Hymenophore-based leather

Abstract

The present invention relates to a method for producing a hymenophore material using Fomitopsis quercina grown on a lignin-reduced softwood substrate. The invention further relates to the hymenophore material at different production steps, and its use as a leather or in producing a packaging material.

Description

[0001] EMPA106EP

[0002] Hymenophore-based Leather

[0003] Field

[0004] The present invention relates to a method for producing a hymenophore material using Fomitopsis quercina grown on a lignin-reduced softwood substrate. The invention further relates to the hymenophore material at different production steps, and its use as a leather or in producing a packaging material.

[0005] The function of the mycelium is to provide a transportation network to pass nutrients to the fungal fruit body. Mycelium that is used for producing mycelium-based materials is short-lived and enables fungi to colonize, secrete enzymes and to degrade an organic substrate.

[0006] Since it is generally known that a high CO2 atmosphere encourages the growth of mycelium and inhibits the formation of fruit bodies, companies such as Ecovative's Forager™ use an active growing technique to generate mycelium-based materials. This process involves pumping huge amounts of CO2 into the growth chamber. These "fungal leathers," which are made through an active growing process, have an extremely high carbon footprint (1). The Ecovative process, which produces both their Forager™ material and the mycelium for Bolt Threads’ Mylo™ material, is known to consume so much CChthat it may surpass the CO2 consumption of animal leathers (32.97 kg CC>2 / m2). Active-gas mycelium growth processes also require additional fuels to meet high CO2 input requirements (1). Furthermore, it is impossible to produce a tough material from mycelium without chemical modification because most fungal mycelium has a short lifespan and hardly ever differentiates in the presence of high CO2 levels. Therefore, most mycelium-based materials (that are chemically treated) have reported tensile strengths in the range of 0.2-2 MPa in the literature.

[0007] Based on the above-mentioned state of the art, the objective of the present invention is to provide means and methods to provide an environmentally-friendly alternative to leather and plastic packing material. This objective is attained by the subject-matter of the independent claims of the present specification, with further advantageous embodiments described in the dependent claims, examples, figures and general description of this specification.

[0008] Summary of the Invention

[0009] A first aspect of the invention relates to a method for producing a hymenophore material comprising the steps of a. Provision of Fomitopsis quercina in a cultivation chamber; EMPA106EP b. Addition of a lignin reduced softwood substrate; c. Incubation step; d. Removal of the hymenophore material.

[0010] A second aspect of the invention relates to a hymenophore material derived from Fomitopsis quercina characterised in that the hymenophore material comprises 10-20 tubular branches per 10 cm2. An alternative of the second aspect of the invention relates to a hymenophore material derived from Fomitopsis quercina characterised in that the hymenophore material has a tensile strength of more than 0.5 MPa.

[0011] Further aspects of the invention relate to methods based on the method of the first aspect, and resulting hymenophore materials derived from Fomitopsis quercina.

[0012] Terms and definitions

[0013] General

[0014] For purposes of interpreting this specification, the following definitions will apply and whenever appropriate, terms used in the singular will also include the plural and vice versa. In the event that any definition set forth below conflicts with any document incorporated herein by reference, the definition set forth shall control.

[0015] The terms “comprising”, “having”, “containing”, and “including”, and other similar forms, and grammatical equivalents thereof, as used herein, are intended to be equivalent in meaning and to be open-ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. For example, an article “comprising” components A, B, and C can consist of (i.e., contain only) components A, B, and C, or can contain not only components A, B, and C but also one or more other components. As such, it is intended and understood that “comprises” and similar forms thereof, and grammatical equivalents thereof, include disclosure of embodiments of “consisting essentially of’ or “consisting of.”

[0016] Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit, unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure.

[0017] Reference to “about” a value or parameter herein includes (and describes) variations that are directed to that value or parameter per se. For example, description referring to “about X” includes description of “X.” EMPA106EP

[0018] As used herein, including in the appended claims, the singular forms “a”, “or” and “the” include plural referents unless the context clearly dictates otherwise.

