Patent landscape analysis for materials based on fungal mycelium: a guidance report on how to interpret the current patent situation

Abstract

Background

Recent advancements in the collaboration between two scientific disciplines—fungal biotechnology and materials sciences—underscore the potential of fungal mycelium as renewable resource for sustainable biomaterials that can be harnessed in different industries. As fungal mycelium can be biotechnologically obtained from different filamentous fungi and is as a material very versatile, respective research and commercial application should be thriving. However, some granted patents in the field of fungal mycelium-based materials have caused uncertainty in the community as to which subject matter is patent-protected and for how long the protection is expected to last.

Results

This opinion paper therefore maps the patent landscape of fungal mycelium-based materials with a specific focus on technical applications including building construction, insulation, packaging, and the like. We provide an overview of granted patents (73) and pending applications (34) related to granted patents, the dominant patent portfolios (five, with the number of patents and/or applications per owner between six and 44), the patent owners, and highlight the key claims formulated to protect the inventions. Additionally, we outline various options towards an increased activity in the field.

Conclusion

Patent developments in the field leave the impression that fungal materials, despite their high potential as renewable and biodegradable materials, have been held back due to patent over-protection. Considering the need for replacing current petroleum-based materials with renewable biomaterials, coordinated efforts may be called for to intensify efforts in the field.

Introduction

Fungal products contribute with more than 54 trillion US Dollar to the global economy [1]. This incredibly high value is generated in fungal biotechnology through harnessing the versatile metabolic power of several dozens of unicellular and filamentous fungi and the production of a very diverse set of products including food, beverages, pharmaceuticals, cosmetics, enzymes, and biofuels [1]. For comparison, the global market value of the food, chemical, automotive, and pharmaceutical industries was in 2022 8.75 trillion USD, 7.68 trillion USD, 2.56 trillion USD, and 1.28 trillion USD, respectively [2]. Fungal biotechnology is thus an important innovation driver and economic player.

Recent breakthroughs in fungal biotechnology could even potentiate its impact on human welfare and pave the way towards a new era in the materials and building sectors [3]. The 2021–2022 Special Issue ‘Connecting materials science with fungal biology’ published in this Journal (and the first of its kind in the scientific literature) brought together 12 publications that highlighted ‘breakthroughs in the fabrication of fungal mycelium-based materials, all of which have been made possible by the interdisciplinary and transdisciplinary collaboration of fungal biologists and biotechnologists with artists, designers, materials scientists, and architects.’ (In Ref. [4] and references therein). Many actors from academia, industry, art, design, and citizen science are thus engaged in the quest for new renewable materials based on fungal mycelium [5, 6] and market-driven research on fungal materials is conducted in several companies including MycoWorks (US), Ecovative Design (US), Mogu (IT), Loop Biotech (NL), Arup (UK), PLP labs (UK), GrownBio (NL), Mycotech lab (IDN), and Biotopa gGmbH (DE).

The innovation path towards exploiting fungal mycelium as building material, insulation material, or packaging aims to eliminate fossil dependency for material production in the built environment. The vision is to biotechnologically produce fungal mycelium-based materials, mainly composite materials, from renewable lignocellulosic agricultural and forestry resources [3]. In 2023, the Global Alliance for Buildings and Construction (GlobalABC) of the UN Environment Programme stated in their report ‘Building Materials and the Climate: Constructing a New Future’ that the ambitious target of net zero emissions from the built environment sector by mid-century could be achievable when about 40% of building materials are biobased and when the production of fungal mycelium-based building materials can be up-scaled [7]. The vision, the opportunities and challenges of a fungal biotechnology contributing to a sustainable construction industry are thus crystal clear. But how to get there?

