EP3665259A1

EP3665259A1 - Method for fermenting a juice containing sugars and apparatus for implementing same

Info

Publication number: EP3665259A1
Application number: EP18765943.8A
Authority: EP
Inventors: René Chelle; François DAVAUX
Original assignee: AB7 Industries SA
Current assignee: AB7 Industries SA
Priority date: 2017-08-11
Filing date: 2018-08-02
Publication date: 2020-06-17
Also published as: FR3070044B1; US20200172840A1; WO2019030434A1; FR3070044A1

Abstract

The method comprises a step for culturing microorganisms and a fermentation step. The apparatus comprises two compartments (5 6), one for each step of the method, and the two are separated by a filtering barrier (8), which allows circulation of the medium to be fermented.

Description

PROCESS FOR FERMENTATION OF JUICE CONTAINING SUGARS AND APPARATUS

FOR ITS IMPLEMENTATION

The present invention relates to the field of production by fermentation of beverages from liquid nutrient media containing sugars and, in particular to the field of the production of an alcoholic beverage such as wine, fermented fruit juice or beer.

It has already been proposed in French Pat. No. 2,887,257 a process for preparing a fermented beverage from a fruit juice; in this patent, the main aim is to produce a low-alcohol drink from a natural fruit juice, whose initial sugar level can potentially lead to a beverage having a higher degree of alcohol. This process uses only biological methods of culture and fermentation of yeasts: it is based on fermentation mechanisms identical to those commonly used for the production of wines and makes it possible to obtain a beverage possessing attractive organoleptic qualities for the production of wines. consumers. This method consists, on the one hand, in feeding an aerobic culture reactor containing yeasts in multiplication phase with a first fraction of fruit juice, on the other hand, feeding an anaerobic fermentation reactor with the yeast-laden medium. obtained at the step mentioned above and with a second fraction of fruit juice, to obtain a must, and finally to filter the must to separate the yeasts and the fermented drink thus obtained. This patent also describes a device for the implementation of the aforementioned method; this device comprises a first reactor for the aerobic culture of yeasts, a second reactor for anaerobic fermentation by means of said yeasts, these reactors being equipped with means for introducing a determined fraction of fruit juice, a unit of filtration fermentation product and transfer means between the reactors and the filtration unit to obtain, by batch, the desired product.

The disadvantage of this state of the art is to require the implementation of expensive equipment and not to allow continuous production of the final product. The scope of the process according to this state of the art obviously includes the production of wines. In the case of wine, grape juice is traditionally subject to alcoholic fermentation and malolactic fermentation: these fermentations are carried out on the must in unstirred tanks, which requires a relatively long time, not conducive to obtaining high productivity.

It has therefore been proposed to improve the performance by using immobilized microorganisms and no longer free microorganisms in the liquid medium where the fermentations take place, but this procedure is not yet perfectly perfected (Z.Genisheva, J. Teixeira and JM Oliveira, Trends in Food Science and Technology, 40 (2014), pp. 33-47). We know, in particular, that the mode immobilization of microorganisms may affect the rate of the fermentation reaction, the ease of separation of microorganisms from the circulating liquid medium and the possibility of recovery of microorganisms after the end of fermentation (P. Strehaiano, F Centeno - IFV Midi-Pyrénées: "Microorganism Technical Meetings and Thermal Management", (18.12.2008), pp. 26-27). Among the difficulties that arise, some are related to the activity of the microorganisms used for the fermentations, others come from the methods of maintaining in place microorganisms that are immobilized on supports, others come from the structure internal of the reactors where the immobilized microorganisms are arranged.

In the state of the art (European Patent Application 0046613) it has been stated that the immobilization of microorganisms by adhesion on a solid support has, compared to other methods, the advantage of maintaining direct contact with the microbial population. with the liquid medium and, consequently, to reduce the limitations, by so-called "fusion" phenomena, of the transfer of the nutritive substances or substances produced by the microorganisms; it has also been reported that a high proportion of adherent microorganisms retain the ability to perform enzymatic reactions and to reproduce. By the same document, one skilled in the art knows that the adherent microorganism supports usable can be very diverse inorganic and organic materials.

