Investigating the impact on microorganisms of environmental toxins in freshwater

How algae, fungi and bacteria adapt to different concentrations of pollutants and pesticides found in freshwater is the primary focus of Daniela’s thesis.  

She’s taken samples of microorganisms in the Mölndalsån river and the Göta älv river. These samples were then tested in the lab for different levels of contamination. In the final stage, Daniela has examined the microorganisms on a molecular level using DNA tests.  

- Half of my research work is done in the lab, and half at my computer.

Adaptation apparent 

Daniela found a number of interesting results when studying how microorganisms adapted to toxins and pollution,. For instance, the microalga Raphidocelis subcapitata adapted to Diflufenican, a herbicide widely used in Europe, by reducing in size. 

The algae were capable of recovering and adapting to high concentrations of the herbicide. But they had to fight to do that. 

- Their adaptation came at a cost. The algae that adapted could reproduce just as in normal conditions, but they had to pay the price for that. They became smaller, the cell cycle became unregulated and they had less pigment for photosynthesis.

Studying the aquatic environment as a whole 

Daniela Gomez Martinez undersökningar omfattar även bakterier och vattensvampar, som lever på flod- och sjöbottnar tillsammans med mikroalger.

- I look at the whole composition of microorganisms, and I’ve noticed changes in the species available, i.e. in biodiversity. With microfungi, for example, some species are more capable of surviving toxins and pollution. But we don’t know how well the remaining species are working.

The analyses show that the number of aquatic fungi decreases overall as pollution in the water increases. And this presents a problem, because aquatic fungi break down large amounts of organic material such as leaves.  

- This reduces the food supply for crustaceans and small fish, for instance. And the entire aquatic ecosystem is disrupted when we see a decline in the numbers of fungi.

Loves living in Gothenburg  

After completing a bachelor’s degree in biotechnology and a master’s degree in environmental toxicology at the Polytechnic University of Valencia in Spain, Daniela was on the lookout for suitable third-cycle education.  

- I had a strong interest in environmental issues even before I started university. And when I read that microorganisms can counter pollution in rivers and lakes, I decided that was what I wanted to study it in my bachelor’s project. That taught me a lot about microbiology, says Daniela

She looked for universities in Europe and eventually decided to study at the University of Gothenburg. She arrived here in November 2020. Daniela loves living in Gothenburg and embraces the non-hierarchical structure of the University of Gothenburg. 

- I can talk to my professor and have a pleasant conversation, and I don’t need to feel nervous. My views are listened to and I have the opportunity to develop my own ideas. I think it’s brilliant!

Moreover, the structure of the third-cycle programme allows her to plan her work and adapt it to fit in which her main leisure interest. Daniela has been riding horses since she was seven years old, and she regularly takes part in both dressage and showjumping.  

She’s learning Swedish, too. She’s planning to stay in Gothenburg in the future and look for a job in industry. 

- I love living in Gothenburg. The city is just the right size, and there are so many great things going on here. People are generally very nice – a bit reserved at first, but they warm up as you get to know them better.