Biggest microbial hurdle

[FistFullaRoux]

Which microbe is the hardest to get rid of? And have there been any instances of food related illnesses while in space?

Also, has anyone suggested trying to make pizza dough in microgravity? The reaction of the yeast to the environment would be fascinating. The tossing of the dough could be an interesting thing to watch as well. It gives the kids working Sbarro's something to dream about...

[Vickie Kloeris]

Our food is not sterile, so it is not microbe free. We process our food using procedures to assure that no pathogenic bacteria are present. There are still spoilage bacteria present in the food and we use various methods to keep those under control. For instance, freeze-dried foods have had so much moisture removed that they will not support growth of the spoilage bacteria that may be present in the food. However, once a crewmember rehydrates a freeze-dried item, it can grow bacteria since there is no refrigertor on orbit for "left-overs". Thus, they must eat a product right away after rehydration or discard it. No know instance of food bourne illness on orbit. Can't guarantee about indigestion though! No pizza dough has been tossed in space. In fact, no food preparation of that type at all. Too messy in microgravity.