The present invention aims to reduce the time of obtaining a fermented product from a fruit juice and, in particular, a wine from a must, using microorganisms fixed on a solid support , the overall equipment implemented remains of a reduced cost despite the significant increase in productivity due to the rapid execution of the necessary fermentations. In the case of the treatment of a grape must with a view to obtaining a wine, the process can be used for alcoholic fermentation and / or for malolactic fermentation. The process according to the invention gives rise to continuous production, which is particularly advantageous in terms of operation.

The present invention accordingly has, as a first object, a process for fermenting a continuous feed stream of liquid nutrient medium using yeasts or bacteria, this process comprising two stages, in the first of which, multiplication is ensured. aerobic said microorganisms through the feed stream with which they are brought into contact, and in the second of which, the microorganisms thus multiplied during the first step are used to ensure the fermentation of said nutrient medium and to output a flow of medium fermented nutrient, process for which the continuous implementation consists in ensuring, in the first step, the adhesion-fixing of at least a portion of the microorganisms, on at least one fractional solid support, in order to constitute, with the (or the) supports) solid (s) thus loaded (s) microorganisms, at least one filtering barrier interposed between the supply of nutrient medium f and the outlet of the nutrient medium fermented, characterized in that, to form the filter dam, the nutrient medium is passed on said solid supports loaded microorganisms grouped within one or more housing, to output, peripherally, the fermented nutrient medium.

According to a first implementation of the process according to the invention, the microorganisms are yeasts of alcoholic fermentation.

According to a second implementation of the method according to the invention, the microorganisms are malolactic fermentation bacteria. In this case, the liquid nutrient medium is a nutrient medium at least partially fermented and aeration is low.

According to one implementation of the method according to the invention, in the first step, the microorganisms are fixed to a plurality of fractional solid supports placed during said first step in the nutrient medium feed stream. .

In an implementation of the above-defined variant, the fractional solid supports made of wood, metal, sintered metal, a porous or non-porous plastic material, a porous organic material or a porous mineral material, in particular a porous ceramic material, or any other porous material compatible with the liquid to be fermented.

In another implementation, one chooses solid supports constituting threads, steel wires, stainless or not, lamellae, agglomerates of lamellae and / or son, metallic helicoids of cylindrical or frustoconical shape, or grids metal.

In an implementation of the method according to the invention, to constitute a filtering barrier with the fractional supports placed in the feed flow of nutrient medium during the first step, said feed stream is passed through a fixed tray, which redraws the fractional supports to form a bed containing a large part of the microorganisms multiplied during the first stage.

In an implementation of the method according to the invention, to constitute a filtering barrier with the fractional supports placed in the feed flow of nutrient medium during the first step, said feed stream is passed vertically to through a stack of horizontal grids arranged parallel to each other, the fractional supports remaining trapped in the spaces between the grids.

In one implementation of the process according to the invention, the filtering barrier is constituted around a cylindrical feed zone in nutrient medium, the outlet of which is carried out peripherally, said filtering barrier being constituted by a cylindrical crown of fractional supports retained externally by a sleeve, which constitutes the housing and which passes the liquid flow of nutrient medium to form the outlet of the fermented nutrient medium. In one embodiment of the method according to the invention, the housing is a plurality of cartridges, which may be removable, containing the fractional supports, substantially tubular in shape implanted on a tray, impervious to liquid, placed in the passage between the two compartments, cartridge whose upper part, impermeable to liquid, overflows with respect to the horizontal plane of said plate, on the one hand and, whose side wall is perforated material or metal grids, on the other hand The height of the overflow of the upper part of each cartridge corresponds substantially to the thickness of the bed of fractional solid supports on the plate which ensures the realization of a first fermentation. In this case, the flow of partially fermented nutrient medium from the bed is poured into each of the cartridges to undergo the second fermentation.