[0019] "And / or" where used herein is to be taken as specific recitation of each of the two specified features or components with or without the other. Thus, the term "and / or" as used in a phrase such as "A and / or B" herein is intended to include "A and B," "A or B," "A" (alone), and "B" (alone). Likewise, the term "and / or" as used in a phrase such as "A, B, and / or C" is intended to encompass each of the following aspects: A, B, and C; A, B, or C; A or C; A or B; B or C; A and C; A and B; B and C; A (alone); B (alone); and C (alone).

[0020] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art (e.g., in cell culture, molecular genetics, nucleic acid chemistry, hybridization techniques and biochemistry, organic synthesis). Standard techniques are used for molecular, genetic, and biochemical methods (see generally, Sambrook et al., Molecular Cloning: A Laboratory Manual, 4th ed. (2012) Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. and Ausubel et al., Short Protocols in Molecular Biology (2002) 5th Ed, John Wiley & Sons, Inc.) and chemical methods.

[0021] The term feeder wood block in the context of the present specification relates to a wood block which is used to pre-culture Fomitopsis quercina before the hymenophore material is grown.

[0022] The term Fomitopsis quercina in the context of the present specification relates to a fungi species which is also named oak mazegill, and which was formerly grouped under the genus Daedalea.

[0023] The term inert in the context of the present specification relates to a material which does not react in a chemical reaction with the fungi of the invention or with the softwood substrate.

[0024] The term liquid-impermeable in the context of the present specification relates to a material which is able to separate a first aqueous phase and a second aqueous phase from each other without liquid exchange between them.

[0025] The term softwood in the context of the present specification relates to wood from gymnosperm trees such as conifers. The main softwood species (pines, spruces, larches, false tsugas) also have resin canals (or ducts) in their structure.

[0026] The term hardwood in the context of the present specification relates to the wood from angiosperm trees. The main differences between hardwoods and softwoods is that the softwoods completely lack vessels (pores).

[0027] The term lignin in the context of the present specification relates to a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignin is a collection of highly heterogeneous polymers derived from a handful of precursor lignols. Heterogeneity arises from the diversity and degree of crosslinking between these EMPA106EP lignols. The lignols that crosslink are of three main types, all derived from phenylpropane: coniferyl alcohol (3-methoxy-4-hydroxyphenylpropane; its radical, G, is sometimes called guaiacyl), sinapyl alcohol (3,5-dimethoxy-4-hydroxyphenylpropane; its radical, S, is sometimes called syringyl), and paracoumaryl alcohol (4-hydroxyphenylpropane; its radical, H, is sometimes called 4-hydroxyphenyl).

[0028] The term natural wood or untreated wood in the context of the present specification relates to a non-processed form of wood which has the characteristics of wood which has just been cut. The natural wood which serves as a comparison is of the same origin as the wood which has undergone natural weathering.

[0029] The term light source in the context of the present specification relates to a source of light comprising UV light. UV light is responsible for lignin degradation.

[0030] Any patent document cited herein shall be deemed incorporated by reference herein in its entirety.

[0031] Detailed Description of the Invention

[0032] A first aspect of the invention relates to a method for producing a hymenophore material comprising the steps of a. Provision of Fomitopsis quercina in a cultivation chamber; b. Addition of a lignin reduced softwood substrate; c. Incubation step; d. Removal of the hymenophore material.

[0033] In certain embodiments, before the removal of the hymenophore material, a moisture removal step is performed.

[0034] In certain embodiments, the incubation step is characterized by ~ 6 months of incubation inside a culture vessel. In certain embodiments, the culture vessel is fitted with a leak-proof, glass lid, the side with a round hole (particularly 040 mm diameter) and plugged with a foam wad to allow gaseous exchange.

[0035] In certain embodiments, before the addition of the lignin reduced softwood substrate, a precultivation step is performed, wherein Fomitopsis quercina is incubated on a hardwood feeder wood block (yielding a colonized hardwood feeder wood block). In certain embodiments, the hardwood feeder wood block is made of beech wood.

