“Homogenisation process for the preparation of a cellular component homogenate”

The present invention relates to a cellular component homogenate in liquid form, as well as to a cellular component homogenate in solid form, preferably as a freeze-dried or sprayed powder. Furthermore, the present invention relates to a homogenisation process for the preparation of said cellular component homogenate in liquid form and said cellular component homogenate in solid form, preferably as freeze- dried or sprayed powder. Lastly, the present invention relates to a composition comprising said cellular component homogenate in solid form and, optionally, one or more pharmaceutical or food grade or cosmetic additives and excipients, for use in the pharmaceutical, nutraceutical, medical devices, foods for special medical purposes, dietary supplements and food industry both in the human and veterinarian field, as well as for use in the cosmetics industry.

The techniques and methods of extraction of the various bacterial components present in bacteria, generally Gram-positive and Gram-negative on a large scale at industrial level still reveal many limits and drawbacks both in terms of the process methods used and in terms of the plant equipment used.

The limits and drawbacks still existing in the industrial production of bacterial components or bacterial extracts (more generally of lysates or bacterial homogenates) cause the product obtained, by means of partial or total breaking down of the cell wall following a whole cell processing, not to be functional (able to carry out its probiotic functional activity), not to be stable over time, well conserved under the operating conditions and processable for subsequent transformation into finished products, for example nutraceutical or cosmetic products. In addition, the product obtained ca be reproduced or standardised from a qualitative and quantitative point of view.

The technique for preparing a bacterial lysate, obtained through the lysis of whole cells mechanically, is affected by the preparation process used because the breaking down or lysis of the cell is carried out by means of a strong mechanical action carried out using mechanical stirrers or mixers or centrifuges.

During the research and development activity thereof, the Applicant was able to verify that when the partial or total breaking down, or lysis of the cells, is carried out mechanically, this type of breaking down or lysis is not able to preserve and conserve the bacterial components contained in the cells or belonging to the cells, in an optimal way, both from the productive point of view and from the point of view of metabolic activity and functional properties in terms of stability (stability over time and/or upon temperature change). The partial or total breaking down or lysis of the cells is carried out mechanically through the direct contact of the liquid in which the cells, for example a bacterial biomass, are present and the mechanical cutting elements (rotating blades), or turbines or mixing blades, or centrifugation mills present in a mechanical stirrer or in a mixer or in a centrifuge.

The direct contact that occurs when the cells, contained in the bacterial biomass, are subjected to mechanical processing, for example, in a mechanical stirrer or mixer provided with stirring means (mixing knives or blades) or cutting means (cutting blades), which rotate at high rotation speeds, significantly affects the final product or bacterial lysate obtained, in terms of metabolic activity, functional properties and stability.

Furthermore, during the research and development activity thereof, the Applicant was able to verify that when said cell lysis is carried out through methods other than the mechanical one (for example, by means of a pressure homogenisation), the operating conditions are decisive toward producing a lysate or homogenate of bacterial strains capable of keeping the metabolic activity and the functional properties of the bacterial strains - from which said lysate or homogenate derives - intact, live and viable, and so that said activities and functionalities of the lysate or homogenate are stable over time and/or upon temperature change.

After a long and intense research and development activity, the Applicant developed a new process for the preparation of a homogenate or bacterial lysate which advantageously overcomes the aforementioned limits and drawbacks. In particular, provided through the process of the invention is a homogenate or bacterial strain lysate (liquid or solid) in which some components of the cell walls (for example, peptidoglycan or murein) of the bacterial strains subjected to the process maintain their structure (or three- dimensional structure) and thus their functionality. Furthermore, said components of the cell wall comprised in the lysate or homogenate (liquid or solid) obtained by the process of the invention are not bound to other cellular components and, therefore, they are capable of carrying out their metabolic and functional activity. Lastly, the structure and the amount of said components of the cell walls (e.g. peptidoglycan) included in the homogenate (liquid or solid) obtained by means of the process of the invention are stable over time (for example, from 1 to 6 months or 12 months) and upon temperature change (for example from 5°C to 40°C). In the light of the above, the process of the present invention provides a functional product comprising cell wall components of bacterial strains (e. g. peptidoglycan or murein) wherein said cell wall components are active, effective and stable over time.

Forming an object of the present invention is a process for the preparation of a cellular component homogenate in liquid form having the characteristics as defined in the attached claims. Forming an object of the present invention is a process for the preparation of a cellular component homogenate in solid form, preferably as a freeze-dried or sprayed powder, having the characteristics as defined in the attached claims.

