[higgmeister]

Many years ago I read a book series where they developed an organism that ate oil to clean up the oceans. It did not end well.

Doorways (1993) was a proposed science fiction pilot that was never picked up.   A mysterious alien feral woman appears on a freeway and after causing an accident with her weapon is taken to a hospital where she and the doctor that treated her eventually jump between alternate Earths to flee from the alien overlords who are chasing the alien woman.

They end up in a world where, 15 years ago, a microbe gene was created to clean up an oil spill, but it ate all petroleum in the world. They hitch a ride on a wagon (an Airstream trailer pulled by draft horses) with Jake (Hoyt Axton) and his granddaughter Cissy (Tisha Putman), who give them a ride to the nearest truck stop.

The pilot is on Prime video, or video on the link which I started with the pair of protagonist are hitching a ride on the Airstream trailer.

[Harmless Teddy Bear]

The book I was remembering was “Pandora's Genes” and was written in the 80s. There were a couple of sequels.

The starting event sounds exactly like the one in the book except that bacteria mutated and began to eat everything made with oil so all plastic, nylon and so forth. The end result was the release of all the germs in laboratories resulting it "wild deenas (DNA)" causing runaway mutations.