Rick a jet engine is one of the most forgiving engines out there. You can run everything from jet fuel to diesel to car gas. Diesel could be substituted with bio-diesel. They could use ethanol as well.
It's not uncommon for people to run a few hundred gallons of gas through an jet engine a year to clean the lines of algae that grew in the tanks of a jet. I believe they've put an additive in the fuel now where it isn't an issue but I know people who did it until recently. They still might.
I've personally flown a turbo-prop with avgas because jet fuel was not available in New Mexico when their pumps broke. The main disadvantages of running a jet engine on avgas or car gas is that it's more flamable. Your temps run higher easier so you can't get near the power out of your engine without over temping it.
Military vehicles even are designed to be able to run on JP8 if necessary which can be used in things from Humvees to jets. The main difference between Jet-A and diesel is the lubricants. You can take a VW with a diesel engine and fill the entire tank up with Jet-A and run it all day long if you add oil directly into the fuel tank with the jet-a. Jet-A/Diesel is slower burning and runs at lower temps which makes it more suitable for jet engines. Gas just burns them up too fast.
The engines can already run diesel so running bio-diesel shouldn't be that hard and bio-diesel is much cleaner and very easy for factories to produce and for us to farm.