Environmental Catastrophe Sci-fi book, 80s

i bought the original book back in 1986 or ’87 when i was a kid. the cover was yellow with silhouettes on it.

the storyline: in order to try and clean up oil spills, a lab had created oil eating microbes. when they tested them out on a slick on the open ocean, the microbes ate all the oil as promised, but instead of dying out according to a built-in engineered life span they began evolving super fast. eventually they ate all the oil and petroleum-based products on earth sending it into a dark age.

in addition, hybridized humans who had been created in the same labs escaped and began breeding with one another creating an entirely new interspecies race of human-animal hybrids....the regular humans were at war with these hybrids and the science cabals who survived and were continuing experiments....

ive been trying to find this book for ages....does it sound familiar to anyone? and no it’s not pandora’s genes, but its similar....the 80s were fertile ground for an end of the world boom in books

Ooh, this sounds good. I look forward to finding out the title.

yes, from what i remember it was an awesome read i sure hope someone remembers more :)

Sounds similar to Pandora's Genes by Kathryn Lance that was published in 1985.

From FictionDB: In this absorbing and unique novel, Kathryn Lance asks how far the folly of mankind can go, how much science can be substituted for nature before the imbalance proves disastrous. In a world of the future, great machines lie rusting as their fuel has finally run out and humanity faces the possibility of extinction as altered strands of DNA run rampant through the gene pool. Several forces emerge, each hoping to be humanity's saving grace, but which one will ultimately save the world?

The date's off by a decade - it was published in the mid-1990s - but on the off-chance that you're conflating two stories here, the "engineered bacteria are released to eat an oil spill, and eat all the petroleum and petroleum products (i.e. plastics) on the planet" is also the end-of-civilization mechanism in Ill Wind (which I thought was pretty bad, so I wouldn't recommend it if it isn't your original book)

My first thought was a book from the late 1960's called "The Hendon Fungus" by Richard Parker . But, that book was for older Elementary School / early Junior High age kids and British. Two siblings father discovers a new mushroom species (?) and gets out of the lab. The fungus eats either mortar or stone/concrete foundations and most of the buildings in Britain collapses and the country is put under quarantine.

Black Monday by Bob Reiss?

I think this might be World Enough, and Time by James Kahn. Check out the covers, there is one that matches your description perfectly. There were two sequels: Time's Dark Laughter and Timefall as well.

I'm increasingly wondering whether my "conflating two different books" guess wasn't correct; there are what look like really good guesses for each half of the description but nothing that gets both pieces.

yes! thats exactly it...world enough, and time by james kahn....i had no idea there were 2 more out since then. will def check them out. thank you SO SO much :)