Method for producing mycelial sheet

A method for producing a mycelial sheet includes: subjecting a fungus to static cultivation in a liquid medium containing a cellulose, so as to allow the fungus to form the mycelial sheet on a surface of the liquid medium; and collecting the mycelial sheet from the surface of the liquid medium containing the cellulose.

1. 11. A method for producing a mycelial sheet, comprising: subjecting a fungus to static cultivation in a liquid medium containing a cellulose having a particle size ranging from 0.035 mm to 4 mm, so as to allow the fungus to form the mycelial sheet on a surface of the liquid medium; collecting the mycelial sheet from the surface of the liquid medium containing the cellulose; and subjecting the mycelial sheet collected from the surface of the liquid medium containing the cellulose to a washing treatment so as to remove the cellulose, wherein the mycelial sheet is free of the cellulose and the static cultivation is the only cultivation performed in the method and the static cultivation is performed under a stationary condition without stirring or shaking.
2. 22. The method as claimed in claim 1, wherein the cellulose is present in an amount ranging from 0.05 wt % to 0.5 wt % based on 100 wt % of the liquid medium.
3. 33. The method as claimed in claim 1, wherein the cellulose is selected from the group consisting of a bacterial cellulose, a plant cellulose, and a combination thereof.
4. 44. The method as claimed in claim 3, wherein the plant cellulose is selected from the group consisting of a potato cellulose, a wheat cellulose, an oat cellulose, and combinations thereof.
5. 55. The method as claimed in claim 3, wherein when the liquid medium contains the bacterial cellulose, the mycelial sheet thus obtained is free from the bacterial cellulose.
6. 66. The method as claimed in claim 3, wherein when the liquid medium contains the plant cellulose, the mycelial sheet thus obtained is free from the plant cellulose.
7. 77. The method as claimed in claim 3, wherein when the liquid medium contains the combination of the bacterial cellulose and the plant cellulose, the mycelial sheet thus obtained is free from the combination of the bacterial cellulose and the plant cellulose.
8. 88. The method as claimed in claim 1, wherein the fungus is selected from the group consisting of Cordyceps spp., Trametes spp., Ganoderma multipileum, Inonotus tabacinus, Irpex brevis, Pleurotus cornucopiae, Schizophyllum commune, Terana coerulea, and combinations thereof.
9. 99. The method as claimed in claim 8, wherein the Cordyceps spp. is selected from the group consisting of Cordyceps cateniobliqua, Cordyceps farinosa, Cordyceps militaris, Cordyceps tenuipes, and combinations thereof.
10. 1010. The method as claimed in claim 8, wherein the Trametes spp. is selected from the group consisting of Trametes hirsuta, Trametes gibbosa, Trametes versicolor, and combinations thereof.

CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to Taiwanese Invention patent application No. 113122371, filed on Jun. 17, 2024, the entire disclosure of which is incorporated by reference herein.
FIELD
The disclosure relates to a method for producing a mycelial sheet.
BACKGROUND
A mycelial sheet, also known as mycelial mat, is a sheet material generated from a fungus. The mycelial sheet has been used as a substitute for leather or cloth due to good mechanical property (generally with a tensile strength of approximately 1 MPa to 5 MPa) thereof. The mycelial sheet is mainly composed of mycelia, and some studies have found that adding a cellulose to the mycelial sheet to form a mycelium-cellulose composite material can further improve the mycelial sheet's mechanical property. Currently, one of two commonly used methods for producing the mycelial sheet may include subjecting the fungus to solid-state cultivation, so as to allow the fungus to form the mycelial sheet, followed by collecting the mycelial sheet on a surface of a solid culture medium; another one of the methods may include subjecting the fungus to shaking cultivation in a liquid medium, so as to obtain a resultant liquid culture, followed by subjecting the resultant liquid culture to filtration (in some cases, further subjected to pressing after the filtration), thereby obtaining the mycelial sheet. However, with respect to the aforesaid two methods, the former is more time-consuming, and the latter is more complicated in operation.
SUMMARY
Therefore, an object of the disclosure is to provide a method for producing a mycelial sheet, which can alleviate at least one of the drawbacks of the prior art. The method includes:

    
    
        subjecting a fungus to static cultivation in a liquid medium containing a cellulose, so as to allow the fungus to form the mycelial sheet on a surface of the liquid medium; and
        collecting the mycelial sheet from the surface of the liquid medium containing the cellulose.
    
