Characterization of spore appendages from Bacillus cereus strains

Aims: Further characterization and comparison of spore appendages from Baci llus cereus strains. Methods and Results: Appendages were isolated from 10 B. cereus strains fro m the food industry and food-borne outbreaks. The appendage proteins were d issolved in sample buffer containing 2% SDS and 5% mercaptoethanol at 100 d egreesC, and subjected to SDS-PAGE. None of the appendages showed identical protein patterns. Western blots, using antibodies raised against a 3.5 kDa appendage protein, showed that the majority of the appendage proteins reac ted with the antibody. Removal of the appendages by sonic treatment of the spores did not alter their heat resistance. The appendages were digested by proteinase K, pepsin, and the enzymes in the detergent Paradigm 10, but no t by trypsin or chymotrypsin. Spore adhesion to stainless steel was scarcel y affected by removal of the appendages. Digestion of adhered intact spores (with appendages) with Paradigm 10 showed a high degree of variation. Conclusions: Spore appendages from B. cereus are complex proteinaceous stru ctures that differ among strains. Significance and Impact of the Study: Information about spore appendages an d their involvement in spore adhesion is crucial for improving cleaning met hods used for control of bacterial spores in the food industry.