NewIn: Li Deng

The virus as the ally of humanity

The struggle Prof. Li Deng has taken on has been raging for billions of years. "I conduct research on bacterial viruses, more precisely phages, the natural enemies of bacteria," says the scientist, whose research deals specifically with the lungs and groundwater. The two may seem unrelated, but they are habitats for countless microorganisms – e.g., bacteria and viruses. And approximately 90 percent of all of the estimated 10^31 viruses in the world are phages. Bacteriophage is the scientific term referring to viruses which do not infect humans or animals, but which kill bacteria instead.

Viruses that infect only bacteria

This characteristic makes them welcome allies to physicians and plant researchers ideal antibacterial with no known adverse effect on host microbiota. “Phages are highly specific to their hosts,” Deng explains. "Antibiotics on the other hand work on a very broad scope against a large number of bacteria – unfortunately, also against useful ones." Another factor is the constantly increasing rate of bacterial resistance to antibiotics. "And that's a great danger to patients: Without effective antibiotics, we're almost completely defenseless against infections."

In the future phages are to take on this task and fight pathogenic bacteria as medication-based active ingredients. Deng has already helped develop the first effective phage cocktails, including one that fights the infamous hospital germ carbapenem-resistant Pseudomonas aeruginosa, which in the meantime can hardly be combatted with antibiotics at all. The scientist has also set her sights on the dangerous bacterium Acinetobacter baumannii, which can trigger serious and often fatal blood poisoning and pneumonia.

The agricultural sector also has a lot of expectations when it comes to phages. Agriculture presently accounts for approximately 80 percent of all the antibiotics used in many countries, the subject of repeated criticism. These antibiotics are meant to keep plants and animals healthy by killing bacterial pathogens – but the increasing scope of resistances is constantly lowering the rate of success. This endangers the ability to produce enough food for the constantly growing world population. Thus, Professor Deng is concerned with highly fundamental and societally relevant topics on a daily basis.

Always sought proximity to the best researchers

She began her scientific career at Tsinghua University in China, a TUM flagship partner, where she earned her Bachelor's degree in Biology and Environmental Engineering. Deng completed her Master's studies in Environmental Sciences at the University of Nottingham in England. She also earned her doctorate in England, at the University of Bristol. This was followed by research activities in Innsbruck and Arizona; Professor Deng came to the German Research Center for Environmental Health, Helmholtz Zentrum München in 2011. "I have always chosen my stations very carefully, following the criterion of excellence. I've always sought proximity to the best researchers in my field, worked together with them and learned from them."

Ultimately, she chose to remain in Munich because of love: She is married to an Austrian citizen and has two children. "I've been very fortunate in Munich," says Deng. "It's a wonderful, very open-minded place." She began learning German during her parental leave. "I need German in my daily work activities as well as in my leisure time. I still teach in English, but I hope that will soon work in German."

In 2015 Deng headed a research group at the Institute for Groundwater Ecology at the Helmholtz Zentrum München on an Emmy Noether scholarship for the support of outstanding young researchers granted by the German Research Foundation (Deutsche Forschungsgemeinschaft or DFG).

When taking time off to recharge for her intensive research work, Deng enjoys hiking in the Alps with her husband, who is also a natural scientist, and their two children. But in some senses, she's still on the job even in her free time. Everywhere their hikes take them, Professor Deng collects samples of soil and water from the mountain lakes. To her, science is more than just a job, it's a true passion.