    





BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the disclosure will become apparent in the following detailed description of the embodiment(s) with reference to the accompanying drawings. It is noted that various features may not be drawn to scale.
The FIGURE shows a dry weight of a mycelial sheet determined in each group of each fungal strain of Example 1, infra.



DETAILED DESCRIPTION
It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Taiwan or any other country.
For the purpose of this specification, it will be clearly understood that the word “comprising” means “including but not limited to”, and that the word “comprises” has a corresponding meaning.
Unless otherwise defined, all technical and scientific terms used herein have the meaning commonly understood by a person skilled in the art to which the present disclosure belongs. One skilled in the art will recognize many methods and materials similar or equivalent to those described herein, which could be used in the practice of the present disclosure. Indeed, the present disclosure is in no way limited to the methods and materials described.
By conducting research, the applicant surprisingly found that by subjecting a fungus to static cultivation in a liquid medium containing a cellulose, a mycelial sheet can be formed on a surface of the liquid medium, which not only makes forming of the mycelial sheet quick and easy, but also allows the mycelial sheet to be completely formed and to have a good tensile strength.
Therefore, the present disclosure provides a method for producing a mycelial sheet, which includes:

    
    
        subjecting a fungus to static cultivation in a liquid medium containing a cellulose, so as to allow the fungus to form the mycelial sheet on a surface of the liquid medium; and
        collecting the mycelial sheet from the surface of the liquid medium containing the cellulose.
    
    


