U.S. patent application number 13/492230 was filed with the patent office on 2012-12-13 for substrate composition and method for growing mycological materials.
Invention is credited to Eben Bayer, Gavin McIntyre.
Application Number | 20120315687 13/492230 |
Document ID | / |
Family ID | 47293513 |
Filed Date | 2012-12-13 |
United States Patent
Application |
20120315687 |
Kind Code |
A1 |
Bayer; Eben ; et
al. |
December 13, 2012 |
Substrate Composition and Method for Growing Mycological
Materials
Abstract
A substrate is provided for growing basidiomycete mycelium
comprised of nutritional and one of non-nutritional particles and
fiber characterized in that the substrate promotes the growth and
differentiation of basidiomycete mycelium without supporting the
production of a basidiocarp. The method of growing the
basidiomycete mycelium includes inoculating the substrate with a
vegetative mycelium and incubating in a first incubation period at
controlled temperature, humidity and carbon dioxide levels followed
by a finishing incubation period.
Inventors: |
Bayer; Eben; (Troy, NY)
; McIntyre; Gavin; (Troy, NY) |
Family ID: |
47293513 |
Appl. No.: |
13/492230 |
Filed: |
June 8, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13454856 |
Apr 24, 2012 |
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13492230 |
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61494477 |
Jun 8, 2011 |
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Current U.S.
Class: |
435/254.1 |
Current CPC
Class: |
C12N 1/14 20130101 |
Class at
Publication: |
435/254.1 |
International
Class: |
C12N 1/14 20060101
C12N001/14 |
Claims
1. A substrate for growing basidiomycete mycelium comprising
nutritional and one of non-nutritional particles and fiber
characterized in that said substrate promotes the growth and
differentiation of basidiomycete mycelium without supporting the
production of a basidiocarp.
2. A substrate for growing basidiomycete mycelium comprising
non-nutritional material, nutritional particles and nutrient
3. A substrate as set forth in claim 2 where said non-nutritional
material is selected from the group consisting of rice hulls, oat
hulls, cottonseed hulls, buckwheat hulls, soybean hulls, perlite,
cotton fiber and cotton burs.
4. A substrate as set forth in claim 2 where said nutritional
particles are maltodextrin.
5. A substrate as set forth in claim 2 where said nutrient is
calcium sulphate.
6. A substrate as set forth in claim 2 comprising 335 g Rice Hulls,
432 g Cottonseed Hulls and 8 g Maltodextrin.
7. A substrate as set forth in claim 2 comprising 450 g Buckwheat
Hulls, 432 g Cottonseed Hulls and 8 g Maltodextrin.
8. A substrate as set forth in claim 2 comprising 335 g Soybean
Hulls, 432 g Cottonseed Hulls and 8 g Maltodextrin.
9. A substrate as set forth in claim 2 comprising 300 g Perlite,
432 g Cottonseed Hulls and 8 g Maltodextrin.
10. A substrate as set forth in claim 2 comprising 520 g Cotton
Fiber and 32 g Maltodextrin.
11. A substrate as set forth in claim 2 comprising 480 g Cotton
Burs, 40 g Cottonseed Hulls and 32 g Maltodextrin.
12. A method of growing basidiomycete mycelium comprising the steps
of providing a substrate comprised of non-nutritional material,
nutritional particles and nutrient capable of promoting the growth
and differentiation of basidiomycete mycelium without supporting
the production of a basidiocarp; adding water to said substrate;
inoculating the substrate with a vegetative mycelium; and
thereafter incubating the inoculated substrate in a first
incubation period at a temperature between 24 and 30.degree. C. and
an operating relative humidity of 80 to 100% while allowing carbon
dioxide levels to build over the course of incubation to in excess
of 5000 ppm.
13. A method as set forth in claim 12 further comprising the step
of subjecting the incubated substrate to a secondary incubation
period wherein said temperature is maintained between 15 and
25.degree. C.
14. A method as set forth in claim 12 further comprising the step
of subjecting the incubated substrate to a secondary incubation
period wherein said carbon dioxide level is elevated to between
10,000 and 60,000 ppm,
15. A method as set forth in claim 12 further comprising the step
of subjecting the incubated substrate to a secondary incubation
period wherein said relative humidity is greater than 90%.
