PROCESS AND APPARATUS FOR DYEING TEXTILES

Abstract

This invention relates to a process and apparatus for dyeing of textiles, to an immobilized enzyme comprised in said apparatus required for carrying out the process, and to a method to produce enzymatically indigo and derivatives thereof.

Claims

1. A process for dyeing a textile (22), comprising an enzymatic synthesis of a dye precursor, characterized in that it comprises the following steps: a) contacting a solution comprising at least a first dye precursor (112) with at least a first immobilized enzyme (12), to convert at least part of said first dye precursor (112) into at least a second dye precursor (113), to obtain a solution comprising said at least second dye precursor (113); b) generating a flow of said solution comprising said second dye precursor (113), whereby said solution comprising said second dye precursor (113) flows from said first immobilized enzyme (12) to said textile (22); c) contacting said solution comprising said second dye precursor (113) with said textile (22); and d) converting at least part of said second dye precursor (113) to at least one dye (111), whereby at least part of said textile (22) is dyed; wherein said first immobilized enzyme (12) is spaced apart from said textile (22).

2. A process according to claim 1, wherein an exhaust solution obtained in step d), and a flow of said exhaust solution is generated whereby said exhaust solution flows to said at least first immobilized enzyme (12).

3. A process according to claim 1, wherein said at least a first dye precursor (112) is indole and/or derivatives thereof, said at least a second dye precursor (113) is indoxyl and/or derivatives thereof, and said at least a dye (111) is indigo and/or derivatives thereof.

4. A process according to claim 1, wherein said first immobilized enzyme is an oxidizing enzyme, whereby said first dye precursor is oxidized to obtain said second dye precursor when contacted by said oxidizing enzyme.

5. A process according to claim 1, further comprising an immobilized cofactor-regenerating enzyme.

6. A process according to claim 5, wherein said cofactor-regenerating enzyme is a dehydrogenase selected from the group consisting of: glucose dehydrogenase (GDH), phosphite dehydrogenase (PTDH), and formate dehydrogenase (FDH).

7. A process according to claim 5, wherein said first immobilized enzyme and said immobilized cofactor-regenerating enzyme are provided as an immobilized fusion enzyme.

8. A process according to claim 4, wherein oxygen is added to said solution.

9. A process according to claim 1, wherein step a) is carried out in at least a first chamber (11), and wherein the dyeing of at least part of said textile (22) is carried out in at least a second chamber (21).

10. A process according to claim 9, wherein said first dye precursor (112) is produced enzymatically starting from one or more starting compounds (114) in one or more reactors (51) different from said first chamber (11) and said second chamber (21).

11. A process according to claim 9, wherein said first dye precursor (112) is produced enzymatically starting from one or more starting compounds (114) in said first chamber (11).

12. An apparatus (10) for dyeing a textile (22) comprising a first chamber (11) containing at least a first immobilized enzyme (12) and a solution comprising at least a dye precursor, at least a second chamber (21) containing a textile (22), and means to generate a flow of a solution (50), wherein said first chamber (11) is in fluid connection with said second chamber (21) whereby said solution comprising at least a dye precursor can flow from said first chamber (11) to said second chamber (21) where at least part of said dye precursor is converted to a dye (111) to dye at least part of said textile (22), and wherein said second chamber (21) optionally comprises outlet means (21a) to remove said solution from said second chamber (21).

13. The apparatus (10) according to claim 12, wherein said first immobilized enzyme (12) is an oxidizing enzyme.

14. The apparatus (10) according to claim 12, wherein said first chamber (11) further contains at least a, a cofactor-regenerating enzyme selected from the group consisting of: glucose dehydrogenase (GDH), phosphite dehydrogenase (PTDH), and formate dehydrogenase (FDH).

15. The apparatus (10) according to claim 14, wherein said first immobilized enzyme (12) and said second enzyme are provided as an immobilized fusion enzyme.

16. The apparatus (10) according to claim 15, wherein said immobilized fusion enzyme is PTDH-mFMO.

17. The apparatus (10) according to claim 12, further comprising: one or more reservoirs (31) in fluid connection with at least said first chamber (11), so that a solution comprising a dye precursor can flow from said reservoir (31) to said first chamber (11); and/or one or more collection tanks (41) in fluid connection with said outlet means of said second chamber (21).

