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In order to improve energy performance of buildings, insulation materials (such as mineral glass and rock wools, or fossil fuel-based plastic foams) are being used in increasing quantities, which may lead to potential problem with materials depletions and landfill disposal. One sustainable solution suggested is the use of bio-based, biodegradable materials. A number of attempts have been made to develop biomaterials, such as sheep wood, hemcrete or recycled papers. In this paper, a novel type of bio insulation materials – mycelium is examined. The aim is to produce mycelium materials that could be used as insulations. The bio-based material was required to have properties that matched existing alternatives, such as expanded polystyrene, in terms of physical and mechanical characteristics but with an enhanced level of biodegradability. The testing data showed mycelium bricks exhibited good thermal performance. Future work is planned to improve growing process and thermal performance of the mycelium bricks.
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Growing and testing mycelium bricks as building insulation materials
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EEEP2017 IOP Publishing
IOP Conf. Series: Earth and Environmental Science 121 (2018) 022032 doi :10.1088/1755-1315/121/2/022032
Growing and testing mycelium bricks as building insulation
materials
Yangang Xing1,4 , Matthew Brewer2, Hoda El-Gharabawy 2,3, Gareth Griffith2
and Phil Jones1
1 Welsh School of Architecture, Cardiff University, CF10 3NB, UK;
2 IBERS, Cledwyn Building, Aberystwyth University, Aberystwyth SY23 3DD, UK ;
3 Botany and Microbiology Department, Faculty of Science, Damietta University, New
Damietta, EGYPT
4 xingy5@cardiff.ac.uk
Abstract. In order to improve energy performance of buildings, insulation materials (such as
mineral glass and rock wools, or fossil fuel-based plastic foams) are being used in increasing
quantities, which may lead to potential problem with materials depletions and landfill disposal.
One sustainable solution suggested is the use of bio-based, biodegradable materials. A number
of attempts have been made to develop biomaterials, such as sheep wood, hemcrete or recycled
papers. In this paper, a novel type of bio insulation materials mycelium is examined. The aim
is to produce mycelium materials that could be used as insulations. The bio-based material was
required to have properties that matched existing alternatives, such as expanded polystyrene, in
terms of physical and mechanical characteristics but with an enhanced level of biodegradability.
The testing data showed mycelium bricks exhibited good thermal performance. Future work is
planned to improve growing process and thermal performance of the mycelium bricks.
1. Introduction
Building insulation plays an important role in improving thermal comfort, health and wellbeing of
occupants and reducing heating and cooling energy consumptions, carbon emissions and pollutions [1].
However, most of the buildings insulation materials are manufactured using mined and/or fossil fuel-
based materials. In this study, we prepared and tested alternative building insulation materials. We
selected three species of basidiomycete fungi and used these to grow mycelium bricks on straw waste.
Dual-needle probes are used to measure the thermal conductivity and specific heat capacity. It is based
on the transient hot wire method in which a small constant heat pulse is supplied to the sample through
a heating probe and the rise in temperature is noted by a sensing probe located at a fix distance from
the heating probe. We carried out preliminary thermal characterisation tests. The paper concludes
with a discussion on future research needs in this area.
2. Fungi species and growing process
2.1. Basic information about the fungi
The realm of Fungi is a diverse kingdom, with members of the phylum Basidiomycota exhibiting a
range of ecological strategies, ranging from the familiar edible or poisonous mushrooms to human and
plant pathogens. However, a key feature restricted to certain members of this phylum is the ability to
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decay lignin and as such a wide range of basidiomycetes have been studied as agents of wood decay.
In the past, most research activities have focused on elucidating the mechanisms of lignocellulose
degradation both in an ecological context and also to mitigate the harmful effects of such fungi for
instance in wooden buildings etc. [2]. The use of wood decay fungi for colonizing waste materials has
received limited attention. Here we explore the potential of waste materials partially colonized by
white rot fungi as potential thermal insulation material.
2.2. Species selected in this experiment
Three species of basidiomycete fungi (order Polyporales) were chosen because they were known to
grow quickly on agar media and to be powerful colonisers and degraders of lignocellulose (table 1).
All were originally isolated from trees (both live and dead) in the Nile Delta region of Egypt (El-
Gharabawy, 2016). All grew rapidly (8.7-13 mm/day at 25oC on 3% Dark Malt Extract Agar
[DMEA]).
Table 1. Species.