The invention also relates to an apparatus for implementing the method defined above, an apparatus which comprises two compartments, one of the compartments being equipped with a withdrawal outlet for the extraction of a liquid constituted by a nutrient medium, which has already undergone the desired fermentation, the other compartment being equipped with a feeding feed of said nutrient medium, not or weakly fermented, and a transit outlet to the first compartment, a filtering dam being disposed between the two compartments and allowing the transit of the nutrient medium between the two compartments, the liquid of one of the compartments containing, during operation, at least one solid support on which microorganisms have adhered, which have been introduced into said first compartment during a start-up phase, characterized in that the filtering barrier consists of said solid supports which are grouped together inside the r of one or more housing, optionally removable, to output, peripherally, the fermented nutrient medium.

In a variant of ^'the apparatus of the invention, during the startup phase, the microorganisms are introduced into the first compartment by recycling a fraction of the nutrient medium which has already undergone at least partially, the desired fermentation .

In a variant of the apparatus according to the invention, the filtering dam is a bed consisting of a layer of fractional carrier (s) carrying (s) adherent microorganisms, this bed being supported by a perforated plate or a fixed grid placed in the passage between the two compartments.

In a variant of the apparatus according to the invention, the two compartments are arranged in line with each other, the transit of the flow of nutrient medium being effected by gravity. In such a case, the housing may be a plurality of cartridges, containing the fractional supports, substantially tubular in shape implanted on a tray, impermeable to liquid, placed in the passage between the two compartments, the cartridge whose upper part, waterproof to the liquid, overflows with respect to the horizontal plane of said plate, on the one hand, and whose side wall is perforated material or in metal grilles, on the other hand. The height of the overflow of the upper part of each cartridge corresponds substantially to the thickness of the bed of fractional solid supports.

In a variant, the apparatus according to the invention comprises two units of the same structure, the withdrawal outlets of which are arranged in series to feed the inlet of a fermented product storage tank, one of the units ensuring a fermentation. by yeasts and the other by bacteria.

In a variant of the apparatus according to the invention, the bed of fractional supports is fluidized by the nutrient medium or air especially when it comes to yeasts.

In a variant of the apparatus according to the invention, the filtering dam is a cylindrical ring cluster of fractional supports retained, around a cylindrical feed volume of the nutrient medium, by a sleeve, which constitutes the housing, and which let the outlet flow of the fermented nutrient medium pass.

In a variant of the apparatus according to the invention, the second compartment is a closed volume delimited by a permeable perforated fabric or material fed by a pipe which brings therein the microorganisms, the oxygenated gas and the partially fermented liquid nutrient medium. . no, this second compartment enclosing the fractional supports on which the microorganisms adhere, the first compartment being an enclosure inside which said second compartment is disposed, said chamber being filled with the fermented liquid nutrient medium produced and then ejected from the second compartment the liquid circulation that passes through it, to feed an external storage tank.

Perforated material may be chosen as a plastic or metal material, the whole of which in its overall structure is permeable to the liquid nutrient medium. Such a material is in the form of film or membrane, flexible or not and thin.

In a variant of the apparatus according to the invention, the enclosure, which constitutes the first compartment is secured to the second compartment and its pipe to be placed in a storage tank as a unitary assembly constituting a cartridge .

In a variant of the apparatus according to the invention, the pipe of the second compartment is equipped with a pipe which, when its orifice is immersed in the tank, with which it is associated, allows a partial recirculation of the liquid contained in said tank .

In a variant of the apparatus according to the invention, the second compartment is an element containing at least one metal grid, whose son form supports for the culture of microorganisms.

In a variant of the apparatus according to the invention, the element comprises a plurality of grids, whose wires are close to each other to improve the efficiency of the fermentation, said grids being flat and parallel or rolled cylindrically, the element being provided with end sleeves, which hold the grids together and ensure the entry and exit of the liquid nutrient medium.

In a variant of the apparatus according to the invention, the liquid nutrient medium is a grape must and the fermented liquid nutrient medium obtained is a wine.

In a variant of the apparatus according to the invention, the liquid nutrient medium is a fruit juice and the apparatus produces a fermented juice.

In a variant of the apparatus according to the invention, the fermented nutrient medium obtained by the implementation of the apparatus, is a beer.

To better understand the invention, will be described hereinafter several embodiments and implementation shown in the accompanying drawing.

