Mycotoxin contamination poses significant health risks to humans and animals due to its widespread and unpreventable presence in foods and feeds. These are secondary metabolites, produced by molds, namely aflatoxins, ochratoxins, fumonisins, and zearalenone.
A global survey of mycotoxin contamination in animal feed ingredients from 2008 to 2017, found that 88% of samples were contaminated with at least one mycotoxin. There were clear regional trends in the prevalence of mycotoxin, and the climate played a major role in determining these trends.
However, 41.1%, 38.5%, and 20.9% of samples from South Asia, Sub-Saharan Africa, and Southeast Asia respectively exceeded the maximum level for aflatoxin B1. Most common mycotoxin mixtures were combinations of deoxynivalenol, zearalenone, fumonisins, and aflatoxin B1. (Dorninger et al 2019).
Understanding that mycotoxins are predominantly produced by fungi in standing crops underscores the imminent threat they pose to both human and animal health, when these crops are utilized for food and feed. Although considerable attention in the animal industry has historically been directed towards post-harvest management, there is a pressing need to shift focus towards comprehensive studies on the prevalence patterns and proactive forecasting of mycotoxins directly from the field. By prioritizing research at this crucial juncture, we can better equip ourselves to mitigate the pervasive challenge of mycotoxins and the associated mycotoxicos is, thereby safeguarding both agricultural productivity and public health. With a brief highlight on the existing post-harvest techniques of mycotoxin management, let us explore several futuristic innovative techniques for forecasting, monitoring, and analysing mycotoxins, spanning from the standing crops to their utilization in animal or poultry feed.
A review on conventional post-harvest techniques involved in mycotoxin decontamination
Preventing mycotoxin formation in crops often involves conventional techniques such as drying and the use of chemicals like ammonia, ozone, alkalis, aldehydes, chlorine, or oxidizing agents. However, these methods can prove impractical, especially in the face of changing climatic conditions. Alternatively, physical methods such as utilizing clay-based toxin binders & biological detoxification agents, like microorganisms and enzymes, present a promising solution & offer a feasible approach. However, these agents function only when the feed is ingested along with mycotoxins by the animals, making them particularly suitable in scenarios where regular testing of feeds is not commonly practiced, and contaminated grains are unintentionally used for feed formulations. By leveraging these approaches, agricultural stakeholders can managethe risks associated with mycotoxin contamination, yet without a complete assurance. With advancements in technology and analytical methods, researchers are developing tools and approaches to ensure the safety and quality of agricultural products. From field-based technology to sophisticated laboratory assays, these techniques enable early detection, quantification, and mitigation of mycotoxin contamination throughout the production chain.
Future visions in Pre-harvest predictive modelling: A GIS-Remote sensing technique
This technique uses Agricultural Satellite Remote Sensing to study the health of crop or vegetation in a particular geography by studying the absorption of electromagnetic red spectrum and reflection of near infrared spectrum to determine the Normalised Difference Vegetation Index (NDVI). This index along with its representative mapping is compared with plant microbiological analysis in-situ. This analysis gives potential relationship between remotely sensed data and mycotoxin accumulation to examine its utility in future risk prediction (Battilani & Leggiari 2014). The model also uses GPS coordinates that can determine other correlated indicators like timing of rainfall, rather than total amount of rainfall, that determines spatial risk of mycotoxin accumulation. Soil characteristics is also studied that may influence plant stress that is a pre-harvest factor for fungal infection and mycotoxin production (Smith et al.2016).
Significantly this model helps to minimize mycotoxin exposure to humans and animals and is suitable for worldwide mycotoxin risk prediction. Past, historical, and future data are used to predict crop ripening, pre-seasonal decisions, and climate change scenarios. These predictions can be useful for all stakeholders like poultry institutions, researchers, and farmers.
Future vision on OMICS Technique- A genetic tool in crop modification
OMICS techniques are a class of analytical tools used in the biological sciences to investigate different genetic processes in crops & fungal species. It has emerged as a key tool in the study of mycotoxins, particularly in the identification of biomarkers that may be used to identify mycotoxigenic species and to collect data on the pathways by which mycotoxins are biosynthesized in various environments. OMICS tool involves various systematic studies like Genomics, Transcriptomics, Proteomics & Metabolomics.
Genomics focuses on identification and characterization of the genes or complete set of DNA responsible for the biosynthetic pathways of mycotoxins in mycotoxigenic fungi. Thereby it helps in identification of genes involved in the mycotoxin biosynthetic pathways, that determine various fungal species that produces same mycotoxins. Since the genes contains specific instructions that are necessary for the organism to build and maintain, genomics tool helps in understanding the host-fungus interaction and to how it can affect genetic factors controlling mycotoxin production, helping the development of more effective control and prevention strategies. Genomics study involves analytical methods like Microarray, Quantitative RT-PCR & LAMP (Loop-mediated isothermal amplification).
Transcriptomics approach focuses on the study of complete set of transcribed RNA from DNA. This study helps to determine the functional role of the genes involved in the biosynthesis of mycotoxins&to determine the toxicological mechanisms of their biomarkers. Through toxicokinetic evaluation, transcriptomics also provides information for predicting genotoxicity & carcinogenicity, which in turn generates relevant epigenetic information in the study of mycotoxins. Classical example of this are studies using in vitro& in vivo approach of transcriptomic alterations associated with A. flavus growth &that influences AFB1 production (Pauletto et al. 2020). Transcriptomics study involves analytical methods like RNA analysis by microarray, RNA-Sequencing and isothermal amplification.
Proteomicsen ables the identification and characterization of the entire peptide and protein profile involved in the biosynthetic pathways of mycotoxins. It plays an important role in biomarker determination and pathophysiology in the hosts. Proteomics in mycotoxicology, not only provides an idea of mechanism of mycotoxin biosynthesis, meanwhile also determine the factors that allow to favour or inhibit the synthesis of different mycotoxins. For instance, a study involving proteomics helped in demonstrating a plant pigment quercetin, as an anti-aflatoxigenic agent which efficiently prevents fungiA. flavusto produce aflatoxins by inhibition of enzymes that promote their synthesis (Rhigetti & C. Dall’ Asta 2018). Proteomics involve analysis methods like Matrix-assisted laser desorption ionisation-time-of-flight mass spectroscopy (MALDI-TOF) & LC- MS/MS.
Metabolomics tool allows the characterization of the metabolic profile in different biological samples, identifying primary and secondary metabolites (mycotoxins) synthesized by a fungal species. This tool has a great impact, since presence of mycotoxins or toxins are found at the metabolite level rather than macromolecules (Raychlik et al 2019). The analytical instruments applied in metabolomics are based on mass spectrometry like HRMS, LC-MS/MS, NMR (Nuclear Magnetic Resonance Spectroscopy).
OMICS techniques usually generate a huge amount of data, which requires statistical analysis. Accordingly, the integration of these technique may lead to an understanding of interactions among molecular components and their changes in biological system &the toxic effects of mycotoxins. Omics tools have become vital approach in the field of mycotoxin study, allowing researchers tounderst and the biosynthetic processes within crops & fungus related to the production of these mycotoxins.
Advances in the field of pre-harvest predictive modelling for geo-climatic behaviour combined with OMICS analytical techniques to study the processes involved in the biosynthesis of mycotoxins, will be critical in future tounderst and the mechanisms&helping the identification of emergingmycotoxigenic species. In the same way this will also help in generating tools to establish more precise prevention, control, and mitigation strategies of these mycotoxins and will additionally help in developing and utilising mycotoxin sequestering toxin binders/bio-transforming agents in more efficient manner.
by Dr Rajib Upadhyaya, Cargill India
