Enabling the widespread use of an insect-killing fungus to control crop pests; from lab to regulator to commercial success.
Submitting Institution
Swansea UniversityUnit of Assessment
Earth Systems and Environmental SciencesSummary Impact Type
EnvironmentalResearch Subject Area(s)
Chemical Sciences: Organic Chemistry
Biological Sciences: Biochemistry and Cell Biology, Microbiology
Summary of the impact
Research conducted by Professor Butt at Swansea University has led to
significant environmental
and economic impacts. It has provided evidence critical to the successful
registration and
commercialisation of the fungus Metarhizium anisopliae as a biocontrol
agent in Europe and
North America for insect pests, thereby enabling a reduced
dependency on chemical
pesticides. Insect pests cause £billions of crop losses globally;
this is projected to increase due to
intensified farming, pesticide resistance and climate change. Many
chemical pesticides have been
withdrawn due to the risks they pose to human health and the environment,
creating a need for
benign alternatives. A novel risk assessment showed that the risk to human
and animal health was
minimal, as metabolites generated by these fungi did not enter the food
chain. Furthermore, the
data and risk assessment methodology developed have been used by industry
and regulatory
authorities (such as the European Food Safety Authority) to make informed
decisions about the
safety of fungal biocontrol agents.
Underpinning research
The underpinning research results from a series of EU-funded projects
conducted by Prof Butt and
European partners between 1999 and 2004 to assess the potential health and
environmental risks
associated with metabolites generated by insect-killing (entomopathogenic)
fungi [R1]. In contrast
to pesticides, at that time no clear risk assessment guidelines existed
for biological control agents
(BCAs), impeding their registration and use.
Butt and Research Assistants Shah (1999-2006) and Wang
(1999-2004) characterised the
chemical compounds (metabolites) secreted by the insect-killing fungi Beauveria
brongniartii and
Metarhizium anisopliae. They established that these fungi, found
naturally in soils around the
world, produce a vast array of metabolites [R2], and that the range of
compounds (e.g. potentially
cytotoxic alkaloids and cyclic peptides) produced differed between species
and strains. They found
that specific metabolites, such as destruxins, can serve as markers of the
fungal species. This
work was funded by the European Union under [G1]. Regulators responsible
for risk assessment
and approval of plant protection products require information on all
metabolites generated by
insect-killing fungi. Given the large number of metabolites produced by
the two fungi tested, risk
assessment would have been prohibitively expensive, and deterred industry
from developing these
products. More in depth analysis of the risks of these metabolites was
investigated and studies
extended to other species of fungal BCAS. This work was funded by the EU
[G2]).
Butt and Research Assistants Skrobek (2001-2011), Wang and Shah
carried out research to
determine the potential risk to human and animal health of metabolites
generated by M. anisopliae
and other insect-killing fungi, and to establish whether these metabolites
entered the food chain.
Specifically, they optimised metabolite isolation methods and evaluated
different toxicity testing
systems (using protozoa, crustaceans and other invertebrates) to identify
the most ecologically
sensitive indicator species as an ethical and experimentally tractable
alternative to mammalian
models [R3, R4]. Following this, they investigated the persistence
of key fungal metabolites in field
trials, residues were undetectable in plant and soil samples even at a
100-fold increased
application rate. It was concluded that the metabolites would not enter
the food chain and
therefore did not pose a risk to human and animal health [R3-R5].
It was also shown the
insect-killing fungi examined did not produce genotoxic compounds [R6].
The research group then determined the quantity of selected metabolites
in the formulated (spore
coated rice grain) and unformulated (pure spores) product as well as in
the insects treated with M.
anisopliae and how environmental factors contributed to their
degradation in soil samples [R5, R6].
Overall, the research showed that metabolites of M. anisopliae and
other insect-killing fungi did not
enter the food chain or persist in the environment.
References to the research
R1 Strasser, H, Abendstein, D, Stuppner, H & Butt,
T.M. 2000. Monitoring the spatial-temporal
distribution of secondary metabolites produced by the entomogenous fungus
Beauveria
brongniartii with particular reference to oosporein. Mycological
Research. 104: 1227-1233.
(Google Scholar — Cited 50 times, IF 2.9)
R2 Strasser, H., Vey, A. & Butt, T. M. 2000. Are there
any risks in using entomopathogenic
fungi for pest control, with particular reference to the bioactive
metabolites of Metarhizium,
Tolypocladium and Beauveria species? Biocontrol Science
and Technology. 10: 717-735.
(Google Scholar — Cited 146 times, IF 0.71)
R3 Skrobek, A. & Butt, T.M. 2005. Toxicity testing of
destruxins and crude extracts from the
insect-pathogenic fungus Metarhizium anisopliae. FEMS
Microbiology Letters. 251: 23-28.