On this drawing :

- Figure 1 shows schematically, in axial section, a first embodiment of an apparatus according to the invention for ensuring the alcoholic fermentation of a grape must, the withdrawal of the fermentation product being a wine;

- Figure 2A shows schematically, in axial section, a second embodiment of an apparatus according to the invention having the same function as that of Figure 1, in its version for autonomous operation;

FIG. 2B represents the apparatus of FIG. 2A when it is directly associated with a vinification tank, this apparatus constituting a removable cartridge that can be associated with a tank or another;

- Figures 3 to 7 show schematically different embodiments of supports for yeasts or bacteria, which can be inserted into devices according to Figures 1, 2A or 2B;

- Figure 8 shows schematically the combination of an alcoholic fermentation reactor and a malolactic fermentation reactor with a wine storage tank.

Referring to FIG. 1, it can be seen that the reactor according to the invention has the shape of a cylindrical vessel designated by 1 as a whole, the vessel 1 comprising at the top a channel 2, through which a flow rate of air by means of a conventional device, whose detail is not shown (the arrow F0 symbolizes the air flow). At the base of the tank 1, there is a pipe 3, which allows to introduce into the tank 1 according to the arrow Fl, a flow of wort which is the liquid nutrient medium to ensure the filling of the tank. In the vicinity of the upper part of the tank 1, there is provided a withdrawal orifice 4, which allows, according to the arrow F2, the exit of the fermented liquid product that is desired. The tank 1 is separated into two compartments 5 and 6 by a perforated plate 7 parallel to the bases of the cylindrical tank 1. The perforated plate 7 is made of stainless steel and fixed on the side walls of the vessel 1; it is covered with a bed, of a certain thickness, consisting of small slices or wood chips on which adhere the yeasts that will be used to practice the alcoholic fermentation on the wort treated by the reactor. The wort introduced along the arrow Fl passes through the perforated plate 7, so that the bed of wooden slats, designated pat 8 as a whole, constitutes a fluidized bed due to the upward movement of the liquid introduced along the arrow Pl. The nature of the Wood slats 10 can be used to improve the organoleptic amounts of the fermentation product obtained.

The state of the fluidized bed 8, which has just been described, is that which exists in the vessel 1 in steady state; but, in a start-up phase, there is placed in the compartment 5, through the orifice 9, a load of wood slats 10 intended to constitute the bed 8. In the drawing, there is shown slats of wood thus introduced and falling by gravity towards the bed 8. The wood slats thus loaded into the reactor, have, by a prior treatment, been covered with yeasts which have adhered to them, these yeasts being those which will allow the alcoholic fermentation of the must introduced in the tank. In a variant, since the wort contains, in the natural state, the yeasts of alcoholic fermentation, it is possible not to carry out, as a preliminary, the adhesion of the yeasts on the wood slices, but to add more or less Yeast trade through the orifice 9 so that the adhesion of yeasts on the wood slices 10 is carried out in the compartment 5.

To regulate, in the compartment 5, the alcoholic fermentation, it is possible to implement a bypass circulation by means of a pipe 11, which connects the compartment 6 and the compartment 5 to prevent passage through the fluidized bed 8 , the flow rate of this pipe 11 being regulated by a pump 12.

When the start-up phase is complete and the degree of fermentation desired in the compartment 6 has been reached, the degree of fermentation in the compartment 6 remains constant since the yeasts of the fluidized bed 8 are multiplied as and when because of the oxygenation due to the introduction of air according to the arrow F0 and that the feeding according to the arrow Fl undergoes the alcoholic fermentation by the increase of the yeasts in the compartment 5. The possibility of modification by the pump 12 the amount of bypass makes it possible to predict, if desired, a production of yeasts to be extracted from the withdrawal stream according to arrow F2. The person skilled in the art knows the quantity of air necessary for the multiplication of the microorganisms, without altering, by oxidation, the quality of the desired final product.

It is clear that in the steady state the compartment 5 has practically no lamellae 10 which, after start-up, have all sedimented in the bed 8. The fact that the yeasts are adhered to the fractional supports constituted by the wood lamellae , is favorable for their efficiency in fermentation. It is clear that in the start-up phase of the reactor, which has just been described, a phase which is essentially used for culturing yeasts, it is possible to use, as nutritive medium, a solution of molasses which will subsequently be removed from the reactor via line 3.

