ITMI20060776A1 - PROCESS OF BIO CLEANING OF DIFFERENT NATURAL CHEMICALS AND BUILDINGS SURFACES - Google Patents

Description

DESCRIPTION

The present invention relates in general to a process for cleaning the surfaces of manufactured articles of different chemical nature and buildings. In particular, the invention refers to a bio-cleaning process of said surfaces through the use of microorganisms.

In external environments in the last decades, particularly in urban areas, alterations such as nitration, sulfation, black crusts and deposits of various kinds on the surfaces of buildings and artifacts of different chemical nature have increased considerably. A particular and frequent case is the alterations caused by atmospheric pollutants such as nitrogen oxides and sulfur dioxides. The above compounds are oxidized in the air to nitric acid and sulfuric acid which, after deposition on the surfaces, are in turn converted into nitrates and sulphates. The formation of nitric acid (HNO3) and sulfuric acid (H2SO4) and their deposition on surfaces of different chemical nature, such as stone or metal, in the form of acid rain causes the transformation of the substrate and consequent nitration and sulfation.

In addition, the so-called black crusts are the result of the action of sulfuric acid on calcium carbonate (CaC03 + H2S04 → CaS04.2H20 + C02) resulting in the formation of calcium sulphate or gypsum which traps carbon residues. Phenomena of nitration and sulfation can be due not only to pollution but also to processes of movement of salts, for example by rising from the ground.

In confined environments, the alterations can be caused by agents other than atmospheric pollutants. In particular, previous restoration interventions based on the application of organic and inorganic substance can be considered over time as alterations themselves.

To treat the surfaces of buildings and artifacts of various chemical nature, chemical products are usually used, often combined with mechanical action. Although in some cases the chemical action possibly combined with the mechanical action has proved effective in removing the alterations, some relevant drawbacks have been noted.

First of all, cleaning through the use of chemicals is usually carried out with organic solvents and solubilizing agents that can give unsatisfactory results, be too aggressive towards the substrate, be not very selective, pollute the environment and be dangerous for the operator and possibly cause changes in the optical properties of the substrate itself.

The mechanical action involves a particularly delicate and precise actuation, to avoid irreparably physical damage to the surface below the alteration, and therefore sometimes 1 <1> use of long times.

To remove alterations such as nitration, sulfation and black crusts, the use of denitrifying and desulfurizing microorganisms respectively applied to the surfaces to be treated has been proposed in order to obtain a biological cleaning avoiding on the one hand the use of substances and methods that are too aggressive and the manipulation by the personnel assigned to the cleaning of any toxic substances, on the other hand accelerating the time of the intervention.

The application of microorganisms has been tested for some years and has proven to be a valid alternative to the systems mentioned above. In particular, it has been proposed to treat marble statues by immersion in a bath of desulfuricating bacteria to eliminate encrustations caused by hydrated gypsum (Gauri et al., 1989, The sulfation of marble and the treatment of gypsum crusts. Stud. Cons. 34: 201-206).

However, this application entails drawbacks linked to the volume of the treatment bath compared to the generally considerable dimensions of the objects to be treated. For example, such a treatment cannot be done for buildings. Furthermore, a phase of consolidation of the statues is necessary before treatment to avoid serious damage caused by immersion in the treatment bath.

Alternatively, the use of sepiolite as a support medium for trapping the cells of microorganisms in a matrix and applying said medium to the objects to be treated has been proposed (Ranalli et al., 1997, The use of microorganisms for the removai of sulphates on artistic stoneworks, Int. Biodet. Biodegr. 40: 255-261).

This method requires a laborious and long preparation (no less than a week to allow microbial growth and colonization on the sepiolite particles). Furthermore, the system does not maintain favorable conditions, in particular the availability of water, so that the microorganisms can carry out their action effectively and therefore requires a large concentration of microorganisms to overcome the adverse conditions.

To overcome problems related to the colonization of inorganic supports, organic supports such as polyacrylic acid were tested. The microorganisms are trapped in the organic gel during the formation of the gel which takes about ten minutes on average. On the contrary, in the case of inorganic supports, colonization generally requires growth and adhesion on the particles of the inorganic matrix, a process of at least 7 days.

It is also true that organic substrates such as the polyacrylic acid mentioned above show a great limitation represented by the very poor adhesive capacity on any type of stone artefacts (eg, both smooth and rough plasters), metals, etc ....

