WO2011141559A1

WO2011141559A1 - Apparatus for incubating eggs and/or embryos of aquatic organisms and a method thereof

Info

Publication number: WO2011141559A1
Application number: PCT/EP2011/057722
Authority: WO
Inventors: Giulio Jori; Michela Magaraggia; Monica Camerin; Laura Guidolin; Matteo Meneghini; Enrico Zanoni; Alessandro Barbato; Nicola Trivellin; Gaudenzio Meneghesso
Original assignee: Universita degli Studi di Padova
Current assignee: Universita degli Studi di Padova
Priority date: 2010-05-14
Filing date: 2011-05-12
Publication date: 2011-11-17
Anticipated expiration: 2012-11-14
Also published as: IT1400911B1; ITTV20100075A1

Abstract

The present invention relates to an apparatus for incubating eggs and/or embryos of aquatic organisms, for example for incubating fish eggs. The apparatus comprises at least one incubation chamber (10) suitable for containing said eggs and/or embryos in contact with a solution (100) that comprises water and at least one photosensitive substance of the tetrapyrrole family and/or structural analogs thereof. The apparatus comprises at least one light source (20, 21), operatively associated to said incubation chamber so as to illuminate at least partly said solution. Said light source emits a light radiation (11) with wavelength (lambda) comprised between 580nm and 900nm, suitable for stimulating said photosensitive substance so that the latter originates one or more active chemical species, capable of contrasting the presence or proliferation of pathogenic agents such as bacteria, germs, fungi, yeasts, mildew and the like.

Description

APPARATUS FOR INCUBATING EGGS AND/OR EMBRYOS OF AQUATIC

ORGANISMS AND A METHOD THEREOF DESCRIPTION

The present invention relates to the field of plants for the aquaculture of aquatic organisms. In particular, the present invention relates to an apparatus for incubating eggs and/or embryos of aquatic organisms, for example for incubating fish eggs.

In a further aspect thereof, the present invention relates to a method for contrasting the presence or proliferation of pathogenic agents, for example bacteria, germs, fungi, yeasts, mildew and the like, in an apparatus for incubating eggs and/or embryos of aquatic organisms. As known, aquaculture plants are used for hatching aquatic organisms, such as fish, mo Husks, shellfish and so on, on an industrial scale.

In aquaculture plants, the use of incubating apparatus is widespread for leading large amounts of eggs and/or embryos of aquatic organisms, for example fish eggs, to maturing.

Traditionally, an incubating apparatus comprises a silos structure wherein a large amount (even more than 50000 specimens) of eggs and/or embryos is arranged, immersed in a continuous flow of water at controlled temperature and oxygenation and often kept in the dark.

It is widely known that in the field of aquaculture, a highly felt problem is the disinfection of the waters where the aquatic organisms are grown.

The contamination by pathogenic agents, for example bacteria, germs, fungi, yeasts, mildew and the like could impair the growth of the aquatic organisms, cause the deterioration or death thereof, or even pose a hazard to the human health.

In the case of hatching of eggs and/or embryos, the problem of disinfecting the farming waters is critical for the following reasons:

- eggs and/or embryos are very sensitive to contaminations of a microbial nature;

- the risk of spreading of infections is very high, due to the high density of population present in the hatching apparatus;

- the economical risk is very high since the contamination of even a small number of specimens grown may cause the need of eliminating the entire population grown in the apparatus.

Over the years, several methods have been developed for contrasting the presence or proliferation of pathogenic agents in the apparatuses used for hatching eggs and/or embryos of aquatic organisms. An approach that is still much widespread is treating the water circulating in the incubating apparatus with water-soluble biocide agents, for example malachite green or formalin, capable of performing an effective disinfection action.

However, some studies have shown that such biocide agents exhibit teratogenic properties and should be considered as potentially carcinogenic.

To this end, see for example the following publications:

M. Meyer, D:J: Alderman in Aquaculture and Environment, European Aquaculture Society Special Publication 16, eds. N. De Pauw, J. Joyce, EAS, Brussels, 1983, pages 235-244;

- E. Fernandes, L.G. Willoughby, R.J. Roberts, J. Fish Dis. 15: 1-13, 1992;

S. Srivastava, R. Sinha, D. Roy Aquat. Toxicol. 66: 319-329, 2004;

CM. Gieseker, S.G. Serfling, R. Reimschuessel Aquaculture 253: 120-129, 2006.