As used herein, the terms “mycelial sheet,” “mycelial mat,” “fungal sheet” and “fungal mat” can be interchangeably used, and mean a continuous flat sheet formed by interconnection of fungal hyphae.
As used herein, the term “fungus” is intended to cover any fungal species that is capable of producing a mycelium (i.e., a mycelium-producing fungus or a filamentous fungus). Examples of the fungal species may include, but are not limited to, Cordyceps spp., Trametes spp., Ganoderma multipileum, Inonotus tabacinus, Irpex brevis, Pleurotus cornucopiae, Schizophyllum commune, Terana coerulea, and combinations thereof.
In certain embodiments, the Cordyceps spp. may be selected from the group consisting of Cordyceps cateniobliqua, Cordyceps farinosa, Cordyceps militaris, Cordyceps tenuipes, and combinations thereof. In some embodiments, the Cordyceps farinosa may be Cordyceps farinosa deposited at the Bioresource Collection and Research Center (BCRC) under an accession number BCRC FU30829, or Cordyceps farinosa deposited at the BCRC under an accession number BCRC FU31128. In still some embodiments, the Cordyceps tenuipes may be Cordyceps tenuipes deposited at the BCRC under an accession number BCRC FU31198. In yet some embodiments, the Cordyceps cateniobliqua may be Cordyceps cateniobliqua deposited at the BCRC under an accession number BCRC FU31225. In still yet some embodiments, the Cordyceps militaris may be Cordyceps militaris deposited at the BCRC under an accession number BCRC FU31818. In other embodiments, the Cordyceps spp. may be selected from the group consisting of the Cordyceps farinosa deposited at the BCRC under the accession number BCRC FU30829, the Cordyceps farinosa deposited at the BCRC under the accession number BCRC FU31128, the Cordyceps tenuipes deposited at the BCRC under the accession number BCRC FU31198, the Cordyceps cateniobliqua deposited at the BCRC under the accession number BCRC FU31225, the Cordyceps militaris deposited at the BCRC under the accession number BCRC FU31818, and combinations thereof.
In certain embodiments, the Trametes spp. may be selected from the group consisting of Trametes hirsuta, Trametes gibbosa, Trametes versicolor, and combinations thereof. In some embodiments, the Trametes gibbosa may be Trametes gibbose deposited at the BCRC under an accession number BCRC MU30502. In still some embodiments, the Trametes hirsuta may be Trametes hirsuta deposited at the BCRC under an accession number BCRC MU30685. In still some embodiments, the Trametes versicolor may be Trametes versicolor deposited at the BCRC under an accession number BCRC MU30810. In other embodiments, the Trametes spp. may be selected from the group consisting of the Trametes gibbose deposited at the BCRC under the accession number BCRC MU30502, the Trametes hirsuta deposited at the BCRC under the accession number BCRC MU30685, the Trametes versicolor deposited at the BCRC under the accession number BCRC MU30810, and combinations thereof.
In certain embodiments, the Ganoderma multipileum may be Ganoderma multipileum deposited at the BCRC under an accession number BCRC 37180. In certain embodiments, the Inonotus tabacinus may be Inonotus tabacinus deposited at the BCRC under an accession number BCRC MU30009. In certain embodiments, the Irpex brevis may be Irpex brevis deposited at the BCRC under an accession number BCRC 35360. In certain embodiments, the Pleurotus cornucopiae may be Pleurotus cornucopiae deposited at the BCRC under an accession number BCRC MU30825. In certain embodiments, the Schizophyllum commune may be Schizophyllum commune deposited at the BCRC under an accession number BCRC MU30359. In certain embodiments, the Terana coerulea may be Terana coerulea deposited at the BCRC under an accession number BCRC MU30808. In other embodiments, the fungus may be selected from the group consisting of the Ganoderma multipileum deposited at the BCRC under the accession number BCRC 37180, the Inonotus tabacinus deposited at the BCRC under the accession number BCRC MU30009, the Irpex brevis deposited at the BCRC under the accession number BCRC 35360, the Pleurotus cornucopiae deposited at the BCRC under the accession number BCRC MU30825, the Schizophyllum commune deposited at the BCRC under the accession number BCRC MU30359, the Terana coerulea deposited at the BCRC under the accession number BCRC MU30808, and combinations thereof.
According to the present disclosure, the cellulose may be a commercially available product, or may be obtained from a natural source using microbiological techniques and/or isolation techniques well known to those skilled in the art. In this regard, those skilled in the art may refer to, e.g., Wang J. et al. (2019), Carbohydr. Polym., 219:63-76, or Guo. Y. et al. (2021), Trans. Tianjin Univ., 27(5):385-393.
Alternatively, the cellulose may be made by utilizing synthetic techniques well known to those skilled in the art.
In certain embodiments, the method for producing the mycelial sheet may further include, subjecting the mycelial sheet collected from the surface of the liquid medium containing the cellulose to a washing treatment, so as to remove the cellulose.
In certain embodiments, the cellulose may be selected from the group consisting of a bacterial cellulose, a plant cellulose, and a combination thereof.