It should also be borne in mind that the presence of microorganisms causes the release of catabolites including some substances such as organic and inorganic acids, which in turn are corrosive. In the case of desulfurizing bacteria, precipitates of iron sulfide are formed in the culture medium in which the microorganisms are grown before being trapped in the support medium.

The technical problem underlying the present invention is that of providing a process for cleaning manufactured articles of different chemical nature and buildings which involves the use of microorganisms for simple and effective cleaning.

This problem is solved by the use of a support means for microorganisms able to maintain the necessary and sufficient conditions so that they can perform their function as bio-cleaners of artifacts of different chemical nature and variously altered buildings.

A first object of the invention is therefore to provide a more appropriate support for microorganisms applicable to surfaces of manufactured articles and buildings to be treated.

A second object is to provide a process for cleaning surfaces of manufactured goods and buildings comprising the use of said support.

A further object is to provide a kit for the implementation of said procedure.

Further characteristics and advantages of the present invention will become more evident from the following detailed description of an embodiment given purely by way of non-limiting example.

The idea behind the invention is to devise a system to support a sufficient number of cells of interest in order to guarantee on the one hand their minimum vitality, necessary to carry out their function as bio cleaners and on the other hand, an adhesion optimal for any type of artefact or buildings that show alterations of various kinds.

Following numerous experiments, an optimal support for bio-cleaning microorganisms has been developed that mainly meets the aforementioned desired requirements. This support (which if together with the microorganisms is indicated hereinafter as a biological formulation) is in the form of a matrix comprising a polymeric organic compound in which an inorganic compound based on silicates or a silica is dispersed.

In numerous experiments, polymeric compounds have been tested in general based on a polymer that forms a lattice capable of trapping the cells of microorganisms. Preferably, the compound is in the form of an organic hydrogel. For example, the polymeric compound may be a mixture of functionalized acrylamide (PAAM) with different molecular weights or a polyvinyl alcohol (polyacrylamide, polyvinyl alcohol and water). In particular, the polymer is an acrylic hydrogel resin such as Hydrobiogel 97 (EniTecnologie, San Donato, Milan).

Preferably, the polymer is based on acrylic resins capable of forming networks and trapping microorganisms. Said compounds, in the form of acrylic polymers, are more preferably the polyacrylic acid (propenoic acid monomer) Carbopol® 934 (CST, Vicenza), it is a hydrophilic cross-linked polymer that swells in water and, not dissolving, gives rise to a dispersion due to the high P.M. of the molecules and a pH of about 3.0, and appears slightly viscous; the modified polyacrylic acid Carbogel (CST, Vicenza), obtained by alkalinization with Carbopol® 934 bases. The preparation of the modified polyacrylic acid based gel (Carbogel) takes place by simple addition of water and the viscosity of the gel can be modified by varying the amount of polymer added to a given volume of water. In particular, the formation of a Carbogel can comprise an amount by weight of organic compound on volume of water from 0.1% to 15.0%, in relation to the need for a greater or lesser fluidity of the gel, preferably from 1.0 % to 4.0%.

In general, the inorganic compound based on silicates or silica can be any compound which, when mixed with the organic polymeric matrix, changes its thixotropic property making it suitable for being applied to any type of surface. In particular, the inorganic compound can be any compound comprising silicates such as, for example, phyllosilicates type T-0 (1: 1) and type T-O-T (2: 1), such as sepiolite and silica. Preferably, said compound is represented by a hydrated silica such as micronized silica. More preferably, the inorganic compound is hydrated micronized silica manufactured by PPG Industries (Pittsburgh, PA) under the trade name of Lo-Vel® 27 (CAS Registry No. 63231-67-4). This product, in particular, belongs to the category of amorphous synthetic silicas, it is presented in the form of dry white powder (particles of 2 microns) and a specific surface of 180 m <2> per gram of product.

It has been surprisingly found that a support such as the one just described, consisting of an organic and an inorganic component, has unexpected properties.

First of all, thanks to the action of the organic polymer, it is able to trap and keep alive an adequate number of microorganisms for a useful time so that they perform their function of biocleaners while maintaining the water content necessary for the completion of the desired microbial activity.

Secondly, thanks to the action of the inorganic component, for example micronized silica as mentioned above, the support can be easily applied on both horizontal and vertical surfaces or ceilings without encountering unwanted detachments. In fact, it has been observed that the polymeric matrices alone when applied to walls / ceilings can easily detach especially if the walls are vertical or vaulted as often happens for example in historical monuments.