The use of these biocide agents can therefore be considered as potentially hazardous for the human health.

An alternative disinfection method, of known type, provides for treating the water circulating in the apparatus with hydrogen peroxide.

The experience shows that such substance is difficult to use in the practice: even minimal variations in the dosage may cause significant damages and even an extended mortality in the population treated or, on the contrary, make the treatment totally ineffective as regards contrasting the pathogenic charge present in the apparatus.

Finally, some studies have shown that hydrogen peroxide is toxic for some species of fish or may cause significant variations in the physiological parameters of the population treated. On this issue, see for example the following articles:

- L.L. Costello, J.J. Rach, T.M. S chreier Progr. Fish-Culture 56: 225-231, 1993;

- L. Mansell, M. Miura, I. Ridge Fish Pathol. 40: 81-86, 2005.

Other disinfection methodologies, currently adopted, provide for treating the farming waters with ultraviolet rays (UV).

Some drawbacks should be noted in this case as well.

UV rays can easily cause the onset of mutations in the genetic complement of the population treated and in general, they are toxic for eggs and/or embryos.

In an incubating apparatus, the UV ray treatment of the circulating water must therefore be necessarily performed in a special disinfection chamber.

This causes an increase in the structural complexity of the apparatus and in the relevant installation and operating management costs but above all, it does not allow reducing, in a satisfactory manner, the risk of infections or contaminations, due to the impossibility of intervening directly at the incubation chamber level.

UV rays have a poor penetration in water (about 3 cm). It is therefore difficult to illuminate relatively large volumes of water with ultraviolet light, with relatively low energy costs.

Generally, UV ray lighting devices are relatively expensive and of difficult operating management.

Patent application W097/29636 describes a method that provides for using photosensitive substances of a natural origin, such as porphyrins, for disinfecting the farming waters for aquatic organisms.

If illuminated with visible light, such photosensitive substances are capable of generating iper-reactive oxygen species, known to be provided with a high antimicrobial power and selective action towards microbial cells.

The apparatuses for incubating eggs and/or embryos that use such disinfection methodology traditionally provide for treating the farming water in special disinfection chambers and subsequently sending the disinfected water into the relevant incubation chambers.

This is due to the fact that some components of the visible light, for example light radiations in the band of blue or violet, are harmful to eggs and/or embryos.

Also in these apparatuses, operating the contrast action on the microbial charge directly in the site where the aquatic organisms are hosted therefore is not possible.

The incubating apparatuses currently available, moreover, have a relatively complex structure, difficult to install and manage operatively.

The main technical aim of the present invention is to provide an apparatus for incubating eggs and/or embryos of aquatic organisms that allows solving and overcoming the drawbacks mentioned above.

Within this aim, an object of the present invention is to provide an apparatus capable of controlling and effectively preventing the onset of infections in the population grown, without impairing the physiological condition and the development thereof.

A further object of the present invention is to provide an apparatus that is relatively easy to install and to manage operatively.

A further object of the present invention is to provide an apparatus that is operatively reliable, that has a relatively simple structure and easy to manufacture at an industrial level at a competitive cost.

This aim and these objects, as well as other objects that shall appear clearly from the following description and the annexed drawings, are achieved according to the invention by an apparatus for incubating eggs and/or embryos of aquatic organisms, for example for incubating fish eggs, according to the following claim 1.

The apparatus, according to the present invention, comprises at least one incubation chamber suitable for containing eggs and/or embryos in contact with a solution that comprises water and at least one photosensitive substance of the tetrapyrrole family and/or structural analogs thereof.

Preferably, such photosensitive substance consists of a substance of the porphyrin family, for example porphyrin C12 (see figure 11).

The apparatus, according to the invention, comprises at least one light source, operatively associated to the incubation chamber, so as to illuminate the solution present therein at least partly.

Such light source emits a light radiation with wavelength comprised in the interval between 580nm and 900nm, which stimulates the photosensitive substance present in solution within the incubation chamber, to generate one or more active chemical species, capable of contrasting the presence or proliferation of pathogenic agents.

Such active chemical species may comprise, for example, singlet oxygen molecules or other volatile cytotoxic agents.

