Panel A) and with Ulva (Panels B and C). do 4d : Illuminates the amount of virus-like particles expressed as particle count / ml. Seawater was filtered through 0.2 µm. Specific details for implementing the invention

[0081] Examples

[0082] The present invention is further explained by the following examples.

[0083] Examples : Ulba Rocktuka's Identification of seawater samples that promote mortality

[0084] 1) Materials and Methods

[0085] a) Ulba Rocktuka Polymorphism

[0086] Green algae were collected from the Trieufjord on the north coast of Brittany (48°46'N, 3°06'W). Propagation was performed in vitro using seawater samples from the Bay of Marseille (Southern Provence, France). Green tubular algae previously named Enteromorpha were collected in November 2018 following an outbreak in the Trieufjord on the north coast of Brittany (48°46'N, 3°06'W). Culture was performed for one month using seawater collected in June 2018 from the north bay of Marseille (43°18'N, 5°16'E; RN) at 20°C and under sunlight exposure.

[0087] b) Ulba Rocktuka multiplication

[0088] Seawater samples were taken from three different locations in Marseille ( Fig. 2 ), 2 branches in Provence, 3 branches in Brittany( Table 1 Surface samples were collected during the spring (June 2018, 2019, and 2020) at eight different locations, including the reference. Seawater samples were divided into three groups of tubes (n=36). The British Ulva lactuca collected at Brehec (north coast of Brittany, 48°43'N 2°6'O) in June 2018 was 1 cm 2 The samples were cut into pieces and placed into three groups of Falcon tubes (50 ml) corresponding to points X, Y, and Z in the Bay of Marseille collected one day prior to sampling (D1). Acidity was tested using a Crisson pH meter (Barcelona, ​​Catalonia). The pH meter was calibrated prior to each measurement. Nitrate was measured using a METRHOM chromato-ion apparatus (Bern, Switzerland) equipped with a Metrosep column A supp 5 150 / 4 mm, using 3.2 mM Na2CO3 / 1 mM NaHCO3 as the eluent. The amount of nitrate was calibrated using a standard after diluting the seawater by 1 / 8.

[0089] c) Optical microscopy examination

[0090] Optical microscopy (10X) was performed using water samples collected at the Z(PR) point of the Gulf of Marseille from healthy Ulva lactuca and white Ulva lactuca after acid biodegradation before the confluence point and 5 days later. Imaging was performed using a Nikon D3100 camera connected to a Nikon Eclipse Ti L100 microscope (Nikon, Tokyo, Japan).

[0091] d) Diode array detection high-performance liquid chromatography (DAD) HPLC )

[0092] Seawater samples were filtered through 0.2 µm and analyzed using a Beckman HPLC system Gold apparatus equipped with a reversed-phase (C8) column with H2O 0.1% TFA (A) and CH3CN 0.1% TFA (B). The gradient was 10% to 50% B at 40 min, 10 min at 90% B, and 10 min at 10% B. A diode array detector Beckman apparatus was coupled after the injector. The flow rate was 0.8 ml / min.

[0093] e) SYBR Fluorescence microscopy after staining

[0094] Mediterranean seawater with or without Ulva lactuca samples was filtered through a 0.22 µm membrane filter (Millex®; catalog number SLGP033RS) to remove cells, and then virus particles were collected by filtering through a 0.02 µm anode filter (Whitman®; catalog number WHA68096002) using a vacuum filtration system.

[0095] Then, the filter was stained with SYBR Gold dye (N',N'-dimethyl-N-[4-[(E)-(3-methyl-1,3-benzothiazole-2-ylidene)methyl]-1-phenylquinoline-1-ium-2-yl]-N-propylpropane-1,3-diamine) which binds valuably to DNA (Invitrogen®; catalog number S11494) at room temperature in the dark for 15 minutes, and washed three times with 500 μL of sterile 0.02 μm-filtered mQ water. The stained virus-like particles were observed using a surface fluorescence microscope, Leica SP2.

[0096] 2) Result

[0097] a) Britain Ulba Raktuca is It can grow in the Mediterranean and has different phenotypes in relation to salinity.