FIG. 2A represents, in schematic axial section, a second embodiment of the reactor according to the invention. This reactor is in the general form of a cylinder 100, which is filled with a nutrient medium 101 consisting of a grape must. According to the axis of the cylinder 100, there is arranged a pipe 102 through which can be introduced into the cylinder 100, firstly, according to the arrow F'O a flow of air and secondly, according to the F'I arrow, a flow of nutrient medium that is to be subjected to a fermentation step; this flow of nutrient medium is pumped by means of the pump 112 inside the cylinder 100.

In the cylinder 100, there is arranged around the pipe 102, a compartment which is delimited by a cylindrical sleeve of fabric, inside which buffers consisting of metal strips have been packed, this filling being sufficiently tight for liquid flow. brought by the pipe 102 has a large contact area with the filling; it is arranged that the outlet of the pipe 102 is situated mainly towards the bottom of the cylinder 100 and that the flow in the sleeve 107 is upward, the ends of the sleeve being hermetically closed, the flow of nutritive medium 101 is evacuated radially to through the metal pad that has been designated 108 as a whole.

Since the flow F 'contains yeasts, these yeasts adhere to the constituent metal of the buffer 108 before the liquid flow exits the sleeve 107 to go into the cylinder 100 and can therefore ensure the exit of the nutrient medium 101 thus treated by the upper part of the cylinder 100, this outlet not being shown in FIG. 2A. The reactor of Figure 2A. can be used in isolation as in Figure 1; but it can also (see Figure 2D) be used in combination with a tank, which contains a wine that has already undergone alcoholic fermentation from the original must. In this case, the wine is placed in a tank 120, which has a manhole at its upper part, the hole being closed by a lid 121. The lid 121 is assembled on the apparatus of FIG. 2A, so that the cylinder 100 is immersed in the tank 120 and the free end of the pipe 102 also plunges into the liquid contained in the tank 120. The cylinder 100 comprises at its base a pump 112, whose sorb ejects the liquid , according to the arrow F'2, contained in the cylinder 100 inside the tank 120.

In this use, the subset of FIG. 2A is therefore mobile and can be used, like a removable cartridge, on different storage tanks 120. It is also possible to provide an installation consisting of two reactors 131 and 132 respectively for the alcoholic and malolactic fermentations; each of the reactors is of the type shown in FIG. 2A and the outlets are connected in series to feed a storage tank 130. When it is considered that the yeast multiplication is maximum in reactor 131, the temperature is adjusted to around 15 ° C to initiate the establishment of alcoholic fermentation; once this is complete, the alcoholic beverage is withdrawn and introduced into the malolactic fermentation reactor 132; after which, the wine is sent to a storage tank 130. This embodiment is shown in FIG.

Different embodiments of metal material supports that may be used for carrying out the process according to the invention will be described below, in particular in the embodiments previously described for the apparatus according to the invention.

In Figure 3, there is shown, in perspective, a textile formed of stainless steel son; this textile is wound on itself to form a substantially tubular three-dimensional shape designated 200 as a whole. The constituent steel wire of this textile may have a diameter up to about 1 mm; the adhesion of microorganisms is improved by streaking the surface of the wire, the hollow space along the axis of the winding allows to set up a perforated pipe (not shown) to ensure the aeration of microorganisms fixed on the wire

Figure 4 shows, in perspective, another textile support made of stainless steel wire; this support 201 consists of several coaxial cylindrical windings, each sheet is spaced from neighboring sheets by a distance of up to 5 mm. The spacing between the layers allows good air circulation, which is necessary for the multiplication: microorganisms, especially yeasts.

FIG. 5 represents, in perspective, a cylindrical cartridge 202 intended to be placed vertically in a reactor according to the invention; the feeding of this cartridge is carried out from bottom to top, the nutrient medium being sent by the two low inputs and the output being effected at the top of the cartridge. The interior of the cartridge 202 contains the fractional solid supports 202b, which are necessary for the fermentation; the cartridge is delimited, in the upper part as in the lower part, by plugs 202a, which hold the particulate supports arranged inside.