18. The apparatus (10) according to claim 12, wherein said outlet means (21a) of said second chamber (21) are in fluid connection with said first chamber (11).

19-20. (canceled)

21. A method for the production of indigo or an indigo derivative by enzymatic synthesis that comprises the following steps: a′) converting tryptophan or a tryptophan derivative in the presence of at least a tryptophanase, to obtain indole or an indole derivative; b′) hydroxylating said indole or said indole derivative obtained in step a′) in the presence of at least an oxidizing enzyme, to obtain indoxyl or an indoxyl derivative; and c′) converting said indoxyl or said indoxyl derivative obtained in step b′) to indigo or an indigo derivative.

22. The method according to claim 21, wherein said tryptophan derivative of step a′) is a tryptophan halogenated derivative, comprising the further step of: i) halogenating tryptophan to obtain said tryptophan halogenated derivative in the presence of at least a tryptophan halogenase and a halogen source.

23. The method according to claim 21, wherein said tryptophanase, said oxidizing enzyme, and said tryptophan halogenase are isolated enzymes, preferably immobilized enzymes.

24. The method according to claim 21, wherein steps a′) to c′) are carried out in an aqueous medium and a flow of the aqueous medium is generated, whereby said steps a′) to c′) are carried out in different reactors or in different locations of a reactor.

25. The method according to claim 22, wherein said halogen source is bromine, said tryptophan derivative is 6-bromotryptophan and said indigo derivative is Tyrian purple.

26. The method according to claim 21, wherein step c′) is carried out in the presence of a textile that is spaced apart at least from said oxidizing enzyme, whereby at least part of said textile is dyed.

27. A dyed textile as obtainable according to claim 26.

28. A process according to claim 4, wherein said first immobilized enzyme is a monooxygenase.

29. A process according to claim 7, wherein said fusion enzyme is PTDH-mFMO.

Description

DESCRIPTION OF THE FIGURES

[0129] FIG. 1 is a schematic view of the process of the invention.

[0130] FIG. 2 schematically shows another embodiment of the process of the invention.

[0131] FIG. 3 schematically shows an embodiment of the process;

[0132] FIG. 4 is a schematic view of the apparatus 10.

[0133] FIG. 5 is another schematic view of the apparatus 10.

[0134] FIG. 6 schematically shows an embodiment of the apparatus 10, including a reservoir;

[0135] FIG. 7 schematically shows a further embodiment of the apparatus 10, including a collection tank;

[0136] FIG. 8 schematically shows an embodiment of the apparatus 10; and

[0137] FIG. 9 schematically shows another embodiment of the apparatus 10.

DESCRIPTION OF THE INVENTION

[0138] The objects and embodiments of the invention are now disclosed in more details with reference to the figures.

[0139] Object of the present invention is a process for dyeing a textile 22, comprising an enzymatic synthesis of a dye precursor, characterized in that it comprises the following steps: [0140] a) contacting a solution comprising at least a first dye precursor 112 with at least a first immobilized enzyme 12, to convert at least part of said at least a first dye precursor 112 into at least a second dye precursor 113, to obtain a solution comprising said at least second dye precursor 113; [0141] b) generating a flow of said solution comprising said at least second dye precursor 113, whereby said solution comprising said at least second dye precursor 113 flows from said first immobilized enzyme 12 to said textile; [0142] c) contacting said solution comprising said at least second dye precursor 113 with said textile 22; and [0143] d) converting at least part of said second dye precursor 113 to at least a dye 111, whereby at least part of said textile 22 is dyed;
wherein said at least first immobilized enzyme 12 is spaced apart from said textile 22, for example as represented on FIG. 1.

[0144] FIG. 1 represents a schematic view of the process of the invention, in particular is represented the conversion of said first dye precursor 112 to said second dye precursor 113 by means of said first immobilized enzymes 12, then the flow of the solution comprising at least said second dye precursor 113 to the textile 22 (which is spaced apart from said first immobilized enzyme 12), and finally the conversion of said second dye precursor 113 to said insoluble dye 111 directly onto said textiles 22.

