Hydrogen sulfide, the pungent stuff often referred to as sewer gas, is a deadly substance implicated in several mass extinctions, including one at the end of the Permian period 251 million years ago that wiped out more than three-quarters of all species on Earth.
But in low doses, hydrogen sulfide could greatly enhance plant growth, leading to a sharp increase in global food supplies and plentiful stock for biofuel production, new University of Washington research shows.
"We found some very interesting things, including that at the very lowest levels plant health improves. But that's not what we were looking for," said Frederick Dooley, a UW doctoral student in biology who led the research.
Dooley started off to examine the toxic effects of hydrogen sulfide on plants but mistakenly used only one-tenth the amount of the toxin he had intended. The results were so unbelievable that he repeated the experiment. Still unconvinced, he repeated it again – and again, and again. In fact, the results have been replicated so often that they are now "a near certainty," he said. "Everything else that's ever been done on plants was looking at hydrogen sulfide in high concentrations," he said.