Furthermore, it has been seen that the preparation of the support with the microorganisms is considerably accelerated compared to the use of the inorganic component alone. The preparation time of the polymeric matrix with the trapped microorganisms is in fact only about 10 minutes against the aforementioned at least 2 days necessary for the colonization of some inorganic supports such as sepiolite.

In particular, the support of the invention can comprise, for a suspension of 100 mL, from 0.1 to 15 g by weight, preferably from 1 to 4 g (for example Carbogel) and from 5 g to 20 g, preferably from 8 g to 15 g of inorganic compound (for example micronized silica). The relationship between the two organic and inorganic components may vary in relation to the effectiveness and efficiency of adhesion and anchoring of the final formulation with respect to the chemical nature of the material to be treated, the position and position of the product itself (vertical, horizontal, inclined, vaulted , etc.), climatic conditions (high or low temperatures, humidity, etc.) and oxyc conditions (in the air, in the presence of oxygen), or anoxic conditions (in the absence of oxygen).

When microorganisms are added to the substrate, a biological formulation is obtained in which different microorganisms such as prokaryotes, for example bacteria, and eukaryotes, for example yeasts, microfungi in general are trapped in an organic and inorganic matrix as described above.

By way of example, the formulation can include desulfuricating and / or denitricating bacteria capable of removing sulphates and nitrates respectively.

Desulfuricating bacteria can be selected from the Desulfovibrio genera, in particular between the Desulfovibrio vulgaris and Desulfovibrio desulfuricans species. Among the Desulfovibrio vulgaris bacteria, the preferred bacterium is Desulfovibrio vulgaris subspecie vulgaris, more preferably the bacterium Desulfovibrio vulgaris subsp. vulgaris ATCC 29579. Among the preferred Desulfovibrio desulfide cans bacteria are Desulfovibrio desulfuricans ATCC 13541 and ATCC 29577. In general, all microaerotolerant and aerotolerant desulfurizing bacteria can be used.

Denitrifying bacteria can be selected from the genera Pseudomonas, in particular Pseudomonas stutzeri. Preferably, the species are Pseudomonas stutzeri strain A29 DISTAM, Pseudomonas stutzeri DSMZ 5190, Pseudomonas stutzeri ATCC 23856.

The biological support of the invention can be prepared according to a process which comprises the preparation of an aqueous solution in which 0.1 g to 15 g, preferably 1 to 4 g per 100 are dissolved under stirring in every 100 ml of water. ml, of the polymeric component reported above and from 5 g to 20 g, preferably from 8 g to 15 g, of the inorganic component.

Once the support has been prepared, the microorganism of interest can be added in the form of a cell suspension in order to give rise to the formulation ready for the application of interest.

Alternatively, the support of the invention can be prepared directly in a cell suspension so as to create within a cell suspension the polymeric matrix suitable to support the microorganisms. The step of adding the organic compound to the cell suspension generally takes place slowly and under stirring for 7-10 minutes in the amounts indicated above.

In this case, the preparation of the organic component usually includes the addition of 0.1-10 g of polymer to 100 ml of cell suspension and stirring until a gel is obtained under oxy (air) conditions, while under anoxic conditions ( in the absence of oxygen) about 1-15 g must be added (maintaining a gentle stirring of the mass with a mechanical stirrer at 50 rpm).

Subsequently, 5 to 15 g of the inorganic component such as micronized silica is added to the cell suspension with organic polymer.

The cell suspension is prepared in accordance with the normal microbiological techniques known in the art, ie by growing the microorganisms in a suitable culture medium until the desired cellular biomass is reached. In the event that strains deriving from national and international collections of microorganisms such as those listed above are used, the preparation conditions are substantially those recommended by the collections themselves.

A further innovative element and reason for the present invention is specifically the identification of a process capable of solving the undesired phenomena described and the problems connected with the preparation and use of microorganisms. In particular, when desulfurizing microorganisms are used, they form hydrogen sulphide which in the presence of iron ions in conventional culture media suitable for these microorganisms causes the formation of a black inorganic precipitate (iron sulphide).

In fact, to overcome this drawback the procedure for the preparation of the cell suspension comprises a step of transferring the cell culture, grown in a conventional medium, in a medium free of iron ions and its incubation for about 2-4 days in anoxic conditions.

