Discovering fungi in the most extreme places on Earth — including your dishwasher

Some of the organisms found living in domestic kitchens.  (Photo: PLOS ONE / Jerneja Zupančič, Monika Novak, Babič Polona Zalar, Nina Gunde-Cimerman)

Some of the organisms found living in domestic kitchens. (Photo: PLOS ONE / Jerneja Zupančič, Monika Novak, Babič Polona Zalar, Nina Gunde-Cimerman)

Microbiologist Nina Gunde-Cimerman travels the world searching for organisms that break the evolutionary mold. She seeks out fungi that can live where others can’t — in super-salty soil, in the midst of glaciers and in the driest place in the world. Why? Because these organisms — many new to science — could give clues as to how to help the rest of us thrive in less than favorable conditions.

Gunde-Cimerman started this work not far from her office at the University of Ljubljana. Out in the salterns of Sečovlje, Slovenia, she and colleagues searched for life in a place where living isn’t easy, she says in a talk at TEDxLjubljana. “If a cell isn’t adapted [to this environment], in hypersalinity, water goes out of the cell and the cytoplasm shrinks … sodium and chlorine ions invade the cell and they are toxic … Every textbook repeated that they’re [fungi] are not there [in salterns],” she says. “That they do not exist.”

But Gunde-Cimerman wanted to find them. And find the she did. Fungi had adapted to live in the Slovenian salterns and she and her team discovered several new salt-loving organisms, including some very extreme yeast.

By Jarba - Own work, CC BY 3.0,

Sečovlje Saltpans Natural Park, Slovenia (Photo by Jarba)

H. werneckii colonies on agar (Photo: Lenassi, Metka; Gostinčar, Cene; Jackman, Shaun; Turk, Martina; Sadowski, Ivan; Nislow, Corey; Jones, Steven; Birol, Inanc; Gunde Cimerman, Nina; Plemenitaš, Ana / PLOS ONE)

H. werneckii, a type of black yeast that inhabitant of Sečovlje Saltpans Natural Park (Photo: PLOS ONE)

Gunde-Cimerman took this as a sign to explore more extreme environments, and she and colleagues went on to discover new species in glacial areas in Svalbard, Norway; living on spiderwebs in the entrance to caves in the Atacama Desert, the driest area in the world; and in other salterns around the globe. “We discovered and described around 25 new species for science,” she says.

Her team even found fungi inside he extreme environment of a dishwasher. “[A dishwasher] has high temperatures; it has high salinity; it has very, very varied pH,” she says, making it a perfect places for fungi to hang out. Gunde-Cimerman took samples from her dishwasher and found that the black yeast Exophiala dermatitidis was thriving in her home. She then asked her team to test their dishwashers, and her students to do the same, and found fungi throughout.

Exophiala dermatitidis from Gunde-Cimerman's dishwasher (Photo: Nina Gunde-Cimerman / Fungal Biology)

Exophiala dermatitidis from Gunde-Cimerman’s dishwasher (Photo: Nina Gunde-Cimerman / Fungal Biology)

“Before I found it in my dishwasher, [Exophiala dermatitidis] was known only from [medical] patients,” she says. “It’s connected with cystic fibrosis; it can infect the intestinal tract; it can be spread via the nervous system,” she says. And because this fungi can survive in extreme conditions, it thrives in this environment where many other organisms die. “Each time your press the [dishwasher] button, you start an evolutionary cycle,” Gunde-Cimerman says, “off goes the competition [organisms], on goes the selected pathogen.”

But Gunde-Cimerman’s goal wasn’t ever to just discover new fungi, but to see how these special organisms could help us survive in changing global environments. “Due to global warming, more and more land is being irrigated and — sequentially — [becoming] saline,” she says. “And we are creating saline deserts, where no normal crops can grow, so they’re lost for us … unless we manage to produce transgenic plants.”

The researcher looked at one black yeast that can withstand high-salt environments, Aureobasidium pullulans, and sought to figure out what in its genes helped it adapt. This DNA coding, the ApHAL2 gene, was then to be transferred to Arabidopsis thaliana, the first plant to have its entire genome sequenced. Gunde-Cimerman’s team did just that, seeking to create a transgenic Arabidopsis plant that could survive in high-salt and drought environments.

On the left, wild A. thaliana plants exposed to salt stress. On the right, transgenic plants exposed to salt stress grow longer roots (Photo: PLOS ONE)

On the left, wild A. thaliana plants exposed to salt stress. On the right, transgenic plants exposed to salt stress grow longer roots (Photo: PLOS ONE)

“[The transgenic plant] had longer and more extensive roots,” Gunde-Cimerman says, “and it can reach deeper into the soil to avoid the salinity on the surface.” This is a small win, but Gunde-Cimerman hopes it is just the tip of the iceberg, and that new fungi will lead us to new solutions.

To learn more, watch Gunde-Cimerman’s whole talk below:

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