What do you mean, biological process? For a removable mat, I would use laundry detergent with enzymes, which will break apart the proteins, and some oxygen bleach, which reduces just about anything organic, in HOT water. Let it soak for maybe an hour. Rinse, and let dry in the sun. That is what I would do if it were my car mat. Aggressive oxygen bleach+heat+sun can fade colors, so if you're sensitive to that, test first of course.

Enzymatic process. We bought something from Home Depot today that is an enymatic cleaner. Wait to 'smell' the results.

Be sure and soak the area well and wait at least overnight to sop it up. The enzymes need time to do their work.
You may have to do it more than once.

I'd go to a carwash and have the interior cleaned. After that, time, fresh air and sunshine are the best things. I once left a tray of shrimps on the floor of my car, another time spilled a gallon of milk. Time,air, sun.

The insurance company is going to put out about $2000 to have the carpets replaced and the underlying metal floor cleaned and disinfected. All this for a $50 deductible. I can tell you,though, rotting ground turkey is pretty putrid smelling.

Thanks for the suggestions...

Wow, I didn't know the insurance company would pay for something like that. Lucky you!