FIG. 6 represents a cartridge 203 of the type of that of FIG. 5 placed inside a vinification tank 204. The structure of this cartridge comprises, at the bottom, a plug 203a, which receives the nutritive medium at ferment, in the upper part, a plug 20312, which also receives a feed and, between the two plugs, a side wall capable of passing the treated liquid medium. This arrangement makes it possible to ensure good contact between the nutrient medium and the yeasts which have adhered to the filling elements 203c. placed in the volume between the side wall of the cartridge and its two plugs; this filling may be, as indicated in the state of the art, made of any suitable material, for example materials described in Figures 3 and 4 of this patent application. In this embodiment, the cartridge 203 is placed inside a vinification tank 204.

FIG. 7 represents, in perspective, a stack 205 of wire mesh constituting planar grids. These superposed metal sheets hold between them fractional supports 207, which are trapped between the parallel grids 206. As indicated for the embodiment of FIG. 6, the materials that can be used for the structures according to FIG. 7, are all the materials indicated in FIG. state of the art relating to the adhesion of microorganisms.

FIG. 9 shows in perspective, not in scale, cartridges 91 implanted vertically on a horizontal plate 92 arranged in a reactor according to the invention. The upper portion 93 of the cartridge 91, which protrudes with respect to the plane of the plate 92, is impervious to the liquid. The tray 92 is liquid-tight which allows the implementation of a first fermentation of the nutrient medium by the fractional solid supports loaded with microorganisms, forming a bed on the tray. The nutrient medium having partially fermented from the bed is poured into the cartridge 91 to undergo a second fermentation with the solid supports it contains. In this cartridge 91, the liquid having undergone the second fermentation leaves peripherally at its side walls 94. Advantageously, the cartridges 91 may be removable for replacement or loading solid supports outside the reactor. By-pass circulation can be provided, by means of a pipe which connects the compartment 6 and the compartment 5, with the liquid having undergone the first and the second fermentation (not shown).

Claims

1. A method for fermenting a continuous feed stream of liquid nutrient medium with yeasts or bacteria, this method comprising two steps, in the first of which aerobic multiplication of said microorganisms is provided by the feed flow with which they are brought into contact, and in the second of which, the microorganisms thus multiplied during the first step are used to ensure the fermentation of said nutrient medium and to provide at the outlet a flow of fermented nutrient medium, process for which the implementation continuously, consists in ensuring, in the first step, the attachment by adhesion of at least a portion of the microorganisms to at least one fractional solid support, in order to constitute, with the solid support (s) (s) ) thus loaded with microorganisms, at least one filtering barrier interposed between the feed in a nutrient medium and the outlet of the fermented nutrient medium, characterized in that in order to constitute the filtering barrier, the nutrient medium is passed over said solid supports loaded with microorganisms grouped together inside one or more housings, in order to output, peripherally, the fermented nutritive medium.

2. Method according to claim 1, characterized in that the microorganisms are yeasts of alcoholic fermentation.

3. Method according to claim 1, characterized in that the microorganisms are malolactic fermentation bacteria.

4. Method according to one of claims 1 to 3, characterized in that, in the first step, the fixation of the microorganisms on a plurality of fractional solid supports set up, during said first step, in the flow feeding nutrient medium.

5. The method of ^* Claim 4, characterized in that one realizes the solid supports wooden fractional, metal, sintered metal, a porous plastic material or not, porous organic material, porous mineral material, particularly in a porous ceramic material.

6. A method according to claim 5, characterized in that one chooses solid supports constituting son, stainless steel wire, stainless or not, lamellae, agglomerates of lamellae and / or son, metallic helicoidal shape cylindrical or frustoconical, or metal grids.

7. Method according to one of claims 1, 4 to 6, characterized in that one constitutes the filtering barrier around a nutrient feed zone of cylindrical shape, the output is carried out peripherally, said filtering barrier being constituted by a cylindrical ring, fractional supports held externally by a sleeve, which constitutes the housing and which passes the liquid flow of nutrient medium to form the outlet of the fermented nutrient medium.