[0098] Ulva lactuca naturally inhabits the Gulf of Marseille (Provence, southern France) and appears every winter. The Ulva grows rapidly from February to March and then disappears rapidly in the spring. Although Ulva lactuca blooms have not been reported in the Gulf of Marseille as observed in Brittany, this bay features shallow beaches with high concentrations of phosphate and nitrogen. The first hypothesis is that British Ulva lactuca can grow easily in Brittany but not in the Mediterranean, and more specifically, that nitrate concentrations are lower compared to the seawater in Brittany. Five locations near Marseille were selected, seawater samples were collected, and compared with three locations in Brittany ( Table 1 ).

[0099] [Table 1]

[0100]

[0101] *Statistical analysis of in vitro British wool bleaching using seawater samples collected in the spring. All experiments (n=8) were performed using British wool collected from the Trieufjord (TR) in northern Brittany in 2018, 2019, and 2020. Wool is 1 cm 2 It was cut into pieces, placed in seawater (40 ml) in tape-sealed tubes (n = 25), and left in sunlight at an average temperature of 25°C.

[0102] The Gulf of Marseille is located 20 km from the mouth of the Rhône River, and is dominated by northwesterly winds (Mistral and Tramontan) that regularly blow from the Rhône River to Marseille. graph 1 It shows that pH and conductivity measurements (mainly related to salinity) are low in RN, likely due to the influence of the Rhone River. graph 1 It shows that the concentration of nitrate in coastal seawater is equivalent in Brittany (BR and PO) and Provence (RN, WF, RS). However, nitrate concentrations can be much higher in the Brittany Fjords (TR) or in the Calrank (MU) and Marina (PR) of Provence.

[0103] As indicated above, British woolly lactuca can grow rapidly in the seawater of Marseille ( Fig. 1 ). The polymorphism of Ulva lactuca is 20℃ ± 10℃ and sun exposure ( Fig. 1c A green ornamental bird previously named Enteromorpha, collected in the Trieufjord near Painpol (Northern Brittany), which became a typical Ulva lactuka three months after ) Fig. 1a It was tested as ). This experiment demonstrates the importance of salinity in the polymorphism of Ulva lactuca as previously described (cf. Rybak, Ecological Indicators, 2018, 85, 253-261).

[0104] b) Britain Ulba Rocktuka The proliferation varies in the location and timing of water sampling in the Bay of Marseille.

[0105] Natural biodegradation on the beach occurs when Ulva lactuca reaches a confluence point that induces anoxia characterized by H2S generation. In the case of this biodegradation, the Ulva can turn white due to dehydration. However, this is a different phenomenon observed by the inventors in British Ulva lactuca in seawater collected in Marseille. British Ulva lactuca rapidly turned white (bleached) within one day without dehydration. To simulate this natural process, the cultivation of Ulva lactuca was performed using seawater in a 50 ml tube sealed with tape to induce anoxia.

[0106] Statistical analysis was performed using seawater samples collected from three different locations in Brittany, including the Bay of Marseille, and five locations in Provence ( Table 1 and Fig. 2 ). Seawater samples were divided into 8 groups of tubes (n=36). British Ulva lactuca 1 cm 2 It was cut into pieces and placed into 8 groups of tubes corresponding to points X (RN), Y (RS) and Z (PR) of the Bay of Marseille, PR and MU of Provence, TR and BR (Northern Brittany) and PO (Southern Brittany), which were collected one day before sampling (D1).