[0036] In certain embodiments, in the incubation step, the colonized hardwood feeder wood block is separated from the lignin reduced softwood substrate by an inert liquid-impermeable material. In certain embodiments, the inert liquid-impermeable material is a glass plate. EMPA106EP

[0037] Glass supports are used to prevent direct contact of the specimens with the culture medium. Glass has the advantage of being simple to sterilize and being inert.

[0038] In certain embodiments, the lignin reduced softwood substrate is selected from Norway spruce wood (Picea abies), and white fir wood (Abies alba). In certain embodiments, the softwood is Norway spruce wood.

[0039] In certain embodiments, the lignin reduced softwood substrate comprises a reduced lignin amount in the range of 1 to 10 % compared to the natural wood. In certain embodiments, the lignin reduced softwood substrate comprises a reduced lignin amount in the range of 3 to 8 % compared to the natural wood.

[0040] In certain embodiments, the lignin amount is reduced by at least 2% (w / w) compared to untreated softwood. In certain embodiments, the lignin amount is reduced by at least 3% (w / w). In certain embodiments, the lignin amount is reduced by 3% to 20% (w / w). In certain embodiments, the lignin amount is reduced by 3% to 10% (w / w). A maximum of 20% (w / w) lignin removal due to artificial weathering will only take place on the surface of the softwood substrate, not in greater depth of the wood. To quantify the extension of lignin degradation, ATR-FTIR (Attenuated total reflection fourier transform infrared spectroscopy) analysis can be performed.

[0041] In certain embodiments, the reduced lignin amount is achieved with treatment of the softwood substrate with a light source and / or water or with an oxidizing agent. In certain embodiments, the oxidizing agent is H2O2.

[0042] In certain embodiments, the reduced lignin amount is achieved by natural weathering of the softwood substrate. In certain embodiments, natural weathering is applied for at least 4 months. In certain embodiments, natural weathering is applied for at least 6 months. In certain embodiments, natural weathering is applied for 4 to 24 months. In certain embodiments, natural weathering is applied for 6 to 24 months.

[0043] In certain embodiments, natural weathering is the exposure to sunlight and rain. Wood absorbs or loses moisture until it reaches an equilibrium with the surrounding air.

[0044] In certain embodiments, no additional carbon dioxide is added during the process. Conventional fungi-growing methods often rely on the need to add additional carbon dioxide which is detrimental for the environment.

[0045] A second aspect of the invention relates to a hymenophore material derived from Fomitopsis quercina characterised in that the hymenophore material comprises 10-20 tubular branches per 10 cm2. A hymenophore material not grown with the method of the invention comprises ~1 to 5 tubular branches per 10 cm2in nature. This parameter can be measured with a ruler. EMPA106EP

[0046] In certain embodiments, the hymenophore material is obtained by a method of the first aspect.

[0047] An alternative of the second aspect of the invention relates to a hymenophore material derived from Fomitopsis quercina characterised in that the hymenophore material has a tensile strength of more than 0.5 MPa. In certain embodiments, the hymenophore material has a tensile strength of more than 1 MPa. In certain embodiments, the hymenophore material has a tensile strength of more than 2 MPa. In certain embodiments, the hymenophore material has a tensile strength of 0.5 to 3 MPa. In certain embodiments, the hymenophore material has a tensile strength of 0.5 to 2 MPa. In certain embodiments, the hymenophore material is obtained by a method of the first aspect.

[0048] Another alternative of the second aspect of the invention relates to a hymenophore material derived from Fomitopsis quercina characterised in that the hymenophore material comprises 10-20 tubular branches per 10 cm2and a tensile strength of more than 0.5 MPa, particularly more than 1 MPa, more particularly more than 2 MPa, most particularly 0.5 to 3 MPa.

