Evolution of stress resistance in bacterial spores
Bacterial spores are the most resistant life forms known. They can survive extremes of heat and pH, and high doses of radiation and disinfectants. For this reason, they are often implicated in the spoilage of processed foods, and some species can additionally cause foodborne infection or intoxication. Traditionally, the resistance of spores to heat and other stresses has been considered a stable property,characteristic for each species, and food processing conditions have been designed based on the resistance parameters documented in the literature. However, this view is being increasingly challenged,and “super-resistant” spores have occasionally appeared and caused problems in the food industry. In this project, how fast and how far spores can stretch their resistance to various stresses will be investigated by making use of adaptive laboratory evolution experiments (ALE). Furthermore, the genetic and physiological mechanisms will be unravelled underlying the evolved spore stress resistance by using whole genome sequencing and a range of genetic, biochemical and microbiological approaches.