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Mark Shwartz, News Service (650) 723-9296; e-mail:

New Biofilm Research Center will explore the wonderful world of slime

Whether it's the disgusting yellow film coating your teeth or the slippery crud clogging your kitchen sink, slime is something most of us want to eliminate, not cultivate. But for scientists, microbial slime or "biofilm" has become the focus of intense interest.

This week, members of the Stanford faculty announced the official opening of the Biofilm Research Center. The new facility includes a $350,000 Zeiss confocal laser-scanning microscope that will allow researchers, on and off campus, to investigate the intricate world of slime.

"Microbial biofilms are actually complex, structured communities where bacteria and other microorganisms interact with each other," said Alfred M. Spormann, associate professor of civil and environmental engineering and director of the new center. "Biofilms play critical roles in diseases, in the environment and in industry."

Last year, Spormann and two other faculty members Gary K. Schoolnik in the Department of Medicine and Gordon E. Brown Jr. in the Department of Geological and Environmental Sciences received a grant from Stanford's interdisciplinary Bio-X program to establish the center. Additional funding was provided by the schools of Engineering, Medicine and Earth Sciences.

"Increasingly, more and more Stanford researchers from all three schools are focusing on harmful and beneficial aspects of microbial biofilms," Spormann observed.


Billions in damage

In nature, free-floating bacteria often live solitary lives, drifting alone in water or air. But when they become attached to a wet surface, individual bacteria begin secreting carbohydrates and other molecules that ooze together to form a slippery film that covers everything from teeth (dental plaque) to rocks (pond scum) to various manufactured products. In fact, the accumulation of biofilms costs American industry billions of dollars every year, according to Spormann.

"Biofilms are responsible for corrosion of metals in water pipes and on marine vessels," he noted, adding that bacterial biofilm can be 1,000 times more resistant to antibiotics than solitary organisms a problem that is especially acute in long-term catheters, artificial heart valves and other medical implants, where the accumulation of slime often results in serious infections.

"But not everything related to biofilms is harmful," added Spormann. "They also play an important part in the ecosystem of soils and sediments, and are beneficial in bioremediation of soil and water sites contaminated with toxic substances."


Microbial communities

Researchers long have been fascinated with the communal nature of biofilms. Once imbedded in their slimy matrix, solitary bacteria turn on a unique set of genes that allows them to signal each other as well as hundreds of different microbial species including fungi and algae.

"They become metabolically codependent inside the matrix and begin talking to each other," Spormann explained. "They can even sense the density of how many friends are around them a process called quorum sensing."

In addition to enhancing their chance of survival, biofilms also provide ecological advantages to microorganisms, according to Spormann.

"By adhering to a wet surface, bacteria can wait for food to come by in the water," he noted. "In fact, trickling filters in sewage treatment plants depend on biofilms to treat wastewater."

Spormann said the new confocal microscope located in Room 18 of the Terman Engineering Center will give researchers the ability to image living biofilms that are still attached to various surfaces.

"By understanding the basic science of biofilms, researchers expect to have better tools to fight biofilm-caused infections in patients and to engineer biofilms for environmental cleanups," he concluded.

Details on the Stanford Biofilm Research Center may be found on the web at http://www.stanford/group/


By Mark Shwartz

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