BACILLUS-CEREUS AND ITS FOOD POISONING TOXINS

Bacillus cereus is becoming one of the more important causes of food p oisoning in the industrialised world. It produces one emetic toxin and three different enterotoxins. The emetic toxin is a ring-shaped struc ture of three repeats of four amino and/or oxy acids: [D-O-Leu-D-Ala-L -O-Val-L-Val](3). This ring structure has a molecular mass of 1.2 kDa, and is chemically closely related to the potassium ionophore valinomy cin. Two of the three enterotoxins have been shown to be involved in f ood poisoning. They both consist of three different proteins that act together. One of these enterotoxins is also a haemolysin. This haemoly tic enterotoxin is transcribed from one operon. The third enterotoxin is a single component protein, but has not been shown to be involved i n food poisoning.