16. A method as set forth in claim 12 further comprising the step
of subjecting the incubated substrate to a secondary incubation
period wherein the incubated substrate is nested in a configuration
that offers no light exposure.
Description
[0001] This application claims the benefit of Provisional Patent
Application 61/494,477.
[0002] This application is a Continuation-in-Part of pending U.S.
patent application Ser. No. 13/454,856, filed Apr. 24, 2012.
[0003] This invention relates to a substrate composition and method
for mycological materials.
[0004] As is known from published United States Patent Application
2008/0145577, use can be made of a fungus to form composite
materials by mixing an inoculum including a preselected fungus with
discrete particles and a nutrient material capable of being
digested by the fungus. It is also known from U.S. Pat. No.
8,001,719 to enclose and grow a fungal primordium in a mold to
obtain a mass of fungal tissue in the form of low density chitinous
material.
[0005] Briefly, this invention provides an engineered substrate for
the production of mycological materials as well as an improvement
on the method described in published US Patent Application
2008/0145577 for the production of mycological materials. In this
regard, the method also provides for an optimal incubation
environment to promote various types of mycelium physiology on the
substrate.
[0006] In accordance with the invention, the substrate is comprised
of both nutritional and non-nutritional particles or fiber, which
promote the growth and differentiation of basidiomycete mycelium
but does not support the production of a basidiocarp (fruiting body
or mushroom). A nutritional particle or fiber is defined as
providing an easily accessible carbon source for the fungal
mycelium; this includes simple sugars (dextrose, cellulose,
maltose), carbohydrates (maltodextrin, starch), and lignin. These
nutritional carbon sources can be used either in their raw form, as
in a reagent grade chemical, or as the prevailing plant matter
component. A prevalent carbon source is defined as comprising more
than 20% of dry mass, and a nutritional particle must contain at
least one dominate carbon source.
[0007] The summation of carbon source composition, such as a
combination of a starch and lignin, does not meet the criteria
since basidiomycetes can alone breakdown one carbon source at a
time and enzymatic repression has been found to promote singular
carbon source selection.
Nutritional Particle Example:
[0008] Softwood sawdust, such as Scot Pine or Birch, range in
cellulosic starch composition by greater than 40% by dry weight.
Hemicelluloses are also prevalent, which serve as a secondary
carbon source for the fungal mycelium, and typically compose more
than 20% of the tree biomass. Cottonseed hulls, which are a
byproduct from cottonseed extraction, have an average lignin
content in excess of 21% and a starch content of 1.7%3.
[0009] A non-nutritional particle or fiber either offers a carbon
source accessible by the fungal mycelium but is less than 20% of
the material's total dry mass, or the material offers no
nutritional value. This particle or fiber could be carbon
deficient, such as the silicon dioxide found in rice hulls, or
offer a carbon source that is not accessible by most basidiomycete
species.
Non-Nutritional Particle Example:
[0010] Oat hulls have low starch content and a naturally high
lignin content of 14.8% and 5.4% by dry weight respectively. Rice
hulls represent a carbon deficient particle, since 67.3% of the
material's composition is silicon dioxide. Similarly buckwheat
hulls do not offer starch content and the remaining fiber does not
offer the lignin necessary to maintain growths.
Substrate Composition Examples:
[0011] Each of the following substrate compositions composes 5 L
volume of dry substrate
TABLE-US-00001 Nutritional Non-nutritional Particle Trace Nutrient
Water Particle or Fiber (g) or Fiber (g) (g) (mL) 335 g Rice Hulls
8 g Maltodextrin 10 g Calcium 1000 mL 432 g Cottonseed Hulls
Sulphate 450 g Buckwheat Hulls 8 g Maltodextrin 10 g Calcium 1000
mL 432 g Cottonseed Hulls Sulphate 335 g Soybean Hulls 8 g
Maltodextrin 10 g Calcium 700 mL 432 g Cottonseed Hulls Sulphate
300 g Perlite 8 g Maltodextrin 10 g Calcium 1000 mL 432 g
Cottonseed Hulls Sulphate 520 g Cotton Fiber 32 g Maltodextrin 10 g
Calcium 1100 mL Sulphate 480 g Cotton Burs 32 g Maltodextrin 10 g
Calcium 800 mL 40 g Cottonseed Hulls Sulphate
[0012] Of note, oat hulls are density equivalent and
interchangeable with rice hulls and kenaf fiber, hemp pith, sorghum
fiber and flax shive are density equivalent and interchangeable
with cotton fiber.