Preferably, the preparation also comprises a subsequent step of eliminating the inorganic precipitates preferably by filtration with filters having pores having a minimum diameter of between 2 and 10 µm, preferably 8 µm, which retain the precipitates allowing the cells to pass.

It has been noted that the elimination step by filtration, commonly used, is very slow and difficult as the filters have small filtration surfaces and tend to clog up quickly.

To speed up the filtration step, a prefiltration step with a glass wool filter has been advantageously arranged in order to separate the largest possible number of precipitates and facilitate the actual filtration step.

Thereafter, the cells are recovered and resuspended in a suitable buffer such as potassium or sodium phosphate before being added to the organic polymeric component or to the mixture of said component with the inorganic one.

However, it has been found that even this last step of resuspension in potassium / sodium phosphate buffer can actually cause the drawback of the release of potassium / sodium ions which remain on the surface of the product and are themselves sources of alteration.

To solve this further problem, the potassium / sodium phosphate has been replaced with ammonium phosphate which releases ammonium in the form of ammonia. Ammonia, being a gas, is released into the air without the deposition of salts on the product to be treated. In general, however, all buffers which are effective around neutrality, non-toxic and which do not inhibit the activity of microorganisms can be used.

For anaerobic microorganisms all the steps of preparation of the cell suspension described take place under anoxic conditions.

Now, the support of the invention, which can be defined as a biological formulation, is ready to be applied on the surfaces of manufactured articles or buildings to be treated with bio-cleaning microorganisms in accordance with the procedure described below.

The bio-cleaning method of the invention comprises the steps of:

make available an organic formulation such as the one described above;

applying a layer of said formulation on the surface to be treated;

leaving said layer on the surface for a sufficient time for the microorganisms to carry out their action as bio cleaners;

remove said layer once their action is over.

In particular, the step of applying a layer of the biological formulation can be carried out through the use of a spatula. The layer is applied evenly and with a thickness between 0.5-3 cm.

Furthermore, to increase the retention of the water contained in the organic polymer and reduce the diffusion of oxygen in the case of anaerobic microorganisms, the biological formulation is in turn covered with an elastic plastic film. In this way, the action of anaerobic microorganisms can be increased.

After application, the biological formulation is left in position for a time ranging from 6 hours to 7 days, more preferably from 8 to 72 hours, depending on the type of microorganism or the conditions of the chemical composition of the product to be treated. Several subsequent applications can be envisaged.

If the environmental conditions (eg temperature and in the case of rain) are not favorable, simple precautions can be taken within the reach of the technician in the sector. For example, the working temperature of the microorganisms can be adjusted by applying a black plastic film to balance temperature drops possibly in association with heating lamps. For drier climates, it is possible to increase the number of applications in order to apply a layer of fresh and therefore hydrated formulation and vary the quantity of organic component. Furthermore, measures can be taken to avoid, in the case of an outdoor artifact, the washout due to rain and other unwanted events (wind, snow, etc.) such as the use of fixed coverings (canopy, mobile or fixed shelters, etc.).

Preferably, the application also includes a preliminary phase of glazing the surface to be treated with Japanese paper (weight of 0.20-0.40 g / m <2>) soaked with distilled water (or the same buffer) to facilitate the phase removal of the formulated layer at the end of the bio-cleaning treatment.

Once the action of the biocleaning microorganisms has ended, the biological formulation is taken away by, for example, removing the Japanese paper.

As previously mentioned, the main advantage of the present invention lies in the fact that the support has been designed in such a way as to guarantee on the one hand the optimal conditions for the survival of microorganisms and on the other hand a better adhesion on the surfaces to be treated without, moreover, to interfere with the activity of the microorganisms themselves.

In fact, thanks to the particular combination of the polymeric organic component with the inorganic component, the microorganisms have a sufficient quantity of water for their survival, with a limited amount of loss of vital cells over time and at the same time they can be applied to any type of surface even in vertical positions / ceilings such as the vaults of monuments or buildings in general, without detaching due to the weight of the polymeric component and its poor adherence to said surfaces when used without the aforementioned inorganic component.

Furthermore, the procedure aimed at fine-tuning the optimal formulation was created by devising ideal preparation conditions so that the microorganisms trapped in it can act without causing unwanted side effects themselves.

As previously reported, the microorganisms are prepared in such a way that their subsequent entrapment in the polymeric component takes place in the best conditions, in other words eliminating or at least significantly reducing the formation / production and release of unwanted substances on the surface in contact with the substrate to be treated. .

