A day in the life of an environmental microbiologist, Ass. Prof. Sarahi Garcia

Environmental microbiology is the study of microorganisms thriving in nature, and how they impact ecological interactions with other organisms. Microbes are excellent indicators of global climate change and understanding the immediate effects of rising temperatures. Their role in decomposing organic matter into simple elements, such as carbon, sulfur, and nitrogen, is crucial for the survival of other lifeforms on Earth. Therefore, a sudden shift in their numbers and diversity become the representation of micro-alterations in the environment.

So, how do scientists study these natural microbial communities?

We share the experience of Dr. Sarahi Garcia, a professor at Stockholm University, during one of her fieldwork studies. Sarahi and her team study the role of aquatic microbes on the carbon cycle. 

The work involves sampling sediments from pond areas, and then back in the lab, characterizing and identifying microbial communities present in the samples. Through these experiments, researchers can get an overview of which species are abundant in what tropic zones, how microbial genome sizes vary depending on ecosystems, and which species stay together as a consortium.

 Here is an excerpt from Sarahi’s post on Instagram: 

“Sampling ponds formed by thawing ice-rich permafrost in Stordalen Mire, Sweden.

Sampling today went smoothly. We had perfect sampling weather, meaning it was cold and windy but sunny, which meant we stayed dry and had no mosquitos.

Walking in the mire is quite an experience. The easiest is when walking on the wood path. But to find the ponds we had to walk either on the palsas (perennial frost mounds), which feel like walking on sponges or walk on the "grass". The "grass" is very tricky since in reality is growing on top of bogs and as soon as you walk a step, water starts filtering your shoes. 

Mariana and I had the perfect field and lab assistant, Anelise. You can see her in a photo with her characteristic smile.

This project builds on top of one of Mariana's previous projects published in Global Change Biology. Climate change–driven permafrost thaw strongly influences pan‐Arctic regions, via, for example, the formation of thermokarst ponds. These ponds are hotspots of microbial carbon cycling and greenhouse gas production.”

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