Forming an object of the present invention is a cellular component homogenate in liquid form having the characteristics as defined in the attached claims.

Forming an object of the present invention is a cellular component homogenate in solid form, preferably as a freeze-dried or sprayed powder, having the characteristics as defined in the attached claims.

Forming an object of the present invention is a composition comprising said cellular component homogenate in solid form (preferably as a freeze-dried or sprayed powder) and, optionally, one or more pharmaceutical or food grade additives and excipients, for use according to the attached claims.

Preferred embodiments of the present invention will be described in greater detail hereinafter without wishing to limit the scope of the present invention in any manner whatsoever.

The terms "sprayed” or "spraying” can be used as nouns or adjectives related to a spraying step.

The term "room temperature” indicates a temperature comprised from 15°C to 35°C, preferably from 20°C to 30°C, even more preferably at about 25°C.

DESCRIPTION OF THE FIGURES

Figure 1 refers to the process diagram of the homogenisation process (P0M01 and P0M02) subject of the present invention, according to FR-I or FR-II.

Figure 2 refers to a diagram of a homogeniser valve (or valve of a homogeniser capable of homogenising).

Figure 3 refers to the dot plots of cytofluorimetric reading (with cytofluorimeter) of a bacterial strain L. fermentum LF5 DSM 32277 (deposited by Probiotical S.p.A. on 18.3.2016) for the evaluation of the processing steps of the homogenisation process, subject of the present invention.

Figures 4A, 4B and 4C refer to gravimetric quantitation (% w/w) of the peptidoglycan in samples of cellular component homogenate of bacterial strains after 3, 6 and 12 months at 40°C, 25°C or 5°C. DETAILED DESCRIPTION OF THE INVENTION

The Applicant found it useful to develop a new process (fig.1) for the preparation of a cellular component homogenate in liquid form (or cell homogenate in liquid form (0M01) that is stable and reproducible (homogenisation process (P0M01), subject of the present invention. Said cells subjected to the homogenisation process are cells of live and viable bacterial strains with metabolic activities and functional properties beneficial to the subjects to whom they are administered (probiotic bacterial strains).

Said cell homogenate in liquid form (0M01), obtained from said homogenisation process (P0M01), is then subjected to a further processing process (P0M02) which provides for a step in which the freeze drying or spraying of said 0M01 is carried out, optionally preceded by a cryoprotection step, to obtain a homogenate (0M02) in a freeze-dried or sprayed solid form (powder), preferably sprayed.

Said freeze-dried or sprayed homogenate (0M02) in solid form (powder) obtained from said processing process (P0M02), is then used in mixture with at least one or more pharmaceutical or food grade or cosmetic additives and excipients, to obtain a product for use in the pharmaceutical, nutraceutical, medical devices (EU Reg. 2017/745), foods for special medical purposes (FSMPs), dietary supplements and food industry both in the human and veterinarian field, as well as for use in the cosmetics industry.

According to a first embodiment (in short FR-I), the process for the preparation of a cellular component homogenate in liquid form (homogenisation process (P0M01) subject of the present invention) schematically provides for:

- a step in which at least one probiotic bacterial strain is activated or revived;

- a step in which said strain is grown to obtain a laboratory stock culture containing said strain;

- a step in which said laboratory stock culture is fermented in a fermentation broth to obtain a fermented biomass having a concentration comprised from 1x10 ⁶ to 1x10 ¹⁰ AFU ( active fluorescent unit), preferably from 1x10 ⁷ to 1x10 ⁹ AFU or preferably from 10x10 ⁹ AFU to 50x10 ⁹ AFU;

- a step in which a said fermented biomass is concentrated by a factor from 5 to 20 times, to obtain a concentrated biomass;

- a step in which the concentrated biomass is washed to obtain a concentrated and washed biomass;

- a homogenization step carried out in a pressure homogeniser, to obtain a cellular component homogenate in liquid form, wherein said homogenisation is carried out at a pressure from 1200 bar to 2000 bar (for example, 1250 bar, 1300 bar, 1350 bar, 1400 bar, 1450 bar, 1600 bar, 1700 bar, 1800 bar or 1900 bar), preferably from 1500 bar to 2000 bar.

