Can botulism endospores be destroyed by heat?

Yes, botulism endospores can be destroyed by heat. They are highly resistant to heat, but boiling (100°C or 212°F) for at least 10 minutes destroys the endospores. This is why home canning instructions always require boiling. In the absence of oxygen, such as in sealed cans, the boiling time needs to be extended to 20-25 minutes to effectively destroy the endospores. The high heat disrupts the structure and composition of the endospore, especially disrupting the enzymes in the germinating endospore that could lead to cell replication of new bacteria cells.