[0049] Tensile strength

[0050] The mechanical characterization of samples is performed on a dual column universal testing machine (ZwickRoell). 4 mm wide, 25 mm long strips are cut from samples grown for 20 days in rectangular shape with thickness ranging between 0.1 and 0.3 mm, and mounted on the machine clamps. The samples are deformed at a rate of 2 mm / min until failure. The Young’s modulus E, ultimate tensile strength UTS and elongation at fracture are extracted from the stress-strain curves. Fracture energy is calculated as the area beneath each curve. Six measurements are conducted on each sample in order to confirm the reproducibility of the tensile tests, and results are reported as average values and standard deviation. All tests are carried out at room temperature, 23 °C.

[0051] A third aspect of the invention relates to a method for producing a dehydrated hymenophore material comprising a. provision of a hymenophore material obtained by a method of the first aspect, b. performing a dehydration step yielding a dehydrated hymenophore material.

[0052] A fourth aspect of the invention relates to a dehydrated hymenophore material derived from Fomitopsis quercina characterised in that the hymenophore material has a tensile strength of more than 0.5 MPa. In certain embodiments, the hymenophore material has a tensile strength of more than 1 MPa. In certain embodiments, the hymenophore material has a tensile strength of more than 2 MPa. In certain embodiments, the hymenophore material has a tensile strength of 0.5 to 3 MPa. In certain embodiments, the hymenophore material is obtained by a method of the third aspect. EMPA106EP

[0053] A fifth aspect of the invention relates to a method for producing a hymenophore material sheet comprising a. provision of a hymenophore material obtained by a method according to the first aspect, or b. a hymenophore material obtained by a method according to the third aspect, c. applying pressure to the hymenophore material yielding a hymenophore sheet material.

[0054] A sixth aspect of the invention relates to a hymenophore sheet material derived from Fomitopsis quercina characterised in that the hymenophore sheet material has a tensile strength of more than 8 MPa. In certain embodiments, the hymenophore sheet material has a tensile strength of more than 9 MPa. In certain embodiments, the hymenophore sheet material has a tensile strength of 10 MPa. In certain embodiments, the hymenophore sheet material has a tensile strength of 8 to 12 MPa. In certain embodiments, the hymenophore material has a tensile strength of 10 times the tensile strength of the non-pressed hymenophore material according to the fourth aspect. In certain embodiments, the hymenophore material is obtained by a method of the fifth aspect.

[0055] An alternative of the sixth aspect of the invention relates to a hymenophore sheet material derived from Fomitopsis quercina.

[0056] A seventh aspect of the invention relates to the use of the hymenophore sheet material according to the sixth aspect in producing a packaging material.

[0057] An eighth aspect of the invention relates to a method for producing a hymenophore leather material comprising a. provision of a hymenophore sheet material obtained by a method according to the fifth aspect, b. surface modification increasing hydrophobicity, particularly by lubricating the hymenophore sheet material with a wax, particularly with bees’ wax creme.

[0058] A nineth aspect of the invention relates to a hymenophore leather material derived from Fomitopsis quercina characterised in that the hymenophore material has a tensile strength of more than 4 MPa. In certain embodiments, the hymenophore material has a tensile strength of more than 8 MPa. In certain embodiments, the hymenophore material has a tensile strength of 10 MPa. In certain embodiments, the hymenophore material has a tensile strength of 4 to 15 MPa. In certain embodiments, the hymenophore material has a tensile strength of 10 times the tensile strength of the non-pressed hymenophore material according EMPA106EP to the fourth aspect. In certain embodiments, the hymenophore material is obtained by a method of the eighth aspect.

[0059] An alternative of the nineth aspect of the invention relates to a hymenophore leather material derived from Fomitopsis quercina.

[0060] Wherever alternatives for single separable features are laid out herein as “embodiments”, it is to be understood that such alternatives may be combined freely to form discrete embodiments of the invention disclosed herein. Thus, any of the alternative embodiments for a hymenophore material may be combined with any of the alternative embodiments of a pre-incubation step and these combinations may be combined with any condition mentioned herein.

[0061] The invention further encompasses the following items:

[0062] Items’.