The industrial fermentation step is preceded by a step in which the bacterial cell strain to be subjected to homogenisation is first activated/revived after thawing the respective cryovial. The cryovials of the WCB (working cell bank) of said strain are collected from the freezer and inoculated in anaerobiosis in a test tube, for example measuring about 15 ml, in the medium provided for by the protocol (variable from strain to strain) at an appropriate temperature (range 32°C-37°C). Growth steps are carried out in test tube, sterile disposable Petri dish and in a conical flask to obtain the laboratory stock culture to be fermented. The stock culture is then subjected to a fermentation step. The industrial fermentation phase is carried out by using methods, fermentation media and equipment known to the man skilled in the art of fermentations of lactic bacteria and bifidobacteria or other genus of anaerobic bacteria.

Obtained at the end of the industrial fermentation step is a bacterial biomass in liquid form which, once produced, is preferably concentrated by means of techniques and equipment known to the man skilled in the art (for example, continuous discharge or discontinuous loading centrifuges, filtration systems) by a factor of 5-20, preferably 10, with respect to the concentration of the cells used in the fermentation step, to obtain a concentrated bacterial biomass. If, for example, at the end of the step in which the fermentation takes place there is a fermented biomass having a concentration of bifidobacteria or lactic bacteria or other genus of anaerobic bacteria (in live and viable form) from 1x10 ⁹ AFU to 50x10 ⁹ AFU, preferably of about 10x10 ⁹ AFU, at the end of the step in which the biomass is concentrated, there will be a biomass concentration from 10x10 ⁹ AFU to 500x10 ⁹ AFU, preferably from 50-200x10 ⁹ AFU, more preferably 100x10 ⁹ AFU. The concentration step is carried out with continuous discharge centrifuges at room temperature.

The concentrated bacterial biomass of bifidobacteria or lactic bacteria or other genus of anaerobic bacteria (in live and viable form) is then preferably washed to obtain a washed and concentrated bacterial biomass of the bacterial strain in question. The washing step is carried out with sterile water cooled at a temperature comprised from 5°C to 45°C, preferably from 10°C to 25°C, to obtain a concentrated and washed biomass of said bacterial cell strain.

The washed and concentrated bacterial biomass is in liquid form and it contains live and viable cells, it is a biomass that is stable and reproducible from an industrial point of view and in terms of functional properties and activities.

The washed and concentrated bacterial biomass has a bacterial concentration, for example in the order of 100 billion (100-200x10 ⁹ ) and it contains - therein - for example water, fermentation residues, elements of the medium of choice for the growing bacterial strain, the release factors of the bacterial strain itself (postbiotic factors).

The washed and concentrated bacterial biomass exiting from the fermentation step having a temperature comprised from 10°C to 35°C, preferably from 20°C to 25°C, is supplied, for example by means of a pipe and a volumetric pump, flowing into a collection tank and subsequently transferred to the industrial homogeniser. According to a second embodiment (in short FR- II), the process for the preparation of a cellular component homogenate in liquid form (homogenisation process (P0M01) subject of the present invention) schematically provides for:

- a step of preparing at least one batch of a cell strain of probiotic freeze-dried bacteria, such as bifidobacteria or lactic bacteria or other genus of anaerobic bacteria;

- a step of re-hydrating - in a suitable hydrating fluid - said batch of a bacteria cell strain freeze-dried at room temperature to form a biomass of the bacteria cell strain (or suspension of the strain in said hydrating fluid) having a bacterial cell concentration comprised from 10c10 ^L 9 to 500c10 ^L 9 AFU, preferably from 100C10 ^L 9 to 300C10 ^L 9 AFU, more preferably 200-250x10 ⁹ AFU, measured by means of cytofluorimetry;

- a step of homogenising said suspension of a bacterial strain carried out in a pressure homogeniser, to obtain a cellular component homogenate in liquid form, wherein said homogenisation step is carried out at a pressure from 1000 bar to 2000 bar (for example, 1200 bar, 1250 bar, 1300 bar, 1350 bar, 1400 bar, 1450 bar, 1600 bar, 1700 bar, 1800 bar or 1900 bar), preferably from 1500 bar to 2000 bar.

For example, according to the second embodiment (FR-II), one of the freeze-dried bacterial strains of the Probiotical collection is resuspended in drinking water or physiological solution at room temperature in an industrial dissolver to obtain a concentrated biomass from 100C10 ^L 9 to 300C10 ^L 9, preferably 200C10 ^L 9.

