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Professor Mary Fletcher

Professorial Research Fellow

Centre for Animal Science
Queensland Alliance for Agriculture and Food Innovation
mary.fletcher@uq.edu.au
+61 7 344 32479

Overview

Professor Mary Fletcher is a natural product organic chemist, and leads the Natural Toxin group within the Centre for Animal Science, Queensland Alliance for Agricultural and Food Innovation (QAAFI). She has previously worked as a research chemist at both The University Queensland and Queensland Primary Industries (Biosecurity Queensland), before joining the Queensland Alliance for Agricultural and Food Innovation in 2010. Prof Fletcher is based at the Health and Food Sciences Precinct (Coopers Plains), and her current work focuses on bioactives that reduce enteric methane and the application of slow release delivery systems appropriate to rangeland grazing systems. Prof Fletcher has an industry recognised expertise as an applied organic chemist with a specialist interest in the identification and analysis of natural toxins and other bioactives in a range of plants, fungi and agricultural products. Such toxins and bioactives can affect both human and animal health posing risks to livestock production, food safety and market access.

Prof Fletcher is also an Affiliate Associate Professor in the School of Chemistry and Molecular Biosciences (http://www.scmb.uq.edu.au/index.html), and an Affiliated Scientist at the Biosciences eastern & central Africa-International Livestock Research Institute (BecA-ILRI) Hub in Nairobi, Kenya (http://hub.africabiosciences.org/).

Prof Fletcher is a Fellow of the Royal Australian Chemical Institute and in 2016 was elected President of the Queensland Branch of the Royal Australian Chemical Institute (http://www.raci.org.au/branches/qld-branch).

Research Interests

  • Biopolymers to deliver bioactive compounds that reduce enteric methane
    Methane emissions from the beef cattle sector accounts for ~7% of Australia’s greenhouse gas emissions. This collaborative UQ-DAF project brings together a team of interdisciplinary scientists and applies novel biopolymer technologies to progress the industry goal of achieving a carbon neutral beef industry by 2030. The synthetic feed additive 3 nitrooxypropanol (3-NOP) has shown promise in enteric methane mitigation. This compound targets the nickel enzyme methyl-coenzyme M reductase (MCR) in rumen archea, thereby inhibiting the last step of CH4 formation by reversibly oxidizing the nickel cofactor from Ni(I) to Ni(II). Applications to date have necessitated daily dosing regimes relevant mostly for intensive cattle systems, and this project seeks to provide alternate delivery mechanisms to enable application in extensive systems. In extensive grazing systems, most supplements are normally delivered through licks, with little or no control of intake by individual animals. Many methane mitigating active-agents including 3-NOP are required to be delivered consistently to the rumen to be effective. This project seeks to deliver a bolus-like biopolymer rumen insert for controlled release of active-agents to provide a sustained slow-release dose. Such technology avoids any process issues associated with traditional bolus capsule systems, where the capsule itself presents problems at abattoir. It is envisaged that the biopolymer insert by comparison would be completely biodegraded with no problematic remains at abattoir.
  • Beneficial Sugars in Stingless Bee Honey
    Stingless bees (Meliponini) occur in all tropical and sub-tropical regions, and honey from these native bees has a long history of traditional indigenous use with a range of purported therapeutic properties. Prof Fletcher's research has identified the unusual low GI disaccharide trehalulose as a predominant sugar and distinctive marker of stingless bee honey in five species across three continents Australia, Malaysia and Brazil. The presence of this beneficial sugar has added support to the health claims of these native Meliponini honeys and provided impetus to this emerging industry. This is the first report of this unusual disaccharide as a major component of honey, and indeed the first significant natural occurrence in any food. Prof Fletcher's research team has further demonstrated that this rare sugar is produced by the bees themselves via an enzymatic isomerisation of nectar sucrose - further evidence of the unique characteristics of these stingless bees and the honey they produce.
  • Natural Toxins
    Prof Fletcher's research interests also encompass the identification and analysis of natural toxins and bioactives in a range of plants, fungi and agricultural products. Such toxins have the potential to form residues in agricultural products and pose a risk to both livestock and human consumers. Toxins of particular interest include mycotoxins, pyrrolizidine alkaloids, indospicine and simplexin. Her natural toxin research focusses on minimising the impacts of plant toxins on Australian livestock production. Plant toxins can have wide ranging animal impacts, depending on their chemical structure and have the potential to contribute to ill thrift through specific toxicoses such as Pimelea poisoning and pyrrolizidine alkaloid associated liver disease, and reproductive losses through abortion and teratogenic effects, or calf losses associated with premature births, weak calves, or failure to suckle. Devising strategies to deal with diverse plant toxins is not easy, as the chemical action and target organ varies considerably, and the best line of action is prevention rather than remedial treatment. In pasture systems, it is difficult to prevent consumption of poisonous plants, other than by total removal from the pasture which is generally not possible. However, plant consumption does not necessarily equal uptake of the toxin, and the approach of the proposed research is to devise strategies to enable toxin breakdown within the rumen before absorption into the animals circulatory systems. Our research approach is to capitalise on natural rumen response by isolating microbes capable of degrading toxins (for use as preventative probiotics), and investigating toxin absorbents and/or biopolymers to foster toxin-degrading microbe populations. Initially this research will be applied to the Pimelea toxin, simplexin, which causes frequently fatal poisoning in cattle grazing inland pastures of Australia with productivity losses estimated to be up to $50 million in bad years. Further interests include the presence of pyrrolizidine alkaloids in Australian honey and identification of diverse floral sources of these alkaloids using LCMS technologies to confirm alkaloid profiles. A collaborative project with Queensland Health is also investigating authenticity, adulteration and providence of these honeys using stable isotope MS techniques.