[0107] No bleaching was observed in seawater collected in Brittany during the spring when Ulva proliferation was highest. For five different locations in Provence, the number of tubes where proliferation could occur was not the same. Proliferation was observed in only 25 tubes / 36 (69%) at location X, which corresponds to the open sea, 14 tubes / 36 at location Y, and 1 tube / 36 at location Z, which is closest to the coast. do 3aAs presented in [reference], Ulva lactuca could not grow in the tubes, and Ulva lactuca turned white under sunlight at 20°C within 5 days without detectable acidity. This white phenotype of Ulva lactuca was not similar to the white dehydrated Ulva lactuca observed in Brittany when Ulva lactuca remained on the shore during low tide. In the tubes where Ulva lactuca could proliferate, confluence was reached after one week, and acidity was observed in accordance with the normal process of Ulva lactuca biodegradation (cf. Dominguez and Loret, Mar Drugs. 2019 Jun 14;17(6). Pii: E357). As observed under natural conditions, Ulva lactuca remained green upon biodegradation. Seawater from point Z ( Fig. 2 ) was maintained from D30 to D180 before being recultured with Brittany Ulva lactuca, and proliferation was observed in 12 tubes / 36 tubes for D30 and 36 tubes / 36 tubes for D180( Fig. 2 The active ingredient promoting the death of British Ulva lactuca cells is not a contaminant that would have produced the same effect from D1 to D180. Other British algae (mostly brown) were not affected by the seawater in the Bay of Marseille (data not shown).

[0108] c) 3 different states of Ulba Rocktuka's Comparison with optical microscopy shows that the tissue is white Ulba Rock to Caro Not being destroyed Shows

[0109] Showing a white Ulva lactuca Fig. 3a What happens in it was studied at the tissue level using optical microscopy. do 3b The white tissue of Ulva lactuca has a thallus composed of rigid cells containing chlorophyll present in the cytoplasm that provides green to the cells ( Fig. 3cIt shows that it remains unaffected in the regular tissue of ulvaractuka cells comparable to healthy ulvaractuka. do 3b The white color indicates that the cells have died, but this death is not caused by macro-predators or environmental conditions capable of destroying the tissue of algae as illustrated in Fig. 3c. It is not spore formation capable of providing a white color. The primary explanation derived from these preliminary experiments is that microorganisms unique to Ulva lactuca control the Ulva lactuca macrophylla in the Mediterranean. Only microbial attacks, particularly viral attacks, could explain this rapid death of Ulva lactuca cells without tissue damage. Furthermore, this hypothesis has been confirmed. Indeed, when seawater is filtered at 0.2 µm, Ulva lactuca can still turn white, demonstrating that the bleaching activity is not attributed to plankton, amoebas, or bacteria with a size greater than 0.2 µm.

[0110] d) to high-performance liquid chromatography combined Diode array detection (DAD) HPLC )

[0111] Mediterranean seawater that causes bleaching was filtered through a 0.2 µm sieve and then analyzed using DAD HPLC, which enables UV spectral analysis of each body eluted at different times from a hydrophobic C8 column with an acetonitrile gradient. Most of the peaks eluted between 5 and 45 minutes feature UV spectral signatures exhibiting maximum absorption at 243 nm and correspond to organic macromolecules referred to as colloids. A 3D view of the DAD HPLC run shows that colloids are the major components of the seawater filtered through the 0.2 µm sieve. Three peaks have different UV spectral signatures. The peak indicated by the red arrow at 3.5 minutes may correspond to the presence of viral particles and features the first maximum absorbance at 266 nm due to nucleic acids and aromatic amino acids. Two other peaks correspond to free nucleic acids at 6 minutes and free proteins at 45 minutes, featuring maximum absorbances at 260 and 280 nm, respectively. When British Ulva lactuca is added to Mediterranean seawater for 5 days and bleaching occurs, the virus-corresponding peak increases significantly at 266 nm with a maximum absorbance in the range of 7 to 32 mAU. Interestingly, this peak compatible with virus particles increases by 78%, while the colloidal peak decreases (presumably due to Ulva ingestion).

[0112] e) Virus-like particle staining and fluorescence microscopy

[0113] Mediterranean seawater containing or without Ulva lactuca was filtered through 0.2 µm and then stained with an aromatic compound designated as SYBR Gold dye (N',N'-dimethyl-N-[4-[(E)-(3-methyl-1,3-benzothiazole-2-ylidene)methyl]-1-phenylquinoline-1-ium-2-yl]-N-propylpropane-1,3-diamine), which binds preferentially to DNA. This dye is widely used in virology to stain and visualize virus-like particles (VLPs) present in seawater and other aquatic samples. There are hundreds of published reports on counting and detecting viruses in biological samples using this methodology (cf. Shibata et al., Aquat Microb Ecol. 2006, 43, 223-231). do 4a-c Fluorescence microscopy after SYBR staining shows that Ulva lactuca indicates high virus production when added to seawater. This high virus production is already significant when Ulva lactuca is still green. However, when Ulva lactuca turns white, the virus abundance is 6.5 × 10⁻⁶ 8 It reaches virus / ml, which is a high concentration of atypical viruses ( Fig. 4d This experiment suggests that the virus is actively generated and released at a higher rate when Ulva lactuca is bleached.

