MADISON, WI, APRIL 30, 2007 -- Scientists from the University of California-Davis recently developed a mathematical model of the rate of gene transfer among bacteria in the environment. Researchers believe this new model improves upon existing models by taking into account characteristics of the natural subsurface environments, the typical bacteria hangouts. This model will help scientists to quantify the spread of important bacterial traits.
The swapping of genetic material between bacteria leads to bacterial adaptation and evolution; however, bacterial adaptation is a double-edged sword for the environment. While the genetic exchange among bacteria can lead to positive environmental outcomes, such as improved bioremediation qualities, bacterial adaptation can also create potentially harmful bacteria that are resistant to antibiotics and increase gene flow from genetically modified organisms to native soils. By developing a real-life model of bacterial gene transfer, UC-Davis researchers hoped to gain insight into the rates of bacterial adaptation in the environment. They report their findings in the May 2007 issue of Vadose Zone Journal in a special section on soil biophysics.
Researchers believe that one of the major mechanisms for the transfer of genetic information in the environment occurs through a conjugation. According to study co-authors, Timothy Ginn and Arash Massoudieh, donor bacteria cells act like vampires, latching onto nearby unsuspecting non-related bacteria cells. Just as the bite from a vampire leads a victim to be transformed into a vampire, the donor bacterias "bite" injects genetic material into the recipient, causing the recipient to become a donor. The controlling rates of conjugative gene transfer and the kinetics of conjugative gene transfer are unknown.
The study of conjugative gene transfer centers on biofilms, a coat formed by colonizing bacterial cells.