UFSC Research Investigates How Antarctic Bacteria May Help Us Understand Climate Change
Alanna and Professor Rubens studying material collected in Antarctica.
Thousands of microorganisms inhabit our planet, most of them still unknown to science. These microscopic life forms may also provide answers to one of today’s greatest global challenges: climate change. A series of research projects at the Federal University of Santa Catarina (UFSC), coordinated by Prof. Dr. Rubens Tadeu Delgado Duarte from the Department of Microbiology, Immunology and Parasitology, investigates how Antarctic bacteria can improve our understanding of climate change while also revealing new opportunities for biotechnology.
One of these studies was conducted by undergraduate researcher Alanna Maylle Cararo Luiz as part of her final-year research project and was recently presented at the Brazilian Society for Microbiology meeting. The study, Growth Strategies of Microorganisms from Antarctic Glacier Forefield Soils in Terms of r/K Selection, is based on samples collected during a 2017 Antarctic expedition as part of the Microsfera Project – Microbial Life in the Antarctic Cryosphere: Climate Change and Bioprospecting.
The research is carried out at the Laboratory of Molecular Ecology and Extremophiles (LEMEx). Molecular ecology combines molecular techniques with ecological studies to investigate living organisms, while extremophiles are organisms capable of surviving under extreme environmental conditions, such as those found on the coldest continent on Earth. At LEMEx, researchers use molecular approaches to characterize Antarctic bacteria and uncover previously unknown biological properties and functions.
“There are thousands—indeed tens of thousands—of bacterial species in just a single gram of soil,” explains Prof. Duarte. “A teaspoon of soil contains millions of microbial individuals waiting to be studied.”
Antarctica is central to these investigations because of its importance in understanding climate change. As glaciers retreat, rising sea levels and cascading ecological changes affect biodiversity worldwide. The researchers aim to determine whether specific bacterial communities can indicate the rate of environmental change. “We want to use these bacteria as biological thermometers that can help us monitor climate change,” says Duarte.
While larger organisms, such as penguins, are commonly used as indicators of environmental change, their responses occur over relatively long timescales because they depend on reproduction and population dynamics. Bacteria, in contrast, respond much more rapidly to environmental disturbances, making them potentially more sensitive indicators of ecosystem change.
Collins and Baranowski Glaciers
The UFSC studies focus on soil and ice samples collected from two Antarctic glaciers: Collins Glacier and Baranowski Glacier. These glaciers exhibit markedly different retreat rates. According to Prof. Duarte, Baranowski Glacier retreated in only 43 years by approximately the same distance that Collins Glacier required more than one thousand years to retreat.
As glaciers recede, newly exposed soils become available for microbial colonization. This process creates a natural space-time gradient that allows researchers to collect samples immediately adjacent to the glacier, where the soil has only recently been exposed, as well as from locations that have remained ice-free for 20, 30, or 40 years.
“This gradient allows us to understand how bacterial communities change over time,” Duarte explains.
Comparing both glaciers also enables scientists to identify microorganisms associated with different glacier retreat rates. Bacteria characteristic of rapidly retreating glaciers may serve as biological indicators of accelerated climate change.
Ecological Succession in Antarctic Soils
Alanna’s research investigates how glacier retreat influences ecological succession by examining bacterial communities isolated from the 2017 expedition samples.
To illustrate ecological succession, Prof. Duarte compares glacier retreat to forest recovery after a wildfire. Following a fire, grasses colonize first, followed by shrubs and eventually trees, while animal communities gradually return. Antarctic glacier retreat follows a similar ecological sequence, although involving microorganisms rather than plants.
Once glacier ice melts, newly exposed soil comes into contact with atmospheric oxygen. Certain bacterial species colonize the soil first, followed by progressively more diverse microbial communities.
“The populations change over time,” Duarte explains. “This happens after virtually any environmental disturbance.”
The succession reflects natural selection according to resource availability and the growth strategies of different microorganisms.
Some Antarctic bacteria grow rapidly, forming visible colonies within approximately 48 hours, whereas others require much longer incubation periods. Recently exposed soils tend to be dominated by fast-growing bacteria, while older soils exhibit greater microbial diversity. These patterns also differ between Collins and Baranowski glaciers.
Researchers collected soil samples at distances of 0, 50, 100, 200, 300, and 400 meters from both glaciers. Viable bacterial cells were quantified, and colonies were monitored daily and classified according to whether they became visible before or after 48 hours of incubation.
Ecological theory predicts that fast-growing organisms dominate the earliest stages of succession and are gradually replaced by slower-growing species. Therefore, detecting fast-growing bacteria far from the glacier could indicate recent glacier retreat and accelerated ice loss. Comparing these observations between the two glaciers, together with regional climate records, may provide a novel biological tool for monitoring climate change in polar environments.
Although studies such as these generally require genetic sequencing of selected bacterial isolates, the high costs of sequencing and limited research funding often restrict this stage of the investigation.
Microbial Diversity and Biotechnological Applications
The Antarctic samples collected by UFSC also support research into the biotechnological potential of extremophilic microorganisms. In addition to Alanna’s project, at least seven other studies at LEMEx currently utilize these samples.
One important adaptation of cold-loving microorganisms is the production of antifreeze proteins, which interfere with ice crystal formation and recrystallization, protecting cells from freezing damage.
According to Prof. Duarte, these proteins have promising applications in biotechnology. One potential use is improving the stability of DNA- and viral vector-based vaccines during freezing and storage, including technologies similar to those developed for COVID-19 vaccines.
A related project led by Ph.D. candidate Joana Camila Lopes focuses on characterizing these antifreeze proteins and exploring their potential technological applications. Although still in its early stages, the research may also contribute to agricultural innovations, such as improving crop resistance to frost.
All of these studies rely on soil and ice samples collected during scientific expeditions conducted through the Brazilian Antarctic Program (PROANTAR), with LEMEx’s most recent expedition taking place in 2017. The preserved samples remain stored at the laboratory and continue to support research projects ranging from undergraduate studies to doctoral research, while also serving as a valuable resource for future scientific investigations.
Material coletado na Antártida – 2021
Material coletado na Antártida – 2021