A further advantage is determined by the fact that the preparation of the biological formulation starting from the suspension of cells, its application and its function have been significantly accelerated allowing corresponding considerable savings in time, preparing everything in a few minutes compared to 7 days and more. in the case of <'> use of colonized sepiolite as a matrix.

A further object of the invention is a kit for the bio-cleaning of surfaces of manufactured articles of different chemical nature and buildings comprising:

an organic component as described above;

an inorganic component as described above;

a possible pad or medium; bio-cleaning microorganisms of interest such as those described above;

means for applying the biocleaning microorganisms to a surface to be treated; a leaflet containing the instructions for use of the kit.

In particular, the organic and inorganic components, the buffer / medium and the microorganisms are contained in suitable conventional containers such as bottles or sealed sachets.

Alternatively, the organic and inorganic components can be premixed and ready to be combined with the microorganisms just before use.

The microorganisms can be kept alive in freeze-dried form and hydrated at the moment of use through the buffer / medium which is preferably an aqueous solution capable of restoring the vitality of the microorganisms and at the same time giving rise to the gel matrix of the organic and inorganic component of the organic formulation to be applied.

The application means can be represented by conventional spatulas, suitable brushes or other tools known in the field.

Some embodiments of the invention will be reported hereinafter purely by way of non-limiting example.

EXAMPLE 1

Process for the preparation of bacterial microorganisms Desulfovihrio vulgarìs subsp. vulgaris ATCC 29579

The preparation of the cell suspension comprises the use of the preferred microorganism Desulfovihrio vulgaris subsp. vulgaris ATCC 29579.

Strain ATCC 29579 is maintained in the medium Desulfovibrio DSMZ 63 (K2HP040.5 g 1-1, NH4C11.0 g 1-1, Na2S04 1.0 g 1-1, CaC12x2 H200.1 g 1-1, MgS04x7 H202.0 g 1 -1, DL-Na-lactate 2.0 g 1-1, yeast extract 1.0 g 1-1, resazzurin 1.0 mg 1-1, FeS04 * 7 H200.5 g 1-1, Natioglycolate 0.1 g 1-1, ascorbic acid 0.1 g 1-1) and incubated at 30 ° C for 4 days under anoxic conditions.

For the removal of the sulphides generated first of all a modified DSMZ 63 medium is used which does not contain iron source (unlike the standard DSMZ 63 medium it does not contain FeS04x7H20). Strain ATCC 29579 maintained in standard DSMZ63 medium also grows efficiently in iron-free medium if the inoculum is at least 8% (v / v). Once grown in the modified medium, a pre-filtration is carried out with glass wool which retains the black precipitates of iron sulphide and allows the cells to pass, followed by actual filtration with the Rapida A perfecte® cellulose filter (Cartiera di Cordenons , Vicenza, Italy) with a pore diameter of 8 μ to allow the retention of precipitates but allow the passage of the cells.

After filtration the cells are washed by centrifugation (twice at 8000 rpm for about 10 minutes) with buffer.

At this point, the cell pellet is recovered and resuspended with an ammonium phosphate (NH4) H2P04lg buffer per liter at pH 7 and (ΝΗ4 ΗΡΟ41.1 g per liter added with sodium lactate in a quantity of 0.599 g / 1 up to to reach a cell density of about 10 cells per ml <-1>.

EXAMPLE 2

Procedure for the preparation of the formulation with sulphate reducers and its application

Once a cell suspension has been prepared as described in example 1, under anoxic conditions 1 g of Carbogel is mixed in 100 ml of suspension until a dense suspension is obtained and then the addition of micronized silica (Lo-Vel®) in a quantity of 13 g. The area to be treated altered by black crust is covered with Japanese paper soaked in distilled water until perfect contact with the surface of the altered stone is obtained.

with spatulas until a thickness of about 1 cm is obtained and finally covered with plastic film. The total duration of the application is 45 hours with three successive applications of 15 hours each. The removal of sulfates evaluated by ion exchange chromatography demonstrates the removal of 98% of the sulfates.

EXAMPLE 3

Procedure for the preparation of the biological formulation for the removal of organic substance (oxyc conditions) In oxyc conditions, 0.5 g of Carbogel are mixed in 100 ml of cell suspension until a dense suspension is obtained and then the addition of micronized silica (Lo-Vel ®) in quantities of 13 g.