[0145] More in particular, with reference to FIG. 1, the process of the invention will be disclosed with reference to the indole to indigo route. The process provides the dyeing of textiles 22 as a result of the following steps: a flow of a solution comprising indole dye precursor 112 is contacted with at least a first immobilized enzyme 12 or an enzymatic system (step a)), thus obtaining the conversion of at least part of indole into indoxyl 113, due to enzymatic catalysis. The solution is now comprising indoxyl 113. The flow of solution allows contact of solution comprising indoxyl 113 with the textile 22; advantageously, parameters, such as flow rate, are controlled in order to have the solution reaching said textile 22 immediately or shortly after indoxyl 113 is synthesized. Conversion of indoxyl 113 to indigo 111 can be thus obtained onto said textile 22, and dyeing of said textile 22 is achieved. In particular, when said solution comprising indoxyl 113 wets said textile 22, at least part of said indoxyl 113 is converted into indigo 111 directly onto said textile 22.

[0146] According to the present invention, the process provides for generating a flow of the solution initially to the enzymes 12 (or enzyme system) and then from the enzymes 12 (or enzyme system) to the textile 22, for example as shown by FIG. 1, wherein the straight arrows represent the direction of the flow of solution. Any direction of the flow of solution is possible, provided that such flow of solution is first fed to said enzymes 12, and then from said enzymes 12 to said textile 22. For example, another direction of the flow of solution can be from the bottom to the top when the first immobilized enzymes 12 are below said textile 22, or can be from top to bottom when the first immobilized enzymes 12 are above said textile 22, or can be circular when the first immobilized enzymes 12 and said textile 22 are housed within different areas of an annular chamber, such as a toroidal chamber, for example, when they are held in diametrically opposed areas within such toroidal chamber.

[0147] The use of a flow in the process of the invention prevents the precipitation of indigo 111 at and/or near the immobilized enzymes 12, as the solution comprising at least said second dye precursor 113 flows to said textile 22, which is spaced apart from said first immobilized enzyme 12, and then conversion of said second dye precursor 113 into said insoluble dye 111 occurs.

[0148] In particular, when said second dye precursor 113 can spontaneously convert into say insoluble dye 111, for example when said second dye precursor 113 is indoxyl and/or derivatives thereof and said insoluble dye 11I is indigo and/or derivatives thereof, a flow of the solution comprising at least said second dye precursor 113 is generated whereby said solution flows to said textile 22 before said second dye precursor 113 spontaneously converts and precipitate as said insoluble dye 111 at and/or near the immobilized oxidizing enzyme.

[0149] When said second dye precursor 113 does not spontaneously convert into said insoluble dye 111, or when it does not spontaneously convert in suitable amount, it is possible to change conditions, such as pH and/or temperature, and/or to add reagents, and/or supply with gasses, such as oxygen, where the textile 22 and said second dye precursor 113 are, in order to drive the conversion of said second dye precursor 113 to said insoluble dye 111 on the textile 22. Vice versa, the solution conditions may be controlled also in step a) of the process to prevent conversion until the solution has reached the textile.

[0150] Moreover, two or more different first dye precursors 112 can be contacted with the enzymes 12 according to step a) of the process, thus obtaining two or more different second dye precursors 113. Such two or more different second dye precursors 113 can then convert according to step d) of the process to obtain one or more different dyes 111 onto the textile 22; eventually, the conversion of step d) of such two or more different second dye precursors 113 can be achieved by adding further reactants, and/or by changing the parameters of the solution comprising them, if such conversion does not occur spontaneously, or if it does not occur in suitable amount. An illustrative example wherein two or more different dye precursors are contacted with the enzymes 12 is represented in Scheme 5 above. When two or more different first dye precursors 112 are used according to the process of the invention, two or more different enzymes 12 may be required; for example, when the two or more different first dye precursors 112 require different enzymatic reaction to be converted to the respective two or more different second dye precursors 113, or when the two or more different first dye precursors 112 cannot be substrates of the same enzymes 12.

[0151] The solution comprising at least a first dye precursor 112 can comprise also other solutes and is the solution that is contacted with the first immobilized enzyme 12 or the enzyme system in step a) of the process. The solution comprising at least a second dye precursor 113 is the solution obtained after at least part of said first dye precursor 112 is converted into said second dye precursor 113 after step a) and may comprise also other solutes, e.g. some unreacted first dye precursor 112.

