
Overview
Background
Professor Mary Fletcher is a natural product organic chemist, and led the Natural Toxin group within the Centre for Animal Science, Queensland Alliance for Agricultural and Food Innovation (QAAFI) 2010-2024,before being appointed Emeritus Professor in 2024. She 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's current interest 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 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).
Availability
- Emerita Professor Mary Fletcher is:
- Not available for supervision
Fields of research
Qualifications
- Bachelor of Science, The University of Queensland
- Bachelor (Honours) of Chemistry, The University of Queensland
- Doctor of Philosophy, The University of Queensland
Research interests
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Slow release inserts 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 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 novel 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 novel insert by comparison would be completely biodegraded with no problematic remains at abattoir.
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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.
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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.
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 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.
Works
Search Professor Mary Fletcher’s works on UQ eSpace
2020
Conference Publication
Stingless bee honey as a unique source of trehalulose
Hungerford, Natasha L., Zhang, Jiali, Carpinelli de Jesus, Matheus, Yates, Hans, Webber, Dennis, Stone Isolbella S. J., Blanchfield, Joanne T., Zawawi, Norhasnida and Fletcher, Mary T. (2020). Stingless bee honey as a unique source of trehalulose. 5th Queensland Annual Chemistry Symposium, QACS 2020, Brisbane, QLD Australia, 27 November 2020.
2020
Conference Publication
Identification of volatile plant compounds in Pimelea trichostachya responsible for livestock aversion
Loh, Z. H., Hungerford, N. L., Ouwerkerk, D., Klieve, A. V. and Fletcher, M. T. (2020). Identification of volatile plant compounds in Pimelea trichostachya responsible for livestock aversion. 5th Queensland Annual Chemistry Symposium, QACS 2020, Brisbane, QLD, Australia, 27 November 2020.
2020
Conference Publication
A new test and guidelines for the authentication of new-world honeys
Chowdhury, Sadia A. , Carter, James F. , Anuj, Shalona R. , Cozzolino, Daniel , Hungerford, Natasha L. and Fletcher, Mary T. (2020). A new test and guidelines for the authentication of new-world honeys. 5th Queensland Annual Chemistry Symposium, QACS 2020, Brisbane, QLD, Australia, 27 November 2020.
2020
Journal Article
Toxin degradation by rumen microorganisms: a review
Loh, Zhi Hung, Ouwerkerk, Diane, Klieve, Athol V., Hungerford, Natasha L. and Fletcher, Mary T. (2020). Toxin degradation by rumen microorganisms: a review. Toxins, 12 (10) 664, 1-37. doi: 10.3390/toxins12100664
2020
Journal Article
Mineral and Trace Element Analysis of Australian/Queensland Apis mellifera Honey
Hungerford, Natasha L., Tinggi, Ujang, Tan, Benjamin L. L., Farrell, Madeleine and Fletcher, Mary T. (2020). Mineral and Trace Element Analysis of Australian/Queensland Apis mellifera Honey. International Journal of Environmental Research and Public Health, 17 (17) 6304, 6304-14. doi: 10.3390/ijerph17176304
2020
Journal Article
A review on Pimelea poisoning of livestock
Gordon, Russell J., Hungerford, Natasha L., Laycock, Bronwyn and Fletcher, Mary T. (2020). A review on Pimelea poisoning of livestock. Toxicon, 186, 46-57. doi: 10.1016/j.toxicon.2020.07.023
2020
Journal Article
Stingless bee honey, a novel source of trehalulose: a biologically active disaccharide with health benefits
Fletcher, Mary T., Hungerford, Natasha L., Webber, Dennis, Carpinelli de Jesus, Matheus, Zhang, Jiali, Stone, Isobella S. J., Blanchfield, Joanne T. and Zawawi, Norhasnida (2020). Stingless bee honey, a novel source of trehalulose: a biologically active disaccharide with health benefits. Scientific Reports, 10 (1) 12128, 1-8. doi: 10.1038/s41598-020-68940-0
2020
Journal Article
Emerging food safety risk of hepatotoxic indospicine in feral Australian camel meat