(Google Scholar — Cited 24 times, IF 2.05)
R4 Skrobek, A. Boss, D. Défago, G. Butt, T.M. &
Maurhofer, M. 2006. Evaluation of different
biological test systems to assess the toxicity of metabolites from fungal
biocontrol agents.
Toxicology Letters 161: 43-52. (Google Scholar — Cited 18 times, IF
3.15)
R5 Skrobek, A., Shah, A. F. & Butt, T.M. 2008.
Destruxin production by the entomogenous
fungus Metarhizium anisopliae in insects and factors influencing
their degradation.
BioControl. 53: 361-373. (Google Scholar — Cited 13 times, IF 2.22)
R6 Kouvelis V.N., Wang C., Skrobek A., Pappas K.M.,
Typas, M. A. & Butt T.M. 2011.
Assessing the cytotoxic and mutagenic effects of secondary metabolites
produced by
several fungal biological control agents with the Ames assay and the
VITOTOX(®) test.
Mutation Research 722:1-6. (Google Scholar - Cited 3 times, IF
2.22)
Papers R1, R4 and R6 best represent the quality of the underpinning
research.
Relevant research grants
G1 Biological Pest Control (BIPESCO); (PI: Butt, EU &
Industry Funding; 1999-01; £92,662 of
total grant £3,452,000). The EC identified this project as one of the
sixteen agricultural
success stories under the Fourth Framework Programme (ranked 5th
out of 239).
G2 Risk Assessment of Fungal Biological Control Agents (RAFBCA);
(PI: Butt, EU & Industry
Funding; 2001-04; £284,992 of total grant: £2,627,000). Cited by
Government regulatory
authorities and industry in registration dossiers/reports, and risk
assessment strategy for
fungal metabolites adopted by REBECA EU policy support project.
G3 Development of the entomogenous fungus, Metarhizium anisopliae,
for the control of vine
weevils and western flower thrips in horticultural growing media;
(PI: Butt, DEFRA,
Horticulture Development Council & Industry Funding; 2004-06;
£346,474).
G4 Determination of the stability and conidial yield of M.
anisopliae; (PI: Butt, NERC and
Koppert; 2004-06; £112,938). Quality control markers validated and used by
industry e.g.
MycoSolutions Ltd a microenterprise established 2010, produces M.
anisopliae and other
BCAs for industry, academia and US Navy.
G5 Development of biocontrol agents and strategies for
subterranean crop pests (INBIOSOIL);
(PI: Butt, EU & Industry Funding; 2012-15; £267,000 of total grant:
£5,000,000). Prof Butt
contributes to the risk assessment of M. anisopliae and validation
of RAFBCA strategy.
Details of the impact
The research has led to the commercialisation of new pest-control
products. Biological
pesticides must be registered and approved by regulatory authorities
(e.g., UK Chemicals
Regulation Directorate) before they can be sold, and must demonstrate that
they adhere to a large
number of criteria (including fate in the environment, impact on
non-target organisms), and safety
requirements before being registered for use on an industrial scale in
food production. Prior to the
work outlined in Section 2, companies developing plant protection products
did not have complete
data on the risks posed by insect-killing fungi to support their
application for registration and
regulators had no information on the risks these new products posed. As a
result, food producers
and consumers had few alternatives to chemical pesticides. The research
findings have informed
the European Commission on the risk assessment of BCA metabolites
generated by insect-
killing fungi, enabling the registration of M. anisopliae and
other insect-killing fungi, leading to their
commercialisation and use as an alternative to chemical pesticides.
International reach is evidenced through impact on regulatory
authorities: RAFBCA [G2] data
demonstrated that by focussing on the crude and selected metabolite
extracts the risk assessment
process could be simplified, impacting Directive 91/414/EEC and Directive
2001/36/EEC for the
registration of biopesticides. The RAFBCA risk assessment strategy for
entomopathogenic fungal
metabolites, endorsed by REBECA [C2], accelerated the registration process
and reduced
registration costs by removing the need to test hundreds of metabolites
produced by fungal BCAs.
This research led to Draft Assessment Reports in 2007 (on Lecanicillium)
and 2008 (on
Metarhizium), with European Food Safety Authority (EFSA) conclusions
approved in 2009
and 2011 [C3, C4]. The EFSA conclusions have directly enabled the
economic impacts described
below.
The Organisation for Economic Cooperation and Development (OECD) was
tasked by its 34
member countries to harmonise risk assessment and registration
requirements for BCAs. Its
recommendations are usually accepted by the 70 non-member partner
countries. A 2010 meta-
analysis review [C5], which concluded that spores of insect-killing fungi
did not persist in the
environment, was adopted as a position paper by the OECD BioPesticide
Steering Group, which
decided to:
"refer directly to your work that is contributing to further
international harmonization in the
assessment of microbial biological control agents"
Head of OECD Pesticides Programme
The OECD proposed the review be used as a waiver for the data requirement
usually needed for
registration to show that fungal biopesticides do not persist in soil
[C6], reducing registration time
and costs for companies developing fungal BCAs.