[0114] 3) Discussion

[0115] The average nitrate concentration in global seawater and the Mediterranean is approximately 1 μM. If nitrate concentrations were the reason for the absence of Ulva lactuca proliferation in Marseille, nitrate concentrations of up to 100 μM could have been expected on the northern coast of Brittany, where algal blooms are most significant in Western Europe, particularly in the spring, but this was not the case in rivers or fjords. Table 1). Nitrate concentrations vary seasonally. On the northern coast of Brittany, the average at the Roscoff marine station was 5 μM, nearly 10 μM in the winter of 2018 and 2019, and 1 μM in the summer (Reference: Service d'Observation en Milieu Littoral (SOMLIT), INSU-CNRS, Roscoff and Marseille" http: / / somlit-db.epoc.u-bordeaux1.fr / bdd.php). Other parameters, such as pH and conductivity measurements, also vary seasonally at Roscoff (Reference: http: / / somlit-db.epoc.u-bordeaux1.fr / bdd.php). Data from BR on the northern coast of Britain ( Table 1) is within the range of nitrate concentrations observed in Roskopf, and the same seasonal variability is observed in Marseille (http: / / somlit-db.epoc.u-bordeaux1.fr / bdd.php). This seasonal variability has also been observed in Galicia, in western Spain (Villares et al., Bol. Inst. Esp. Oceanogr. 1999, 15, 337-341). It is also important to point out that the origin of Ulva algal blooms is not necessarily from the coast of Brittany. Ulva proliferation is observed in the central North Atlantic, and Ulva drifts to Brittany due to the dominant westerly winds in the North Atlantic. Chlorophyll anomalies appear to be occurring increasingly frequently in the North Atlantic, and the main cause of algal blooms may be primarily due to global warming. Continuous monitoring of nitrate concentrations was not performed because the purpose was to compare with the same analytical method and to explain the absence of Ulva proliferation only in the spring, when nitrate concentrations in Marseille could be much lower than on the northern coast of Britain. This turned out not to be true, and according to a very interesting study conducted in the Gulf of Marseille by IFREMER in 2007 and 2008, nitrate concentrations can be as high as in the open sea near Marseille on the northern coast of Brittany, with nitrate concentrations of over 8 μM measured three times in June 2008 (cf. Young et al., PLoS One. 2016, 11(5):e0155152). In addition, chlorophyll activity appears to be abnormally low in relation to nutrient concentration (0.2 μg / ml) and can grow up to 1 μg / ml for a very short period that can be explained by viral lysis regulating proliferation (cf. Young et al., PLOS One. 2016, 11(5):e0155152).

[0116] While it is well known that viruses participate in controlling microalgal blooms, this has not been proven for macroalgae until now. Viral control of microalgal blooms involves two microalgae, *Aureococcus anopageferrens*, which causes harmful blooms on the East Coast ( Aureococcus anophagefferens )(Reference: Moniruzzaman et al., Front Microbiol. 2018, 9,752-758) or Tetraselmis of Hawaii( Tetraselmis It was recently observed in the United States (see Schvarcz and Steward, Virology 2018, 518, 423-433). In both cases, it was due to a recently discovered virus named giant viruses. Giant viruses were first discovered in amoebas (see La Scola et al., Science 2003, 299, 2033-2038). do 3b It is interesting that moving amoebas were detected under a microscope. The size of most viruses known since the 1st century is less than 400 nm; for example, HIV is 160 nm and minimal viruses (parvoviruses infected pigs) are 20 nm, whereas the size of giant viruses is up to 1 µm. Since then, giant viruses have been found all over the world and have infected many species, especially marine species (cf. Abergel et al., FEMS Microbiol Rev 2015, 39,779-796).

