University of Delaware Office of Public Relations The Messenger Vol. 5, No. 2/1996 Where the warm worms are Lurking around the steaming chimneys that form in the deep- sea hydrothermal vents off the west coast of Mexico are small tube worms that may be the most heat-tolerant species on Earth. Craig Cary, UD marine biologist, is collecting and characterizing these 4-inch-long Pompeii worms, whose very tolerance to hot and cold extremes may make them valuable to the chemical and pharmaceutical industries. "What makes the worm exciting," Cary says, "is that it carries a unique bacterial community on its back, and their symbiotic relationship may be what makes it possible for the worm to live in this very extreme environment." Hot fluids laden with hydrogen sulfide and heavy metals constantly move through the tubes in which these worms live. In addition, the Pompeii worm lives within the broadest temperature range-from 10 degrees to 80 degrees C-of any organism on the planet, Cary says. (On the Celsius temperature scale, 0 degrees C represents the freezing point of water and 100 degrees C is the boiling point.) Cary looks at molecular aspects of unique bacterial symbioses with marine invertebrates. He collects the Pompeii worm from hydrothermal vents at several locations along the East Pacific Rise-an area of the sea floor where crustal plates are moving apart and new crusts are forming. Over the last 10 years, Cary, a molecular physiologist, has made eight trips to these sites. His most recent cruise last November was to the Axial Summit Caldrea, located nine degrees north of the equator on the East Pacific Rise and the site of a recent volcanic eruption and lava flow. During this cruise, he made two dives in the research submersible, DSV Alvin, to a location about 1-1/2 miles below the ocean surface. Although the temperature at the top of the hydrothermal vent chimneys may reach more than 400 degrees C, the Pompeii worms live along the chimney sides where the flow of water is more diffuse. Using a sensitive temperature recorder, Cary has measured the water flowing through the tubes of the Pompeii worm at 80 degrees C, while the water outside is a chilly 2 degrees C. Although French researchers originally described this worm in the early 1980s, Cary says an international collaborative effort is now being made to examine in more depth the bacteria that cover the worm host with hair-like strands. Cary's laboratory is studying the metabolic links between the worm and these bacteria, which he suspects have allowed the obscure organism to adapt to live in such an incredibly harsh environment on the sea floor. "If the bacteria on the Pompeii worm utilize eurythermal enzymes [enzymes that operate efficiently over a wide range of temperatures], this research will be appealing to industry, which wants more aggressive enzymes or biocatalysts that work over a broader temperature span," Cary says. "These protein-based catalysts also are sought by other industries where chemical processes work better at higher temperatures, such as pharmaceutical production, agriculture, food and beverage, pulp and paper and textiles." Cary collaborates in this National Science Foundation-funded research project with a former graduate school colleague, Jeff Stein of Recombinant Biocatalysis Inc (RBI). Based in La Jolla and Philadelphia, the newly formed company is dedicated to the discovery and development of new protein-based catalysts. Cary says their two linked proposals demonstrate how basic science and industry can benefit from collaboration. "The analytical power and enthusiasm of RBI takes us years ahead in our studies," he says. One goal of RBI is to collect thermally stable biocatalysts from such hostile environments as volcanoes, hot springs and hydrothermal vents, Cary says. "The general idea is to collect the bacteria, stabilize the nucleic acids [DNA and RNA] and then head back home to create libraries of pieces of this genetic material. RBI is now screening the Pompeii worm's DNA for novel enzymes that could break down fats, proteins, DNA and even wood products more efficiently," he explains. -Cornelia Weil