[0013] Blending substrate, either through stratification or
intermixing, can also enhance mycological material characteristics.
For example, a low density and elastic modulus substrate (cotton
moots) can be applied to external features of a tool while a high
density and elastic modulus substrate can be internalized within
the material to stiffen the core. An elongated fiber, such as
coconut coir, can be positioned along the exterior of a substrate
to create a tensile skin to increase surface energy and bolster
flexural strength.
Incubation Conditions For Mycological Materials
[0014] The incubation environment for the production of mycological
materials promotes the continuous production of vegetative tissue
(mycelium, "mycelium run") and inhibits primordial formation or
fruiting (the production of a basidiocarp or mushroom). Fungal
tissue differentiation, physiology and morphology, is dictated
through tropisms, which stimulate various growth characteristics
based on the surrounding environment. The proposed is two-phase
approach that can be implemented in either batch or continuous
processing.
[0015] In accordance with the method for the production of
mycological materials, the engineered substrate is inoculated with
a vegetative mycelium as described in the parent patent application
and subjected to a two step incubation treatment.
[0016] The initial incubation environment at the point of substrate
inoculation with the vegetative mycelium is designed to accelerate
mycelium run. Full colonization of the substrate can be achieved in
as little as four days, and the mycelium can inhibit competitive
organisms (mold and bacteria) with metabolic standoff exudates. The
environment has an operating relative humidity (RH) of 80-100%,
carbon dioxide (CO2) levels that build over the course of the
incubation period to be in excess of 5000 ppm, and a temperature
between 24 and 30.degree. C. The heightened temperatures support
the production of generative hyphae, which achieves rapid
colonization but does not offer ideal strength characteristics.
[0017] Furthermore, minimizing light exposure or a direct view
factor is crucial as light cycling can trigger the fungal circadian
rhythm to produce a fruiting body. Reducing the direct light
exposure to the mycelium can be achieved with part nesting
configurations or ensuring that the light used is outside of the
380 to 500 nm range. Once full colonization is established
secondary incubation can be initiated as a finishing step.
[0018] The secondary environment can modify any of the following
individual growth conditions or a combination thereof depending on
the mycelium species and strain: [0019] 1. Reducing or maintaining
the temperature between 15 and 25.degree. C. This promotes the
formation of binding hyphae, which is a different mycelium
physiology that offers the optimal strength characteristics for a
mycological material. These hypahe are finely branched and
non-septate. Basidiocarp formation typically occurs for polypores
in temperatures in excess of 21.degree. C., thus fruiting is
inhibited and tissue differentiation is predominately within
vegetative hyphae. [0020] 2. The carbon dioxide levels can be
elevated between 10,000 and 60,000 ppm, which is within range for
mycelium run and primordial formation, but not for the formation of
a fruiting body. The induction of a primordial surface finish
(20,000 to 40,000 ppm), which offers a smooth, homogenous surface
finish, and superior surface tension strength. The commercial
cultivation of mushrooms requires constant air exchanges to
maintain an environment containing less than 2000 ppm of CO2.
[0021] 3. Relative humidity should be elevated to greater than 90%,
since the surface area to volume ratio of the nested, pre-colonized
materials can be prone desiccation. Moisture and turgor pressure
accelerate mycelium growth and ambient humidity can ensure growth
is not hampered. The relative humidity can be passively retained
using an open filtered water source or actively with misting
through distributed nozzles. This is not an issue with substrate
prepared for mushroom production since the trays or bags that house
the mycelium culture are either fully enclosed or minimize the
surface area to total volume. Furthermore, the relative humidity
for mushroom production is typically less than 95% since moisture
can activate spores found in mushrooms and result in autolysis. 4.
The mycological materials should remain nested in a configuration
or environment that offers low or no light exposure.
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