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