In said first embodiment (FR-I) and in said second embodiment (FR-II) the homogenisation step takes place under similar conditions to obtain a cellular component homogenate in similar liquid form.

The industrial homogeniser (fig.1 , according to FR-I or FR-II), used both in said first embodiment (FR-I) and in said second embodiment (FR-II) is of the pressure type to carry out a homogenisation step by means of pressure only. The homogenisation step is solely and exclusively carried out using a pressure exerted on a portion of the biomass volume in a continuous dynamic process. The homogenisation step does not in any way provide for the use of the mechanical cutting elements or turbines or mixing blades, or centrifugation mills present in a mixer or in a centrifuge at direct contact with the biomass.

In the homogenisation step, the cell wall is broken down solely and exclusively using the operating pressure, which is exerted on a portion of the biomass volume (for example a volume from 10 litres to 100 litres) and not by means of a mechanical breaking down using metal cutting parts, or turbines, or mixing blades, or centrifugation mills.

The pressure homogenisation step applied to the concentrated and washed biomass according to FR-I or to the biomass according to FR-II is able to determine the breaking down of the bacterial wall and micronize the particles of the treated product (cells present in the biomass) in order to improve the mixing and stability thereof. In other words, the homogenisation step carried out with a pressure homogeniser allows to make the cellular components - such as for example the cell wall or the components of the cell wall - present in the biomass cells homogeneous. An emulsion biomass (homogenate in liquid form) is obtained with a high degree of suspension and dispersion in which the micronized particles (the cellular components, for example peptidoglycan) are stable (with time and/or upon temperature change) and uniform. Preferably, said biomass has a density comprised from 1.02 to 1.10 weight/volume.

One type of industrial pressure homogeniser that can, for example, be used in the context of the present invention is of the 3 plunger type, with rear cooling chamber, positioned on the rear part of the compression head. Housed in the compression head are the plungers, whose task is to pump the biomass under pressure (for example, product input pressure: 3-4 bar), the intake and delivery valves, and the homogeniser valve (figure 2), where the biomass is homogenised (at an operating pressure comprised from 1200 bar to 2000 bar, preferably from 1500 bar to 2000 bar). Figure 2 shows a diagram of a homogeniser valve in which the product being processed (biomass), pushed by a discontinuous pump, is forced to sudden changes in energy, from potential (high pressure (or primary pressure), low speed) to kinetics (low pressure (secondary pressure), high speed).

Said primary pressure is comprised in a range from 1200 bar to 2000 bar, preferably from 1500 or 1600 bar to 2000 bar. Said primary pressure is also defined as the "operating pressure” being the higher pressure exerted during the homogenisation step.

Said secondary pressure is comprised in a range from 50 bar to 200 bar, preferably from 100 bar to 150 bar.

One type of homogeniser may have, for example, a supply pressure of about 3-4 bar, a supply flow rate of about 1500-2500 L/hour and an operating pressure up to about 2000 bar.

For example, a type of homogeniser that can be used in the context of the present invention may have the following specifications:

1. flow rate range 1000-2000 litres/hour;

2. primary pressure range: 1600-2000 bar;

3. secondary pressure range: 100-150 bar;

4. condensate temperature range: 45°C-65°C;

5. Water pressure range: 2.5-3.5 bar (for vapour condensation);

6. product input pressure range: 3-4 bar.

The two pressures, the primary and the secondary, are exerted in line and both are fundamental for the optimal homogenisation of the product: as a matter of fact, pressure shocks obtained at different pressures with respect to each other are needed to improve the homogenisation. The homogenisation step with the relative pressures is set at the beginning of the first cycle and it remains stable and unchanged throughout the homogenisation process during the processing steps, which can vary from strain to strain.

The homogenisation step comprises a number of processing cycles or steps comprised from 1 to 10 for the total volume of the biomass, preferably from 4 to 8, even more preferably from 3 to 6. The homogenisation step is carried out over a period of time which depends on the number of cycles or steps carried out on the biomass and on the type of homogeniser (flow rate in litres/hour and operating pressure in Kg/cm ² or bar) used. For example, when processing of 1000 litres of biomass in a pressure homogeniser having a flow rate of 2000 litres/hour and an operating pressure of 2000 bar, a processing cycle or step will last about 0.5 hours. If the homogenisation step provides for 6 cycles, the homogenisation step of 1000 litres of biomass is carried out in 3 hours.