Preferably, the light source of the apparatus, according to the present invention, emits a light radiation having wavelength comprised in an interval [λ_ί-0.05λ_ί , λ_ί+0.05λ_ί ], where i=l, 2, ...N and λ; corresponds to the wavelength of a peak of the absorption spectrum of the photosensitive substance.

Advantageously, such light source may comprise one or more LED (Light Emitting Diodes) devices.

The apparatus, according to the present invention, may further advantageously comprise waveguide means, suitable for conveying the light radiation emitted by said light source at the position of eggs and/or embryos.

The apparatus, according to the invention, preferably comprises at least one support plate, operatively positioned within the incubation chamber and shaped so as to seat, at least partly, the eggs and/or embryos.

According to a preferred embodiment of the present invention, one or more LED devices are operatively associated to said support plate.

The structure of the support plate may further advantageously comprise at least one waveguide suitable for conveying the light radiation emitted by the LED devices at the seats wherein eggs and/or embryos are seated. According to an alternative embodiment, the above waveguide means may comprise at least one waveguide set up for crossing, at least partly, the incubation chamber volume, in the longitudinal direction.

The apparatus, according to the present invention, exhibits several advantages compared to the prior art.

In the apparatus, according to the invention, it is possible to perform the disinfection of the farming waters directly within the incubation chamber wherein eggs and/or embryos are grown.

It has been proven that the contact with a solution of water and photosensitive substance does not impair the physiological condition and the development of eggs and/or embryos.

The possibility of performing the disinfection process at the incubation chamber level allows reducing the structural complexity and the overall dimensions of the apparatus, while making the action of contrast of the pathogenic charge and of infection prevention easier and safer. The use of LED devices for emitting the light radiation offers significant advantages in terms of operating reliability, energy consumption reduction and overall dimensions reduction. It has been experimentally proven that the irradiation by LED devices, capable of emitting a light radiation with a length in the interval between 580nm and 900nm, mentioned above, does not impair the physiological condition of eggs and/or embryos.

The use of waveguide means allows illuminating eggs and/or embryos with greater efficacy, and evenness, activating the photosensitive substance in the proximity of or at, the surfaces of the same.

It has been experimentally proven that this contributes to improving the efficacy of the disinfecting action performed by the active chemical species generated by the photosensitive substance.

The apparatus, according to the invention, exhibits a relatively simple structure, inexpensive to manufacture at an industrial level, easy to install and convenient to manage operatively. In a further aspect thereof, the present invention also relates to a method for contrasting the presence or proliferation of pathogenic agents in an apparatus for incubating eggs and/or embryos of aquatic organisms, for example for incubating fish eggs, according to the following claim 12.

The method, according to the invention, advantageously comprises the following steps:

providing at least one incubation chamber of the apparatus with a solution comprising water and at least one photosensitive substance of the tetrapyrrole family and/or structural analogs thereof, so that said eggs and/or embryos are in contact with such solution; providing at least one light source that emits a light radiation with wavelength comprised between 580nm and 900nm;

illuminating, at least partly, the solution present within said incubation chamber, by said light source, the light radiation emitted by said light source stimulating said photosensitive substance to generate one or more chemical species, suitable for contrasting the presence or proliferation of said pathogenic agents.

Additional characteristics and advantages of the apparatus and method thereof, according to the present invention, will become apparent from the description given below and from the annexed figures, wherein:

figure 1 schematically shows the structure of the apparatus, according to the present invention;

figure 2 schematically shows the structure of the apparatus, according to the present invention in an embodiment thereof;

figure 3 schematically shows a structural detail of the apparatus of figure 2;

figure 4 schematically shows a further structural detail of the apparatus of figure 2;

figure 5 schematically shows the structure of the apparatus, according to the present invention in a further embodiment thereof;

figures 6A-6B schematically show the absorption spectra of some photosensitive substances usable in the apparatus according to the present invention;

figure 7 schematically shows the spectrum content of the light radiation emitted by the light source of the apparatus, according to the present invention, in relation to the water absorption spectrum;

figure 8 schematically shows the spectrum content of a LED device of the red type, in relation to the absorption spectrum of a photosensitive substance of the porphyrin family, usable in the apparatus, according to the present invention;

figure 9 schematically shows some experimental results relating to the disinfecting action performed by the chemical species generated by a photosensitive substance of the porphyrin family, usable in the apparatus, according to the present invention;

figure 10 shows the chemical structure of some families of photosensitive substances usable in the apparatus, according to the present invention;

figure 11 shows the chemical structure of some photosensitive substances belonging to the porphyrin family.

