Daniel Upton

A Systems biology approach to bioenergy; Metabolic investigation of the filamentous fungi Aspergillus niger

Present: PhD student with Jamie Wood and Simon McQueen-Mason, University of York.
Past: BSc (Hons) Biochemistry, University of York

The world’s principal producer of citric acid, the fungus Aspergillus niger is a well-established industrial organism. Citric acid is a valuable compound, widely used in the food and drinks industries for its acidulant, preservative and flavouring properties. It is also used in cleaning products and pharmaceuticals, and its chelating properties make it important in metal cleaning as well as animal feed. Citric acid is most efficiently produced by fermentation with A. niger. Today, food-based feedstocks such as molasses and maize starch are still used for citric acid production. These are becoming more expensive due to rising global food shortages, and so a switch to cheap feedstocks like waste plant biomass and glycerol, a by-product of biodiesel production, is becoming essential. This requires strain development of A. niger, previously achieved by the slow process of random mutagenesis. With advances in genome sequencing, Systems biology approaches are becoming increasingly possible. The project aims to investigate the metabolism of A. niger with relevance to citric acid production, and to develop and use a mathematical metabolic model of A. niger to predict genetic changes that increase citric acid yield on waste streams.