As used herein, the term “bacterial cellulose” means a cellulose that is produced by natural mechanism in bacterial cells. Examples of a bacterial species suitable for use in the present disclosure may include, but are not limited to, Acetobacter spp., Gluconacetobacter spp., Komagataeibacter spp., Alcaligenes spp., Pseudomonas spp., Rhizobium spp., Argobacterium spp., and Scarcina spp. In some embodiments, the Gluconacetobacter spp. may be Gluconacetobacter xylinus (also known as Komagataeibacter xylinus; formerly named as Acetobacter xylinum).
As used herein, the term “plant cellulose” means a cellulose produced by a plant species. Examples of the plant species suitable for use in the present disclosure may include, but are not limited to, Solanum spp., Triticum spp., and Avena spp. In some embodiments, the Solanum spp. may be Solanum tuberosum. In still some embodiments, the Triticum spp. may be Triticum aestivum L. In yet some embodiments, the Avena spp. may be Avena sativa. 
According to the present disclosure, the cellulose may have a particle size ranging from 0.035 mm to 4.0 mm.
In certain embodiments, the cellulose may be the bacterial cellulose having a particle size of not lower than 0.035 mm to less than 3.0 mm.
In certain embodiments, the cellulose may be the plant cellulose having a particle size ranging from 0.035 mm to 0.09 mm. In an exemplary embodiment, the particle size of the plant cellulose is 0.035 mm. In another exemplary embodiment, the particle size of the plant cellulose is 0.09 mm.
According to the present disclosure, the liquid medium containing the cellulose may be prepared by adding the cellulose to a basic medium that is suitable for growth of fungal mycelia.
According to the present disclosure, the cellulose may be present in an amount ranging from 0.05 wt % to 0.5 wt % based on 100 wt % of the liquid medium. In an exemplary embodiment, the cellulose is present in an amount of 0.15 wt % based on 100 wt % of the liquid medium. In another exemplary embodiment, the cellulose is present in an amount of 0.5 wt % based on 100 wt % of the liquid medium.
In certain embodiments, the cellulose is the bacterial cellulose, and the mycelial sheet is free from the bacterial cellulose (i.e., the mycelial sheet is composed solely of the fungal hyphae). In certain embodiments, the cellulose is the plant cellulose, and the mycelial sheet is free from the plant cellulose (i.e., the mycelial sheet is composed solely of the fungal hyphae). In certain embodiments, the cellulose is the combination of the bacterial cellulose and the plant cellulose, and the mycelial sheet is free from the combination of the bacterial cellulose and the plant cellulose (i.e., the mycelial sheet is composed solely of the fungal hyphae).
According to the present disclosure, the basic medium suitable for the growth of fungal mycelia is well known to those skilled in the art, and may be a self-formulated medium, or a commercially available product. Examples of the basic medium may include, but are not limited to, a malt extract broth (MEB) medium and a potato dextrose broth (PDB) medium.
The basic medium suitable for use in the present disclosure may contain a carbon source selected from the group consisting of a glucose, a fructose, a lactose, a sucrose, a maltose, a galactose, a mannose, a trehalose, a starch, a potato starch, a malt extract, a maltodextrin, a dextrin, a corn flour, and combinations thereof.
The basic medium suitable for use in the present disclosure may contain a nitrogen source selected from the group consisting of a peptone, a polypeptone, ammonium sulfate ((NH4)2SO4), ammonium nitrate (NH4NO3), ammonium chloride (NH4Cl), ammonium citrate, a casamino acid, a tryptone, a meat extract, a yeast extract, a yeast powder, a milk, a skimmed milk powder, a casein, a soybean flour, a whey, an amino acid, and combinations thereof.
As used herein, the term “static cultivation” means a culture performed under a stationary condition without stirring or shaking, e.g., performed in an incubator in a stationary mode.
As used herein, the term “cultivation” and “culturing” may be interchangeably used.
According to the present disclosure, procedures and parameter conditions regarding the static cultivation are within the expertise and routine skills of those skilled in the art. In this regard, reference may be made to, e.g., El-Enshasy H. A. (2007), Bioprocessing for Value-Added Products from Renewable Resources, 225-261.
According to the present disclosure, the static cultivation may be carried out at a temperature ranging from 20° C. to 30° C. for 7 days to 28 days. In an exemplary embodiment, the static cultivation is carried out at a temperature of 25° C. for 14 days.
The disclosure will be further described by way of the following examples. However, it should be understood that the following examples are intended solely for the purpose of illustration and should not be construed as limiting the present disclosure in practice.
EXAMPLES
General Experimental Materials
1. Malt Extract Agar (MEA) Plate
The MEA plate used in the following examples was prepared using different ingredients dissolved in reverse osmosis water and each having a certain concentration, as shown in Table 1 below.










