From the Great Lakes to Argentina , Europe and the great river systems of Asia , nitrate contamination of drinking water is a global problem that threatens the health of humans and ecosystems. When chemical fertilizers and animal or human waste pollute surface and ground water, toxic nitrate ions can reach concentrations high enough to kill aquatic life and produce serious health problems for those who drink the water, especially babies and infants.

Maria Carolina Festa, a Grade 10 student at Villa Sainte-Marceline school in Montreal , became interested in the growing scourge of nitrate pollution after reading an article on the Internet.

“I did a lot of research and learned that bioremediation had been used successfully to purify water contaminated with heavy metals,” said Carolina . “I decided to find out if nitrate contamination could also be tackled using biotechnological methods.”

Working in the school science lab with the help of chemistry teacher Guillermo Pieli and lab technician Andre Lukumbo, Carolina set out to test the effectiveness of a common bacterium found in soil to purify nitrate-contaminated water. Her project won her the 2009 Montreal regional Sanofi-Aventis Biotalent Challenge.

Carolina cultured the common bacterium (P. fluorescens) in magnesium nitrate solutions of varying concentrations, and demonstrated that a two-day bioremediation using P. fluorescens, followed by chlorination and filtration, could render water containing up to 71 milligrams of nitrate per liter fit for human consumption.

Though only 15, Carolina already knows that she is destined for a career in science but unsure in what capacity or in which field. Until those decisions have to be made, she leads a busy life as a competitive runner and many other interests, including classical music, architecture and travel.