Life cycle assessment of cultured meat production

Abstract

Cultured meat is produced in vitro by using tissue engineering techniques. It is being developed as a poten-tially healthier and more efficient alternative to conventional meat. The goal of this study was to estimate energy use, land requirements, and greenhouse gas (GHG) emissions for large-scale cultured meat produc-tion. Life cycle assessment (LCA) research method was used for assessing the environmental impacts along the production chain. Cyanobacteria hydrolysate was assumed to be used as the nutrient and energy source for muscle cell growth. The results showed that cultured meat production involves approximately 35-60% lower energy use, 80-95% lower GHG emissions and 98% lower land use compared to conventionally pro-duced meat products in Europe. Conventionally produced poultry had slightly lower energy use than cultured meat. It is concluded that the overall environmental impacts of cultured meat production are substantially lower than those of conventionally produced meat.

Full text

7th International Conference on Life Cycle Assessment in the Agri-Food Sector, 22nd - 24th
September 2010, Bari, Italy
Life cycle assessment of cultured meat production
Hanna L. Tuomisto1 and M. Joost Teixeira de Mattos2
1University of Oxford, Wildlife Conservation Research Unit, Tubney House, Abingdon Road, Tubney, Oxon
OX13 5QL, UK, hanna.tuomisto@zoo.ox.ac.uk
2University of Amsterdam, Swammerdam Institute for Life Sciences, Molecular Microbial Physiology
Group, NL-1018 WV Amsterdam, Netherlands
ABSTRACT
Cultured meat is produced in vitro by using tissue engineering techniques. It is being developed as a poten-
tially healthier and more efficient alternative to conventional meat. The goal of this study was to estimate
energy use, land requirements, and greenhouse gas (GHG) emissions for large-scale cultured meat produc-
tion. Life cycle assessment (LCA) research method was used for assessing the environmental impacts along
the production chain. Cyanobacteria hydrolysate was assumed to be used as the nutrient and energy source
for muscle cell growth. The results showed that cultured meat production involves approximately 35-60%
lower energy use, 80-95% lower GHG emissions and 98% lower land use compared to conventionally pro-
duced meat products in Europe. Conventionally produced poultry had slightly lower energy use than cultured
meat. It is concluded that the overall environmental impacts of cultured meat production are substantially
lower than those of conventionally produced meat.
Keywords: in vitro meat, environmental impacts, energy use, greenhouse gas emissions, land use
1. Introduction
Meat production is one of the major contributors to global environmental degradation.
Currently, livestock raised for meat uses 30% of global ice-free terrestrial land and produces
18 % of global greenhouse gas (GHG) emissions, which is more than the global transporta-
tion sector (FAO, 2006). Livestock production is also one of the main drivers of deforesta-
tion and degradation of wildlife habitats. Due to increasing population size and per capita
meat consumption in the developing world, global meat consumption is expected to double
between 1999 and 2050 (FAO, 2006). Such an increase will also double meat’s impacts on
the environment unless more efficient meat production methods are adopted.
One proposed method for reducing the negative environmental impacts of meat produc-
tion is to grow only animal muscle tissue in vitro, instead of growing whole animals
(Edelman et al., 2005). This technology is called cultured meat (or in vitro meat) produc-
tion, and it is currently in a research stage. The aim of this paper is to estimate the potential
environmental impacts of large-scale cultured meat production and compare them with con-
ventionally produced meat products.
2. Materials and methods
The goal of this study is to estimate the energy use, greenhouse gas emissions and land
use of cultured meat production. Life Cycle Assessment (LCA) methodology based on
ISO14044 guidelines is used (ISO, 2006). The functional unit (FU), towards which all the

