SMU’s Alexander Chase leads a groundbreaking study using Small Molecule In situ Resin Capture (SMIRC) to collect oceanic microbial compounds in their natural habitat, paving the way for new pharmaceutical discoveries.
When Alexander Chase was a young boy, he was captivated by the extraordinary diversity of plants in Earth’s tropical rainforests. This early fascination with nature’s untouched wonders led him to a pivotal role at Southern Methodist University (SMU), where he’s pioneering a groundbreaking method to explore the hidden treasures of the ocean.
Chase, an assistant professor in the Roy M. Huffington Department of Earth Sciences at SMU, has developed an innovative technique known as Small Molecule In situ Resin Capture (SMIRC). This method is shedding new light on the enigmatic world of oceanic microbes, potentially unlocking a treasure trove of novel compounds that could lead to next-generation antibiotics and other critical medicines.
Microbial natural products, often derived from tiny organisms invisible to the naked eye, are the backbone of many essential medicines, particularly antibiotics. Traditional methods for discovering these compounds involve culturing individual strains from wild samples in the laboratory — a process that has, over time, become less fruitful in yielding new chemical scaffolds. These scaffolds form the essential structure upon which new chemical compounds are built but are becoming increasingly similar to known types.
“Right now, when we collect new samples and culture the microbes, we’re discovering scaffolds that essentially are very similar to the ones we already know about,” Chase said in a news release. “It’s been really difficult over the last few decades to find something that is new with the ‘microbe-first’ approach, which essentially limits us to the same or similar bacterial strains and their chemical compounds that represent only a fraction of the natural diversity out in the ocean. That’s where SMIRC comes in; it allows us to explore the unknown.”
The ambitious new approach, detailed in a recent study published in Nature Communications by Chase and his colleagues from the University of California San Diego and the University of California San Francisco, illustrates how SMIRC facilitates the collection of microbial natural products directly in their natural oceanic environment without laboratory culturing. This technique leverages an absorbent resin called HP-20, which functions like a sponge to capture chemicals released by microbes.
Initial trials using SMIRC in seagrass-covered areas near San Diego yielded promising results. The team discovered an antibiotic compound and chrysoeriol, a plant-derived chemical with antibacterial properties. Further tests involved blending the resin with agar to promote microbial growth, which led to the discovery of aplysiopsene A, reinforcing the efficacy of SMIRC in recovering useful compounds.
In a particularly thrilling trial at Cabrillo National Monument, a protected marine reserve, the technique amassed larger samples rich in complex chemical mixtures. One notable discovery, cabrillostatin, exhibited bioactivity and is being explored as a possible new pathway in cancer and heart care treatment.
“The ocean is one of the least explored areas on Earth, especially the deep ocean,” Chase added. “There’s so much we don’t understand about marine microorganisms and the compounds they produce. Because of antibiotic resistance and other health challenges, there is a high priority for natural product research. With SMIRC, we now have an easily deployable system that makes it possible for researchers to study compounds previously out of reach.”
The broader implications of Chase’s work are immense. In an era plagued by antibiotic resistance and other emerging health crises, the discovery of novel compounds from the largely uncharted marine environment holds tremendous potential. The pioneering SMIRC technique could redefine how scientists approach natural product discovery, offering new hope and possibilities for the development of treatments that could save countless lives.