Travel with Five Valleys Audubon to the majestic Berkeley Pit in Butte Montana, ground zero of the largest EPA Superfund site in North America. Andrea Stierle will describe some of the research that she and husband/collaborator Donald Stierle have been involved in for the past twenty years.
The Stierles’ research began when they were faculty in the Department of Chemistry at Montana Tech, a small mining college in Butte. Andrea and Don began their exploration of the secondary metabolites of fungi and bacteria surviving and thriving in an abandoned open-pit copper mine that has evolved into an acid mine waste lake. Berkeley Pit Lake now contains over 150 billion liters of metal sulfate rich, acidic “water” (pH 2.5) and sits at the headwaters of the Clark Fork and Columbia Rivers.
With its low pH and high metal content, it was considered too toxic to support life. In 1995, however, Andrea began to isolate fungi and bacteria from water and sediment samples. Although conditions within the Pit Lake System were too toxic for “normal” aquatic biota, these same conditions provided an ideal environment for extremophiles which have proven to be a dynamic source of bioactive drug-like molecules waiting to be discovered. The Stierles moved their lab to the University of Montana in 2009 and are currently Research Professors in the Department of Biomedical and Pharmaceutical Sciences. They have isolated compounds with activity against non-small cell lung cancer, ovarian cancer, melanoma, retinoblastoma and leukemia, as well as a new antibiotic with activity against MRSAs from this collection.
Andrea and Don are organic chemists. Andrea earned her doctorate in Organic Chemistry from Montana State University where she discovered the first host specific toxin against the weed pest spotted knapweed and found that several putative sponge metabolites were actually produced by bacterial endosymbionts. As a Research Assistant Professor at Montana State University she discovered a fungus in the bark of the Pacific yew tree that produced paclitaxel in de novo fashion. This unique fungus—taxomyces andreanae—was named after Andrea, its discoverer.
As Research Professors at the University of Montana, Andrea and Don continue to explore the drug-like molecules produced by mine waste extremophiles, human gut microbes and Ayurvedic plants in their search for new anticancer agents and antibiotics.