The expression processing cycle or step is used to indicate that the whole volume of the concentrated and washed bacterial biomass according to FR-I or of the biomass according to FR-II flowing into the homogeniser is subjected to a pressure homogenisation, homogenization carried out on n portions of said total volume of said biomass (for example, volume portion from 10 ml to 100 ml) in a dynamic continuous process as in figure 1.

Once a volume portion of said biomass has been pressure homogenised, this portion is continuously transferred and collected in a temperature-controlled container (collection tank). Once the whole volume of said biomass has been pressure homogenised, a processing cycle or step is completed. A processing cycle or step will be considered completed once the whole biomass volume will have been collected in said container at a controlled temperature. The temperature of the homogenised biomass exiting from the homogeniser and entering into said container is comprised from 15°C to 35°C, preferably from 20°C to 30°C, even more preferably at about 25°C. The temperature of the homogenised biomass in said container (collection tank) is comprised from 5°C to 20°C, preferably from 10°C to 15°C.

Once the whole biomass volume has been pressure homogenised and collected in said container (collection tank) at the end of a cycle, the volume is once again supplied back into said homogeniser to carry out a further processing cycle or step under the same operating conditions as the previous cycle. Therefore, the whole volume of said biomass will be cyclically supplied to said homogeniser in a number of times equal to the number of cycles or steps established for a given bacterial strain.

At the end of each processing cycle or step a sample of homogenised biomass is taken from said container (collection tank) at a controlled temperature (temperature 5°-20°C or 10°C-15°C) and subjected to a cytofluorimetric reading (cytofluorimetry) by means of a cytofluorimeter to determine the membrane integrity reading value (as the value of cells not lysed by the pressure homogenisation), a value preferably comprised from 0.05% or 1 % to 10% (for example, 0.01%, 0.5%, 1.5%, 2%, 2.5%, 3%, 4%, 5%, 6%, or 8%) of the initial membrane integrity value of the concentrated and washed biomass according to FR-I or of the biomass according to FR-II. Such membrane integrity value is the optimal range that allows to obtain a plate growth comprised from 1 % to 0.01%, preferably of about 0.1 %. For example, if the concentration of bacteria with an intact membrane of the concentrated and washed biomass at the inlet of the homogeniser is about 100x10 ⁹ AFU, at the end of the homogenisation steps, there for example will be (1%) equal to 1x10 ⁹ AFU, so as to have a plate count equal to 1x10 ⁶ CFU (0.1 % with respect to the cytofluorimetric reading after homogenisation).

By way of example, added hereto is fig. 3 (A and B) highlighting the differences between the reading of the concentrated and washed biomass (before the homogenisation step) and the reading at the end of the homogenisation cycle: the membrane integrity cloud disappears completely in box Q3-1 of the T6 dot plot. Dot plot 1 shows the membrane integrity of an L. fermentum LF5 DSM 32277 fermentate (deposited by Probiotical S.p.A. on 18.3.2016) with a cell count of about 100x10 ⁹ (box Q3-1). Dot plot 2 shows that after 6 cycles or steps (homogenisation step completed) the cells are no longer totally intact (only 2.05%) and the cellular components are moved into box Q3-3.

Table 1 refers to fig. 3A, while table 2 refers to fig. 3B.

In tables 1 and 2 and in figures 3A and 3B, the boxes have the following meanings:

Q3-1 : membrane integrity initial value of the concentrated and washed biomass prior to the pressure homogenisation step;

Q3-2: damaged cell value

Q3-2: cellular component value

Q3-2: dead cell value

Table !

Table 2

The homogenisation step ends upon reaching said membrane integrity value comprised from 0.1 % or 1 % to 10%, preferably from 0.5% to 6%, more preferably from 1% to 3%, of the initial value of the concentrated and washed biomass according to FR-I or of the biomass according to FR-II.

At the end of the homogenisation step and, therefore, at the last processing cycle or step of the whole biomass volume, all the homogenised biomass will be present in said collection container at controlled temperature (temperature 5°-20°C or 10°C-15°C).

The concentrated, washed and homogenised bacterial biomass (or biomass at the end of the homogenisation step) is in liquid form and it therein contains cell wall fragments, such as glycoproteins, phospholipids, murein (or peptidoglycan) and all intracellular components such as for example DNA, ribosomes and proteins.