Code
Species
OXY
Oxyporus latermarginatus
MEG
Megasporoporia minor
GAN
Ganoderma resinaceum
2.3. Growing environment, substrate , nutrient, and growing process
In this section, basic information regarding fungi, and growing environment, and the end products will
be described. Fungal cultures were routinely cultivated on 3% DMEA and incubated at 28oC. For the
bulking up of inoculum, 10 g rye grains and 10 ml water were placed in a 25 ml glass (Universal) vial
and sterilised by autoclaving (115oC/15 min). When cooled the rye grains were inoculated at 28oC
with three plugs of mycelium from agar plate cultures, and the lids capped loosely to allow air
exchange. After 14 days, the rye grains were well colonised and then used to inoculated wheat straw
cultures. The orientation of straws was randomly placed (as shown in figure 1).
Straw cultures were established in polycarbonate plant tissue culture vials (Magenta GA7;
77x77x97 mm; Sigma). Wheat straw was cut to 3-4 cm lengths and dispensed 20 g per vial with 40 ml
water added to each vial. Vials were autoclaved (115oC/15 min) and after cooling down, inoculated
with 6-8 colonised rye grains spread around the vial. Cultures were incubated at 28oC for 8 weeks with
the vial lids slightly opened to allow air exchange. No any resins are used in the process. Straw blocks
were removed from the culture vials and dried at 70oC. They showed some loss of fresh weight, dry
weight, and differences in density as in table 2:
Table 2. Weight losses, volume, and density.
FUNGI
SPECIES
Fresh
weight1 (g)
Fresh weight
loss (%)
Dry
weight
(g)
Dry weight
loss (%)
Dry Mass
Volume (cm3)
DENSITY
(KG/M3)
OXY
37.2
38.0
15.61
25.1
285.8
51.098
MEG
37.3
37.8
17.55
12.5
283.2
61.967
GAN
35.6
40.1
14.56
27.5
253.3
57.452
1Initial fresh weight was 60 g (20g wheat straw/40 g water)
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The appearance of the colonized wheat straw differed between the three species. GAN
preferentially colonized the outer parts of the substrate. The exact reason for this is not clear but may
show an avoidance of areas of higher CO2 concentration (with CO2 formed from fungal metabolism).
However, the pattern of mycelial growth may be in response to other gradients within the culture
vessel (e.g. moisture, O2). Different species also exhibit different wood colonization strategies for
other reasons, for example to protect outer boundaries of the colony from attack by other fungi. In any
event colonization of the core of the wheat straw block was poorer than for other species and this is
reflected in the physical properties of the mycelial block. In terms of substrate decay, GAN exhibited
the greatest dry weight loss over the 8 week incubation period, consistent with the pattern of enzyme
production on ashwood sawdust that was observed (as shown in table 3) for this isolate by El-
Gharabawy [3].
The pattern of wheat straw colonization was similar for OXY and MEG with even more
colonization across the centre of the block. In both cases there was more growth at the top of the
culture vessel (where the air vents were located). In the case of OXY, initial growth (weeks 1-2) was
predominantly visible at the top of the culture vessel with colonization of the lower layers of wheat
straw occurring later.
Table 3. Growth rates reproduced from [3]
CODE
Species
RGR Radial
Growth Rate
(mm/d)
AREA (LAT/LONG)
OXY
Oxyporus
latermarginatus
13.0
DAMIETTA; EI-SENANIAH
(N 31.2611 E31.4648)
MEG
Megasporoporia
minor
8.7
DAKAHLIA; MANSOURA
UNIV.(N31.0403, E31.3590)
GAN
GANODERMA
RESINACEUM
10.4
DAKAHLIA;DEKERNIS
(N31.0637, E31.6577)
As shown in figure 1, the three isolates used here grow maximally at 30ºC (GAN and OXY) or
33ºC (MEG) on agar plates so in all three cases incubation at higher temperatures would likely lead to
more rapid substrate colonisation (and thereby shorter incubation periods for mycelial block
preparation maybe as low as 4 weeks). Growth at different temperatures may also alter patterns of
ligninolytic enzyme production which in turn would alter patterns of substrate decay and possibly lead
to differences in the thermal properties of the mycelial blocks. The final mycelium thermal blocks are
shown in figure 2.
Figure 1. Radial growth rate of isolates at different temperatures (upper row is GAN,
middle is MEG, lower is OXY).
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Figure 2. Three Specimens.