"We believe your work has helped our members to make considerable
progress in the
development of entomopathogenic fungi for pest control"
Head, International Biological Manufacturers Microbial Professional Group.
Economic impactshave been achieved through the
research's benefits to businesses and food
producers: M. anisopliae strain Met52 (=F52, BIPESCO 5) was
registered by Agrifutur and
Novozymes BG in 2008 using RAFBCA [G2] data on the risks of metabolites
(including the type,
quantity and stability in different production systems). It is currently
registered for use to target the
black vine weevil (which feed on a wide range of soft fruit and ornamental
plants causing damage
globally of £several hundred million annually) in 11 European countries,
USA and Canada
(registered in the UK in 2010) [C10]. Met52 represents 20% of the UK
market for the control of this
pest in containerised hardy nursery stock, bedding, indoor ornamentals and
soft fruit. As a result:
"annual European sales increased from $100K in 2010 to $900K
in 2012"
Regulatory Specialist, Novozymes BG
"Over 60,000 m3of growing
mediain the UK was treated (with Met52) in 2012"
Technical Manager, Fargro Ltd
During the assessment period, Novozymes BG and Fargro Ltd have invested
resources and
created jobs, expecting increased sales, more pests targeted for control
and registration in more
countries (exact figures on jobs and global sales is commercially
sensitive information but can be
confirmed by C10 and C11). Total investment has "to be counted in
millions of $US" [C10]
Research findings arising from [G2] (i.e. metabolites do not pose any
risks) were cited in Draft
Assessment Reports for the registration of the insect-killing fungus Verticillium
lecanii
(Lecanicillium muscarium) [C4], whilst data on metabolites produced
by [G1] resulted in the
registration of B. brongniartii. The research has provided an
alternative to chemical pesticides
that have been withdrawn by the EU, helping growers to comply with new
legislation that obliges
member states to implement the principles of integrated pest management
with preference given to
benign alternatives such as insect-killing fungi. In addition to reducing
overall pesticide usage and
helping food producers to meet supermarket requirements on minimal
chemical residues, Met52 is
approved for use in organic systems by the Organic Farmers and Growers
(reg. UKE0650, 2013).
Sources to corroborate the impact
C1 Marshall, T. 2011. The New Green Revolution, NERC publications (see
also:
http://tinyurl.com/NERCpublications)
C2 Strasser, H., Typas, M. Altomare, C., Butt, T.M. 2007. Annex
7: Position paper on
microbial metabolite assessment. In: Strauch, Strasser, Ehlers, Hauschild
(eds) 2007.
Report on Deliverable 10: Proposals for improved regulatory procedures for
microbial
BCAs, Regulation of Biological Control Agents (REBECA, EU Specific Support
Action
SSPE-CT-2005-022709).
C3 EFSA conclusions (approved 2011) on Metarhizium (http://tinyurl.com/metarhizium)
arising
from the Draft Assessment Report (2008) on the existing active substance Metarhizium
anisopliae
var anisopliae BIPESCO 5/F52 volumes 1-3. Risk assessment provided
by the
rapporteur Member State The Netherlands for the existing active substance
Metarhizium
anisopliae of the fourth stage of the review programme referred to
in Article 8(2) of Council
Directive 91/414/EEC.
C4 EFSA conclusions (approved 2009) on Lecanicillium (http://tinyurl.com/lecanicillium),
arising
from the Draft Assessment Report (2007) on the active substance Lecanicillium
muscarium strain Ve6 volumes 1-3, prepared by the rapporteur Member
State the
Netherlands in the framework of Directive 91/414/EEC.
C5 Scheepmaker, J.W.A., Butt, T.M. 2010. Natural and released
inoculum levels of
entomopathogenic fungal biocontrol agents in soil in relation to risk
assessment and in
accordance with EU regulations. Biocontrol Science and Technology 20:
503-552.
C6 OECD Environment, Health and Safety Publications Series on Pesticides
No. 67. OECD
Guidance to the Environmental Safety Evaluation of Microbial Biocontrol
Agents.
ENV/JM/MONO(2012)1
C7 Senior toxicologist, Ctgb/Board for the Authorisation of Plant
Protection Products and
Biocides, Dutch Regulatory Authority
C8 Head, OECD Pesticides Programme
C9 Head, Microbial Professional Group, International Biological
Manufacturers Association
C10 Regulatory Specialist, Novozymes BG
C11 Technical Manager, Fargro Ltd