With reference to the aforesaid figures, the present invention relates to an apparatus 1 for incubating eggs and/or embryos 50 of aquatic organisms. Apparatus 1 is particularly suitable for incubating fish eggs and shall be described with reference to such application.

This is not intended to limit in any way the scope of use of the present invention.

Apparatus 1 may in fact be effectively used for incubating eggs and/or embryos of any type of aquatic organism.

Apparatus 1 comprises at least one incubation chamber 10 wherein eggs 50 are placed in contact with a solution 100 that comprises water and at leas one photosensitive substance. The term "photosensitive substance" in this context relates to a substance that chemically reacts subsequent to the exposure to a light radiation.

According to the invention, the photosensitive substance contained in solution 100 belongs to the tetrapyrrole family and/or structural analogs thereof.

Preferably, said photosensitive substance belongs to the porphyrin family, and may consist for example of porphyrin C12 (figure 11).

As an alternative, it may belong to the chlorine or porphycene or phthalocyanine or naphthalocyanine family (figure 10).

Of course, solution 100 may comprise multiple photosensitive substances dissolved in water, for example a mixture of porphyrin C12 and porphyrin C14 (figure 11).

The incubation chamber 10 preferably consists of a container that develops vertically, for example in the shape of silos, and comprises a base wall 104, a removable top cover 105 and side containment walls 106.

Preferably, the incubation chamber 10 is provided with at least one inlet manifold 101 and an outlet manifold 102 operatively associated to pumping means (not shown), so that a continuous flow Fl of solution 100 may cross the incubation chamber 10, ensuring a continuous change and recirculation of the same solution.

Preferably, the inlet manifold 101 and the outlet manifold 102 are respectively positioned in the proximity of or at, the base wall 104 and cover 105, so that the incubation chamber 10 is crossed by a flow Fl of solution substantially directed in longitudinal direction, from the bottom upwards.

In this way, the oxygenation of the water present in solution 100 is thus favored and the latter is allowed to gently lap the surface of eggs 50, while reducing the presence of air bubbles or turbulences.

Of course, manifolds 101 and 102 of the incubation chamber 10 may be positioned in a way other than that shown in figure 2. Preferably, solution 100 is obtained in a special mixing chamber, operatively connected to the incubation chamber 10.

From said mixing chamber, solution 100 is pumped into the incubation chamber 10, by the inlet manifold 101, made to circulate within the incubation chamber 10 and ejected through the outlet manifold 102.

As an alternative, solution 100 may be directly obtained within chamber 10 by the local dispensing of the photosensitive substance. In this case, the incubation chamber 10 may simply be fed with water.

Of course, the incubating apparatus 1 may comprise a plurality of incubation chambers, operatively connected in parallel to a delivery duct and to a discharge duct.

In the incubation chamber 10, eggs 50 are advantageously immersed in solution 100. In this way, the surface thereof is constantly lapped by the flow of solution 100 that crosses the incubation chamber 10, thus favoring the contact between the surface of eggs 50 and the photosensitive substance present in the solution 100.

Preferably, one or more support plates 11 shaped so as to seat or contain eggs 50 are arranged in the incubation chamber.

The support plates 11 may advantageously be made of glass or other material capable of ensuring a high resistance to the attacks of chemical or biological agents and an optimal optical transmission of the light radiation.

Advantageously, each support plate 11 is operatively positioned in horizontal direction, so as to be substantially orthogonal to the flow direction of solution 100.

Preferably, each support plate 11 comprises a plurality of seats 110 suitable for seating eggs 50.

Preferably, each one of seats 110 is shaped so as to seat a single egg 50 (figures 3-4).

In this way, the confinement between the specimens is favored, reducing the risk of spreading of infections, for example of a fungal origin, by the contact in the incubated population.

Advantageously, in order to optimize the spaces, seats 110 are arranged on each plate according to an ordered layout, for example of the matrix type.

