User blog comment:BlackF0xtheorist/Precursor Appearance in the Arctic DLC/@comment-35232988-20180406164437

Its not the Enzyme which killed the flora and fauna and probably some of the precursors, its the Kharaa Virus, the Enzyme works is the Cure. So your theory is weird at the point, where the low temperature should kill the Virus, its a virus, not an enzyme, so low temperature just slows it. And why should the precursors stay on 4546B ? It was just the "Planet 0" here the epidemic started, thousands ago. so its just one of many planets, the precursors worked on or did research... Their Home Worlds are still untouched... Thats why a return to the Main System is much more likely.

But nice try, mate :)