It is generally accepted that patents benefit society because they push innovation and promote new services and products in that they set a basis for inventors to receive a revenue for their innovations, thereby stimulating industry and start-ups to innovate. As Abraham Lincoln so incisively put it: “The patent system adds the fuel of interest to the fire of genius” [8]. A patent is usually valid for 20 years from the filing date (not from the patent granting date) in the country or region where the application was filed. The patent gives its owner the right to exclude others from using, making, and/or selling a new technology or product that makes use of the invention as specified in the patent claims in the country where the patent is valid. The owner may permit others (with or without requesting reimbursement, e. g., through a license) to use the patent-protected invention. This is, however, not to be taken as a permission to manufacture a certain product that uses the invention, since additional permissions arising from other patents may be required. For example, a hypothetical first basic patent may claim a building block that includes mycelium, and a hypothetical second patent may improve the building block by additionally including a stabilizing rod. Neither the owner of the second patent nor a licensee of the second patent would be allowed to commercially use the building block that includes the stabilizing rod unless they also had permission from the owner of the first patent.

Notably, because patents are required to disclose the invention in a way that enables others to execute it, they also stimulate competitors and the public sector to innovate, in particular compared to a situation where a company treats the invention as a trade secret instead. Hence, there is a trade-off between disclosing an invention and the potential of obtaining a temporary protection for commercializing it [9]. Consequently, patent disclosures can be considered as important drivers of innovation because the inventions are freely accessible for everyone. Because of this, some companies deliberately disclose selected knowledge to the public domain to stimulate further innovations in the field [10]. Interestingly, there are also concerns of under-protecting and over-protecting intellectual property in emerging fields. Under-protection is considered as a lack of interest from companies and investors, over-protection hinders competition and may cause market barriers [11]. That said, what are the patenting trends for materials based on fungal mycelium? How vivid, innovative, and competitive is the field?

To answer these questions, we must go beyond what has been published thus far in the scientific literature regarding fungal mycelium-based patents. After the first patent survey that covered patent developments between 2009 and 2018 [12], more recent patent surveys addressed not only the materials field but also the overall intellectual property landscape of filamentous fungi [13,14,15,16]. We thus specifically summarize in this paper the current patent landscape of fungal mycelium-based materials for technical applications including building construction, thermal insulation, soundproofing, packaging, and the like. We provide an overview of both granted patents and pending applications related to (e. g., as family members of) granted patents, the dominant patent portfolios, the patent owners, and highlight the key claims formulated to protect the inventions.

Results

Patent and patent application search

The databases Espacenet of the European Patent Office and DEPATISnet of the German Patent and Trademark Office were used for the patent search. One of our goals was the identification of new application areas of fungal mycelium-based materials. Therefore, the patent search was not limited to specific patent classes. Likewise, no restrictions were made regarding country, patent office, and time window (e. g., filing date of patent application, publication date of patent application, granting date of the patent). In fact, it appears that the very first patent application in the field was filed in 2007 (US2013280791A1, US9803171B2), hence, all patents and patent applications listed currently in patent databases are still in force in 2024. A preliminary search limited to keywords “mycelium OR mycelial” together with “substrate OR carrier” in the summary was used for defining a set of parameters (Table 1) that keeps as many of the patents of interest as possible among the search results, while eliminating those patents from the results list that were directed towards other application fields, e.g. for food production.

Table 1 Search parameters for the patent survey

Our first search was conducted in May 2023 and resulted in a list of 255 using Espacenet and 333 using DepatisNet for the same search parameters. The latter was expected to be more complete and was therefore used as a starting point that still included a reasonably large number of patents that were not of interest, for example patents regarding production of antibiotics or fungicides. Such patents were eliminated by hand (226 in total). The resulting final list thus included 107 patents, wherein EP patents are counted per country in which they are active, and in some cases pending family members. During our second search in May 2024, we were able to update this list for members of pending applications that had been granted in the meantime and some newly filed family members that had been published.

The final list covers a broad range of applications for fungal mycelium-based materials that are presently patent-protected or expected to be in the future. We also conducted a supplementary search for identifying patent applications that have no granted family members yet (for search parameters see Table 2).

Table 2 Search parameters for the supplementary survey

We decided to group the search results into five different sub-groups according to the proposed technical application areas: (i) Building/Construction Materials, (ii) Textile Materials, (iii) Filtration Materials, (iv) Chitosan Materials, (v) Other Materials and Production Methods. We used the scheme shown in Table 3 for all five sub-groups (Tables 4, 5, 6, 7 and 8) to provide an overview on the main protected (or expected to be protected) subject matter (i.e. the most important claim), the inventors, countries, and the patent expiration date. For more detailed information, see Additional File 1, which also provides a link to the DEPATISnet document.