Figure 4 shows a generic portion 11A of plate 11, illustrated in figure 3, in greater detail.

It is possible to see that each seat 110 of the support plate 11 preferably consists of an opening

110A, through the thickness of plate 11.

Such through opening is advantageously shaped as a pyramid or upturned cone so as to offer an adequate support surface HOB to egg 50, seated therein, while allowing solution 100 to flow freely around the outside surface of the same. According to the invention, apparatus 1 comprises at least one light source 20 operatively associated to the incubation chamber 20.

The light source 20 is suitable for emitting a light radiation LI, in particular with wavelength λ comprised in an interval R = [580nm, 900nm].

Preferably, the light source 20 is operatively positioned within the volume of the incubation chamber 10 and is advantageously set up so as to illuminate, at least partly, solution 100. In this way, the light radiation LI is capable of activating the photosensitive substance, present in solution 100, so that said photosensitive substance generates one or more active chemical species, with antimicrobial power, capable of contrasting the presence or proliferation of pathogenic agents.

According to an alternative embodiment of the present invention (not shown), the light source 20 is set up so as to illuminate the incubation chamber 10 from the outside, through one or more walls of the incubation chamber 10, advantageously made of an optically transparent material.

Preferably, the light source 20 emits a light radiation LI having wavelength λ comprised in a portion of said interval R [580nm, 900nm], which corresponds to an interval [λ_ί-0.05λ_ί, λί+0.05λί ], where i=l, 2, ...N and λ; is the wavelength of an i-th peak of the absorption spectrum of the photosensitive substance present in the incubation chamber 20.

Preferably, the light source 20 may emit a light radiation LI, having wavelength λ comprised around a secondary absorption peak of the photosensitive substance, present in the incubation chamber 20, where the term "secondary absorption peak" means an absorption peak subsequent to the first peak that may be identified scrolling the absorption spectrum starting from wavelength λ=0.

The light source 20 thus preferably emits a light radiation LI having wavelength λ comprised in a portion of the above interval R [580nm, 900nm], which corresponds to an interval [λ;- 0.05λί, λί+0.05λί ], where i=l, 2, ...N and λ; is the wavelength at which the absorption spectrum of said photosensitive substance exhibits an i-th secondary peak.

Figures 6A-6D show the absorption spectra of some photosensitive substances usable in apparatus 1, respectively of porphyrin C12, of phthalocyanine ZnPc, of chlorine THPC and of naphthalocyanine PdNc.

With reference to such figures, the light source 20 may for example emit a light radiation LI having wavelength λ comprised in one of the following intervals:

Ι1=[λι-0.05λι , λι+0.05λι], where

or Ι2=[λ₂-0.05λ₂ , λ₂+0.05λ₂], where λ₂=620ηηι; or

Ι3=[λ₃-0.05λ₃ , λ₃+0.05λ₃], where λ₃=680ηηι; or

Ι4=[λ₄-0.05λ₄ , λ₄+0.05λ₄], where λ₄=650ηηι; or

Ι5=[λ₅-0.05λ₅ , λ₅+0.05λ₅], where

or

The emission of light radiation in the above wavelength intervals is advantageous since it allows effectively activating the photosensitive substance, present in solution 100, without the light radiation comprising spectral components that are harmful to the eggs and/or embryos. In general, the light source 20 may comprise any light source operatively associated to suitable filtering means so as to emit a light radiation in the desired wavelength interval.

According to a preferred embodiment of the present invention, the light source 20 comprises one or more LED devices 21.

The use of LED devices is advantageous for various reasons.

LED devices exhibit a relatively narrow emission spectrum, centered on a nominal reference wavelength. They can therefore be easily used for emitting a light radiation with predetermined spectrum content, without the need of setting up filtering means.

The power dissipation in LED devices is very reduced. Undesired heating phenomena of solution 100 can thus be prevented.

The LED devices exhibit a high reliability level, are easily integrable in the structure of the incubation chamber 10, without considerable increases in the overall dimensions, are relatively simple to operatively control and can be easily found on the market at low cost. The LED devices 21 may be positioned on the walls of the incubation chamber 10 so as to illuminate the support plates 11 from the bottom and/or from the top and/or in horizontal direction.

Preferably, however, the LED devices 21 are operatively associated to one or more edges 1 IB of each support plate 11, so as to ensure an effective lighting of eggs 50 seated in the relevant seats 110.

