When the U.S. military was looking for a strong waterproof adhesive, scientists at a Department of Energy laboratory in Idaho went straight to the experts -- sea creatures that have been clinging naturally underwater for millennia. Mussels are the same delicacy often found next to the lobster and shrimp on a seafood buffet. The "feet" of the small mollusks produce an epoxy with adhesive-like properties that rivals any "super" glue on the market.
Unfortunately, it takes about 10,000 mussels or mollusks to produce just one gram of adhesive, resulting in a prohibitive cost, not only in dollars but to the mussel population as well.
So molecular biologists at the DOE^s Idaho National Engineering and Environmental Laboratory (INEEL) are developing methods to clone the mussel^s genes, through DNA technology, that will allow them to economically produce large quantities of the adhesive protein. Because sea water breaks down even the strongest of conventional adhesives, a natural alternative is important to the Navy and private marine industry in building and repairing ships. Mollusks also attach to ships, increasing the drag, and therefore, decreasing the efficiency at which these large vessels operate. Understanding the adhesive will help to prevent this marine fouling.
The building industry also requires a stronger cementing element for manufacturing plywood, oriented strand and other building materials that deteriorate when subjected to water and moisture. Even the dental industry is looking for a better, safer adhesive for dentures and medical disciplines such as surgery and orthopedics are interested in new suture and prosthetic technologies.
Mussels are able to cling to surfaces because they produce attachment threads called "byssal threads." The "foot" of the animal has organs that secrete protein with a catalyst. It takes about one minute for the viscous substance to harden into a thread, attaching itself to a new surface. It enables the mussels to anchor to rocks and pilings in turbulent areas where food and oxygen are more abundant.
The INEEL, in collaboration with scientists at the University of California, Santa Barbara, is identifying five proteins that go into the thread makeup that constitutes the "glue." Cloning the mussel proteins is expected to be the crucial step in opening doors for developing this amazing epoxy. "Right now, companies like 3M and Allied Signal would need about a million mussels just to start their evaluation," says Frank Roberto, molecular biologist at the INEEL. "That^s impossible to provide, but with a method of mass producing them through cloning," he adds, " industry giants will be able to test the natural super glue on their products."
The ability to remain intact in sea water is only one advantage the "mussel glue" offers. "It doesn^t require high temperatures to activate its cementing qualities as do other conventional waterproof glues," says Roberto. "And, it^s also environmentally safe because it comes straight from nature, unlike the standard petroleum and tar-based glues now being used," he adds.
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