Table 3 Organization of entries in Tables 4, 5, 6, 7 and 8

Table 3 summarizes properties of a few so-called “patent families”. Each patent family is based on at least one common priority application for a given invention, usually accompanied, or followed by applications in other countries and/or divisional applications to one or more of those applications. Often, the technical content of the description remains essentially the same across the family members, but the claims that define the scope of the protection may differ for different jurisdictions. Note that an EP patent (patent number starting with “EP”) is granted for a bundle of countries, but whether the patent is in force in a given country depends on further conditions, for example payment of annual fees, filing of translations, etc. For EP patents, countries in which the patent was abandoned are not listed. A PCT application (publication number starting with WO) refers to an application filed with the Patent Corporation Treaty (PCT) which is relevant for 157 PCT contracting states. Note that there is no such thing like a “PCT world patent”. For each country or region (like EP) where protection is sought, an individual patent needs to be obtained, initiated by entering the national or regional phase of the PCT application within a specified period. A PCT application may be described as a “foot in the door” that allows to postpone the decision of whether or not to seek a patent for a certain jurisdiction. Listed in Tables 4, 5, 6, 7 and 8 are only PCT applications where the time limit for entering the national/regional phase has not yet expired. The “Claim” field reproduces, for information purposes, one of the independent claims of the index patent. Even though a patent is supposed to be directed at a single invention, the index patent may include further independent claims directed at other aspects of the invention, and claims of the family members may usually differ somewhat from the claim(s) of the index patent. See Additional File 1 for more information on the family members.

The information provided in Table 9 summarizes current patent applications (status May 2023 with an update from May 2024 for the respective family members). Its organization differs slightly from that of Tables 4, 5, 6, 7 and 8: The claim provided in the second row refers to claim 1 as originally filed, and instead of the (not yet existing) patent expiry date, the link to the original document is provided in the last column of the first row.

Geographical distribution of patents and patent owners

Figure 1A illustrates the regional distribution of the above listed patents and their pending family members (excluding the four EP applications—EP3599832A4, EP3484995A4, EP3860370A4, EP3973055A4—originating from PCT applications, for which it is not yet clear if and for which EP countries they may eventually be relevant). Striking is the large dominance of the US in terms of granted/pending patents (50), while most countries that are represented in Fig. 1 have only one patent that is presently in force or pending. However, Japan has five, China, Australia, and Canada have four each, South Korea and Israel have three each, and eight countries have two patents each in force or pending. Remarkably, about two thirds (70/114) of the patents that are currently in force (and their pending family members) are held by three owners: Ecovative (some together with Rensselaer Polytechnic Institute), Mycoworks, and Bolt Threads Inc (Fig. 1B).

Fig. 1

Patenting countries (A) and patent owners (B) of issuance for materials based on fungal mycelium

Table 4 Building/Construction Materials

Table 5 Textile Materials

Table 6 Filtration Materials

Table 7 Chitosan Materials

Table 8 Other Materials und Production Methods

Table 9 Current patent applications

Discussion

While some of the patents that are currently in force in the field of materials based on fungal mycelium protect a highly specific subject matter that may be relevant only in the context of certain specialized production processes, a few have a very broad scope of protection. This, however, in our view in our view limits new commercial activities in the field due to over-protection. We will therefore discuss in the following such patents and the concerns related. We will refer to previous inventions from the 1940ies – 1950ies and to tacit knowledge from decades of experience in mushroom agricultural cultivation that, in our opinion, were neglected or ignored when the respective patents were granted.

EP2094856B1 (EP856, see Table 8)

Granted claim 1 specifies the following:

A—A method of making a composite material characterized in the steps of

B—forming an inoculum including a preselected fungus;

C—forming a mixture of a substrate of discrete particles and a nutrient material, said nutrient material being capable of being digested by said fungi;

D—adding said inoculum to said mixture; and

E—allowing said fungus to digest said nutrient material in said mixture over a period sufficient to grow hyphae and

F—to allow said hyphae to form a network of interconnected mycelia cells through and around said discrete particles

G—thereby bonding said discrete particles together to form a self-supporting composite material.

