Location: Mycotoxin Prevention and Applied Microbiology Research
2016 Annual Report
Objectives
The goals of this project are to enhance food safety through the development of tools to more effectively monitor for natural toxins, and to reduce exposure to such toxins. The first goal will be addressed by improving methods for toxin detection, in particular methods to detect multiple toxins and their metabolites simultaneously. To meet this goal requires the development of materials with performance characteristics capable of being used in multiplexed assays and materials that can detect toxins that are currently poorly detected (such as the masked mycotoxins). Development of these materials is integrated with a second goal, the removal of toxins from foods, thereby reducing exposure. To meet these goals we have four objectives. Objective 1. Improve detection of foodborne toxins through development of novel technologies based upon biosensor platforms and new component materials. Sub-objective 1.1. Development and evaluation of multiplexed assay platforms. Sub-objective 1.2. Development and evaluation of materials that can function in multiplexed assays. Objective 2. Improve detection of foodborne toxins through development of direct detection technologies based upon novel mass-spectrometric platforms. Sub-objective 2.1. Develop novel ambient ionization mass spectrometric techniques for detecting single or closely related groups of foodborne toxins. Sub-objective 2.2. Expand techniques such that they can detect multiple toxins simultaneously (multiplexed assays). Objective 3. Improve the ability to detect and measure “masked” mycotoxins and biomarkers of mycotoxin exposure in commodities and foods. Sub-objective 3.1. Application of novel mass spectrometric tools to detect masked toxins. Sub-objective 3.2. Development of novel bio-based materials for masked mycotoxin detection. Objective 4. Improve toxin detection methods and reduce exposure through the development and application of synthetic materials. Sub-objective 4.1. Develop synthetic receptor materials using computational methods and materials science/synthetic strategies. Sub-objective 4.2. Characterize and apply synthetic receptor materials in methods to reduce exposure to toxins.
Approach
Food crops are commonly infested with fungi, both in the field and in storage. Certain fungi produce toxins (mycotoxins) that can adversely affect human health and the health of domestic animals. By permitting the timely diversion of contaminated ingredients from the food supply, detection of foodborne toxins can directly improve food safety and the safety of animal feed. Monitoring for the presence of such naturally occurring toxins is widespread and occurs at many of the stages between the producer and the consumer. Increasing the efficiency and improving the accuracy of monitoring results in more appropriate and efficient diversion of contaminated products. The need to monitor for greater numbers of mycotoxins is a trend that will continue, in particular because of recent concern over the so called “masked” mycotoxins. This project seeks to address the need for improved toxin detection by developing rapid, multi-toxin detection methods. Two major approaches will be used: development of advanced biosensor techniques and development of novel chemical methods based upon mass spectrometry. In support of the former, novel biological binding materials will be developed. Certain toxin-binding materials may also have the potential to be used to remove toxins from foods, and this will be approached through the development and application of novel synthetic materials to reduce exposures.
Progress Report
Project 5010-42000-049-00D replaces Project 5010-42000-045-00D and has a start date of 1/19/2016. Scientists have begun planning and conducting research to fulfill the 12-month milestones.
Deoxynivalenol (DON) is a toxin produced by certain fungi that cause Fusarium head blight, a disease of cereal crops that results in substantial economic losses worldwide. DON is both a mycotoxin, capable of causing disease in animals, and a compound that facilitates fungal infection of the host cereal crop (a virulence factor). Progress was made on developing a water-based sample preparation for the screening of DON in wheat and corresponding wheat dust. In collaboration with scientists at Dublin City University, Dublin, Ireland, and at Ghent University, Ghent, Belgium, this sample preparation was coupled to three antibody-based tests for DON. The three types of tests were enzyme-linked immunosorbent assay (ELISA), surface plasmon resonance assay (SPR), and biolayer interferometry (BLI).
In other progress related to DON, X-ray crystallography was used to identify key structural features of an enzyme, a glucosyltransferase, in rice plants. The enzyme is capable of transforming the toxin, effectively disabling it. This is one step in continuing research towards the further development of transgenic and traditional breeding approaches for improving resistance of cereal crops to DON.
Fusaric acid is a toxin produced by fungi that can occur in many different types of agricultural products, including maize. Structure-property relationships for the selective Raman detection of fusaric acid and its derivatives were investigated using spectroscopy and density functional computational methods. Computational methods were successful in predicting the contributions of parts of the chemical structure to Raman spectra. The calculations identified key spectral properties important for selective identification of the toxin based on its unique chemical structure. This research provides a convenient label free approach to identify the toxin fusaric acid.
Accomplishments
1. Rapid methods for detecting deoxynivalenol in wheat and wheat dust. Deoxynivalenol (DON) is a toxin produced by certain fungi that cause Fusarium head blight, a disease of substantial economic significance worldwide. In order to facilitate on-site screening of wheat, ARS scientists in Peoria, Illinois, developed a water-based sample preparation for DON screening in wheat and its corresponding dust. In collaboration with scientists at Dublin City University, Dublin, Ireland, and at Ghent University, Ghent, Belgium, this sample preparation was coupled to three antibody-based tests to screen for DON. The three types of tests were enzyme-linked immunosorbent assay (ELISA), surface plasmon resonance assay (SPR), and biolayer interferometry (BLI). Results suggest that the ELISA and BLI methods can be applied as a sensitive technique for rapid screening of DON in wheat and wheat dust. The analysis of dust is a fast and easy-to-use technique which can be performed on-site.
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