Organization of Novel Marine Bacterial Structures Involved in the Degradation of Agar

University Of Maryland, College Park, College Park MD

Investigators

Abstract

DEB-0109869 Ronald M. Weiner Steven W. Hutcheson A grant has been awarded to Drs. Weiner and Hutcheson of the University of Maryland to investigate the genetics and cell biology of insoluble complex carbohydrate (ICP) degradation by an unusual marine bacterium, Microbulbifer degradans. This bacterium was isolated from the Chesapeake Bay watershed and has the ability to degrade almost all known biological polymers, including ICP's, by forming unusual surface structures. These surface structures appear to be organized consortia of enzymes that allow the bacterium to efficiently degrade and process these very stable polymers. The degradation of such ICP's is not governed by conventional enzymology; the most efficient degradation involves contact with organized consortia of enzymes. Never before has any single organism been reported to have the capability to degrade such a broad spectrum of ICP's. It is also the only microorganism shown to degrade an ICP other than cellulose by this mechanism and the first observation of this degradative mechanism in an aerobic bacterium. This grant will fund research to understand what genes and proteins are involved in the degradation of the ICP, agar, and to determine how the agar-degrading structure is assembled on the bacterial surface. Knowledge of the genetics of this system should provide new tools for the processing of complex carbohydrates into useful byproducts and for bioremediation of the billions of tons of agricultural, aquacultural and algalcultural waste generated each year that contain very stable ICP's. In addition, little is known about how the annual production of the more than 25 billion tons of ICP's produced in the world's oceans are recycled into the biosphere. Thus, this research has potential applications in bioremediation and/or processing of waste products and could provide valuable insights into evolution of bacteria and the ecological role of this marine bacterium in the carbon cycle.