[0063] 1. A method for producing a hymenophore material comprising the steps of a. Provision of Fomitopsis quercina in a cultivation chamber; b. Addition of a lignin reduced softwood substrate; c. Incubation step; d. Removal of the hymenophore material.

[0064] 2. The method according to item 1 , characterized in that before the removal of the hymenophore material a moisture removal step is performed.

[0065] 3. The method according to item 1 or 2, characterized in that before the addition of the lignin reduced softwood substrate a pre-cultivation step is performed, wherein Fomitopsis quercina is incubated on a hardwood feeder wood block, particularly the hardwood feeder wood block is made of beech wood.

[0066] 4. The method according to item 3, characterized in that in the incubation step, the colonized hardwood feeder wood block is separated from the lignin reduced softwood substrate by an inert liquid-impermeable material, particularly by a glass plate.

[0067] 5. The method according to any one of the previous items, characterized in that the lignin reduced softwood substrate is selected from Norway spruce wood, and white fir wood, in particular the softwood is Norway spruce wood.

[0068] 6. The method according to any one of the previous items, characterized in that the lignin reduced softwood substrate comprises a reduced lignin amount in the range of 1 to 10 %, particularly in the range of 3 to 8 % compared to the natural wood.

[0069] 7. The method according to any one of the previous items, characterized in that the lignin amount is reduced by at least 2% (w / w) compared to untreated softwood, EMPA106EP particularly reduced by at least 3% (w / w), more particularly reduced by 3% to 20% (w / w), most particularly reduced by 3% to 10% (w / w).

[0070] 8. The method according to any one of the previous items, characterized in that the reduced lignin amount is achieved with treatment of the softwood substrate with a light source and / or water or with an oxidizing agent, particularly H2O2.

[0071] 9. The method according to any one of the previous items, characterized in that the reduced lignin amount is achieved by natural weathering of the softwood substrate, particularly by natural weathering for at least 4 months, more particularly by natural weathering for at least 6 months, most particularly for 4 to 24 months.

[0072] 10. The method according to any one of the previous items, characterized in that no additional carbon dioxide is added during the process.

[0073] 11. A hymenophore material derived from Fomitopsis quercina, in particular obtained by a method according to items 1 to 10, characterised in that the hymenophore material comprises 10-20 tubular branches per 10 cm2.

[0074] 12. A hymenophore material, in particular obtained by a method according to items 1 to 10, characterised in that the hymenophore material has a tensile strength of more than 0.5 MPa, particularly more than 1 MPa, more particularly more than 2 MPa, most particularly 0.5 to 3 MPa.

[0075] 13. A method for producing a dehydrated hymenophore material comprising a. provision of a hymenophore material obtained by a method according to any one of the items 1 to 10, b. performing a dehydration step yielding a dehydrated hymenophore material.

[0076] 14. A dehydrated hymenophore material, in particular obtained by a method according to item 13, characterised in that the hymenophore material has a tensile strength of more than 0.5 MPa, particularly more than 1 MPa, more particularly more than 2 MPa, most particularly 0.5 to 3 MPa.

[0077] 15. A method for producing a hymenophore material sheet comprising a. provision of a hymenophore material obtained by a method according to any one of the items 1 to 10, or b. a dehydrated hymenophore material obtained by a method according to item 13, c. applying pressure to the hymenophore material yielding a hymenophore sheet material. EMPA106EP

[0078] 16. A hymenophore sheet material derived from Fomitopsis quercina, in particular obtained by a method according to item 15, characterised in that the hymenophore sheet material has a tensile strength of more than 8 MPa, particularly more than 9 MPa, more particularly 10 MPa.

[0079] 17. Use of the hymenophore sheet material according to item 16 in producing a packaging material.

[0080] 18. A method for producing a hymenophore leather material comprising a. provision of a hymenophore sheet material obtained by a method according to item 13, b. surface modification increasing hydrophobicity, particularly by lubricating the hymenophore sheet material with a wax, particularly with bees’ wax creme.

[0081] 19. A hymenophore leather material, in particular obtained by a method according to item 15, characterised in that the hymenophore material has a tensile strength of more than 4 MPa, particularly more than 8 MPa, more particularly 10 MPa, most particularly 4 to 15 MPa.