impacts are allocated, is 1000 kg of cultured meat with dry matter (DM) content of 30% and
protein content of 19.1%.
The system boundaries cover the major processes from input production up to the factory
gate (Figure 1), including production of input materials and fuels, production of the feed-
stock, and growth of muscle cells. It is assumed that cyanobacteria hydrolysate is used as the
source of nutrients and energy for muscle cell production. Cyanobacteria are assumed to be
cultivated in an open pond. The protein content of cyanobacteria species varies generally be-
tween 50-70% of DM (Richmond, 1988), and in this study a protein content of 64% of DM
was assumed. After harvesting, the cyanobacteria biomass is sterilised and hydrolysed in
order to break down the cells. The stem cells are taken from an animal embryo. The quantity
of stem cells needed for producing 1000 kg cultured meat is relatively low, and therefore the
impacts related to the production of the stem cells are not included in this study. Engineered
Escherichia coli bacteria are used for the production of specific growth factors that induce
the stem cells to differentiate into muscle cells. The muscle cells are grown on a medium
composed of the cyanobacterial hydrolysate supplemented with the growth factors and vita-
mins in a bioreactor. The production of growth factors, vitamins and the animals used for
source of the stem cells are not included in this study, due to their minor contribution to the
results.
Figure 1: The system diagram of cultured meat production and the cyanobacteria biomass flows (kg
DM)
The primary energy conversion factors and GHG emission factors for energy sources are
based on the European Reference Life Cycle Database (ELCD, 2009) and Cherubini et al.
(2009). In this study it is assumed that diesel is used in the cultivation of cyanobacteria oper-
ations and transportation of the biomass, and electricity for sterilisation and muscle cell cul-
tivation.
It is assumed that cyanobacteria hydrosylate is used as an energy and nutrient source for
the growth and proliferation of the muscle cells. Nitrogen-fixing cyanobacteria species are

assumed to be used. Cyanobacteria biomass is assumed to be cultivated in an open pond
(0.30 m deep) and harvested by using sedimentation and continuous vacuum belt filters. The
energy requirements used for cultivation of cyanobacteria, harvesting, fertiliser production
and construction and maintenance of the facility are based on the data from Chisti (2008).
Recorded annual production quantities of cyanobacteria vary globally between 7-110
tDM ha-1 (Richmond, 1988; Belay, 1997). In this paper cyanobacteria yield of 30 tDM ha-1
year-1 and 25 g m-2 d-1 are assumed.
It is assumed that the cyanobacteria biomass is transported without drying for 50 km, as-
suming an energy need of 2.6 MJ t-1 km-1 (Liu and Ma, 2009).
Table 1 shows the specifications used for sterilisation and the cultivation processes. The
volume of the culture is assumed to be 30 m3, by assuming maximum muscle cell density of
1*1010 cells dm-3 and weight of a cell 1*10-12 kg.
It is assumed that the bioreactor is made from stainless steel. Production of 1 kg stainless
steel requires 30.6 MJ primary energy and emits 3.38 kg CO2-eq kg-1 (ELCD, 2009). The
bioreactor is assumed to be used for 20 years.
Table 1: Specifications for sterilisation of cyanobacteria biomass and cultivation of muscle cells.
Sterilisation
Method: autoclaving
volume 1500 l, power 140 kW, temperature 220°C, time 20 min
Muscle cell cultivation
Method: cylinder stirred-tank bioreactor
volume 1000 l, height 1.72 m, diameter 0.86 m, weight 93 kg, 80% maximum filling capacity, cell density
1*1010 cells dm-3, time per run 60 days, temperature 37°C, rotation 100 rpm, aeration 0.05 vvm, power input
for agitation 25 W m-3 (Varley and Birch, 1999), power requirement for aeration was 16 W m-3 (Harding et
al., 2007)
3. Results
Total energy use and GHG emissions of producing 1000 kg cultured meat are presented
in Table 2. The energy use for producing cyanobacteria accounts for approximately 8% of
total energy use and 15% of GHG emissions. The cultivation process of muscle cells has the
greatest contribution to the results, accounting for 80% of total energy use and 74% of total
GHG emissions. Sterilisation of the cyanobacteria biomass accounts for approximately 11%
of total energy use and 9% of GHG emissions. Transportation of the cyanobacteria biomass
to the cultured meat production facility has only a minor contribution (less than 2%) to both
of the impacts.
The land requirements for producing feedstock for cultured meat production vary accord-
ing to the location of the facility. Here it is estimated that the world average land requirement
for cultivation of cyanobacteria is approximately 240 m2 ha FU-1. In the highest-yielding re-
gions, the land requirement may be as low as 120 m2 FU-1, while in the lowest-yielding re-
gions the land requirement may be as high as 480 m2 FU-1.

