This question may sound as stupid as it is, but I just want to feed my curiosity (I am not going to eat mouldy food). I am trying to find a common point for these two assumptions (provided that both are true):  Many years ago I was told that microwave heating purifies food out of any valuable nutrition values, because microwave radiation plus high temperature kills all biological forms of life (i.e. "good" bacteria) or organic chemistry (i.e. vitamins) that exists in heated food.  About 2-3 years ago I also run through a question asked here (can't find it now) to which answer explained that there are only 2-3 examples of food that can be still eaten after removing mold. All other thousands of food examples must be recycled, if mouldy.   If both assumptions are correct then how it is that treating a food with a little bit mold over it for about 5-7 minutes in microwave at let's say 800 W doesn't do the same (point 1) to mold, which is after all a biological component (fungi?)? Isn't 5-7 minutes of heat and microwave emission enough to kill all colonies of mold and enough to make food again eatable? (of course I am talking about "bad grey mold", not "good cheesy blue mold") 
No. In many cases, it's not the mould (or bacteria etc.) itself that poisons you, it's toxins released by the pathogen.  Killing the mould doesn't say anything about what happens to the toxins, any more than killing a creature cleans up its excrement.  You should assume this to always be the case as even if you could identify the most visible mould as not too much of a threat, you're quite likely to have other forms as well. It will also taste bad, as you'll know if you've ever bitten into bread that hadn't kept as well as you'd expect, without noticing mould spots. 