Research Impacts

Throughout her career Prof Fletcher has applied her chemical skills to address diverse problems that pose threats to agricultural industries, from the identification of fruit fly pheromones to the determination of plant toxins responsible for livestock deaths, to the identification of bone volatiles attractive to phosphorous deficient cattle and more recently the identification of unusual beneficial sugars in stingless bee honey and the application of slow release devices for the release of bioactives to control enteric methane production in rangeland cattle. Her work has particular application in the areas of food safety and food security, both in Australia and overseas, including projects addressing the impacts of carcinogenic mycotoxin contamination of staple foods in sub-saharan Africa.

Her current research funded by Meat and Livestock Australia (MLA) aims to develop a rumen insert that is applicable in extensive production systems to reduce methane emissions from northern Australia beef herds and applies novel biopolmyer technologies to progress the industry goal of achieving a carbon neutral beef industry by 2030. This collaborative UQ-DAF project aims to produce a biopolymer based rumen insert that slowly releases active-agents (such as 3-NOP) into the rumen over an extended period of time. The use of a rumen insert will mean that each animal will receive the treatment and should establish a more consistent reduced methane emission, when compared to other methods.

Qualifications

  • BSc, The University of Queensland
  • BSc (Hons), The University of Queensland
  • PhD, The University of Queensland

Publications

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Grants

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Supervision

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Available Projects

  • Biopolymers to deliver bioactive compounds that reduce enteric methane

    Methane emissions could be substantially cut through a $7.5-million project to develop slow-release biopolymer technology for cattle containing a gas-reducing bioactive.

    The University of Queensland and Department of Agriculture and Fisheries (DAF) collaboration is being funded by Meat & Livestock Australia (MLA) and the MLA Donor Company Limited, to help producers meet the CN30 target to make the meat industry carbon neutral by 2030. The ability to ensure each animal receives a sustained dose of a methane-reducing active agent over an extended timeframe would be a fantastic win for the beef cattle industry, helping it achieve its goal to reduce methane emissions – particularly in cattle grazing extensive pastures.

    This is a large multdisciplinary project and there is opportunity for PhD candidates with either an animal science or analytical chemistry background to be part of this biotechnology project.

View all Available Projects

Publications

Book

Book Chapter

  • Addressing food insecurity in Papua New Guinea through food safety and sago cropping

    Pue, Aisak G., Fletcher, Mary T., Blaney, Barry, Greenhill, Andrew R., Warner, Jeffrey. M., Latifa, Atagazli and Ng, Jack C. (2018). Addressing food insecurity in Papua New Guinea through food safety and sago cropping. Sago palm, multiple contributions to food security and sustainable livelihoods. (pp. 123-137) edited by Hiroshi Ehara, Yukio Toyoda and Dennis V. Johnson. Singapore: Springer Nature. doi: 10.1007/978-981-10-5269-9

  • Erratum: Addressing food insecurity in Papua New Guinea through food safety and sago cropping

    Pue, Aisak G., Fletcher, Mary T., Blaney, Barry, Greenhill, Andrew R., Warner, Jeffery M., Latifa, Atagazli and Ng, Jack C. (2018). Erratum: Addressing food insecurity in Papua New Guinea through food safety and sago cropping. Sago palm: multiple contributions to food security and sustainable livelihoods. (pp. E1-E1) Singapore, Singapore: Springer Singapore. doi: 10.1007/978-981-10-5269-9_25

  • Mycotoxins

    Fletcher, Mary T. and Barry Blaney (2016). Mycotoxins. Encyclopedia of food grains. Volume 2: nutrition and food grains.. (pp. 290-296) edited by Colin Wrigley, Harold Corke, Koushik Seetharaman and Jon Faubion. Kidlington, Oxford, United Kingdom: Elsevier. doi: 10.1016/B978-0-12-394437-5.00112-1

  • Effect of the Pimelea Toxin Simplexin on Cattle

    Fletcher, Mary T., Ossedryver, Selina M. and Chow, Sharon (2015). Effect of the Pimelea Toxin Simplexin on Cattle. Poisonous Plants: Toxicology, Ecology, Management, and Medicine. (pp. 83-88) edited by Mengli Zhao, Terrie Wierenga and Kip Panter. Hohhot, Inner Mongolia, Chin: ISOPP9.