Table 2: Primary energy use and greenhouse gas (GHG) emissions of producing a Functional Unit
(FU) of 1000 kg cultured meat
Primary Energy GHG
emissions
GJ FU
-1 kg CO2-eq FU-1
CULTIVATION OF CYANOBACTERIA
Construction and maintenance 0.68 66
Cultivation 1.49 145
Harvesting 0.05 5
TOTAL 2.22 217
BIOMASS TRANSPORTATION 0.37 26
STERILISATION 2.87 144
MUSCLE CELL CULTIVATION
Steel production 0.98 108
Aeration 7.89 396
Rotation 12.32 618
TOTAL 21.19 1122
TOTAL 26.64 1508
4. Discussion
The results show that cultured meat production emits substantially less GHG emissions
and requires only a fraction of land compared to conventional meat production in Europe
(Table 3). Energy requirements of cultured meat production are lower compared to beef,
sheep and pork, but higher compared to poultry production. As a comparison with cultivated
Atlantic salmon (Pelletier and Tyedmers, 2007), cultured meat has approximately 36% lower
energy input and 53% lower GHG emissions.
Table 3: Environmental impacts of producing 1000 kg of edible meat (calculated from original data)
Source Energy use GHG emissions Land use
GJ t CO
2-eq ha
Cultured meat (this study) 26.64 1.5 0.02
Beef
Casey and Holden (2006) 55
Kumm (2002) 1.35
Williams et al. (2006) 71.83 40.97 5.96
Elferink and Nonhebel (2007) 7.52
Lamb
Williams et al. (2006) 50.71 38.2 3.03
Pork
Kumm (2002) 1.57
Basset-Mens and van der Werf (2005) 47.59 6.88 1.63
Williams et al. (2006) 37.48 14.25 1.66
Elferink and Nonhebel (2007) 2.24
Dalgaard et al. (2007) 8.46 2.04
Poultry
Williams et al. (2006) 23.3 8.90 1.24
Elferink and Nonhebel (2007) 1.46
The energy input calculations of cultured meat production in this study are based on
many assumptions, and therefore, have high uncertainty. Energy consumption for cultured
meat production may be higher if additional processing is required for improving the texture

of meat. However, the efficiency of both cultivation of cyanobacteria and muscle cell culti-
vation can be improved by technology development. For example, closed bioreactors for
cyanobacteria and microalgae production could improve the efficiency of biomass produc-
tion (Ugwu et al., 2008).
Table 3 shows that the energy input for cultured meat production is 63, 47 and 37 %
lower compared to conventionally produced beef, sheep and pork, respectively, but requires
14 % more energy compared to conventionally produced poultry. However, energy input
alone does not necessarily provide a sufficient indicator about the energy performance, if the
opportunity costs of land use are not taken into account (Tuomisto et al., 2009). Cultured
meat production requires only about 2% of the land area that is used for producing the same
mass of conventionally produced poultry meat. Therefore, more land could be used for
bioenergy production and it can be argued that the overall energy efficiency of cultured meat
would be more favourable.
As the majority of GHG emissions during the production of cultured meat are associated
with the use of fuels and electricity, the emissions could be reduced by using renewable en-
ergy sources. In conventional meat production, the potential for reducing GHG emissions is
more limited, because most of the emissions are due to methane from manure and ruminants’
enteric fermentation, and nitrous oxide from soil. The replacement of conventionally pro-
duced meat by cultured meat could potentially contribute to the mitigation of GHG emis-
sions, because instead of clearing more land for agriculture, large land areas could be refor-
ested or used for other carbon sequestration purposes.
Cultured meat production could also have potential benefits for wildlife conservation for
two main reasons: i) it reduces pressure for converting natural habitats to agricultural land,
and ii) it provides an alternative way of producing meat from endangered and rare species
that are currently over-hunted or – fished for food. Cultured meat production also has sub-
stantially lower nutrient losses to waterways compared to conventionally produced meat,
since wastewaters from cyanobacteria production can be more efficiently controlled com-
pared to run-offs from agricultural fields.
This study concentrated only on the production chain from input production up to the fac-
tory or farm gate, and therefore, does not provide the full comparison of the impacts during
the whole life cycle of the products. However, it can be estimated that the relative impacts of
cultured meat maybe even lower if the whole product life cycles were compared. The trans-
portation requirements for cultured meat are likely to be lower, since whole animals are not
transported and the production sites may locate closer to the consumers. Also refrigeration
needs may be reduced, since cultured meat would potentially have less microbial contami-
nants compared to slaughtered meat. Further research is needed for estimating the total envi-
ronmental impacts of cultured meat production during the whole life cycle from production
to the consumer.
5. Acknowledgements
We thank New Harvest for funding the project.
6. References
Basset-Mens C., van der Werf H.M.G. (2005): Scenario-based environmental assessment
of farming systems: the case of pig production in France. Agriculture, Ecosystems &
Environment 105(1-2) pp. 127-144.