8. Method according to one of claims 1, 4 to 6, characterized in that the housing is a plurality of cartridges, containing the fractional supports, substantially tubular in shape implanted on a tray, impervious to liquid, set up in the passage between the two compartments, cartridge whose upper part, impermeable to liquid, overflows with respect to the horizontal plane. of the plate, on the one hand and, whose side wall is perforated material or metal grids, on the other hand

9. A method according to claim 8, characterized in that the height of the overflow of the upper part of each cartridge substantially corresponds to the thickness of the bed of fractional solid supports on the plate which ensures the realization of a first fermentation.

10. Apparatus for carrying out the method according to claim 1, which apparatus comprises two compartments (5, 6), one of the compartments being equipped with a withdrawal outlet (4) for extracting a liquid. constituted by a nutrient medium, which has already undergone the desired fermentation, the other compartment being equipped with a feeding feed (3) of said nutrient medium, not or weakly fermented, and a transit outlet to the first compartment , a filtering barrier (8) being arranged between the two compartments and allowing the nutrient medium to pass between the two compartments, the liquid of one of the compartments containing, during operation, at least one solid support (10) on which have adhered microorganisms, which were introduced into said first compartment (S) during a start-up phase, characterized in that the filtering barrier (8) consists of said solid supports (10) which are grouped together in the The interior of one or more housing (107,200,201,203,91), optionally removable, to output, peripherally, the fermented nutrient medium.

11. Apparatus according to claim 10, characterized in that, during the startup phase, the microorganisms are introduced into the first compartment (5) by recycling a nutrient medium fraction which has already undergone at least partially fermentation desired.

12. Apparatus according to claim 10, characterized in that the two compartments (5,6) are arranged in line with each other, the flow of the nutrient medium flow being carried out by gravity and that the housing is a plurality of cartridges (91), enclosing the substantially tubular shaped fractional supports (10) implanted on a liquid-impervious tray (92) provided in the passage between the two compartments (5, 6), the cartridge of which upper part (93), impermeable to liquid, overflows with respect to the horizontal plane of said plate, on the one hand, and whose side wall (94) is perforated material or metal grids, on the other hand

13. Apparatus according to claim 12, characterized in that the height of the overflow of the upper portion (93) of each cartridge (91) substantially corresponds to the thickness of the bed of fractional solid supports (10).

14. Apparatus according to claim 10, characterized in that it comprises two units of the same structure (131,132), the withdrawal outlets are arranged in series to feed the inlet of a storage tank (130) of fermented product , one of the units (131) providing fermentation by yeasts and the other (132) by bacteria.

15. Apparatus according to claim 10, characterized in that the filtering dam (8) is a cylindrical ring cluster of fractional supports (10) retained, around a feed volume cylindrical nutrient medium, by a sleeve (107) which is the housing (107,200,201,203), and which passes the outlet stream of the fermented nutrient medium.

16. Apparatus according to claim 15, characterized in that the second compartment is a closed volume delimited by a fabric or permeable perforated material and fed by a pipe (102) which brings the microorganisms, the oxygenated gas and the liquid nutrient medium. partially fermented or not, this second compartment enclosing the fractional supports (108) on which the microorganisms adhere, the first compartment being an enclosure inside which said second compartment is disposed, said chamber being filled with the fermented liquid nutrient medium produced then ejected from the second compartment by the liquid flow that passes through it, to feed an external storage tank.

17. Apparatus according to claim 16, characterized in that the enclosure, which constitutes the first compartment is secured to the second compartment and its pipe (102) to be put in place in a storage tank (120) as monoblock assembly constituting a cartridge.

18. Apparatus according to claim 17, characterized in that the pipe (102) of the second compartment is equipped with a pipe which, when its orifice is immersed in the tank (120), with which it is associated, allows partial recirculation. liquid contained in said tank.

19. Apparatus according to one of claims 17 or 18, characterized in that the second compartment is an element containing at least one metal gate, whose son form supports for the culture of microorganisms.

20. Apparatus according to claim 19, characterized in that the element comprises a plurality of grids (203g), whose son are close to each other to improve the efficiency of fermentation, said grids being flat and parallel or rolled cylindrically, the element being provided with end sleeves (202a, 203¾, 203b), which hold the grids together and ensure the entry and exit of the liquid nutrient medium.