Tan, Eddie T. T., Ng, Jack C., Al Jassim, Rafat, D’Arcy, Bruce R., Netzel, Gabriele and Fletcher, Mary T. (2020). Emerging food safety risk of hepatotoxic indospicine in feral Australian camel meat. Food Control, 113 107205, 107205. doi: 10.1016/j.foodcont.2020.107205
2020
Journal Article
Management of phosphorus nutrition of beef cattle grazing seasonally dry rangelands: a review
Dixon, R. M., Anderson, S. T., Kidd, L. J. and Fletcher, M. T. (2020). Management of phosphorus nutrition of beef cattle grazing seasonally dry rangelands: a review. Animal Production Science, 60 (7), 863-879. doi: 10.1071/an19344
2020
Journal Article
Food safety and natural toxins
Fletcher, Mary T. and Netzel, Gabriele (2020). Food safety and natural toxins. Toxins, 12 (4) 236, 236. doi: 10.3390/toxins12040236
2020
Conference Publication
Phosphorus nutrition in ruminants grazing tropical rangelands
Dixon, Rob, Anderson, Stephen, Kidd, Lisa and Fletcher, Mary (2020). Phosphorus nutrition in ruminants grazing tropical rangelands. Third International Tropical Agriculture Conference (TROPAG 2019), , Brisbane, QLD Australia, 11-13 November 2019. Basel, Switzerland: MDPI . doi: 10.3390/proceedings2019036200
2020
Journal Article
Dual-locus DNA metabarcoding reveals southern hairy-nosed wombats (Lasiorhinus latifrons Owen) have a summer diet dominated by toxic invasive plants
Camp, Amanda, Croxford, Adam E., Ford, Caroline S., Baumann, Ute, Clements, Peter R., Hiendleder, Stefan, Woolford, Lucy, Netzel, Gabrielle, Boardman, Wayne S. J., Fletcher, Mary T. and Wilkinson, Mike J. (2020). Dual-locus DNA metabarcoding reveals southern hairy-nosed wombats (Lasiorhinus latifrons Owen) have a summer diet dominated by toxic invasive plants. PLoS One, 15 (3) e0229390, e0229390. doi: 10.1371/journal.pone.0229390
2020
Journal Article
Indospicine combined with arginine deprivation triggers cancer cell death via caspase-dependent apoptosis
Shuvayeva, Galyna Y., Bobak, Yaroslav P., Vovk, Olena I., Kunz-Schughart, Leoni A., Fletcher, Mary T. and Stasyk, Oleh V. (2020). Indospicine combined with arginine deprivation triggers cancer cell death via caspase-dependent apoptosis. Cell Biology International, 45 (3) cbin.11321, 518-527. doi: 10.1002/cbin.11321
2020
Conference Publication
Analysis of environmental contaminants in Australian honey and comparison to stingless bee honey from Queensland and Malaysia
Hungerford, Natasha L., Tan, Benjamin L.L., Tinggi, Ujang, Zawawi, Norhasmida, Farrell, Madeleine, Tsai, Heng Hang, Hnatko, Darina, Swann, Lorinda J., Kelly, Cassandra L., Anuj, Shalona R., Webber, Dennis C., Were, Stephen T. and Fletcher, Mary T. (2020). Analysis of environmental contaminants in Australian honey and comparison to stingless bee honey from Queensland and Malaysia. The Third International Tropical Agriculture Conference TropAg 2019 , Brisbane, QLD Australia, 11-13 November 2019. Basel, Switzerland: MDPI. doi: 10.3390/proceedings2019036101
2020
Conference Publication
Adsorbents for the sequestration of the Pimelea toxin, simplexin
Gordon, Russell, Hungerford, Natasha L., Laycock, Bronwyn, Ouwerkerk, Diane and Fletcher, Mary T. (2020). Adsorbents for the sequestration of the Pimelea toxin, simplexin. The Third International Tropical Agriculture Conference TropAg 2019 , Brisbane, QLD Australia, 11-13 November 2019. Basel, Switzerland: MDPI. doi: 10.3390/proceedings2019036090
2020
Conference Publication
Modelling the controlled release of toxins in a rumen environment
Yuan, Yue, Gauthier, Emilie, Hungerford, Natasha L., Ouwerkerk, Diane , Fletcher, Mary T. and Laycock, Bronwyn (2020). Modelling the controlled release of toxins in a rumen environment. The Third International Tropical Agriculture Conference TropAg 2019 , Brisbane, QLD Australia, 11-13 November 2019. Basel, Switzerland: MDPI. doi: 10.3390/proceedings2019036089
2020
Other Outputs
Improved management of cattle phosphorus status through applied physiology
Dixon, Rob, Fletcher, Mary, Anderson, Stephen, Kidd, Lisa, Benvenutti, Marcelo, Mayer, Bob, McNeill, David and Goodwin, Kerry (2020). Improved management of cattle phosphorus status through applied physiology. North Sydney, NSW Australia: Meat and Livestock Australia.