[0082] The invention is further illustrated by the following examples and figures, from which further embodiments and advantages can be drawn. These examples are meant to illustrate the invention but not to limit its scope.

[0083] Fig. 1 Production process of FBL A: Pure culture of Fomitopsis quercina growing on 3 % MEA. B: Beech feeder wood blocks are placed onto glass banks in Kolleflasks with 35 MEA that were previously incubated with F. quercina. Note: glass supports are used to prevent direct contact of the specimens with the culture medium. C: Beech feeder wood blocks incubated with F. quercina and placed into an autoclavable vessel with moist vermiculite and saw dust. Note: glass supports are used to prevent direct contact of the specimens with the wood planks. D: Norway spruce wood planks exposed for 6 months to natural weathering (sunlight, UV-light, rain). Pre-weathering of the Norway spruce wood takes place using 10 - 20 mm thick and approx. 150 - 170 mm wide boards which are exposed on racks to outdoor weathering for at least 6 months (March - September). The wood is aligned towards the southwest at an inclination of 45°. E: Norway spruce wood planks that have been naturally weathered for six months and placed into the culture vessel onto feeder wood blocks, which were formerly incubated with F. quercina (cf. B). The culture vessel is fitted with a leak-proof, glass lid, the side with a round hole, 040 mm EMPA106EP diameter, and plugged with a foam wad to allow gaseous exchange. F: Norway spruce wood planks in the vessel colonized by mycelium of F. quercina that starts to differentiate into a hymenophore after 4 months incubation. G: Norway spruce wood planks completely covered by the hymenophore after 6 months incubation, dehydration and removal of the lid. H: Removal of the hymenophore from the wood surface for cold pressing of the material. I: Fungal hymenophore with enhanced mechanical properties.

[0084] Fig. 2 ATR-FTIR spectra of both analyzed wood samples. The original wood is represented with a solid line, whereas the naturally weathered wood is represented with a dashed line. The insert plot highlights the three bands of interest, characteristic of lignin (1592, 1505 and 1455 cm-1).

[0085] Fig. 3 Pure culture of Fomitopsis quercina growing on 3 % MEA.

[0086] Fig. 4 Beech feeder wood blocks on glass banks in Kolleflasks incubated with

[0087] Fomitopsis quercina. Note glass supports are used to prevent direct contact of the specimens with the culture medium.

[0088] Fig. 5 Beech feeder wood blocks incubated with Fomitopsis quercina and placed into an autoclavable box with moist vermiculite and saw dust. Note glass supports are used to prevent direct contact of the specimens with the wood planks.

[0089] Fig. 6 Norway spruce wood planks exposed for 6 months to natural weathering (sunlight, UV-light, rain). Pre-weathering of the Norway spruce wood takes place using 10 - 20 mm thick and approx. 150 - 170 mm wide boards which are exposed on racks to outdoor weathering for at least 6 months (March - September). The wood is aligned towards the southwest at an inclination of 45°.

[0090] Fig. 7 Norway spruce wood planks that have been naturally weathered for six months and placed into the autoclavable box onto feeder wood blocks, which were formerly incubated with Fomitopsis quercina (see 2). Note glass supports are used to prevent direct contact of the specimens with the wood planks.

[0091] Fig. 8 Norway spruce wood planks in the culture vessel with a glass lid. The culture vessel is fitted with leakproof lids, the centres of which are pierced with a round hole of typically 040 mm diameter and plugged with a foam wad to allow gaseous exchange.

[0092] Fig. 9 Norway spruce wood planks in the vessel covered by a glass lid and completely colonized by the mycelium of Fomitopsis quercina after 4 months incubation. EMPA106EP

[0093] Fig. 10 Images showing side dehumidification openings within the incubation chambers.

[0094] Fig. 11 Norway spruce wood planks completely covered by mycelium of Fomitopsis quercina after 6 months incubation and after removal of the lid.