This succession of methodical steps is clearly so basic that it contains no specific technical knowledge, application, or mycological skillset. Indeed, these steps are mandatory when a mycelium is to be grown on/in a substrate that includes discrete particles. In fact, the pioneering work of the German mycologist and engineer Walther Luthardt in the 1940s – 1950s laid the technical foundations for controlled cultivation of fungal mycelium on lignocellulosic substrates such as wood and sawdust. Therefore, controlled solid-state fermentation and thus fungal composite production with filamentous fungi is a technology that is at least 80 years old [17]. Arguably, the technology may even be older, but this is the time frame for which easily accessible publications exist. Luthardt’s very first patents from 1944 (DD000000000292B1) and 1951 (DD000000003114A1) describing these inventions and the underlying cultivation steps have been highlighted in [17] and honoured in 1964 with the short film Mykoholz (Mycowood) [18]. This 13 min film clearly demonstrates that there was already an industry in the former German Democratic Republic that produced mycelium-based materials harnessing the methodological steps as described above in claim 1 of EP2094856B1 (EP856). We thus argue that the latter does not include any unique, specific feature or step that may usually not be present, unless the composite material of EP856 is to be produced. In other words, virtually every use of composite mycelium materials – including preparations for growing edible mushrooms—may possibly fall under the scope of protection of EP856 and some of its family members (JP5457194B2, US10589489B2, US10583626B2). It should be noted that the cultivation and manufacturing of edible mushrooms have been well and in detail described in the mushroom agriculture literature from the 1950s to 1960s. For an example, the reader is referred to the book ‘Die Champignonkultur, Grundlagen und Fortschritte im Garten- und Weinbau ‘ (‘Mushroom cultivation, basics and progress in horticulture and viticulture’) published in 1958 [19].

Since the scope of protection varies to some degree between the family members, Additional File 2 gives an overview regarding features of the family member patents of EP856. In this context it is interesting to note that opposition was filed with the European Patent Office (EPO) against EP856 on December 29, 2016, by CNC Holding. In the preliminary opinion, the opposition division concluded that the claims 1 to 7, 13 to 15, 17, 18, 26, and 27 lack novelty over at least one of the following three prior art publications (and claim 1 over all of them): US5074959A; Rush Wayne: ‘Growing Mushrooms the Easy Way—Home Mushroom Cultivation with Hydrogen Peroxide—Volume I’ from 2001 [20]; and Philip Ross: “PURE CULTURE 1997-present” from 2016 [21]. However, the opposition was withdrawn on April 3, 2018, and the opposition division announced on April 30, 2018, that opposition proceedings are discontinued, and the patent was maintained as granted. Given the preliminary opinion of the EPO board of opposition, chances may be reasonable that a nullity suit against any patent that has the scope of protection of EP856 may result in the respective patent being revoked. However, an opt-out has been filed for EP856 regarding the Unified Patent Court (UPC), which means that it is not possible to file a single nullity suit with the UPC. Instead, nullity suits would have to be filed individually with local courts in each country where the patent is to be challenged. Very (or perhaps not very) surprising, Ecovative Design LLC (“Ecovative”) announced on September 15, 2023, ‘the Ecovative European Open Patent Program for Composite Materials to achieve the following goals with respect to composites that include mycelium materials’ to ‘Unleash Mycelium’s Potential together’, to ‘Collaborate with Integrity’, and to ‘Foster Innovation and Protect Ideas’ [22]. In brief, Ecovative announces that patent EP2094856B1 will not be enforced in the EU, and neither its Israeli counterpart in Israel if the technology is used without a licence. It indicates free(er) use of this technology, as Ecovative agrees to refrain from enforcing the rights arising from the European patent EP2094856B1 and the Israeli patent IL199315 against other participants. But in return the Program demands that the participants refrain from taking action against these patents on the one hand, and from enforcing their rights arising from further developments against Ecovative and Ecovative's cooperation partners on the other hand, i.e. to make these freely available to Ecovative until the further development patent expires. As we understand it, ‘further development’ here means that it is a patent that would actually have required permission from Ecovative to be used on the basis of the aforementioned EP or IL patent. (This is because a patent gives the owner the possibility to prohibit others from using/marketing the protected object, but not automatically the permission to use/market the protected object oneself, because this often requires a permission/licence from the owner of the basic patent.) However, a prohibition on filing one's own patent applications or on marketing them to others is not meant by that. A peace offer to re-stimulate competition, which has been limited due to Ecovative’s own patent over-protection? In that case, it may be surprising that the Program is limited to the EP and Israeli patents, rather than including, for example, at least those family members that have a similarly broad scope of protection (e. g., some US, CA, CN, and JP, see Additional File 2).

