Dr. Tomas Hessler is an Earth and Planetary Sciences postdoc hailing from Cape Town, South Africa. His research takes place at the Innovative Genomics Institute and studies entire microbial communities by extracting and analyzing all their DNA at once. Dr. Hessler explains, “I’ve been learning a lot from Jill Banfield about how to reconstruct genomes directly from environmental samples. Before coming to Berkeley, I did my PhD in bioprocess engineering at the University of Cape Town, where I studied bioreactor systems. That background turned out to be surprisingly useful for microbiome research, because bioreactors offer tightly controlled environments—unlike humans who change diets and habits all the time, a bioreactor receives the same input and output every day, which makes it ideal for studying microbial communities.”
To better understand microbial interactions. Dr. Hessler explains, we can think of a community or village. There are different organisms with different roles, like bakers, bus drivers and doctors, and each organism mutually depends on the labor of its fellow villagers.
Recently, Dr. Hessler and his team uploaded a preprint about a technique they developed to study microbial interactions more realistically. Traditionally, people isolate individual microbes and study their interactions in test tubes, but that doesn’t necessarily reflect how they behave in a natural community.
“We used viruses to selectively remove a specific organism from a complex microbial community, allowing us to observe what happens when that one piece is taken out. It's a tricky thing to do, but using viruses to target them made it a lot more feasible.”
Dr. Hessler recounted that he was initially drawn to Berkeley for its diversity and interdisciplinary research. “People here come from all over the world and from so many different fields. You can have conversations with brilliant researchers who have totally different expertise, and that cross-pollination of ideas has been amazing.”
Outside the lab, Dr. Hessler greatly enjoys pottery and gardening, and feels these activities help center him and provide a low-pressure creative outlet. Looking ahead, Dr. Hessler is excited to learn what makes individual organisms and whole microbiomes robust and resilient. “With new tools and AI, I think we’ll be able to go even further. I'm hoping to bring these tools into real-world applications—likely in plant systems next, which does tie back nicely to my interest in gardening.”