3. Preliminary transient thermal testing
3.1. Transient thermal measurement approach
In order to determine basic thermal characteristics (i.e. thermal conductivity k-value and specific heat
capacity) of the mycelium blocks, KD-2 Pro thermal analyser (model KD-2 Pro, Decagon Device, Inc.)
was used as shown in figure 3. High accuracy, shorter measurement time and easy to use are the main
advantages of this method [4]. There are commonly two types of thermal needle probe: single and
dual-needle. In this study, we have used dual-needle probe. Heat is applied to the heated needle for a
set heating time, th, and temperature is measured in the monitoring needle, 6 mm distant during
heating and during the cooling period following heating. The readings are then processed by
subtracting the ambient temperature at time 0, multiplying by 4π and dividing by the heat per unit
length, q. The resulting data are were fitted to the following equations [5] using a nonlinear least
squares procedure [6] which is calculated using the KD 2 Pro Analyszer.
Ei is the exponential integral, and bo, b1 and b2 are the constants to be established. To is the
temperature at the start of the measurement and q is the heat input. The first equation applies for the
first th seconds, while the heat is on. The second equation applies when the heat is off. Compute
thermal conductivity from Equation 4 and diffusivity from 5.
where, k is thermal conductivity, D is specific heat capacity, r is the distance between the heater
and the sensor where temperature is measured.
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Figure 3. Thermal properties measurement.
3.2. Preliminary thermal test results and limitations
Four tests were carried to each specimen placing the dual needle probes in different directions. The
average thermal conductivity and specific heat capacity readings are listed in table 4. Thermal
conductivity measures the ease with which heat can travel through a material by conduction.
Conduction is the main form of heat transfer through insulation. The lower the figure, the better the
performance. In general, a good insulator has a higher Specific Heat Capacity because it takes time to
absorb more heat before it actually heats up (temperature rising) to transfer the heat. High Specific
Heat Capacity is a feature of materials providing Thermal Mass or Thermal Buffering (Decrement
Delay). Based on this experiment, OXY has the best thermal insulation performance (lowest thermal
conductivity). GAN has the worst thermal insulation performance (i.e. higher thermal conductivity and
lowest specific heat capacity).
TABLE 4. Thermal performance.
Thermal conductivity
(W/(mK)
Specific Heat Capacity
MJ/(m3*k)
OXY
0.078
0.418
MEG
0.079
0.501
GAN
0.081
0.369
Nevertheless, the measured thermal conductivities of these three specimens measured in this paper
are similar (0.074-0.087 W/mK). A study demonstrated that the decrease of the thermal conductivity
of a hay bio-composite is proportional to the decrease of its bulk density, the latter depending on the
increase of fibres in the mix [4]. Comparing with other light weight synthetic insulation materials,
such as polystyrene (density 2845 kg/m3), thermal conductivity varies between 0.029 and 0.039
W/mK [7] [8]. However, the mycelium bricks is performing better than some other biocomposite
materials, such as raisin-based bio-composite 0.09179 W/mK to 0.1534 W/mK [9].
Transient thermal analyses have been utilized in a number of porous insulation materials studies
[10-12], however, it should be noted the high porosity of the mycelium materials tested in this study
may cause readings to become inaccurate, future calibration and steady-state testing, such as guarded
hot plate or hot box may is needed.
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4. Discussion and conclusions
4.1. Selection of fungal species, growing substrates and growing environment
From this study, it can be seen that different species have dramatically different of growth patterns
within the substrate and bonding. Thus, it is important to select appropriate fungi species to form
building insulation materials. In choosing suitable fungi, several factors must be considered: rapid
mycelial growth to bind the substrate is desirable but rapid rates of substrate decay (as found here for
GAN) are less desirable (potentially weakening the blocks). Even growth at the edges and in the
middle of the substrate blocks is also desirable (as shown here for OXY and MEG). These patterns of
growth presumably reflect the nature of substrate colonisation by these fungi in nature. El-Gharabawy
[3] investigated the spatial patterns of enzyme production by these three fungi on cellophane strips.
MEG and OXY produced greatest levels of ligninolytic activity (bleaching of dye) in older zones of
mycelial growth, whereas GAN generally secreted these enzymes in a more patchy manner (and less
so in areas initially colonised).
4.2. Improvement of the growing process
The cultures used here originated from a warm subtropical climate (Nile Delta region, Egypt) and all
three grow well at 33oC so could potentially be grown at 5oC warmer than the temperature used for
these trials allowing more rapid colonisation of straw or other substrate, possibly in as little as 4
weeks.