Belay A. (1997): Mass Culture of Spirulina Outdoors -The Earthrise Farms Experience.
In Spirulina platensis (Arthrospira): Physiology, Cell-biology and Biotechnology, ed. A.
Vonshak, 233. London: Taylor & Francis Ltd.
Casey J.W., Holden N.M. (2006): Quantification of GHG emissions from sucker-beef
production in Ireland. Agricultural Systems 90(1-3) pp. 79-98.
Cherubini F., Bird N.D., Cowie A., Jungmeier G., Schlamadinger B., Woess-Gallasch S.
(2009): Energy- and greenhouse gas-based LCA of biofuel and bioenergy systems: Key
issues, ranges and recommendations. Resources, Conservation and Recycling, 53(8) pp. 434-
447.
Chisti Y. (2008): Response to Reijnders: Do biofuels from microalgae beat biofuels from
terrestrial plants? Trends in Biotechnology 26(7) pp. 351-352.
Dalgaard R.J. (2007): The environmental impact of pork production from a life cycle
perspective. In Faculty of Agricultural Sciences, PhD thesis 135 p. Tjele: University of
Aarhus.
Edelman P.D., McFarland D.C., Mironov V.A., Matheny J.G. (2005): Commentary: In
Vitro-Cultured Meat Production. Tissue Engineering, 11(5-6) pp. 659-662.
ELCD (2009): European Reference Life Cycle Database ed. E. Comission.
Elferink E. V., Nonhebel S. (2007): Variations in land requirements for meat production.
Journal of Cleaner Production, 15(18) pp. 1778-1786.
FAO (2006): Livestock’s long shadow –environmental issues and options. 390. Rome:
Food and Agricultural Organization of the United Nations.
Harding K.J., Dennis J.S., von Blottnitz H., Harrison S.T.L. (2007): Environmental
analysis of plastic production processes: Comparing petroleum based polypropylene and
polyethylene with biologically-based poly-hydroxybutyric acid using life cycle analysis.
Journal of biotechnology, 130(1) pp. 57-66.
ISO 14044 (2006): Environmental management - Life cycle assessment - Requirements
and quidelines. International Organization for Standardization.
Kumm K.I. (2002): Sustainability of organic meat production under Swedish conditions.
Agriculture Ecosystems & Environment, 88(1) pp. 95-101.
Liu J., Ma X. (2009): The analysis on energy and environmental impacts of microalgae-
based fuel methanol in China. Energy Policy, 37(4) pp. 1479-1488.
Pelletier N., Tyedmers P. (2007): Feeding farmed salmon: Is organic better? Aquaculture,
272(1-4) pp. 399-416.
Richmond A. (1988): Spirulina. In Micro-algal biotechnology, eds. M. A. Borowitzka &
L. J. Borowitzka, 477. Cambridge: Cambridge University Press.
Tuomisto, H.L., Hodge I.D., Riordan P., Macdonald D.W. (2009): Assessing the
environmental impacts of contrasting farming systems. Aspects of Applied Biology, 93(1) pp.
167-172.
Ugwu C.U., Aoyagi H., Uchiyama H. (2008): Photobioreactors for mass cultivation of
algae. Bioresource Technology, 99(10) pp. 4021-4028.
Varley J., Birch J. (1999): Reactor design for large scale suspension animal cell culture.
Cytotechnology, 29(3) pp. 177-205.
Williams A.G., Audsley E., Sandars D.L. (2006): Determining the environmental burdens
and resource use in the production of agricultural and horticultural commodities. Main
Report. Defra Research Project IS0205. Bedford.