Botulism is an illness resulting from the ingestion of toxins secreted from the bacteria Clostridium botulinum. It is the toxin produced by the bacteria that causes the symptoms in humans. Clostridium botulinum is an obligate anaerobe, which means it prefers conditions with low oxygen. This is why it can grow in sealed cans. Clostridium botulinum form spores that allow the bacteria to survive under non-ideal environmental conditions. These spores can survive harsh conditions like boiling water and cold temperatures. If someone is diagnosed with botulism, the treatment usually involves administration of an antibody or an antitoxin drug, plus hospitalization. To answer your question, bleach and sodium hydroxide (strong base) will kill the bacteria (but obviously you wouldnt want to pour bleach or sodium hydroxide on your food to decontaminate it). C. botulinum spores can be killed by heating to extreme temperature (120 degrees Celsius) under pressure using an autoclave or a pressure cooker at for at least 30 minutes. The toxin itself can be killed by boiling for 10 minutes.

I found some good info. on the CDC web site:

botulism

"What is botulism?Botulism is a rare but serious paralytic illness caused by a nerve toxin that is produced by the bacterium Clostridiumbotulinum. There are three main kinds of botulism.Food borne botulism is caused by eating foods that contain the botulism toxin. Wound botulism is caused by toxin produced from a wound infected with Clostridium botulinum.Infant botulism is caused by consuming the spores of the botulinum bacteria, which then grow in the intestines and release toxin. All forms of botulism can be fatal and are considered medical emergencies. Food borne botulism can be especially dangerous because many people can be poisoned by eating a contaminated food.

What kind of germ is Clostridium botulinum? Clostridium botulinum is the name of a group of bacteria commonly found in soil. These rod-shaped organisms grow best in low oxygen conditions. The bacteria form spores which allow them to survive in a dormant state until exposed to conditions that can support their growth. There are seven types of botulism toxin designated by the letters A through G; only types A, B, E and F cause illness in humans.

How can botulism be prevented?Botulism can be prevented. Food borne botulism has often been from home-canned foods with low acid content, such as asparagus, green beans, beets and corn. However, outbreaks of botulism from more unusual sources such as chopped garlic in oil, chile peppers, tomatoes, improperly handled baked potatoes wrapped in aluminum foil, and home-canned or fermented fish. Persons who do home canning should follow strict hygienic procedures to reduce contamination of foods. Oils infused with garlic or herbs should be refrigerated. Potatoes which have been baked while wrapped in aluminum foil should be kept hot until served or refrigerated. Because the botulism toxin is destroyed by high temperatures, persons who eat home-canned foods should consider boiling the food for 10 minutes before eating it to ensure safety. Instructions on safe home canning can be obtained from county extension services or from the US Department of Agriculture. Because honey can contain spores of Clostridium botulinum and this has been a source of infection for infants, children less than 12 months old should not be fed honey. Honey is safe for persons 1 year of age and older. Wound botulism can be prevented by promptly seeking medical care for infected wounds and by not using injectable street drugs."

What kills botulism?
Oxygen - although the thing about botulism that is poisonous is a waste product of the botulism bacterium, so it is still dangerous even after the bacterium is dead. Having something exposed to oxygen,however, will prevent botulism from infecting it in the first place.

HEAT!from:

botulism

Botulism can be prevented. Foodborne botulism has often been from home-canned foods with low acid content, such as asparagus, green beans, beets and corn. However, outbreaks of botulism from more unusual sources such as chopped garlic in oil, chile peppers, tomatoes, improperly handled baked potatoes wrapped in aluminum foil, and home-canned or fermented fish. Persons who do home canning should follow strict hygienic procedures to reduce contamination of foods. Oils infused with garlic or herbs should be refrigerated. Potatoes which have been baked while wrapped in aluminum foil should be kept hot until served or refrigerated. Because the botulism toxin is destroyed by high temperatures, persons who eat home-canned foods should consider boiling the food for 10 minutes before eating it to ensure safety. Instructions on safe home canning can be obtained from county extension services or from the US Department of Agriculture. Because honey can contain spores of Clostridium botulinum and this has been a source of infection for infants, children less than 12 months old should not be fed honey. Honey is safe for persons 1 year of age and older. Wound botulism can be prevented by promptly seeking medical care for infected wounds and by not using injectable street drugs.