Harnessing the human gut microbiota for mycotoxin detoxification

The Rowett Institute has an international reputation for teaching and research in human nutrition and food science. As part of its funding through the Scottish government we are advertising a number of high-profile PhD studentships in nutrition, food science, microbiology and analytical chemistry.

This project offers exciting training opportunities in a wide range of techniques, encompassing bioinformatics, strictly anaerobic microbiology, molecular biology, biochemistry, toxicology and analytical techniques. The student will benefit from being part of the vibrant research environment of the Gut Health Group at the Rowett Institute and will also participate in knowledge exchange activities and international scientific conferences.

This project aims to harness human gut bacteria for mycotoxin detoxification. Mycotoxins are fungal metabolites that contaminate different food and feed products. They pose a serious health risk to humans and animals and lead to economic losses. In Scotland, fungi belonging to the genus Fusarium frequently contaminate grains with trichothecene mycotoxins and their glycosylated derivatives. These masked mycotoxins are not bioavailable in the upper gut, but the toxic free form can be liberated by the human gut microbiota. Some bacteria have been identified exhibiting hydrolysis activity, but further work is required to obtain a better understanding of microbial liberation of masked mycotoxins. The free mycotoxins may be further transformed, but this varies between faecal microbiota from different human donors. Thus, trichothecene mycotoxins carry an epoxide group that is crucial for their toxicity, but deepoxylation activity is rarely detected in human faecal samples.

In this project we will characterise trichothecene mycotoxin metabolism by gut microbes. The first objective is to carry out an in-depth characterisation of microbes that deglycosylate masked mycotoxins. We will perform in silico analyses of genomes to identify candidate glycosidases from strains previously shown to de-glycosylate mycotoxins. Bacteria will be selected from our strain collection based on genomics and existing data and their deglycosylation kinetics characterised. We will also investigate how the presence of different dietary fibre sources affects mycotoxin deglycosylation activity and gene expression. The most promising glycosidase genes will be cloned and overexpressed for biochemical characterisation.

The second objective encompasses identification of gut microbes that can further degrade free trichothecene mycotoxins. We will mine microbial genome and metagenome databases for candidate genes of the enzymatic functions and screen human gut isolates for mycotoxin conversion. Human faecal samples will be screened for the activities and gut microbes enriched and isolated from positive samples.

This work will form the basis for the development of microbial products that can aid tackling the problem of mycotoxin contamination of foods. They can be applied to the decontamination of food products (for example in fermented food products) or can be developed as probiotics to detoxify mycotoxins reaching the large intestine.

Essential background of student:

First degree in microbiology, biochemistry or related subject. Some background or interest in intestinal microbiology, microbial culture or bioinformatics approaches related to genome and metagenome mining would be desirable.

Informal enquiries would be welcomed for a discussion, Please contact the lead supervisor, Dr Petra Louis ([Email Address Removed]) for more information.

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This project will be based within the Rowett Institute, part of the School of Medicine, Medical Sciences and Nutrition, at the University of Aberdeen. The Rowett Institute is located on the Foresterhill Health Campus, one of the largest clinical complexes in Europe, which also includes the Institute of Applied Health Sciences, a large teaching hospital and the the Institute of Medical Sciences (IMS). 

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APPLICATION PROCEDURE:

International applicants are eligible to apply for this studentship but will have to find additional funding to cover the difference between overseas and home fees (approximately £17,000 per annum)

• Formal applications can be completed online: https://www.abdn.ac.uk/pgap/login.php
• You should apply for the Degree of Doctor of Philosophy in Medical Sciences to ensure your application is passed to the correct team
• Please clearly note the name of the supervisor and exact project title on the application form. If you do not mention the project title and the supervisor on your application it will not be considered for the studentship.
• Candidates should have (or expect to achieve) a minimum of a 2:1 Honours degree (or international equivalent).
• General application enquiries can be made to [Email Address Removed]