Choice of fungi species also needs to consider the degradation rate of straw (as main type of
biomass residuals). It is desirable to have rapid colonisation of straw or other lignocellulosic substrate.
However, excessive degradation of the substrate could lead to weakening of the straw block. The
isolates differ in their growth rates on agar and also on wood but these growth rates do not necessarily
correlate with the extent of dry weight loss. This is because these fungi differ in their colonisation
strategies.
Currently the authors are investigating a number of approaches to improve the thermal insulation
performance of the light weight mycelium materials. Future experiments are needed to improve the
density of the substrates using fine powder, higher density material to increase the overall weight
providing 'low' thermal diffusivity and 'high' thermal mass in order to create a nature-based solution to
the built environment [13]. Based on the transient thermal conductivity tests, all three specimens
exhibit relatively similar thermal characteristics. There is no significant difference between the three
specimens based on this type of tests, the next stage is to carry out research on fireproofing methods
(e.g. adding flame retardants or gypsum and cementitious plasters).
Acknowledgment
Authors wishing to acknowledge assistance or encouragement from colleagues, special work by
technical staff or financial support from the Welsh Government and Higher Education Funding
Council for Wales through the r Cymru National Research Network for Low Carbon, Energy and
Environment.
References
[1] Xing Y, Hewitt N, Griffiths P 2011 Zero carbon buildings refurbishment––A Hierarchical
pathway Renew Sustain Energy Rev 15(6) 3229-3236 doi:10.1016/j.rser.2011.04.020
[2] Rayner A, Boddy L 1988 Fungal Decomposition of Wood: Its Biology and Ecology. Chichester:
John Wiley International
[3] El-Gharabawy HMM, Detheridge APP, El-Fallal AAA, El-Sayed AKAKA, Griffith GWW
2016 Analysis of wood decay and ligninolysis in Polyporales from the Nile Delta region of
Egypt Mycosphere 7(4) 392-404 doi:10.5943/mycosphere/7/4/1
[4] Bristow KL, Kluitenberg GJ, Goding CJ, Fitzgerald TS 2001 A small multi-needle probe for
measuring soil thermal properties, water content and electrical conductivity Comput Electron
7
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EEEP2017 IOP Publishing
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Agric 31(3) 265-280 doi:10.1016/S0168-1699(00)00186-1
[5] DecagonDevices 2012 KD2 Pro Thermal Properties Analyzer, Operator’s Manual.
http://manuals.decagon.com/Manuals/13351_KD2 Pro_Web.pdf.
[6] Abramowitz M and IAS 1972 Handbook of Mathematical Functions. New York: Dover
Publications, Inc.
[7] Schiavoni S, D’Alessandro F, Bianchi F, Asdrubali F. 2016 Insulation materials for the building
sector: A review and comparative analysis. Renew Sustain Energy Rev 62 988-1011
doi:10.1016/j.rser.2016.05.045
[8] Asdrubali F, D’Alessandro F, Schiavoni S. 2015 A review of unconventional sustainable
building insulation materials Sustain Mater Technol 4 1-17
doi:10.1016/j.susmat.2015.05.002
[9] La Gennusa M, Llorach-Massana P, Montero JI, et al. 2017 Composite building materials:
Thermal and mechanical performances of samples realized with hay and natural resins.
Sustain 9(3) doi:10.3390/su9030373
[10] Kim SW, Lee SH, Kang JS, Kang KH 2006 Thermal conductivity of thermoplastics reinforced
with natural fibers Int J Thermophys 27(6) 1873-1881 doi:10.1007/s10765-006-0128-0
[11] Li X, Tabil LG, Oguocha IN, Panigrahi S 2008 Thermal diffusivity, thermal conductivity, and
specific heat of flax fiber-HDPE biocomposites at processing temperatures Compos Sci
Technol 68(7-8) 1753-1758 doi:10.1016/j.compscitech.2008.02.016
[12] Tripathi M, Sahu JN, Ganesan P, Jewaratnam J 2016 Thermophysical characterization of oil
palm shell (OPS) and OPS char synthesized by the microwave pyrolysis of OPS Appl Therm
Eng 105 605-612 doi:10.1016/j.applthermaleng.2016.03.053
[13] Xing Y, Jones P, Donnison I. 2017 Characterisation of Nature-Based Solutions for the Built
Environment Sustainability 9(1) 149 doi:10.3390/su9010149
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