US11277979B2 (US979, see Table 8)

Granted claim 1 specifies the following:

A—A process of growing a mycological biopolymer material, comprising the steps of.

B—providing a tool defining a cavity therein with an opening into said cavity;

C—packing said cavity of the tool with nutritive substrate and a fungus;

D—placing a lid on said tool to cover said cavity, said lid having only one outlet therein defining a void space open to fresh air;

E—allowing said fungus to grow mycelium within said cavity and to allow the mycelium to respirate within said cavity thereby producing carbon dioxide while colonizing the nutritive substrate;

F—allowing the produced carbon dioxide to diffuse out of said outlet in said lid to create a gradient of carbon dioxide; and

G—allowing the mycelium to grow along said gradient to fill said void space without producing a stipe, cap or spore therein and to produce a mycelium biopolymer in said void space.

Also for this patent, we argue that very fundamental tacit knowledge of mushroom agriculture industry has been claimed. For example, for growing edible mushrooms by techniques known for decades, a mycelium-inoculated substrate is placed in a container with a lid that has usually access to fresh air. In our opinion, the patent thus lacks novelty but limits competition unjustifiably and thus poses further market barriers to other actors in the materials science field exploiting fungal mycelium as a renewable resource.

US9951307B2 (US307, see Table 4)

Granted claim 1 specifies the following:

A—A method for growing organically derived building materials in the form of a moldable substrate to serve a wide range of manufacturing and construction applications, the method comprising the steps of:

B—obtaining a lignocellulose based medium capable of supporting the growth of saprophytic fungi;

C—mixing said lignocellulose based medium with water to reach a hydration level;

D—inoculating said lignocellulose based medium with a fungal inoculum;

E—allowing time for said inoculated lignocellulose based medium to become colonized to the extent that said inoculated lignocellulose based medium is transformed into a fungal mycelium without any secondary organisms displacing the process through infection;

F—strictly regulating environmental conditions surrounding the lignocellulose based medium during said inoculation step and allowing step;

G—adding a primary compressive pressure on the lignocellulose based medium of at least 100 PSI;

H—reducing said primary compressive pressure; and

I—drying said colonized fungal mycelium for a specific time period.

Also this patent—even though it has numerous features that leave the impression of being very specific—has a obviously broad scope, since the specific parameters (e.g. the way the inoculated lignocellulose based medium is formed and the pressure of at least 100 PSI) appear to be so common that the subject matter of claim 1 of US307 may be argued to be not novel, for example over US5074959A, or at least not inventive. Note, part B is so vague that all and any white, brown and soft rot species could arguably fall under the patent.

EP2702137B1 (EP137, see Table 4)

Granted claim 1 specifies the following:

A—A method of making dehydrated mycelium elements comprising the steps of:

B—creating a living hydrated mycelium composite containing at least one of a combination of mycelium and fibers, mycelium and particles, and mycelium, particles and fibers;

C—adding a nutrient material to said mycelium composite in an amount to promote mycelia tissue growth;

D—thereafter dehydrating the mycelium composite to a moisture content of less than 50 % by weight to deactivate the further growth of mycelia tissue to form a dehydrated mycelium element;

E—thereafter storing the dehydrated mycelium element at a temperature in the range of from − 50 °F to +200 ºF (− 45.56 to 93.33 ºC); and

F—adding moisture to said mycelium element in an amount sufficient to rehydrate said mycelium element and to re-activate mycelium on the exterior of said mycelium for growth into an adjacent mycelium element to bond said elements together to form a fabricated section; –OR.