[0095] Fig. 12 Fungal mycelium of Fomitopsis quercina incubated for 6 months after dehydration and removal from the vessel.

[0096] Fig. 13 Cold pressing of the mycelium of Fomitopsis quercina after dehydration and removal from the vessel.

[0097] Fig. 14 Mycelium of Fomitopsis quercina after cold pressing with enhanced mechanical properties.

[0098] Example 1:

[0099] Our passive growth process consumes no gases and results in a drastic reduction in total emissions. In the absence of high CO2 levels, the mycelium of F. quercina differentiates into a resupinate hymenophore i.e. an initial stage of a fruit body lying flat on a substrate (Norway spruce wood planks that have been naturally weathered for 6 months). Normally, F. quercina colonizes hardwoods (sweet chestnut and oak) but not softwoods like Norway spruce. Colonization of Norway spruce wood is only possible after exposure to the environment.

[0100] FTIR studies show that colonization of Norway spruce by F. quercina is facilitated by natural weathering of the wood and an average lignin degradation of 5.43 % (Fig. 2). The main function of a fruit body is to produce spores for dissemination and colonization of new wood substrates, it is extremely tough and can survive in nature in time and space for 50-100 years. F. quercina produces perennial fruiting bodies that can survive for >30 years. Using the hymenophore (the initial stage of a fruit body) of F. quercina enables us to produce a fungal-based material (without chemical modification) that has an enhanced tensile strength of >10 MPa. In Figure 1 our novel production process is described in detail.

[0101] To quantify the extension of lignin degradation during the natural weathering process, ATR- FTIR analysis was performed (Fehler! Verweisquelle konnte nicht gefunden werden.). In the insert of Fehler! Verweisquelle konnte nicht gefunden werden., the lignin characteristic bands are highlighted. There are 1592 and 1505 cm-1, both characteristic of the C=C stretching of the aromatic ring of lignin, and 1455 cm-1, characteristic of lignin's asymmetric bending in CH3.[1] EMPA106EP

[0102] Numerical analysis of the obtained FTIR spectra was performed to quantify the area under each band highlighted in the insert of Fehler! Verweisquelle konnte nicht gefunden werden.. Since these are lignin's characteristic bands, the calculated areas correspond to amount of each chemical group present in lignin structure. As stated above, the 1592 and 1505 cm-1bands correspond to the aromatic rings, and the 1455 cm-1correspond to the CH3 asymmetric bending. For each band, the difference was obtained by subtracting the lignin content in the naturally weathered wood by the lignin content in the original wood. In Table 1 , it is observable that, in the one hand, the most degraded lignin's structures were the aromatic rings (6.14% and 11.02%, respectively for the 1598 and 1505 cm-1bands, averaging 8.58% lignin degradation). On the other hand, lignin's CH3 structures seem to not suffer any damage from the natural weathering, turning the average with the other two bands into 5.43% lignin degradation.

[0103] Table 1. Lignin characteristic band areas, calculated through numerical analysis.

[0104] 1592 1505

[0105] 1455

[0106] (C=C (C=C

[0107] (asymmetric stretching of stretching of bending in the aromatic the aromatic

[0108] CH3) ring) ring)

[0109] Original wood 100.00% 100.00% 100.00%

[0110] Naturally weathered 93.86% 88.98% 100.87% wood

[0111] Difference -6.14% -11.02% 0.87%

[0112] Material and methods

[0113] ATR-FTIR spectroscopy was performed on fine sawdust obtained by filing the surface (under 1 mm), of each sample. The spectra were obtained in the absorbance mode, using a Bruker Tensor 27 spectrometer (USA), over a scan range of 4000 to 400 cm-1, to detect changes in the lignin content both in the original wood and the naturally weathered wood.

[0114] Numerical analysis (Gaussian fit), was performed to determine the FTIR band areas of interest, namely 1592, 1505, and 1455 cm’1.[1]During the calculations, the lignin content in EMPA106EP the original wood sample was considered to be 100%. This analysis was performed using the software OriginPro 2024b.