According to a preferred embodiment of the present invention, apparatus 1 advantageously comprises waveguide means, suitable for conveying the light radiation LI emitted by the light source 20 at the position of eggs 50.

This allows obtaining an optimal lighting of the volume of solution 100 flowing around the surface of eggs 50, ensuring an effective activation of the photosensitive substance in the proximity of or at, the outside surface of the same. Preferably, said waveguide means are integrated with the support plates 11 suitable for seating eggs 50.

According to a preferred embodiment of the present invention, each support plate 11 comprises, integrated in the structure thereof, at least one waveguide suitable for conveying, at seats 110 seating eggs 50, the light radiation emitted by the LED devices 21, operatively associated to the side edges 1 IB.

Each egg 50 can thus be directly illuminated, increasing the efficacy of the disinfection process and, at the same time, reducing the possibility of onset of infections and transmission of the same from one specimen to the other.

Preferably, the waveguide of a support plate 11 comprises at least one layer of material 121, which is transparent relative to the light radiation LI, for example glass.

Such waveguide further comprises layers 122 and 123, made of a material reflecting the light radiation LI, for example silver, and set up so as to cover the top and bottom surface of the transparent layer 121, with the exception of surfaces 110B of each seat 110.

As shown in figure 4, the waveguide formed by layers 121, 122 and 123 is thus capable of favoring the propagation of the light radiation LI along directions substantially parallel to the extension plane of plate 11, preventing the diffusion thereof through the top and bottom walls.

The light radiation LI can reach eggs 50 passing through surfaces 110B of each seat 110.

To increase the confinement of the optical path and reduce the dispersions of light radiation, in one embodiment of the present invention (not shown), the waveguide means may comprise other types of waveguides, for example optical fibers, operatively associated to the structure of each plate 11, so as to convey the light of the relative LED devices 21.

According to an alternative embodiment, shown in figure 5, the waveguide means may advantageously comprise one or more waveguides 30 set up for crossing, at least partly, the volume of the incubation chamber 10, in the longitudinal direction, that is, parallel to the flow of the solution 100.

In this case, eggs 50 can be arranged on support trays or simply left free to fluctuate in the volume of the incubation chamber 10.

The waveguides 30 may for example comprise optical fibers integrally connected to cover 105 and/or to one or more walls 104, 106 of the incubation chamber 10.

The waveguides 30 are operatively associated to the light source 20, which may advantageously comprise an array of LED devices, so as to convey the light radiation thereof at the position of eggs 50. According to an embodiment of the present invention, apparatus 1 comprises a control apparatus suitable for ensuring an optimal automated operation, so as to reduce the need of human interventions.

Preferably, apparatus 1 comprises dispensing means 140, suitable for dispensing the photosensitive substance, so as to keep the con concentration values of solution 100 constant. Such dispensing means may be positioned within the incubation chamber 10 (figures 2 and 5) or outside the same, for example at a mixing chamber located upstream of the inlet manifold 101.

Preferably, apparatus 1 also comprises first means 150 for sensing the quality of solution 100, which allow obtaining information (temperature, pH, presence of pathogenic agents, transparency level, etc.) on the actual status of solution 100 present in the incubation chamber 10.

Apparatus 1 may advantageously comprise second means 160 for sensing the fluency (light power per surface unit) of the light radiation LI for allowing controlling that solution 100 is constantly illuminated in an optimal manner by the light radiation LI .

Preferably, apparatus 1 also comprises a control unit 130 operatively connected to the dispensing means 140 and/or to the first sensing means 150 and/or to the second sensing means 160.

Such control unit 130 may advantageously be connected to a computer or a computer network, positioned remotely relative to apparatus 1.

The operation of apparatus 1 can thus be easily regulated, also remotely, with simple management features for alarms, signals, interventions and so on.

In a further aspect thereof, the present invention relates to a method for contrasting the presence or proliferation of pathogenic agents in an apparatus 1 for incubating eggs and/or embryos, for example for incubating fish eggs 50.

The method, according to the invention, comprises a first step of providing a solution 100 to the incubation chamber 10 of apparatus 1, wherein eggs 50 are seated so that the last mentioned are in contact with solution 100.