[0152] As above mentioned, the solution according to the invention may comprise other functional solutes, such as salts, buffering agents, co-factors and oxygen and/or peroxide scavengers (e.g. catalases). Preferably, the concentration of substrates comprised in the aqueous solution saturate said catalyzing enzymes, so that said first immobilized enzymes can effectively catalyze a conversion of said first dye precursor 112 to the second dye precursor 113. An illustrative solution according to the present invention may comprise 100 mM potassium phosphate buffer pH 8.0, 0.5 M NaCl, 100 microM NADPH, 20 mM sodium-phospite and 1 nanoM bovine liver catalase with water as a solvent, when said first dye precursor 112 is indole, said first immobilized enzyme 12 is mFMO, and said second immobilized enzyme is PTDH.

[0153] The process of the invention can provide dyeing of textile 22 in batch or in continuous. To carry out the latter, addition of said first dye precursor 112, for example to the solution before step a), is required, so that a solution comprising at least a first dye precursor 112 is continuously contacted with said first immobilized enzymes 12 and the second dye precursor 113 is continuously synthesized. Said first dye precursor 112 is advantageously added keeping said first immobilized enzymes 12 saturated. Also addition of other solutes, for example before step a), could be required to carry out the process of the invention in continuous, such as cofactor(s), buffering agents, and oxygen.

[0154] Temperature and pH values according to the process of the invention can vary and can be those conventionally used in enzymatic synthesis of insoluble dyes.

[0155] The temperature of the solutions according to the process of the invention can be, for example, in the range comprised from 20 to 40, preferably from 25 to 30. pH of the solutions according to the process of the invention can be, for example, in the range comprised from 7.0 to 10.0, preferably from 7.5 to 9.0, even more preferably from 7.5 to 8.5, and most preferably is 8.0.

[0156] The contact time between said first immobilized enzyme 12 and said solution comprising indole 112 in step a) can be varied to achieve different shading of the dyed textile, and can be varied e.g. by varying the flow rate of the solution.

[0157] Oxygen concentration in the solution can be a relevant parameter for the overall dyeing process yield, as oxygen can take part in the conversion of the first dye precursor into the second dye precursor, and/or in the conversion of the second dye precursor into the insoluble dye (for example when the first dye precursor is indole and/or derivatives thereof, the second dye precursor is indoxyl and/or derivatives thereof, and the insoluble dye is indigo and/or derivatives thereof). Oxygen concentration in the solution can thus vary, for example, based on the amount of insoluble dye to be synthesized, or by the amount of textile to be dyed. The solution is advantageously saturated with oxygen in order to achieve maximum conversion of, for example, indole and/or derivatives thereof, and of indoxyl and/or derivatives thereof. Oxygen concentration is also advantageously monitored and controlled, and oxygen can be added when required in order to keep the solution saturated.

[0158] Other parameters of the process of the invention can be chosen according to, for example, which type of textile has to be dyed and which dye is chosen as a final dye.

[0159] According to an embodiment of the process of the invention, a flow of a solution, a so called “exhaust solution”, resulting from step d) is directed back to the chamber or areas housing the immobilized enzyme system. The exhaust solution is the solution obtained after at least part of indoxyl 113 is converted into indigo 111, which is fixed on said textiles 22, and may comprise unreacted first dye precursor 112, e.g. unreacted indole, in particular if said first dye precursor 112 did not react completely with said enzyme 12 in step a) of the process invention. This embodiment is shown in FIG. 2. The exhaust solution comprising indole is fed back directly or indirectly, continuously or batch-wise, to the enzyme system to react the remaining indole.

[0160] Preferably, the process provides a step of adding some first dye precursor 112 to the exhaust solution. Said first dye precursor 112 is advantageously added keeping said first immobilized enzymes 12 saturated. This can provide the process of the invention carried out in continuous.

[0161] In an embodiment of the invention, said first immobilized enzyme 12 is an oxidizing enzyme as previously defined. Use of oxygenases is particularly useful when said first dye precursor 112 has to be oxidized in order to be converted to said second dye precursor 113, e.g. when said first dye precursor 112 is indole and/or derivatives thereof, said second dye precursor 113 is indoxyl and/or derivatives thereof, and said insoluble dye 111 is indigo and/or derivatives thereof.

[0162] The process of the invention may further provide for a second immobilized enzyme, preferably an immobilized cofactor-regenerating enzyme as previously defined, to be present in the plant for dyeing. This provide an enzyme system wherein the first immobilized enzyme catalyzes the conversion of the first dye precursor 111 and the immobilized cofactor-regenerating enzyme regenerates the co-factor(s) needed by the first dye precursor 111. The carriers used to immobilize said second immobilized enzymes may be the same as the ones used to immobilize said first immobilized enzymes or may be different, depending on the surface-exposed groups of said second enzymes. If possible, the same carriers are used to immobilize both said first and second enzymes.