TABLE 1







Ingredient
Concentration (g/L)



















Malt extract
20



Peptone
1



Glucose
20



Agar
15










2. Malt Extract Broth (MEB) Medium

The MEB medium used in the following examples was prepared using different ingredients dissolved in reverse osmosis water and each having a certain concentration, as shown in Table 2 below.










TABLE 2







Ingredient
Concentration (g/L)



















Malt extract
20



Peptone
1



Glucose
20










3. Fungal Strains

The fungal strains used in the following examples were purchased from the Bioresource Collection and Research Center (BCRC) of the Food Industry Research and Development Institute (FIRDI) (No. 331, Shih-Pin Rd., Hsinchu City 300, Taiwan). The fungal strains included:

    
    
        (1) Cordyceps spp., such as Cordyceps farinosa deposited at the BCRC under an accession number BCRC FU30829 (hereinafter “Cordyceps farinosa BCRC FU30829”), Cordyceps farinosa deposited at the BCRC under an accession number BCRC FU31128 (hereinafter “Cordyceps farinosa BCRC FU31128”), Cordyceps tenuipes deposited at the BCRC under an accession number BCRC FU31198 (hereinafter “Cordyceps tenuipes BCRC FU31198”), Cordyceps cateniobliqua deposited at the BCRC under an accession number BCRC FU31225 (hereinafter “Cordyceps cateniobliqua BCRC FU31225”), and Cordyceps militaris deposited at the BCRC under an accession number BCRC FU31818 (hereinafter “Cordyceps militaris BCRC FU31818”);
        (2) Trametes spp., such as Trametes gibbosa deposited at the BCRC under an accession number BCRC MU30502 (hereinafter “Trametes gibbosa BCRC MU30502”), Trametes hirsuta deposited at the BCRC under an accession number BCRC MU30685 (hereinafter “Trametes hirsuta BCRC MU30685”), and Trametes versicolor deposited at the BCRC under an accession number BCRC MU30810 (hereinafter “Trametes versicolor BCRC MU30810”);
        (3) Terana coerulea deposited at the BCRC under an accession number BCRC MU30808 (hereinafter “Terana coerulea BCRC MU30808”);
        (4) Inonotus tabacinus deposited at the BCRC under an accession number BCRC MU30009 (hereinafter “Inonotus tabacinus BCRC MU30009”);
        (5) Schizophyllum commune deposited at the BCRC under an accession number BCRC MU30359 (hereinafter “Schizophyllum commune BCRC MU30359”);
        (6) Pleurotus cornucopiae deposited at the BCRC under an accession number BCRC MU30825 (hereinafter “Pleurotus cornucopiae BCRC MU30825”);
        (7) Irpex brevis deposited at the BCRC under an accession number BCRC 35360 (hereinafter “Irpex brevis BCRC 35360”); and
        (8) Ganoderma multipileum deposited at the BCRC under an accession number BCRC 37180 (hereinafter “Ganoderma multipileum BCRC 37180”).

4. Preparation of Inoculum

    
    


Each of the aforesaid fungal strains was inoculated into the MEA plate (with a diameter of 9 cm), and then cultured at 25° C. for 1 week to 3 weeks, so as to obtain a mycelium formed on the MEA plate. Thereafter, the mycelium was cut into mycelial pieces, and then the mycelial pieces were added to 90 ml of sterile water, so as to form a mixture, followed by subjecting the mixture to a homogenization treatment with a homogenizer (Oster, Model: BO-00001), thereby obtaining a homogenate. Next, the homogenate was inoculated into the MEB medium at an inoculation amount of 10 vol % based on a total amount of the homogenate and the MEB medium as 100 vol %, followed by shaking cultivation in a thermostatic shaking incubator (25° C., 150 rpm) for 5 days to 7 days, thereby obtaining a resultant culture which was to be used as an inoculum of the fungal strain.
5. Cellulose
In the following Example 1, the potato cellulose (with a particle size of 0.09 mm) (Cat. No. Pot 90) was purchased from Pennant Hills Pty Ltd., and both the wheat cellulose (with a particle size of 0.035 mm) (Cat. No. WF600-30) and the oat cellulose (with a particle size of 0.0035 mm) (Cat. No. HF600-30) were purchased from Gem Font Corporation. In addition, the bacterial cellulose (with a particle size of less than 3 mm) was obtained by using Gluconacetobacter xylinus which produced a biofilm, and then the biofilm was washed and neutralized with water, followed by a homogenization treatment and lyophilization. Moreover, the bacterial cellulose pulp (with a particle size of less than 3 mm) (Cat. No. ND-A1018-HA-B7) used in the following Examples 2 and 3 was purchased from Chia Meei Food Industrial Corporation. Prior to use, the bacterial cellulose pulp was subjected to a homogenization treatment to form a homogenized bacterial cellulose material, followed by subjecting the homogenized bacterial cellulose material to determination of an amount of bacterial cellulose thereof, which was 1 wt %.
Example 1. Effect of Using Cellulose from Different Sources on Generation of Mycelial Sheet in Static Cultivation
Experimental Procedures and Results
First, the inoculum of each of the Cordyceps militaris BCRC FU31818, the Cordyceps farinosa BCRC FU31128, the Cordyceps farinosa BCRC FU30829, the Cordyceps tenuipes BCRC FU31198, the Cordyceps cateniobliqua BCRC FU31225, the Trametes gibbosa BCRC MU30502, the Ganoderma multipileum BCRC 37180, the Pleurotus cornucopiae BCRC MU30825, and the Trametes hirsuta BCRC MU30685 obtained in Section 4 of General Experimental Materials was divided into five groups, including one control group and four experimental groups (i.e., experimental groups 1 to 4). Next, each group of the inoculum of each of the aforesaid fungal strains was inoculated into a corresponding liquid medium (in a culture bottle having a bottom diameter of 8 cm), which contained the MEB medium described in Section 2 of General Experimental Materials and/or a certain kind of the cellulose described in Section 5 of General Experimental Materials, at an inoculation amount of 10 vol % (based on a total amount of the corresponding liquid medium and the inoculum as 100 vol %), as shown in Table 3 below, followed by conducting static cultivation in a thermostatic incubator (25° C.) for 14 days. Thereafter, a mycelial sheet formed on a surface of each of the liquid media was subjected to observation, and then was collected and washed with water, followed by conducting thermal drying at 40° C. overnight and measurement of a dry weight of the mycelial sheet.