Solution 100 comprises water and at least one photosensitive substance of the tetrapyrrole family and/or structural analogs thereof.

In a second step the method, according to the invention, provides for providing at least one light source 20 that emits a light radiation with wavelength comprised between 580nm and 900nm. The method, according to the invention, comprises a third step of illuminating, at least partly, solution 100 present in the incubation chamber 10, by the light source 20, operatively associable to the incubation chamber 10.

The light radiation LI, emitted by the light source 20, stimulates the photosensitive substance of solution 100 to generate one or more active chemical species, capable of contrasting the presence or proliferation of said pathogenic agents.

Figure 7 shows the spectrum content of the light radiation LI, emitted by the light source 20, in relation to the water absorption spectrum (curve CI).

It can be seen that the interval of wavelengths R = [580nm, 900nm], selected for the light radiation LI, overlaps the water absorption spectrum, in the proximity of a minimum zone of the latter.

It is thus possible to obtain an effective penetration of the light radiation LI in the water. This allows evenly illuminating solution 100, even in the case in which the incubation chamber 10 has a relatively large capacity, with relatively low energy consumptions.

Figure 8 schematically shows a portion (for wavelengths greater than 450nm) of the absorption spectrum (curve C2) of a typical photosensitive substance, porphyrin C12, usable in solution 100, present in the incubation chamber 10 of apparatus 1.

It can be seen that the selected wavelengths are greater than a threshold value

It has been seen that for wavelengths below such threshold value, the light radiation LI is harmful to eggs 50.

As is clear, the range of wavelengths R = [580nm, 900nm] overlaps, at interval Ι1=[λ₁-0.05λ₁, λι+0.05λ₁]

a peak C2_A of the absorption spectrum of porphyrin C12.

Even though peak C2_A is a secondary absorption peak (the main absorption peak, not shown, is located around a wavelength of 420nm), it has been surprisingly found that the light radiation LI, for wavelengths comprised in interval II, allows effectively stimulating the generation of active chemical species by porphyrin CI 2, the light power used being equal. Figure 8 further shows the spectral curve C3 of a red LED device.

The spectral content of the red LED device is substantially overlappable to interval II, selected for the light radiation LI, and therefore, to peak C2_A of the absorption spectrum of porphyrin CI 2.

A red LED device, capable of emitting a wavelength in interval II, is therefore particularly suitable for illuminating solution 100, if the photosensitive substance used belongs to the porphyrin family. Of course, if the photosensitive substance is of a different nature, red or infrared LED devices may be used that are capable of emitting a light radiation at a different emission wavelength, for example comprised in one of intervals 12-16 listed above.

It has been experimentally proven that the direct radiation by a LED device, of the red type, is not harmful to eggs and/or embryos.

Two samples, each comprising about 1000 fertilized but non embryonated eggs of rainbow trout, were incubated in physiological conditions.

A first sample (Sample #1) was used an untreated control specimen whereas a second sample (Sample #2) was exposed to light with a wavelength of 640nm, emitted by a red LED source, with an exposure time of lh/day, for 4 consecutive days.

At daily intervals, the surviving or dead eggs were counted.

The counting data are shown in the following table.

These results show that the mortality of the irradiated trout eggs is substantially the same as that found for the eggs exposed to the red radiation emitted by the LEDs.

It is therefore possible to say that the irradiation with a red LED at 640nm is not intrinsically harmful to the eggs.

Figure 9 schematically shows some experimental results that show the efficacy of the disinfecting action performed by the chemical species generated by porphyrin CI 2, when illuminated with a red LED device, the spectral content whereof is represented by curve C3 of figure 8.

In such experimental test, a sample of MRSA bacteria (Methicillin-resistant Staphylococcus aureus) was placed in a water and porphyrin C12 solution, with concentration of 0.6 mg/1, and illuminated with a red LED device capable of emitting a light radiation with nominal wavelength equal to 645nm. Columns El and E2 respectively show the amounts of surviving bacteria, after a 30 min period in a control sample and in a test tube kept in dark chamber.

Columns E3-E6 respectively show the amount of surviving bacteria in a sample subject to irradiation.

It can be seen that the amount of surviving bacteria drastically decreases when the sample is subject to irradiation (compare, for example, columns E2-E3).