G—creating a living hydrated mycelium composite containing at least one of a combination of mycelium and fibers, mycelium and particles, and mycelium, particles and fibers;

H—adding a nutrient material to said mycelium composite in an amount to promote mycelia tissue growth;

I—thereafter dehydrating the mycelium composite to a moisture content of less than 50% by weight to deactivate the further growth of mycelia tissue;

J—processing the dehydrated mycelium composite into a plurality of discrete particles; and

K—adding moisture to said plurality of discrete particles in an amount sufficient to re-hydrate said discrete particles and to re-activate mycelium on the exterior of said discrete particles for growth into adjacent discrete particles.

We argue that while this patent could conceivably be viewed as technical and specific to a general reader, from a mycological perspective it is clearly so vague and expansive to warrant concern. On the one hand, it includes two sets of features joined by an “OR”, so, it is in effect two alternative claims in one. On the other hand, the specific parameters, like the moisture content being reduced to less than 50% appear to be so common that the subject matter of claim 1 of US137 may be argued to be not novel, for example over ‘Die Champignonkultur, Grundlagen und Fortschritte im Garten- und Weinbau ‘ from 1958 [19], or at least not inventive. Other aspects raise questions- the intention to ‘create a living hydrated mycelium composite’ implies that a mycelium (or composite therefore) can be ‘created’ from a dead, dehydrated fungus. Given that mycelium-composites must by definition be generated from living and hydrated fungi, the adjectives ‘living hydrated’ are essentially redundant. Why are they included in the patent?

Taken together, our analysis of the patent situation in the field of material-oriented applications of fungal mycelium suggests that some patents do not clearly refer to new inventions with significant technological advancements. Some claims are trivial and refer to tacit knowledge in the field of mushroom farming and mycelium technology (e.g. from the former German Democratic Republic). But how to deal with patent (over-)protection?

In general, patent rights can always be fought in court, and there are several legal regulations for contesting and defending patent rights. In addition, other actions can be taken to overcome hindrance of innovation. We have summarized in Table 10 possible actions that can be taken and discuss some of their pros and cons.

Table 10 Options for (i) contesting patents and patent applications and (ii) and joint agreements

As discussed in Table 10, the first two comparatively low-level options are not accessible any more for EP2094856B1, US11277979B2, EP2702137B1, and US9951307B2. Considering the preliminary opinion of the EPO Board of Opposition, chances of winning a nullity suit may be reasonable, but costs for filing and pursuing such a suit would have to be provided up-front, which may exceed financial resources of at least some of those who could potentially benefit from a less severe over-protection in the field. However, such a course of action could be possible in a collaborative community effort.

Conclusions

The patent landscape of fungal-based materials shows that only a few key players have dominated the field right from the beginning. We argue that the current patent situation may have hindered and hinders other institutions and companies to innovate the field. At least for some of the patents causing over-protection, we consider the validity of the patents questionable as they refer to common and tacit knowledge in the mycology community. This may open up possibilities for nullity suits and/or negotiations for cooperation.

Methods

Patent search. The databases Espacenet of the European Patent Office and DEPATISnet of the German Patent and Trademark Office were used for the patent search. The following search term was used in Espacenet: (nftxt = “mycelium” OR nftxt =  “mycelial”) AND (nftxt = “substrate” OR nftxt = “carrier”) AND (nftxt = (“composite” prox/distance < 3 “material”) OR nftxt = (“mycelial” prox/distance < 3 “composite”) OR nftxt = (“mycelium” prox/distance < 3 “scaffolding”) OR nftxt = (“building” prox/distance < 3 “material”) OR nftxt = (“biodegradable” prox/distance < 3 “material”)) AND (pn any “B1” OR pn any “B2”), and a corresponding term using the appropriate syntax was used for DEPATISnet.

The search result was re-examined by hand to exclude patents related to food, pharmaceutical applications (mainly production of antibiotics), fungicides, and other patents that, despite having the keywords, do not fall under the scope of mycelium-based materials for technical applications. The remaining patents were further examined regarding their subjects and actual claims. For retrieving the patent expiration date, Google Patents was used. If a patent family was incompletely reproduced by the search results, the patent family was completed from any of the databases. The patents resulting from the search were grouped topic- and family-wise. In Tables 4, 5, 6, 7 and 8, registered information included patent number, publication date, assignee/owner, title, status (including expiration date and countries where the patent is still pending), and claim 1.