After a postdoctoral position at the ETH of Zurich, she joined the first French biotechnology company, Transgène SA. After 14 years at Transgène SA, Mercenier set up the Department of Microbiology of Ecosystems at the Institut Pasteur de Lille. In 2002, she took a Group Leader position in the Nutrition and Health Department of the Nestlé Research Center in Lausanne, Switzerland.
Mercenier later went on to build and lead the Gut Ecosystem department for Nestlé before retiring in 2018. But her passion for science was still there, and Mercenier came out of retirement to join Nutrileads as Chief Innovation Officer a month later.
Mercenier, who recently celebrated her 70th birthday, said she has a unique perspective because her career began decades ago.
“It was not abnormal to do a PhD thesis but the classical question I would get typically in Switzerland after I graduated is why are you back for postdoc? You have a diploma, why don't you stay home and take care of the children? And I say, well, this is the beginning of something that I like. So I'm not going to stop with a diploma and that gives you a snapshot of how the situation was there. The time was a bit more pronounced in Switzerland where many women work part-time, work less, and then over the years, I could really see a big evolution.”
Mercenier said she is always impressed by the number of women in the field who leave their career for two years or more to raise children and then return to the lab. “It's amazing to see how women cope with their personal life, the family life and are still giving everything they need to push.”