ive done some research into the use of irradiation in decontaminating products of bacteria. Ive found that fruits when treated with UV light have the ability to build up resistance to the bacteria via the hormetic effect. Do you guys think it can work the other way around as well? can bacteria build up mechanisms to become resistant to the effects of UV?

They can, to some extent. But not easily. Radiation has been something they have been exposed to forever, and are still not resistant to.

Actually almost all bacteria (or cells in general) have a certain amount of UV resistance, otherwise they would not be able to withstand sun radiation. The degree varies extremely between species though.

 

One of the most radiation resistant ones (to my knowledge) is Deinococcus radiodurans. However, all resistances are dosage dependent.

Yes, I've even heard of a fungus that thrives (not just survives) on radiation in a nuclear reactor.

Well, yeah. IIRC they reported an enhanced growth of Cryptococcus species. Though the reason for it is still unclear.