Moreover, it can be seen that the amount of surviving bacteria progressively decreases as the exposure time to the light radiation of the red LED device increases.

The above results show that the light radiation emitted by a red LED device is suitable for activating porphyrin CI 2.

Moreover, it is shown that the activation of porphyrin C12 occurs in such a way as to stimulate the generation of an effective amount of active chemical species with antimicrobial power by the above photosensitive substance.

It has been seen in the practice that apparatus 100 and the method thereof according to the invention allows achieving the intended objects.

The apparatus and method, according to the present invention, allow to controlling and effectively preventing the presence or proliferation of pathogenic agents in the incubation chamber, without impairing the physiological condition and the development of the eggs and/or embryos.

The apparatus, according to the present invention, exhibits high reliability levels and can be easily managed from the operating point of view, even remotely.

Thanks to a relatively simple structure, as can be seen in figures 1-5, apparatus 1 is easy and inexpensive to manufacture at an industrial level and easy to operatively install.

Claims

Apparatus (1) for incubating eggs and/or embryos of aquatic organisms characterized in that it comprises:

at least one incubation chamber (10) suitable for containing eggs and/or embryos in contact with a solution (100) that comprises water and at least one photosensitive substance of the tetrapyrrole family and/or structural analogs thereof;

at least one light source (20, 21) operatively associated to said incubation chamber, so as to illuminate at least partly the solution present within said incubation chamber, said light source emitting a light radiation (LI) with wavelength (λ) comprised between 580nm and 900nm, the light radiation emitted by said light source stimulating said photosensitive substance to generate one or more active chemical species, capable of contrasting the presence or proliferation of pathogenic agents.

Apparatus according to claim 1, characterized in that said light source emits a light radiation having wavelength (λ) comprised in an interval [λ;-0.05λ_ί , λί+0.05 λ; ], where i=l, 2, ...N and λ; is the wavelength of an i-th peak of the absorption spectrum of said photosensitive substance.

Apparatus according to claim 1 , characterized in that λ; is the wavelength, at which the absorption spectrum of said photosensitive substance exhibits a secondary absorption peak.

Apparatus according to one o more of the previous claims, characterized in that said light source comprises at least one LED device (21).

Apparatus according to one o more of the previous claims, characterized in that it comprises at least one support plate (11) positioned within said incubation chamber, said support plate being shaped so as to seat, at least partly, said eggs and/or embryos. Apparatus according to claims 4 and 5, characterized in that it comprises at least one LED device (21) operatively associated to said support plate (11).

Apparatus according to one o more of the previous claims, characterized in that it comprises waveguide means (121, 122, 123), operatively associated to said light source, said waveguide means being suitable for conveying the light radiation (LI) emitted by said light source (20, 21) at the position of said eggs and/or embryos. Apparatus according to claims 6 and 7, characterized in that said waveguide means comprise at least one waveguide (121, 122) obtained in the structure of said support plate (123), said waveguide conveying the light radiation emitted by said LED device (21) at the position of said eggs and/or embryos.

Apparatus according to claim 7, characterized in that said waveguide means comprise at least one waveguide (30) set up for crossing, at least partly, the volume of said incubation chamber, substantially in the longitudinal direction.

Apparatus, according to one or more of the previous claims, characterised it is an apparatus for incubating fish eggs.

Aquaculture plant characterized in that it comprises an apparatus according to one or more of the previous claims.

Method for contrasting the presence or proliferation of pathogenic agents in an apparatus (1) for incubating eggs and/or embryos of aquatic organisms (50), said apparatus comprising at least one incubation chamber (10) suitable for containing said eggs and/or embryos, characterized in that it comprises the following steps:

- providing said incubation chamber (10) with a solution (100) so that said eggs and/or embryos are in contact with said solution, said solution comprising water and at least one photosensitive substance of the tetrapyrrole family and/or structural analogs thereof; and

providing at least one light source (20, 21) that emits a light radiation (LI) with wavelength (λ) comprised between 580nm and 900nm; and

illuminating, at least partly, the solution present within said incubation chamber, by said light source, the light radiation emitted by said light source stimulating said photosensitive substance to generate one or more active chemical species, capable of contrasting the presence or proliferation of said pathogenic agents.

Method, according to claim 12, characterised in that said apparatus is an apparatus for incubating fish eggs.