1. Wstęp. 2. Najważniejsze aspekty biologii B. cereus sensu lato. 2.1. Wyzwanie pierwsze – spójna taksonomia. 2.2. Wyzwanie drugie – cykle życiowe i interakcje z otoczeniem. 2.3. Wyzwanie trzecie – adaptacja do niskich temperatur. 2.4. Wyzwanie czwarte – toksyny B. cereus sensu lato. 3. Podsumowanie

Abstract: Bacillus cereus sensu lato is a group of several species of Gram-positive sporeformers ubiquitous in nature and showing huge impact on human activities. They are often found in soil, air, plant material, animal tissues and digestive tracts as well as in food products. Their genetic similarities and frequent horizontal gene transfer causes doubts regarding their taxonomy. In addition, their toxicity and psychrotolerance constitute serious problems in the dairy industry, being responsible for food-poisonings and spoilage of cold-stored products. Finally, recent finding indicate that B. cereus sensu lato toxicity plays an important role not only in their virulence, but also in social interactions with other bacteria.

1. Introduction. 2. The most important aspects of B. cereus sensu lato biology. 2.1. First challenge – coherent taxonomy. 2.2. Second challenge – life cycles and interactions with the environment. 2.3. Third challenge – adaptation to low temperatures. 2.4. Fourth challenge – toxins of B. cereus sensu lato. 3. Summary