2020
Conference Publication
Blood phosphorus concentration as an indicator of phosphorus deficiency in growing cattle
Dixon, Rob, Anderson, Stephen, Kidd, Lisa and Fletcher, Mary (2020). Blood phosphorus concentration as an indicator of phosphorus deficiency in growing cattle. Third International Tropical Agriculture Conference (TROPAG 2019) , Brisbane, Australia, 11–13 November 2019. Basel, Switzerland: MDPI . doi: 10.3390/proceedings2019036136
2020
Journal Article
The impact of commercial prebiotics on the growth, survival and nisin production by Lactococcus lactis 537 in milk
Almutairi, Batlah, Turner, Mark S., Fletcher, Mary T. and Sultanbawa, Yasmina (2020). The impact of commercial prebiotics on the growth, survival and nisin production by Lactococcus lactis 537 in milk. LWT- Food Science and Technology, 137 110356, 110356. doi: 10.1016/j.lwt.2020.110356
2020
Conference Publication
A new method for the authentication of Australian honey
Chowdhury, Sadia A., Anuj, Shalona R., Carter, James F., Hungerford, Natasha L., Webber, Dennis, Sultanbawa, Yasmina and Fletcher, Mary T. (2020). A new method for the authentication of Australian honey. Third International Tropical Agriculture Conference (TROPAG 2019), Brisbane, Australia, 11-13 November 2019. Basel, Switzerland: MDPI . doi: 10.3390/proceedings2019036112
Funding
Current funding
Supervision
Availability
- Emerita Professor Mary Fletcher is:
- Not available for supervision
Supervision history
Current supervision
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Doctor Philosophy
Atypical saccharides in emerging and novel foods
Associate Advisor
Other advisors: Dr Natasha Hungerford, Dr Viviene Santiago
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Doctor Philosophy
Stingless bee enzymes for biotransformation of cane sugar to a low GI sugar
Associate Advisor
Other advisors: Professor James De Voss, Dr Loan Nguyen, Dr Natasha Hungerford
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Doctor Philosophy
Stingless bee enzymes for biotransformation of cane sugar to a low GI sugar
Associate Advisor
Other advisors: Professor James De Voss, Dr Loan Nguyen, Dr Natasha Hungerford
Completed supervision
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2024
Doctor Philosophy
Mitigation of Pimelea poisoning of livestock using adsorbents
Principal Advisor
Other advisors: Professor Bronwyn Laycock, Dr Natasha Hungerford
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2022
Doctor Philosophy
Mitigating the effects of the toxin simplexin in Pimelea poisoning of cattle by development of a microbial probiotic
Principal Advisor
Other advisors: Dr Natasha Hungerford
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2017
Doctor Philosophy
Occurrence of Mycotoxins in Harvested Maize in Kenya and Tanzania and Postharvest Control by Photosensitization
Principal Advisor
Other advisors: Professor Yasmina Sultanbawa, Dr Darren Kriticos
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2016
Doctor Philosophy
Food Safety Risk Assessment of Indospicine in Australian Camel Meat
Principal Advisor
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2023
Doctor Philosophy
Modelling the Controlled Release of Toxins within a Rumen Environment
Associate Advisor
Other advisors: Professor Bronwyn Laycock
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2022
Doctor Philosophy
Developing a new probiotic fermented milk with prebiotics for aflatoxin M1 detoxification
Associate Advisor
Other advisors: Professor Mark Turner, Professor Yasmina Sultanbawa
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2022
Doctor Philosophy
Germination triggers, persistence, and management of Pimelea trichostachya Lindl. in Queensland
Associate Advisor
Other advisors: Associate Professor Shane Campbell, Professor Steve Adkins
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2020
Doctor Philosophy
Assessing the safe use of Terminalia ferdinandiana for dietary purposes
Associate Advisor
Other advisors: Dr Michael Netzel, Professor Yasmina Sultanbawa
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2018
Doctor Philosophy
Health risk assessment of mixed contaminants: Interaction of metals on the uptake of polycyclic aromatic hydrocarbons in human liver cells
Associate Advisor
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2017
Doctor Philosophy
Factors related to differential occurrence rates of aflatoxins in maize grains: investigations with near infrared spectrometry and metabolite analysis
Associate Advisor
Other advisors: Professor Yasmina Sultanbawa
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2013
Doctor Philosophy
Studies on haemolytic compounds from fungi of sago and their role in sago haemolytic disease in Papua New Guinea
Associate Advisor
Media
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