Reducing food waste due to contamination by fungi (Defra Link project FQI 28)

Objectives The principal objective of this proposal is to improve understanding of the responses of fungi to food preservatives and to use this new knowledge to design and test new strategies of food preservation. To achieve this objective, a programme of investigation is proposed that will identify key transcriptional events in the germination of mould conidia (taking Aspergillus niger as the model organism) in the presence of weak acid and other preservatives in combination with exposure to variations in pH and heat. The underlying factors in introducing phenotypic variation, and the importance of inoculum size will be defined in order to inform strategies for food protection against fungal spoilage. Phenotypic variation is a cause of resistance to preservatives and, therefore, gene targets from the GeneChip studies, and a range of natural preservatives, will be tested for their impact in reducing phenotypic variability. New knowledge obtained from the model organism A. niger will be tested with fungal isolates made from factory screens. Novel food preservation strategies will be defined and tested. Key Innovations Spoilage of foods and beverages by fungi (both yeasts and moulds) is currently extremely costly to producing companies despite the use of preservatives. In addition, mould spoilage has associated potential for food safety due to the potential for mycotoxin production. This proposal has identified key areas for investigation that will provide new scientific information on which to base the design of novel preservation strategies. The project will yield new scientific information on fungi as well as practical benefit to food and beverage producers. Principal Methodology This project will employ genomic and molecular biology methods to investigate the key events in conidial outgrowth and responses to preservatives. We will use cell sorting methods to examine the significance of phenotypic heterogeneity in isogenic cell populations. The project will also use microbial physiology approaches and will test new preservative formulations in laboratory and food/beverage tests.