Exploring the Microbial World

A fruiting Zygomycetes fungus, often found in soil. 

"We’re just beginning to understand how much of our world is underpinned by microbial communities," says Dr Eleonora Egidi, microbial ecologist and bioremediation expert at Western Sydney University’s Hawkesbury Institute for the Environment. "It’s such a vibrant area of research to be involved in; we’re uncovering the secrets that microbial communities hold, including how to harness their wide range of adaptive genetic capabilities."

Egidi moved to Australia from Italy in 2014. After a few years in Melbourne, she took a postdoctoral position at Western in 2018 and won a prestigious Discovery Early Career Researcher Award (DECRA) from the Australian Research Council in 2020.  

"My PhD was in mycology, studying fungi in rock formations in extreme environments," says Egidi. "Through this, I became interested in the wider field of microbes in soils — particularly the drivers of diversity in microbial systems. I’m fascinated by the potential applications of microbes in terms of boosting agricultural productivity and regenerating ecosystems."

She feels she was in the right place at the right time, because she completed her PhD just as all the next-generation sequencing techniques were taking off. "I trained in using these techniques for soil microbiology and fungi, and this meant I was learning right at the cutting-edge of a fledgling field of study," she says.   

Fungi activity and diversity has a major influence on the functioning of ecosystems. In 2019, Egidi and co-workers published the first atlas of dominant fungi groups found in soils from across the world. They sampled 235 soils from different locations, and identified 83 dominant taxa.  

The most common fungi by far were species of the wind-dispersed, generalist group known as the Ascomycota. In further research into the fungi present in drylands specifically, she showed that both UV light and climate seasonality were key influences on the composition, turnover and health of these microbial communities. 

"These findings highlight just how vulnerable these microbial communities are to climate and anthropogenic change," says Egidi. 

Egidi’s research feeds directly into several of the UN Sustainable Development Goals, from supporting life on land to building sustainable communities. Egidi’s current DECRA project examines the role of microbes in determining the fitness and spatial distribution patterns of grasses in Australia, and their ability to resist drought.  

"Australian plants, particularly the native grasses, require resilience to drought," says Egidi. "But they also need to be resilient in the face of the oscillations caused by El Niño and La Niña. The drought spells caused by these phenomena are becoming increasingly intense and more frequent. It’s very important that we learn the mechanisms that underpin the health of these grasses, and especially to find out whether microbes play a role in this."

Asking and answering these fundamental questions is crucial. A clearer understanding of how plants and microbes work together to build resilience against a specific kind of stress, such as drought or heat, could enable scientists to harness these natural associations to boost drought resistance in grasses and in other types of plants or biological systems, adds Egidi.  

"In Australia, just as in many countries in the world, the native grasses are critical to pastoral communities and agriculture," she says. "Through our research, we hope to design management strategies to preserve and restore the wealth of biodiversity in our drylands."

In addition, Egidi is keen to find ways to reduce, and eventually eliminate, reliance on fertilisers and pesticides. The overuse of chemicals in farming has meant that soils are depleted of their natural microbial components, lowering the soil’s productivity with a knock-on effect on crop yields. Egidi hopes her work could help to replenish naturally helpful microbes that should be found in Australia’s soils.  

She is also heavily involved in research for sustainable agriculture on a global scale; she is one of the leaders of the Global Initiative of Sustainable Agriculture and Environment and she and her team are currently undertaking a global survey of the microbial communities from crops around the world.