Claims (25)

CLAIMS 1. Microbiological support in the form of a matrix suitable for supporting microorganisms comprising an organic polymeric compound in which an inorganic material based on silicates or a silica is dispersed. Support according to claim 1, wherein the polymeric compound is a polymer which forms a lattice (gel) capable of trapping the cells of microorganisms. Support according to claim 2, wherein the polymer is selected from a mixture of functionalized acrylamide with different molecular weights or a polyvinyl alcohol and an acrylic resin. 4. Support according to claim 3, wherein the polymer is selected from Hydrobiogel 97, Carbopol and Carbogel. Support according to any one of claims 1 to 4, wherein the polymeric compound is present in quantities ranging from 0.1% to 15% with respect to the volume of water. Support according to any one of claims 1 to 5, wherein the inorganic material is based on silicates or silica. 7. Support according to claim 6, wherein the compound is selected from phyllosilicates of the T-0 and T-O-T type, sepiolite and hydrated silica. The support according to claim 7, wherein the hydrated silica is micronized hydrated silica. 9. Biological formulation comprising the support according to any one of claims 1 to 8 in which bio-cleaning microorganisms are trapped. 10. Biological formulation according to claim 9, the microorganisms of which are selected from both prokaryotes and eukaryotes. 11. Biological formulation according to claim 10, wherein the prokaryotes are desulfuricating and / or denitricating bacteria preferably selected from Desulfovibrio vulgaris subsp. vulgaris ATCC 29579, Desulfovibrio desulfuricans ATCC 13541 and ATCC 29577, Pseudomonas stutzeri strain A29 DISTAM, Pseudomonas stutzeri DSMZ 5190, Pseudomonas stutzeri ATCC 23856. 12. Process for the preparation of a microbiological support according to any one of claims 1 to 8, comprising the preparation of an aqueous solution in which 0.1 g to 15 g, preferably 1 g, are dissolved under stirring in every 100 ml of water at 4 g per 100 ml, of the polymeric component reported above and from 5 g to 20 g, preferably from 8 g to 15 g, of the inorganic component. 13. Process for the preparation of a biological formulate according to any one of claims 9 to 11, comprising a step of adding an organic compound in quantities ranging from 0.1-15 g and a step of adding an inorganic material in quantities ranging between 5-15 g to a cell suspension of 100 ml. 14. Process according to claim 13, wherein the cell suspension is prepared by a process comprising a step of transferring a cell culture grown in conventional medium to a medium free of iron ions and its incubation for 2-4 days under anoxic conditions . 15. Process according to claim 14, wherein the process for preparing the cell suspension comprises a step for eliminating the cell precipitates. 16. Process according to claim 15, wherein the step of eliminating the precipitates comprises a step of prefiltration with glass wool and a filtration with filters having pores with a diameter comprised between 2 and 10 µm. 17. Method of bio-cleaning of surfaces of artifacts of different chemical nature and buildings, including the phases of: providing a biological formulation according to any one of claims 9 to 11; applying a layer of said formulation on the surface to be treated; leaving said layer on the surface for a time sufficient for the microorganisms to carry out their action as bio cleaners; remove said layer once their action is over. 18. Method according to claim 17, in which the application step of the formulation is carried out by using a spatula and the applied layer is between 0.5 and 3 cm. 19. Method according to claim 17 or 18, further comprising a step of covering the formulation with a plastic film after its application to the surface to be treated. Method according to any one of claims 17 to 19, further comprising a preliminary step of applying a Japanese paper glaze to the surface to be treated. 21. Kit for the bio-cleaning of surfaces of various chemical artifacts and buildings, comprising an organic component as described above 2 to 5; an inorganic component according to any one of claims 6 to 8; a possible pad / medium; bio-cleaning microorganisms of interest; means for applying the biocleaning microorganisms to a surface to be treated; a leaflet containing the instructions for use of the kit. 22. Kit according to claim 21, wherein the organic and inorganic components, the buffer / medium and the microorganisms are contained in suitable conventional containers such as bottles or sealed sachets. 23. Kit according to claim 22, wherein the organic and inorganic components can be premixed and ready to be joined to the microorganisms just before use. Kit according to any one of claims 21 to 23, wherein the microorganisms can be kept alive in lyophilized form and hydrated at the moment of use by means of the buffer / medium. Kit according to any one of claims 21 to 24, wherein the application means can be represented by conventional spatulas.