[0163] The type of said immobilized cofactor-regenerating enzyme depends on which cofactor(s) is used by said first immobilized enzyme 12. For example, when the first immobilized enzymes 12 are flavin-containing monooxygenases (FMO) (which use NADPH as cofactor), the immobilized cofactor-regenerating enzymes may be at least a dehydrogenase that generates NADPH, such as dehydrogenases selected from the group consisting of: glucose dehydrogenase (GDH), phosphite dehydrogenase (PTDH), and formate dehydrogenase (FDH). PTDH are soluble NADPH-regenerating enzymes obtainable for example from Pseudomonas stutzeri, that use phosphite as a substrate to catalyze the production of NADPH. The use of the FMO (preferably mFMO) along with the PTDH revealed to be effective in the synthesis of many second dye precursor 113, in particular of indoxyl and/or derivatives thereof, as it provides good oxidation rates and an efficient regeneration of NADPH.

[0164] The solutions used in the process and apparatus of the invention may also comprise cofactor(s) and/or substrates of said second immobilized enzymes. For example, if GDH, or PTDH, or FDH, is used as an immobilized cofactor-regenerating enzyme, the solutions may comprise also, respectively glucose, or phosphite salts, or formate (i.e. the substrates of, respectively, GDH, PTDH, and FDH).

[0165] Similarly to the first enzymes, mutant second enzymes (e.g. genetically modified second enzyme) can be employed in the process of the invention, for example to improve the regeneration of the desired cofactor(s) or to improve their binding properties to the carrier(s).

[0166] In an embodiment of the present invention, said first enzyme 12 and said second enzyme are provided as a fusion enzyme as previously defined. This provides an enzyme system.

[0167] With reference to FIG. 3, another embodiment of the process of the invention is illustrated. Such embodiment provides for the production of the first dye precursor 112, e.g. indole, starting from one starting compound 114, e.g. tryptophan. A further step is comprised in the process of the invention according to the present embodiment, namely: contacting a solution comprising at least a starting compound 114 with at least a starting enzyme 14 to convert at least part of such starting compound 114 into the first dye precursor 112 to obtain a solution comprising such first dye precursor 112 so that steps a) to d) of the process of the invention can be carried out as already disclosed with reference to FIGS. 1 and 2. When the first immobilized enzyme 12 and the starting enzyme 14 are spaced apart, in order to contact the solution comprising the first dye precursor 112 (obtained by converting the starting compound 114) with the enzyme 12, a flow of such solution may be generated whereby such solution flows from the starting enzyme 14 to the first immobilized enzyme 12, for example as represented in FIG. 3. As the exhaust solution resulting from step d) may also comprise unreacted starting compound 114, circulating the exhaust solution back to the reactors or areas housing the starting enzymes 14 and/or the first chamber or areas housing the first immobilized enzymes 11 may be advantageous to optimize the conversion of unreacted starting compound 114 and/or first dye precursor 112.

[0168] In a further embodiment of the process of the invention, step a) is carried in a first chamber 11, and the dyeing of textile 22 is carried out in a second chamber 21. A solution comprising the first dye precursor 112 is provided inside the first chamber 11 whereby said solution contacts the first enzyme 12 contained in said first chamber 11 and the first dye precursor 112 is converted enzymatically to the second dye precursor 113. A flow of the solution is then generated and the solution, now comprising at least said second dye precursor 113, flows into said second chamber 21 containing textiles 22, whereby the solution and the second dye precursor 113 can contact and impregnate said textile 22. Finally, the second dye precursor 113 converts directly onto the textile 22 into the dye 111.

[0169] The flow of the solution is generated by any means suitable, e.g. a pump 50 or gravity (if the first chamber 11 is located above the second chamber 21).

[0170] First chamber 11 is a container suitable to contain enzymes 12 or enzyme system including the second immobilized enzymes and aqueous solutions. First chamber 11 can comprise also means to contain and restrain said first immobilized catalyzing enzymes 12 (and eventually, the enzyme system) inside it, for example one or more filters. Said first chamber 11 may advantageously comprise one or more means or sensors to allow monitoring parameters of the solution such as pH, temperature of the solution, oxygen concentration, flow rate, etc. The dimension, shape and material of said first chamber 11 can be chosen arbitrarily according to many factors, such as the amount of textiles 22 to be dyed and the dimension and shape of said second chamber 21.

