Original sentence: Its 2 kilometers maze of passages is etched out of Cretaceous limestone by sulfuric acid and bacteria.Its thermal sulphur springs produce a rotten-egg smell, and bacteria thrive on the resulting hydrogen sulfide gas.National Geographic Magazine,  Mexico’s Poisonous Cave.New Scientist Magazine, Acid House, 06 June 1998
Edited sentence: It is famous for its rotten-egg smell, which results from its thermal sulphur springs, and for the bacteria that thrive on the resulting hydrogen sulfide gas