At first, UNM Chemical and Nuclear Engineering Department Research Assistant Professor Linnea Ista couldn’t understand and kept asking herself why the data she was observing about how bacteria attached to a surface didn’t match the predictions or past results of the model she was using.
“The big big assumption that everybody was making, including me, was that the bacteria themselves were just kind of like rubber balls – that they are uniform all over the surface and that if they are going to stick to a surface that is Teflon-like, they will use the same part of the cell as if they are going to stick to a surface like glass,” Ista said.
In a paper titled, “Thermodynamic analysis of marine bacterial attachment to oligo (ethylene glycol) terminated self-assembled monolayers,” Ista and Duke University Professor of Biomedical Engineering Gabriel Lopez, spell out the details of their discovery.
She could see that in some conditions, rod-shaped bacteria would attach on their ends and sometimes they attached on their long side. "That implied to me that they are not attaching in the same way," she said. The model that explained how bacteria in large groups act has been in widespread use since the late 1980's so Ista was reluctant to challenge it, but the new information about how bacteria attach was important.
The Defense Threat Reduction Agency funds her work. They are interested in controlling the way bacteria attach to surfaces, an important element for soldiers in an environment where biochemical weapons may be in use. Also the U.S. Navy is interested in stopping any sort of bacteria from attaching to its ships and other equipment.
“Just a layer of five bacteria in some cases can produce enough drag to cause significant energy penalties, requiring 20 percent more energy to push the ship through the water,” she says.
Ista, who has authored or co-authored 30 papers, has conducted research in this area since she first arrived at UNM in 1994. She is currently investigating new ways to probe how bacteria attach to substrates.