TABLE 3





Group
Cellulose
Final concentration







Control group
—
0


Experimental group 1
Bacterial cellulose
0.5 wt % based on 100


Experimental group 2
Potato cellulose
wt % of liquid medium


Experimental group 3
Wheat cellulose


Experimental group 4
Oat cellulose









For each of the fungal strains mentioned above, the mycelial sheet formed in each of the experimental groups 1 to 4 was observed to have a complete form, whereas the mycelial sheet formed in the control group was observed to not have such complete form (data not shown). Referring to the FIGURE, for each of the fungal strains, the dry weights of the mycelial sheets measured in the experimental groups 1 to 4 show varying degrees of increase compared with the dry weight of the mycelial sheet measured in the control group, where the dry weight of the mycelial sheet measured in the experimental group 1 of the Cordyceps militaris BCRC FU31818 has the highest degree of increase. Additionally, in this example, the applicant also used the inoculum of each of the Terana coerulea BCRC MU30808 and the Irpex brevis BCRC 35360 to conduct the aforesaid experiments, and similar results were obtained (data not shown).
Furthermore, the applicant also selected the mycelial sheet of the Cordyceps militaris BCRC FU31818 obtained in Experimental group 1 as a representative for determining mechanical strength thereof by utilizing a tensile testing machine (Instron 5965) and with reference to the methods described in Appels F. V. W. et al. (2020), Commun. Biol., 26; 3(1):334. The results showed that a tensile strength of the mycelial sheet could reach up to 6.11 MPa.
These results show that by subjecting a fungus to static cultivation in a liquid medium containing a cellulose, particularly a bacterial cellulose, a mycelial sheet, which is generated from the fungus, has a complete form, and good mechanical strength, can be formed on a surface of the liquid medium, and an enhancement in the yield of the mycelial sheet can also be achieved.
Example 2. Effect of Using Cellulose in Different Concentrations on Generation of Mycelial Sheet in Static Cultivation
Experimental Procedures and Results
First, the inoculum of the Cordyceps militaris BCRC FU31818 described in Section 4 of General Experimental Materials was divided into seven groups, including one control group and six experimental groups (i.e., experimental groups 1 to 6). Next, each group of the inoculum of the Cordyceps militaris BCRC FU31818 was inoculated into a corresponding liquid medium (in a culture bottle having a bottom diameter of 8 cm), which contained the MEB medium described in Section 2 of General Experimental Materials and/or a certain amount of the homogenized bacterial cellulose material described in Section 5 of General Experimental Materials, at an inoculation amount of 10 vol % (based on a total amount of the corresponding liquid medium and the inoculum as 100 vol %). The final concentration of the bacterial cellulose for each group was summarized in Table 4 below. After static cultivation in a thermostatic incubator (25° C.) for 14 days, a mycelia sheet formed on a surface of each of the liquid media was subjected to observation, and then was collected and washed with water, followed by conducting thermal drying at 40° C. overnight and measurement of a dry weight of the mycelial sheet.