Murein (also known as peptidoglycan or bacterial mucopeptide) is a polymer that represents an essential component of the cell wall of bacteria being the main factor responsible for the cell integrity. The bacterial classification resulting from Gram staining is based on the different composition of the wall made of murein. It is therefore well known that murein is a fundamental component of the bacterial wall and it is found both in Gram-positive and in Gram-negative, but in different proportions. It is very abundant in Gram+ (90% of the wall) and less abundant in Gram- (10% of the wall). In the context of the present invention the terms "murein” and "peptidoglycan” are used as synonyms of the same substance.

The concentrated, washed and homogenised bacterial biomass (or biomass at the end of the homogenisation step) of bifidobacteria or lactic bacteria or other genus of anaerobic bacteria represents the cellular component homogenate in stable and reproducible liquid form (OM01), subject of the present invention.

Said cellular component homogenate in stable and reproducible liquid form (OM01), obtained from said homogenisation process (POM01) (according to said FR-I or FR-II), is then subjected to a further processing process (POM02), which provides for a step in which freeze-drying or spraying (preferably a spraying step) is carried out, possibly (optionally) preceded by a step in which a cryoprotection (cryoprotection step) is carried out to obtain a freeze-dried or sprayed homogenate in solid form (OM02) - fig. 1. Thus, said homogenate in a freeze-dried or sprayed solid form can derive from a process according to the invention (P0M01 and P0M02) comprising or not comprising a cryoprotective step.

Basically, according to an aspect of the invention, the concentrated, washed and homogenised bacterial biomass or biomass at the end of the homogenisation step (in short, the homogenised biomass) is subjected to a cryoprotection step using standard cryoprotectants in use, such as for example polysaccharides, such as for example sugars, preferably sucrose alone or in admixture, for example, with sodium, potassium, calcium or magnesium salts of phosphoric acid.

Said cryoprotection step provides for that the cryoprotectant in liquid form, prepared and previously cooled (temperature from 5°C to 15°C, preferably about 10°C), be added, at a concentration comprised from 5% to 40% by weight with respect to the weight of the homogenised biomass in liquid form, preferably equal to about 20%, for transfer under overpressure (pressure from 0.5 bar to 1.5 bar) from the cryoprotectant container to the homogenised biomass in liquid form in the container at a temperature comprised from 5° to 20°C, preferably about 10°C, to obtain a homogenised and cryoprotected biomass.

At the end of the cryopreservation step, the homogenised and cryoprotected biomass, still in liquid form, is subjected to a subsequent freeze-drying or spraying step, preferably spraying step, to obtain a biomass in solid form having a concentration for example 10-15 times (for example 3, 5, 8, or 12 times) more concentrated than the biomass (according to FR-I or according to FR-II) entering the homogeniser.

If, for example, at the end of the step in which the biomass concentration is achieved (according to FR-I) there is a concentrated biomass having a concentration of bifidobacteria or lactic bacteria or other genus of anaerobic bacteria (in live and viable form) of about 100x10 ⁹ AFU, at the end of the freeze-drying or spraying step, there will be a component homogenate in solid form OM02 (powder) which therein contains cell wall fragments, such as for example glycoproteins, phospholipids and peptidoglycan (murein) and all intracellular components, such as for example DNA, ribosomes and proteins.

In this case (both in the presence and in the absence of the cryoprotection step) an amount of murein (or peptidoglycan) comprised from 5% to 40% by weight, preferably from 10% to 30% by weight, even more preferably from 15% to 25% by weight with respect to the weight of the freeze-dried or sprayed sample (homogenate in solid form of the present invention) can be obtained.

Said homogenate in solid form of the present invention (obtained from the process of the present invention according to FR-I or FR-II and from said step of pressure homogenisation step and subsequent freeze drying or spraying step) comprises murein (or peptidoglycan) at an initial amount (for example, at a percentage by weight comprised from 5% to 40%, preferably from 10% to 30%, more preferably from 15% to 25%, with respect to the weight of the homogenate in solid form) predominantly constant over time (for example from 1 month to 5 years or from 6 months to 3 years or 12 months to 24 months) and/or upon temperature change (for example, from 0°C to 50°C, preferably from 5°C to 40°C, more preferably from 15°C to 35°C). Furthermore, said murein (or peptidoglycan) comprised in said homogenate in liquid form and/or in solid form maintains its structure stable (over time and/or upon temperature change), it is mainly not bound to other cellular components and, therefore, it is able to exert a metabolic and functional activity. For example, it can be assumed that, following homogenisation, there be formed cell wall parts tto which the peptidoglycan chains remain complexed and act as activators.

