PROCESS AND APPARATUS FOR GROWING MYCELIUM SHEETS

Abstract

Process for growing mycelium sheets. First, a substrate mixture is prepared in a mixer. Then the substrate mixture is applied as substrate layers on shelves of a rack in a cultivation room. The cultivation room is then closed and subsequently the substrate is pasteurized by injecting a pasteurizing medium, such as steam, into the closed cultivation room. In a next step, the substrate mixture is cooled and subsequently inoculated. During a growing step mycelium is allowed to grow on the inoculated substrate mixture. In a next harvesting step, the mycelium is separated from the substrate.

Claims

1. A process for growing mycelium sheets, comprising the following successive steps: a substrate mixture is prepared in a mixer; the substrate mixture is then applied as substrate layers on shelves of a rack in a cultivation room; in a next step, the cultivation room is closed and subsequently the substrate is pasteurized by injecting a pasteurizing medium, such as steam, into the closed cultivation room; in a next step, the substrate mixture is cooled and subsequently inoculated; during a growing step mycelium is allowed to grow on the inoculated substrate mixture; in a next harvesting step, the mycelium is separated from the substrate.

2. The process according to claim 1, wherein during the growing step, environmental conditions within the cultivation room are adjusted to promote mycelium growth on top of the substrate without fruiting bodies.

3. The process according to claim 2, wherein the CO2 concentration in the cultivation room is at least 3 vol. % on total air volume, and the relative humidity is at least 40%, while the O2 concentration is below 20 vol. % on total air volume.

4. The process according to claim 1, wherein the substrate mixture is applied on the shelves using a head filling machine.

5. The process according to claim 1, wherein the pasteurizing medium is steam of at least 70? C.

6. The process according to claim 1, wherein the substrate mixture comprises lignocellulosic particulate material.

7. The process according to claim 1, wherein the substrate mixture is inoculated using a distributor movable along one or more of the beds of substrate mixture via a guide to distribute spawn over said bed of substrate mixture.

8. The process according to claim 1, wherein the mycelium is separated from the substrate before the cultivation room is emptied.

9. The process according to claim 1, wherein a porous foil is placed on top of the substrate layers before the growing step, and wherein during the harvesting step the porous foil is removed from the substrate together with the mycelium.

10. The process according to claim 1, wherein a temperature of the substrate mixture is controlled independently from an air temperature at least during the growing step.

11. The process according to claim 10, wherein during the growing step the temperature of the substrate mixture is maintained at about 26-30? C., while the air temperature is the cultivation room is maintained at 20-35? C.

12. The process according to claim 1, wherein after the harvesting step the mycelium comprise sheets and the sheets are laid back on the shelves and heated.

13. A cultivation room comprising: an interior space with shelves; and a control unit configured to maintain environmental conditions within the interior space, air temperature, CO2 and/or O2 content and/or relative humidity of the air within the interior space so as to promote mycelium growth on top of a substrate without forming fruiting bodies.

14. The cultivation room according to claim 13, wherein the shelves form or support substrate heat exchange elements arranged to adjust a temperature of the substrate material on the shelves independently from the air temperature.

15. The cultivation room according to claim 14, wherein the substrate heat exchange elements comprise interior channels connected to a source or circulation loop for a heat exchange fluid.

16. The cultivation room according to claim 15, wherein the circulation loop comprises a heat exchanger arranged for heat transfer between the heat exchange fluid in the circulation loop and a second heat exchange fluid in a second circuit for controlling the air temperature.

17. The process according to claim 6, wherein the lignocellulosic particulate material comprises saw dust.

18. The process according to claim 7, wherein the spawn is a grain spawn or liquid spawn.

19. The process according to claim 10, wherein the temperature of the substrate mixture is controlled by substrate heat exchangers formed by the shelves, or by heat exchange plates on top of the shelves supporting the substrate layers.

20. The process according to claim 12, wherein the shelves comprise substrate heat exchangers, or heat exchange plates are provided on top of the shelves supporting the substrate layers.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Aspects of the invention are further explained with reference to the accompanying drawing in FIG. 1, schematically showing an exemplary embodiment.

DETAILED DESCRIPTION

[0031] FIG. 1 shows a cultivation room 1 confining an enclosed space 2 with two racks 3 supporting shelves 4 for supporting substrate layers 5. The cultivation room 1 comprises a control unit 6 outside the enclosed space 2 for controlling growth conditions within the enclosed space 2, including air temperature, O2 and CO2 content, and relative humidity.

[0032] The shelves 4 support flat, plate-shaped rectangular heat exchange elements 7 fully covering the shelves 4. Substrate material is applied on top of the plate-shaped heat exchange elements. The heat exchange elements 7 are provided with interior channels 8 for a heat exchange fluid, such as water. The channels 8 are connected to define a meandering flow path for the heat exchange fluid. The channels 8 are part of a closed circulation loop for circulating the heat exchange fluid.

[0033] The circulation loop also includes a heat exchanger 9 allowing heat transfer between the heat exchange fluid in the circulation loop on the one hand and a second heat exchange fluidagain in particular waterin a second circuit (not shown) for controlling the air temperature.

[0034] The control unit 6 is programmed to control the heat exchanger 9 to heat or cool the heat exchange fluid in the circulation loop. A pump 10 propels the heat exchange fluid to each shelve 4, through the meandering channels 8 of the plate-shaped heat exchange elements 5 of the shelve, and subsequently through a vertical return line 11 back to the heat exchanger 9. After the heat exchange fluid leaves the meandering channels 8 of the plate-shaped heat exchange elements 5 of a shelve 4, the temperature of the fluid is measured. The measured temperature is sent to the control unit 6. If the measured temperature is outside a pre-defined window around a set value, the control unit 6 controls the heat exchanger 9 to adjust the temperature of the fluid to the set value.

[0035] The circulated fluid cools or heats the substrate, which is heated by heat generated by mycelium growth during the colonization step. The substrate material may for example be cooled to a temperature of about 20-35? C., e.g., about 27-30? C., while the air temperature is kept at a temperature which is 0-5? C., e.g., 1-3? C. below the temperature of the substrate. This way, the temperature of the substrate material is controlled independently of the air temperature, so as to promote mycelium growth on top of the substrate without forming fruiting bodies.

[0036] The mycelium grows on top of the substrate to form sheets. After the sheets have a desired thickness, the mycelium sheets are harvested and the substrate material is removed from the heat exchange elements. The harvested mycelium sheets are then dried. To this end, they can be laid on the heat exchange elements 5 to bring the sheets to a drying temperature, e.g., up to about 35? C. to promote drying of the sheets.

[0037] The circulation loop also includes a pressure vessel 12 to maintain the required pressure in the usual manner.