TABLE 4








Final concentration of



Group
bacterial cellulose (wt %)



















Control group
0



Experimental group 1
0.05



Experimental group 2
0.10



Experimental group 3
0.15



Experimental group 4
0.20



Experimental group 5
0.25



Experimental group 6
0.30










The results show that the mycelial sheet formed in each of the experimental groups 1 to 6 was observed to have a complete form, whereas the mycelial sheet formed in the control group was observed to not have such complete form (data not shown). Referring to Table 5 below, the dry weight of the mycelial sheet measured in each of the experimental groups 1 to 6 show a significant increase compared with the dry weight of the mycelial sheet measured in the control group. These results show that by virtue of subjecting a fungus to static cultivation in liquid media containing the bacterial cellulose that was present in an amount within a range from 0.05 wt % to 0.30 wt % based on 100 wt % of the liquid medium, a mycelial sheet, which is generated from the fungus and has a complete form, can be formed on a surface of each of the liquid media, and in particular, a significant increase in the yield of the mycelial sheet can be achieved when the bacterial cellulose was present in the amount ranging from 0.15 wt % to 0.30 wt % based on 100 wt % of the liquid medium.










TABLE 5







Group
Dry weight (g)



















Control group
1.07



Experimental group 1
1.58



Experimental group 2
1.75



Experimental group 3
1.87



Experimental group 4
1.81



Experimental group 5
1.83



Experimental group 6
1.83










Example 3. Production of Mycelial Sheet Having Large Area Size
Experimental Procedures and Results
The inoculum of each of the Cordyceps militaris BCRC FU31818, the Ganoderma multipileum BCRC 37180, the Cordyceps farinosa BCRC FU30829, the Cordyceps tenuipes BCRC FU31198, the Cordyceps cateniobliqua BCRC FU31225, the Inonotus tabacinus BCRC MU30009, the Schizophyllum commune BCRC MU30359, the Trametes gibbosa BCRC MU30502, the Trametes hirsuta BCRC MU30685, the Trametes versicolor BCRC MU30810, and the Pleurotus cornucopiae BCRC MU30825 described in Section 4 of General Experimental Materials was subjected to formation of a mycelia sheet using procedures similar to those described in Example 2, except that a final concentration of the bacterial cellulose in the liquid medium for the respective fungal strain was 0.20 wt % based on 100 wt % of the liquid medium, a bottom area of a culture bottle used for receiving the liquid medium was 20 cm×20 cm, and static cultivation was performed for a period ranging from 7 days to 28 days. The results show that each of the aforesaid fungal strains is capable of forming a mycelial sheet that has a complete form.
Therefore, the applicant further conducted an additional experiment using the aforesaid procedures, except that, in the additional experiment, for each of the abovementioned fungal strains, a culture bottle had a bottom area of 54 cm×41 cm, and found that a mycelial sheet having a complete form could also be formed (not shown).
Based on the results from Examples 1 to 3, the applicant believes that not only a mycelial sheet can be easily produced by subjecting a fungus to static cultivation in a liquid medium containing a cellulose, but also the mycelia sheet thus obtained has a complete form and good mechanical strength. Accordingly, the mycelial sheet can be used to replace a conventional mycelium-cellulose composite material, thereby serving as a substitute for leather or cloth.
In the description above, for the purposes of explanation, numerous specific details have been set forth in order to provide a thorough understanding of the embodiment(s). It will be apparent, however, to one skilled in the art, that one or more other embodiments may be practiced without some of these specific details. It should also be appreciated that reference throughout this specification to “one embodiment,” “an embodiment,” an embodiment with an indication of an ordinal number and so forth means that a particular feature, structure, or characteristic may be included in the practice of the disclosure. It should be further appreciated that in the description, various features are sometimes grouped together in a single embodiment, FIGURE, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of various inventive aspects; such does not mean that every one of these features needs to be practiced with the presence of all the other features. In other words, in any described embodiment, when implementation of one or more features or specific details does not affect implementation of another one or more features or specific details, said one or more features may be singled out and practiced alone without said another one or more features or specific details. It should be further noted that one or more features or specific details from one embodiment may be practiced together with one or more features or specific details from another embodiment, where appropriate, in the practice of the disclosure.
While the disclosure has been described in connection with what is (are) considered the exemplary embodiment(s), it is understood that this disclosure is not limited to the disclosed embodiment(s) but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.