Rock Tasting at Biosphere 2

Susan Swanberg
December 11, 2012
Rock Tasting at Biosphere 2
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Dragos Zaharescu, Ph.D. tastes ground rock used in his plant medium

With a mischievous grin and gleaming dark eyes, Dr. Dragos Zaharescu raises a small spatula to his lips and tastes. At his feet are four containers, each filled with a different type of ground rock--granite, basalt, rhyolite or schist. Zaharescu will blend this rock with bacteria or fungus, creating a sandy medium for seedlings he grows here under the glass dome of Biosphere 2.
The dark-haired scientist cleanses his palate with water and tastes another sample. He won't tell us his opinion yet, but dares us to participate as he serves sand like a sommelier.
"Which one do you want first?" he says.
After we sample the ground rock, Zaharescu agrees that granite tastes like salt.
Biosphere 2, where he does his research, is about 35 miles north of Tucson, Ariz. The dome of Biosphere 2 rises from the mesquite savannah like a cathedral for the celebration of science. Assorted biospherians and scientists have studied within this glass vivarium. The enthusiasm for discovery has not waned since the original crew of biospherians lived here two decades ago. Their mission: To survive for two years sustained only by the food they grew beneath the dome.
The Birth of the Biosphere Concept

The word "biosphere," meaning the place on Earth's surface where life dwells, was coined in 1875 by Edward Seuss, an early ecologist. New life was breathed into the biosphere concept in the 1960s, a fertile era for the melding of ecological principles and New Age philosophy. It was in this rarified atmosphere that the idea for Biosphere 2 was born.
In the early 1980s a team of scientists, architects, adventurers and dreamers decided to build an artificial biosphere--a geodesic-like structure within which they would create a self-sustaining community. Ground was broken for Biosphere 2 in January 1987, and four years later the infrastructure was complete. During construction, in a mysterious process more akin to a vision quest than the vetting of a team of scientists, eight individuals were chosen to inhabit Biosphere 2 for two years. The biospherians survived the experience, living almost entirely without assistance from the outside world. In the process, they learned as much about human relations as anything else.
Biospherian for the 21st Century

Dragos Zaharescu is an intellectual descendant of the original biospherians. He says, without hesitation, that he would go back in time and join them in their grand experiment--if he could. Zaharescu came to Biosphere 2 as a research associate in 2011 after graduating from Vigo University in Galicia, Spain, where he investigated the interface between high-altitude organisms and their environment.
Here at Biosphere 2, Zaharescu sprouts seeds in ground rock, studying the interaction among the organisms living in his unique growth medium. He hopes his research will demonstrate how plants, microbes and fungi contribute to biological weathering, part of the process that changes rock into a living ecosystem and, ultimately, soil.
Some of the rocks that Zaharescu uses come from Arizona or New Mexico. Other rocks are sent to him by mountaineers and explorers affiliated with Adventurers and Scientists for Conservation (ASC). This organization pairs adventure athletes with scientists who need help collecting samples or data from extreme environments. Mountaineers associated with ASC collect bedrock for Zaharescu from the tops of mountain ranges.

The arrival of a new rock in the mail renews his excitement. "I open the package, and it might be a rock from Kilimanjaro. Whoa! Kilimanjaro."
He feels a close bond with these citizen scientists, who risk life and limb to collect samples for him. "Anything can happen to them. They can die."
Zaharescu plans to bring his team of mountaineers to Biosphere 2 for a conference once his research is complete, perhaps within the next five years. "They will be co-authors on the papers," he says. This is the highest honor a scientist can confer on a colleague.
Life in a Bottle

Zaharescu's work harkens back to the studies of Dr. Clair Folsome of the University of Hawaii--a "historic figure in the Biosphere lineage," according to Jane Poynter, one of the original biospherians. In her book The Human Experiment: Two Years and Twenty Minutes Inside Biosphere 2, Poynter describes Folsome's life-in-a-bottle experiments. In 1968 Folsome sealed an amalgam of beach sand, bacteria and algae into flasks, sealed the flasks and sterilized them. "[N]o matter what he did to the flasks, unless he heated them to the point that the proteins broke down irreparably, or deprived the systems of light for a long time, life always persisted inside," Poynter wrote.
Decades later, Zaharescu carries out his own "life-in-a-bottle" project. In his exquisitely designed and executed experiments, he grows grass and ponderosa pine seedlings within specially designed chambers, using rock that he or his collaborators collected and his young associates ground into a sandy mixture.

Zaharescu smiles ruefully as he describes how he burned through at least 20 assistants during the rock-crushing phase of the project. To avoid contamination, any living matter had to be ground off the rock with a drill. Then the rock was crushed and sterilized in an autoclave. Each grain of sand had to be the same size, so the growth medium would be uniform.
Zaharescu didn't spare himself the hard labor, but he wouldn't demonstrate the process for us. "Don't ask me to crush rock again," he says.
"No more," echoes Andrew Toriello, one of the few student assistants still with the project.
Toriello, a nutritional science undergraduate at the University of Arizona, joined the project in March 2012. Toriello helped denude and grind rock for months.
In spite of these monotonous tasks, Toriello enjoys working with Zaharescu. "It makes me want to stay in the science field just to know that there are a lot of people [in science] that are personable and social."

Jennifer Presler, also a University of Arizona undergraduate, started on the project as a summer National Science Foundation intern and was hired on when her internship ended. "I wasn't in charge of the grinding," she says. "I was in charge of the cleaning, thank goodness."
Presler also helped to assemble a watering system for the seedlings. "It's a lot of fun," she says. "His [Zaharescu's] excitement makes me excited, too."
After mastering rock grinding and cleaning, Zaharescu designed and built "rockubators"--hexagonal Plexiglas incubators where seedlings grow in the ground rock medium. These cradles for infant plants are kept as clean as possible during each experiment. Rows of tubes carry water to the seedlings. Gloves dangle from portholes opening into the rockubators. If plants must be handled or tubes adjusted, only gloved hands will enter the clean environment.

To the sandy medium, Zaharescu adds a rich mixture of bacteria and fungus that will jumpstart his plants. As water drains through the Plexiglas columns containing the seedlings, he will collect the runoff and analyze it for nutrients, bacteria, fungi and the chemical metabolites of plant growth. In this way he hopes to learn how plants, bacteria and fungi transform a rocky environment into a living ecosystem. This knowledge will help us understand how the Earth evolved from a rocky, uninhabitable planet into the green, fertile biosphere it is today.
With his experiments, Zaharescu has shown himself to be a consummate scientist with a creative approach worthy of the original biospherians. As he says, "Don't think outside of the box. Just get rid of the box."

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