Meet a Microbiologist: Marcos Voutsinos

While most of us worry about the ripeness of our bananas, Marcos Voutsinos has been preoccupied with something else: the banana freckle. Despite its innocuous name, banana freckle is actually a fungal disease caused by the fungus Phyllosticta cavendishii and characterized by “freckles” of fungus on the banana fruit, leaves, and stems. The fruiting bodies of P. cavendishii can spread up to 1 km during the tropical monsoonal weather making this microorganism a serious concern for the $600 million Australian banana industry.

Marcos’s first job as a scientist was during the 2013 banana fungus outbreak in the Northern Territory of Australia where he helped tracked the spread of banana freckle across farms and properties. In the end, Marcos and his team determined the infection had spread hundreds of kilometers. Unfortunately, without the resources or cure to the infection, every banana plant in the infestation zones was eradicated.

“My first day began in the midst of all this panic and confusion,” Marcos says. “Everything was very secretive. The extent of the incursion wasn’t known and we didn’t want the news to hit the media… Looking back, it’s funny because now that day feels like one of those cheesy outbreak movies.” And for Marcos, this banana freckle epidemic marked the start of his career in microbiology.

“During all the craziness of this work, I had some time to think about what area of microbiology I would like to continue with,” says Marcos. Now, Marcos is pursuing a Ph.D. in geomicrobiology at The University of Melbourne. As the name suggests, geomicrobiology is an interdisciplinary area focusing on how microbes influence fundamental geological and geochemical processes.

Marcos is exploring how microorganisms transform rare earth elements (REEs) in 390 million year old granite rock intrusions that have weathered overtime. REEs are transported and enriched in the weathered material as highly insoluble and acid resistant secondary minerals. In his sampled materials, Marcos found that the minerals are colonized by living and fossilized microbes, suggesting these microbes are dissolving minerals and controlling the REE enrichment process. Marcos is using a multi-omics approach to identify these microbial communities and uses a bioreactor to harnesses their ability to dissolve REE minerals in the laboratory.

Ultimately, Marcos’s research will help scientists understand how microbes break down REE minerals which can be used to develop a biomining strategy for the minerals industry. Over 90% of the worlds REE production occurs in China and REEs are critical in the production of wind turbines, electric vehicles, solar panels, computers, etc. Marcos’s work can help us find a clean and cost-effective way to extract REEs.

Since starting his PhD, Marcos has been fascinated by the field of bioinformatics and how it can reveal and characterize previously unknown microbial communities and their effects on the environment. He is excited by the fact that the same tools used to describe soil microbial communities can be used to describe human microbial communities. “I am looking forward to see what environments my microbial ecology and bioinformatics skills will lead me,” he says.

While not in the field or in the lab, Marcos appreciates nature in a different way. From numerous hiking and camping trips, his favorite have been camping overnight on Mount Rinjani, an active volcano in Indonesia and kayaking down Katherine Gorge amidst many crocodiles.

Marcos’s microbial doppelgänger: Roseburia spp.
Since transitioning to a plant based diet, Marcos has thought about how his gut microbiome has changed. In a study published in Nature, a plant based diet led to higher abundance of microbes in the gut that breaks down plant polysaccharides as compared to an animal based diet. Marcos is particularly fond of Roseburia spp. named after Theodor Rosebury, the “Grandfather of Modern Oral Microbiology.” “Roseburia has a plant based diet and is associated with weight loss and reduce glucose intolerance,” Marcos says. “I like eating a plant based diet, exercising, and trying to be healthy just like Roseburia!”