Potts, Helm study cells from extreme environments
By Netta Smith-Benton
Spectrum Volume 21 Issue 11 - November 5, 1998
Most living cells are so traumatized by removal of water that they die within seconds.
Virginia Tech scientists, however, are studying a cyanobacterium, Nostoc commune, which has the ability to survive in extremely harsh, dry environments. It not only remains alive when air-dried, but when wetted, it absorbs water, swells, turns green again, and is revitalized.
Malcolm Potts, professor of biochemistry at Virginia Tech, and Richard Helm, associate professor of wood science and forest products working in Fralin Biotechnology Center, have received a $950,000 grant from the U.S. Navy to study functional genomics of extremophile biopolymers. Functional genomics utilizes the DNA sequence of an organism and applies that knowledge to the development and genetic engineering of enzymes and of biomaterials.
Potts and Helm are focusing on Nostoc, which is one of a group of special microorganisms called extremophiles. These micro-organisms colonize environments that are extreme in conditions such as the amount of heat or cold, moisture, salinity, alkalinity, acidity, or radiation.
"Nostoc has the capacity to survive in a dry state for hundreds, perhaps thousands of years," Potts said. "We're trying to find out the mechanisms that make this possible at the physiological, structural, and molecular levels."
Desiccation, the drying out of all moisture, is the most acute environmental stress suffered by living cells. Potts and Helm already know that Nostoc produces a unique biopolymer that protects the cells from heat, desiccation, and ultraviolet (UV) radiation. The investigators are studying the cells at the genetic level and isolating the genes involved in polymer synthesis.
Once the mechanisms that provide this protection are understood, Potts said, it may be possible to use them to stabilize other types of cells. It might mean that red blood cells or stem cells could be stored or transported without degrading; seeds and agri-biochemicals could be stored for long periods of time while remaining viable; and pharmaceutical drugs could be given an almost indefinite shelf life.
"The ability to withstand UV radiation is extremely important," Potts said. "Finding the mechanism for this protection could be very useful in protecting other types of cells from this type of radiation."
Potts and Helm have isolated and purified the biopolymer and have devised a new technique for isolating the gene, referred to as high-throughput-coupled, in-vitro expression cloning, fluorophore-assisted carbohydrate electrophoresis (HTC-IVEC-FACE).
The project will involve a diverse range of researchers including graduate and undergraduate students who will be trained in the new developing area of functional genomics. Potts said, as part of the project, they plan to develop a system in which robotics will be used to automate the techniques they are developing.
Some of Potts' and Helm's work will be discussed as part of a conference, "Genomics and Bioinformatics," to be held at Virginia Tech's Fralin Biotechnology Center October 9-10. For more information, visit the Virginia Tech Institute for Genomics web site at http://vigen.biochem.vt.edu.