[0115] Cited references: [1] Williams et al. 2020. Environmental Sciences Europe 34:120 https: / / doi.Org / 10.1186 / S12302-022-00689-x

[0116] [2] X. Colom, F. Carrillo, F. Nogues, P. Garriga, Polym. Degrad. Stab. 2003, 80, 543.

[0117] All scientific publications and patent documents cited in the present specification are incorporated by reference herein.

Claims

EMPA106EPClaims1. A method for producing a hymenophore material comprising the steps of a. Provision of Fomitopsis quercina in a cultivation chamber; b. Addition of a lignin reduced softwood substrate; c. Incubation step; d. Removal of the hymenophore material.

2. The method according to claim 1 , characterized in that before the removal of the hymenophore material a moisture removal step is performed.

3. The method according to claim 1 or 2, characterized in that before the addition of the lignin reduced softwood substrate a pre-cultivation step is performed, wherein Fomitopsis quercina is incubated on a hardwood feeder wood block, particularly the hardwood feeder wood block is made of beech wood.

4. The method according to any one of the previous claims, characterized in that the lignin reduced softwood substrate is selected from Norway spruce wood, and white fir wood, in particular the softwood is Norway spruce wood.

5. The method according to any one of the previous claims, characterized in that the lignin amount is reduced by at least 2% (w / w) compared to untreated softwood, particularly reduced by at least 3% (w / w), more particularly reduced by 3% to 20% (w / w), most particularly reduced by 3% to 10% (w / w).

6. The method according to any one of the previous claims, characterized in that the reduced lignin amount is achieved by natural weathering of the softwood substrate, particularly by natural weathering for at least 4 months, more particularly by natural weathering for at least 6 months, most particularly for 4 to 24 months.

7. The method according to any one of the previous claims, characterized in that no additional carbon dioxide is added during the process.

8. A hymenophore material derived from Fomitopsis quercina, in particular obtained by a method according to claims 1 to 7, characterised in that the hymenophore material comprises 10-20 tubular branches per 10 cm2.

9. A hymenophore material, in particular obtained by a method according to claims 1 to 7, characterised in that the hymenophore material has a tensile strength of more than 0.5 MPa, particularly more than 1 MPa, more particularly more than 2 MPa, most particularly 0.5 to 3 MPa.

10. A method for producing a dehydrated hymenophore material comprisingEMPA106EP a. provision of a hymenophore material obtained by a method according to any one of the claims 1 to 7 or a hymenophore material according to claim 8 or 9, b. performing a dehydration step yielding a dehydrated hymenophore material.

11. A dehydrated hymenophore material, in particular obtained by a method according to claim 10, characterised in that the hymenophore material has a tensile strength of more than 0.5 MPa, particularly more than 1 MPa, more particularly more than 2 MPa, most particularly 0.5 to 3 MPa.

12. A method for producing a hymenophore sheet material comprising a. provision of a hymenophore material obtained by a method according to any one of the claims 1 to 7 or a hymenophore material according to claim 8 or 9 or b. a dehydrated hymenophore material obtained by a method according to claim 10 or a dehydrated hymenophore material according to claim 11, c. applying pressure to the hymenophore material yielding a hymenophore sheet material.

13. A hymenophore sheet material derived from Fomitopsis quercina, in particular obtained by a method according to claim 12, characterised in that the hymenophore sheet material has a tensile strength of more than 8 MPa, particularly more than 9 MPa, more particularly 10 MPa.

14. A method for producing a hymenophore leather material comprising a. provision of a hymenophore sheet material obtained by a method according to claim 12 or a hymenophore sheet material according to claim 13, b. surface modification increasing hydrophobicity, particularly by lubricating the hymenophore sheet material with a wax, particularly with bees’ wax creme.

15. A hymenophore leather material, in particular obtained by a method according to claim 14, characterised in that the hymenophore material has a tensile strength of more than 4 MPa, particularly more than 8 MPa, more particularly 10 MPa, most particularly 4 to 15 MPa.

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