  • Suspected toxic hepatopathy of plant origin in wild southern hairy nosed wombat (Lasiorhinus latifrons)

    Woolford, Lucy, Fletcher, Mary and Boardman, Wayne (2015). Suspected toxic hepatopathy of plant origin in wild southern hairy nosed wombat (Lasiorhinus latifrons). Poisonous Plants: Toxicology, Ecology, Management, and Medicine. (pp. 100-106) edited by Mengli Zhao, Terrie Wierenga and Kip Panter. Hohhot, Inner Mongolia, China: ISOPP9.

  • Improving diagnostics for aflatoxin detection

    Harvey, Jagger, Gnonlonfin, Benoi, Fletcher, Mary, Fox, Glen, Trowell, Stephen, Berna, Amalia, Nelson, Rebecca and Darnell, Ross (2013). Improving diagnostics for aflatoxin detection. Aflatoxins: finding solutions for improved food safety. (pp. 1-2) Washington, DC, USA: International Food Policy Research Institute. doi: 10.2499/9780896296763

  • LC/MS/MS analysis of the daphnane orthoester simplexin in poisonous Pimelea species of Australian rangelands

    Fletcher, M. T., Chow, K. Y. S., Silcock, R. G. and Milson, J. A. (2011). LC/MS/MS analysis of the daphnane orthoester simplexin in poisonous Pimelea species of Australian rangelands. Poisoning by plants, mycotoxins, and related toxins. (pp. 550-556) edited by Franklin Riet-Correa, Jim Pfister, Ana Lucia Schild and Terrie Wierenga. Wallingford, England, U.K.: CAB International.

  • Risks from plants containing pyrrolizidine alkaloids for livestock and meat quality in Northern Australia

    Fletcher, M. T., McKenzie, R. A., Reichmann, K. G. and Blaney, B. J. (2011). Risks from plants containing pyrrolizidine alkaloids for livestock and meat quality in Northern Australia. Poisoning by plants, mycotoxins, and related toxins. (pp. 208-218) edited by Franklin Riet-Correa, Jim Pfister, Ana Lucia Schild and Terrie Wierenga. Wallingford, England, U.K.: CAB International.

  • Risks from plants containing pyrrolizidine alkaloids for livestock and meat quality in northern Australia

    Fletcher, M. T., McKenzie, R. A., Reichmann, K. G. and Blaney, B. J. (2011). Risks from plants containing pyrrolizidine alkaloids for livestock and meat quality in northern Australia. Poisoning by Plants, Mycotoxins, and Related Toxins. (pp. 208-214) OXON, ENGLAND: CABI Publishing.

Journal Article

Conference Publication

Edited Outputs

  • Technology for Food Quality

    Glenn Graham, Michael Netzel, Trudy Graham, Mary Fletcher, Gloria Karagianis, Cindy Giles, Ujang Tinggi and Pieter Scheelings eds. (2012). Technology for Food Quality. 12th Government Food Analysts Conference, Brisbane, Australia, 22-24 February 2011. Health and Food Sciences Precinct (HFSP).

Other Outputs

Grants (Administered at UQ)

PhD and MPhil Supervision

Current Supervision

Completed Supervision

Possible Research Projects

Note for students: The possible research projects listed on this page may not be comprehensive or up to date. Always feel free to contact the staff for more information, and also with your own research ideas.

  • Biopolymers to deliver bioactive compounds that reduce enteric methane

    Methane emissions could be substantially cut through a $7.5-million project to develop slow-release biopolymer technology for cattle containing a gas-reducing bioactive.

    The University of Queensland and Department of Agriculture and Fisheries (DAF) collaboration is being funded by Meat & Livestock Australia (MLA) and the MLA Donor Company Limited, to help producers meet the CN30 target to make the meat industry carbon neutral by 2030. The ability to ensure each animal receives a sustained dose of a methane-reducing active agent over an extended timeframe would be a fantastic win for the beef cattle industry, helping it achieve its goal to reduce methane emissions – particularly in cattle grazing extensive pastures.

    This is a large multdisciplinary project and there is opportunity for PhD candidates with either an animal science or analytical chemistry background to be part of this biotechnology project.

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ResearcherID: G-9584-2019

ORCID: 0000-0003-0189-3376

Scopus ID: 7203082310

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