Reduction/elimination of spore forming bacteria in lightly heat treated foods

The project seeks to identify processes which are able to strongly reduce spore forming bacteria in lightly heat treated (<98 ºC) foods. To solve this task, three research groups with different, complementary competence will cooperate. The project require s characterisation of potentially pathogenic spore formers (Clostridium and Bacillus spp.), identification of genes controlling the germination process, and utilization of increased understanding in food industry. Spore forming bacteria cause a large pa rt of cases of foodborne disease, besides causing problems for the food industry. While the spore secures survival of the bacterium, germination is the crucial step towards an active organism, and understanding of the process is required. The germination process and factors affecting it are still inadequately understood. By using bioinformatics, we wish to gain an overview of genes involved in germination. With the help of molecular biology analyses, we seek to develop a method for spore detection. Heat is known to trigger germination. If spores are germinated before heat treatment, they become heat labile and are killed at 70-80 ºC. This is achieved in double heat treatment (Tyndallization), a traditional but little used industrial process. Its potenti al for spore control purposes has not been fully developed. Many production lines indirectly apply a double heat process, as the product or its constituents are initially cooked or mixed by heat before packaging and heat treatment. Utilization of this pro cess is central in the project aims. A mixture of ten characterized spore formers will be used to optimize a food industry process. We will explore the possibility of using germinants (compounds that trigger germination) to increase the effect obtained by double heat cycles. Recognition of suitable germinants would allow activation of spores prior to heat treatment by direct addition to foods.