[0117] The Ulva lactuca outbreak will remain a cause of problems that may grow alongside global warming. However, there is a hypothesis of a natural law called "killing the winner" that could hinder this Ulva lactuca success story. When a species proliferates, it appears that its predators control this proliferation. Among the most powerful natural predators, the largest is not necessarily the most efficient. The emergence of specific predators for Ulva lactuca may be a result of the high concentration of predators in the Mediterranean, such as viruses, marine bacteria, and amoebas. Viruses are the most abundant organisms in seawater, found even in mesopelagic (1,000 to 2,000 m) regions, and the Mediterranean appears to have the highest concentrations mainly in the surface layer (5 m). When prokaryotes and unicellular algae appear to be the primary hosts of viruses, only 9% of the sequences obtained from viral fractions have an identifiable viral origin, and no studies have been conducted on sequences specific to giant viruses. Predator dynamics can vary with respect to temperature, which may explain why the Ulva lactuca disappears from the Gulf of Marseille in the spring when the temperature reaches 15°C.

[0118] The experiments described for the present invention demonstrate that the proliferation of British Ulva lactuca can be controlled using water samples from the Bay of Marseille. This control is achieved by a microscopic living active ingredient, the concentration of which is not the same for different points in the Bay of Marseille. Importantly, sample collections from the same point (PR) in the Bay of Marseille for three consecutive springs (2018, 2019, 2020) were all able to achieve Ulva lactuca bleaching, which indicates that microorganisms, particularly viruses, were consistently recovered from this marine environment.

Claims

Claim 1 Ulva genus Ulva A method for controlling and / or preventing an algal bloom in a marine environment requiring control and / or prevention of an algal bloom, comprising the step of contacting said marine environment with seawater collected from the Mediterranean Sea, said seawater comprising a living microorganism capable of promoting the death of the algal bloom, said living microorganism being a virus, said virus being filtered from a collected seawater sample, and said filter having a pore size in the range of about 0.01 µm to about 0.2 µm. Claim 2 A method according to claim 1, wherein the virus is filtered from seawater collected from the Mediterranean Sea through a filter with a pore size of about 0.2 μm. Claim 3 In paragraph 1, the above-mentioned Ulva genus bird is the Ulva lactuka species (species Ulva lactuca ) bird, method. Claim 4 A method according to claim 1, wherein the seawater is collected at latitude 43°14'N and longitude 5°21'E, latitude 43°09'N and longitude 5°36'E, latitude 43°18'N and longitude 5°17'E, latitude 43°14'N and longitude 5°17'E, or latitude 43°15'N and longitude 5°19'E. Claim 5 A method according to claim 1, wherein the seawater is collected at latitude 43°14'N and longitude 5°21'E, or latitude 43°09'N and longitude 5°36'E. Claim 6 A method for controlling and / or preventing an outbreak of Ulva algae in a marine environment requiring control and / or prevention of an outbreak of Ulva algae, comprising the step of contacting said marine environment with one or more living microorganism(s) derived from seawater collected in the Mediterranean Sea, wherein said one or more living microorganism(s) are viruses derived from seawater collected in the Mediterranean Sea, said viruses are filtered from a collected seawater sample, and said filter has a pore size in the range of about 0.01 µm to about 0.2 µm. Claim 7 In claim 6, the method wherein the above-mentioned Ulva genus bird is a bird of the Ulva lactuca species. Claim 8 In claim 6, the method wherein the seawater is collected at latitude 43°14'N and longitude 5°21'E, latitude 43°09'N and longitude 5°36'E, latitude 43°18'N and longitude 5°17'E, latitude 43°14'N and longitude 5°17'E, or latitude 43°15'N and longitude 5°19'E. Claim 9 In claim 6, the method wherein the seawater is collected at latitude 43°14'N and longitude 5°21'E, or latitude 43°09'N and longitude 5°36'E. Claim 10 delete Claim 11 delete Claim 12 delete Claim 13 delete Claim 14 delete Claim 15 delete Claim 16 delete

Images