[0171] Second chamber 21 is a container suitable to contain at least said textiles 22 and aqueous solutions, and wherein conversion of said second dye precursor 113 to said insoluble dye 111 can occur. The second chamber 21 may also comprise means that holds said textiles 22 in a predetermined position to allow a faster or more complete dyeing process. Said second chamber 21 may advantageously comprise one or more means or sensors that allow monitoring parameters of the solution such as pH, temperature of the solution, oxygen concentration, flow rate, etc. The dimension, shape and material of said second chamber 21 can be chosen according to many factors, such as the amount of textiles to be dyed, and the dimension and shape of said first chamber 11.

[0172] The first chamber 11 and the second chamber 21 may be thermally regulated individually, for example by means of jackets, e.g. water jackets.

[0173] In FIG. 4, the first chamber 11 is in fluid connection with the second chamber 21. Said fluid connection can be carried out by fluid connectors 11a such as tubes or pipes, which dimension, shape and material can be chosen by the skilled person to ensure the fluid connection between first and second chamber, and that they are able to effectively contain, and advantageously are inert to, the aqueous solutions that circulate in said first chamber 11 and in said second chamber 21. Such dimension, shape and material may vary arbitrarily according to, for example, the amount of textile to be dyed and the flow rate required for the solution. Said fluid connectors (e.g. tubes or pipes) may advantageously comprise probes to measure parameters such as flow rate, temperature, solution pH, and oxygen concentration, as well as portholes, round windows, and/or doors to monitor the process of the invention and to e.g. take samples of the solution.

[0174] Another object of the present invention is an apparatus 10 for dyeing a textile 22 comprising a first chamber 11 containing at least a first immobilized enzyme 12 and a solution comprising at least a dye precursor, at least a second chamber 21 containing a textile 22, and means to generate a flow of a solution 50, wherein said first chamber 11 is in fluid connection with said second chamber 21 whereby said solution comprising at least a dye precursor can flow from said first chamber 11 to said second chamber 21 where at least part of said dye precursor is converted to a dye 111 to dye at least part of said textile 22, for example as represented on FIG. 4. Said second chamber 21 optionally comprises also outlet means to remove said solution from said second chamber 21.

[0175] In particular, FIG. 4 shows said first chamber 11 containing said first immobilized enzymes 12 and said second chamber 21 containing said textiles 22. The straight arrow shows the flow of a solution comprising at least a dye precursor from said first chamber 11 to said second chamber 21. Within said second chamber, at least part of said second dye precursor 113 is converted to an insoluble dye 111 to dye at least part of a textile 22 contained in said second chamber 21.

[0176] FIG. 5 shows a schematic view of an embodiment of the apparatus 10, where the second chamber 21 has outlet means 21a, and wherein the outlet means 21a are in fluid connection with the first chamber 11. This allows the exhaust solution to be removed from said second chamber 21, and be subsequently fed to said first chamber 11 (as represented by the straight arrows of FIG. 5). Outlet means 21a may be any tubes or pipes, for example as described above.

[0177] To carry out the process of the invention in continuous when said apparatus 10 is used, is useful to keep providing cofactors and substrates to the first chamber 11 and the first immobilized enzymes 12, so that they can keep producing the second dye precursor 113. For this reason, compounds (e.g. cofactors and substrates) are added to said first chamber 11 and/or to the exhaust solution that flows back into the first chamber 11. The apparatus 10 of FIG. 5 is accordingly provided with means to carry out such addition, and comprises feeding means 11b connected to the first chamber 11 and/or feeding means 21b connected to the outlet means 21a.

[0178] In an embodiment of the apparatus 10 of the invention, a mean to generate a flow of a solution 50, such as a pump, is further comprised, allowing solutions comprised in the apparatus 10 of the invention to flow.

