Remember collecting shells at the beach, holding them to your ear, and then taking them home and wondering what used to crawl around inside them? Dr. Gary Rosenberg remembers. As chair of the Malacology Department at the Academy of Natural Sciences, Gary gets to play with shells to his heart's content. But thanks to a $4 million grant from the National Institutes of Health, he will soon get to play on a whole new beach.
The hypothesis goes like this: certain mollusks feed on wood--driftwood, the legs of docks and peers, and ship hulls. When they bore into the wood, their digestive systems house symbiotic bacteria that convert it into cellulose, which then becomes sugar. The mollusks survive off this process and the energy it creates. But if scientists can extract the digestive bacteria, perhaps a new biofuel can be created.
Gary and his team will be exploring areas in the Philippine archipelago, considered the most diverse center for marine biodiversity on Earth. The waters they will explore are inhabited by over 10,000 different species of mollusks.
For a guy with an interest in shells and marine crustaceans, Gary certainly came to the right place. The Academy of Natural Sciences houses the second largest collection of mollusks in the U.S, second only to the Smithsonian.
In his tenure here at the museum, Gary has worked to share his love of shells with visitors of all ages. His most common visitors, though, are kids. He is often asked "can you really hear the ocean in a shell?" Like any great teacher, he decided to meet kids on their level. He set up an experiment where kids would hold a shell to their ear and walk towards a fan.
"There are three theories on what happens when you hold a shell to your ear. One is that the sound you hear is the ocean. Another is that the sound of your own blood vessels and pulse are creating a sound and returning it to your ear. The third is that the ambient noise all around us is being refocused into your ear as white noise," Rosenberg recalls. "By having the children walk towards a fan, we eliminate the other two options. Because as the noise of the fan gets louder, the white noise in their ear gets louder."
It is this simple approach that Gary hopes to bring to the team in the Philippines, putting information right out front for anyone to find. Part of the project involves the methodical collection, identification and cataloging of mollusk species from the Philippines, and making this information freely available on the Internet. The project also seeks to train Philippine students in museum curation and building identification guides.
"Mollusks are the second largest group of organisms on Earth after the insects. And while insects are well-known for diversity, there are over 100,000 species of mollusks," Rosenberg says. "I have been to the Philippines before but it's always amazing to see the diversity when you are doing the netting and trawling. You always see something you have never seen before."
The idea of creating energy from biologically digested wood is not exclusive to mollusks. Obviously, a more familiar wood-eating creature, the termite, would seem to be an obvious candidate for study.
Earlier this year, the popular science journal Nature published an article chronicling the research of the U.S. Department of Energy Joint Genome Institute. The JGI found a way to sequence the DNA of a termite so the bacteria responsible for breaking down wood can be analyzed. In previous studies, the bacteria had resisted culturing but in sequencing the DNA, the JGI has taken yet another step toward ethanol fuel free from food-based energies.
"Termites can efficiently convert milligrams of lignocellulose into fermentable sugars in their tiny bioreactor hindguts," said JGI Director Eddy Rubin. "Scaling up this process so that biomass factories can produce biofuels more efficiently and economically is another story. To get there, we must define the set of genes with key functional attributes for the breakdown of cellulose, and this study represents an essential step along that path."
But don't expect these scientists to be racing toward who can get a patent first. When it comes to biofuels, Rosenberg says, there can never be too many eyes on the prize.
"I know there are other research groups that are looking at termites. In fact, that was one of the ideas when we started this," Rosenberg says. "Lets broaden the search and look at all the animals that are eating wood and see what might come from it."
Ship captains and marine dock owners may not share Gary's passion for shipworms and other wood-munching pests of the sea. But if his research works like he thinks it will, these ocean termites may enjoy new-found popularity in the near future.
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