The term "constant” or "prevalently constant,” referring to the amount of peptidoglycan comprised in said homogenate, means that the amount (for example, amount by weight) of peptidoglycan present in the homogenate at the end of the pressure homogenisation step (in short, initial amount of peptidoglycan) remains approximately constant in a time range with a possible change of said amount at a percentage comprised from 0.5% to 10% (for example, 1%, 2%, 3%, 4%, 5%, 6% or 8%) with respect to 100% of the amount.

Freeze-drying and spraying are carried out using methods and equipment known to the man skilled in the art.

For example, spraying can be carried out with an spray dryer normally used for the spraying and drying liquid suspensions with a protocol which provides for an input temperature of the drying air of about 150°C-180°C and an output temperature of about 70°C-90°C.

In an embodiment, the cellular component homogenate in solid form OM02 (freeze-dried or sprayed powder) is used in a manner such to be mixed with one or more pharmaceutical or food grade or cosmetic additives to obtain a composition which can be advantageously used in the production of finished products in the pharmaceutical, nutraceutical, medical devices, food for special medical purposes, supplements and food industry for both human and veterinary purposes, as well as for use in the cosmetic industry.

Aspects of the present invention according to the first embodiment FR-I are reported below (FR-l-n°): FR-l-1. A process for preparing a cellular component homogenate in liquid form comprising the following steps:

- reviving at least one bacterial cell strain selected from among the group comprising bifidobacteria, lactic bacteria or other genus of anaerobic bacteria, after thawing the respective cryovial to obtain a strain culture of viable bacterial cells; - carrying out growth phases - in a test tube, in a sterile disposable Petri dish and in a conical flask - of said strain culture of viable bacterial cells to obtain a laboratory stock culture containing said strain of viable bacterial cells;

- fermenting said laboratory stock culture, after suitable sterile inoculation in the selective culture medium of said strain of viable bacterial cells, to obtain a fermented biomass containing said strain of viable bacterial cells at a concentration comprised from 1x10 ⁶ to 1x10 ¹⁰ AFU, measured using a cytofluorometry method;

- concentrating, by a factor comprised from 5 to 20 times, said fermented biomass containing said strain of viable bacterial cells, preferably for continuous centrifugation, to obtain a concentrated biomass of said bacterial cell strain;

- washing said concentrated biomass of said strain of viable bacterial cells with sterile water at a temperature comprised from 5°C to 45°C, preferably from 10°C to 25°C, to obtain a concentrated and washed biomass of said strain of viable bacterial cells;

- subjecting said concentrated and washed biomass of said bacteria cell strain to a homogenisation step in a pressure homogeniser to obtain a homogenate in liquid form containing the cellular components of said strain.

FR-l-2. The process according to FR-l-1 , wherein said step for fermenting said laboratory stock culture to obtain a fermented biomass is carried out up to reaching a bacterial cell concentration comprised from 1x10 ⁷ to 1x10 ⁹ AFU, preferably 1x10 ⁸ AFU, measured using a cytofluorometry method, in the fermented biomass.

FR-l-3. The process according to FR-l-1 , wherein said step for concentrating said fermented biomass containing said bacterial cell strain is obtained by a factor equal to 10 times, with respect to the bacterial cell concentration comprised from 1x10 ⁶ to 1x10 ¹⁰ AFU, preferably from 1x10 ⁷ and 1x10 ⁹ AFU, even more preferably 1x10 ^s AFU, measured using a cytofluorometry method, present in the fermented biomass. FR-l-4. The process according to FR-l-1, wherein said step of subjecting said concentrated biomass to a homogenisation step is carried out in a pressure homogeniser having, preferably a supply flow rate comprised from 1000 to 2000 litres/hour and an operating pressure, during the homogenisation of said biomass, comprised from 1000 bars to 2000 bars, for each working cycle or step.

FR-l-5. The process according to FR-l-4, wherein said homogenisation step is carried out after completing a number of processing cycles or steps comprised from 1 to 10, preferably from 4 to 8, even more preferably from 3 to 6.

FR-l-6. A cellular component homogenate in liquid form obtained according to the process according to any one of FR-l-1 -5.