[0179] When the first immobilized enzyme 12 is not specific to just one substrate and thus is able to convert different first dye precursors 112, it is possible to provide different colors to the textiles 12 to be dyed just by changing the reagents fed to the apparatus 10. By changing first dye precursors 112 without changing the apparatus 10 and/or the enzymes 12 contained therein, different dyes 111 can be obtained; these dyes 111 are suitable to dye a textile 22 in the second chamber 21. For example, when the enzyme 12 contained in the first chamber 11 is the fusion enzyme PTDH-mFMO (which is able to convert indole as well as its derivatives), feeding a solution comprising indole to the apparatus 10 provides blue textiles. If in the same dyeing process a solution comprising 5-hydroxyindole replaces the solution comprising indole and is fed to the apparatus 10, a brown dye and a brown dyed textile is obtained.

[0180] FIG. 6 shows another embodiment of the apparatus 10 further comprising one reservoir 31 in fluidic connection with at least said first chamber 11, so that a solution comprising a dye precursor can flow from said reservoir 31 to said first chamber 11. FIG. 7 shows another embodiment of the apparatus 10 further comprising one collection tank 41 in fluidic connection with said outlet means 21a of said second chamber 21.

[0181] Reservoir 31 is any container that is able to contain aqueous solutions, such as a solution comprising at least said first dye precursor 112, such as indole and/or derivatives thereof. Reservoir 31 may be the container from which a solution comprising at least said first dye precursor 112 is fed the apparatus 10 in order to carry out the dyeing process of the invention. Therefore, reservoir 31 is advantageously set so that an operator can easily feed solutions and/or solutes therein, and its shape and dimension can be chosen accordingly. The apparatus 10 of FIG. 6 also comprises means 50 to generate a flow of a solution, such as a pump, in order to allow the solution to flow from reservoir 31 to first chamber 11, as represented by the straight arrows on FIG. 6, thus feeding a solution comprising first dye precursor 112 to first chamber 11.

[0182] FIG. 8 shows an apparatus 10 comprising both a reservoir 31 and a collection tank 41. The apparatus of FIG. 8 can be useful to carry out the dyeing process of the invention. A solution comprising at least a first dye precursor is provided in the reservoir 31. Then a flow of such solution is generated by the pump 50 and the solution flows to the first chamber 11 from said reservoir 31. Contacting of such solution with enzymes 12 is obtained within said first chamber 11. The solution, now comprising second dye precursor 113, flows from first chamber 11 to second chamber 21 wherein textiles 22 are located. At least part of said second dye precursor 113 is converted to the dye 111 to dye at least part of said textile 22 within said second chamber 21, and an exhaust solution is obtained. The exhaust solution is removed from the second chamber 21 through outlet means 21a and is collected in the collection tank 41. Collecting the exhaust solution could be advantageous, for example when such exhaust solution has to be treated to remove precipitates (such as insoluble dye 111) that might be present; such treatment can be carried out in the collection tank 41. The exhaust solution flows back to said first immobilized enzymes 12 comprised in said first chamber 11 (flowing through the reservoir 31) so that any unreacted first compound 112 in the solution can be contacted with said first immobilized enzymes 12. Solutes, such as the first dye precursor 111 and cofactors, may also be added to the solution by means of the reservoir 31. The apparatus 10 set as in FIG. 8 may be also provided by other means to carry out addition of solutes, for example feeding means 11b connected to the first chamber 11 and/or feeding means 21b connected to the outlet means 21a (not shown in FIG. 8).

[0183] More than one reservoirs 31 and/or more than one collection tanks 41 may be present in the apparatus 10 of the invention, and they can be set in series and/or in parallel.

[0184] In another embodiment, a reactor 51 for the production of the first dye precursor 112, e.g. indole, starting from one or more starting compound 114, e.g. tryptophan, is further comprised in the apparatus 10 of the invention, for example as represented on FIG. 9. Such reactor 51 contains at least the starting enzyme 14. A solution comprising a starting compound 114 can be fed to the reactor 51 by means of feeding means 51b whereby such solution is contacted with starting enzymes 14 and the starting compound 114 is converted to the first dye precursor 112. The solution comprising the first dye precursor 112 can be then flowed to the first chamber 11 by generating a flow of such solution by means of a second pump 50b. Once the solution comprising the first dye precursor 112 is flowed to the first chamber 11, steps a) to d) of the process of the invention can be carried out. FIG. 9 represents an embodiment wherein the reactor 51 is set in parallel with respect to the flow of the solution flowing from the first chamber 11 to the second chamber 21; however embodiments wherein one or more reactors 51 are set in series with respect to such flow of the solution, preferably are set upstream of the first chamber 11, are encompassed by the present invention.