FR-l-7. A process for preparing a cellular component homogenate in solid form, wherein said process comprises a further step for subjecting said cellular component homogenate in liquid form obtained according to the process according to any one of FR1-FR5 to a cryoprotection step wherein a cryoprotectant solution in liquid form containing at least one sugar, preferably sucrose, and at least one sodium, potassium, calcium or magnesium salt of phosphoric acid, is added to said homogenate to obtain a cryoprotected homogenate.

FR-l-8. The process for preparing a cellular component homogenate in solid form, preferably a freeze- dried or sprayed powder, according to FR-l-7, wherein said cryoprotected homogenate in liquid form is subjected to a further freeze-drying or spraying step to obtain a cellular component homogenate in solid form.

FR-l-9. A cellular component homogenate in solid form, preferably freeze-dried or sprayed powder obtained according to the process according to FR-l-7 or FR-l-8, wherein said homogenate contains murein at an amount comprised from 5% to 40% by weight, preferably from 10% to 30% by weight, even more preferably from 15% to 25% by weight, with respect to the weight of the homogenate.

FR-l-10. A composition comprising said cellular component homogenate in solid form according to FR-l-9 and, optionally, one or more pharmaceutical or food grade or cosmetic additives and excipients, for use in the pharmaceutical, nutraceutical, medical devices, foods for special medical purposes, dietary supplements and food industry both in the human and veterinarian field, as well as for use in the cosmetics industry.

EXPERIMENTAL PART

Study of stability over time at different temperatures of homogenates in solid form of cellular components of strains of bacteria obtained according to the process of the present invention (hereinafter, solid homog enates).

In the present experimental study, stability over a one-year time range at different temperatures was eval uated (stability at: 40°C at 0, 1 , 2, 3, 6 and 12 months; at 25°C at 0, 3, 6 and 12 months and at 5°C at 0, 3, 6 and 12 months) of said solid homogenates (obtained according to FR-I or FR-II).

In particular, the stability study was carried out on samples obtained from homogenised bacterial strains in liquid phase according to FR-II and then sprayed (not freeze-dried), without addition of phosphates and without cryoprotection.

Solid homogenates obtained from strains of bacteria belonging to different genera and species were ana lysed according to Table A. The stability results do not vary considerably with the variation of the genus and species to which the strains belong. The stability data of two samples of representative bacteria strains (in short, test samples or Sample 1 and Sample 2) expressed as the amount (weight/weight per centage) of murein (peptidoglycan) present in each test sample are reported below. An enzymatic mixture and the addition of chemical additives for the digestion of the cellular components, except for the peptidoglycan of interest i.e. murein), were used for the isolation and quantification of the murein in the samples under analysis. The quantification (in triplicate) took place following gravimetric separation of murein from the undesired cellular components.

I. Time zero (tO)

Table 3 shows the results of gravimetric quantitation of the murein of the 2 samples analysed (mean value of 3 replicates), starting from 500 mg of sample at time zero (tO immediately after completing the pressure homogenisation step)

Table 3.

II. Time 1 month (t1)

Table 4 shows the results of gravimetric quantitation of the murein of the 2 samples analysed (mean value of 3 replicates), starting from 500 mg of sample after 1 month (t1) at about 40°C.

Table 4.

III. Time 2 months (t2)

Table 5 shows the results of gravimetric quantitation of the murein of the 2 samples analysed (mean value of 3 replicates), starting from 500 mg of sample after 2 months (t2) at about 40°C.

Table 5.

IV. Time 3 months (t3)

Table 6 (and Figure 4A) shows the results of gravimetric quantitation of the murein of the 6 samples ana lysed (mean value of 3 replicates), starting from 500 mg of sample after 3 months (t3) at about 40°C or 25°C or 5°C.

Table 6

V. Time 6 months (t6)

Table 6 (and Figure 4B) shows the results of gravimetric quantitation of the murein of the 6 samples ana lysed (mean value of 3 replicates), starting from 500 mg of sample after 6 months (t6) at about 40°C or 25°C or 5°C.

Table 7

VI. Time 12 months (t12) Table 8 (and Figure 4C) shows the results of gravimetric quantitation of the murein of the 6 samples ana lysed (mean value of 3 replicates), starting from 500 mg of sample after 12 months (t12) at about 40°C or 25°C or 5°C.

Table 8

CONCLUSIONS

In a time range of 12 months, the quantitation of murein isolated from the two samples of solid homoge nate of cellular components of strains of bacteria obtained by the process of the present invention is al most constant at the three tested temperatures (40°C, 25°C and 5°C).

Table A