Glowing Bacteria: DuPont And UD Scientists Detect Poultry Toxin And Other Environmental Contaminants

March 19, 1999

ANAHEIM, CALIF.--By harnessing glowing bacteria, scientists at the DuPont Co. and the University of Delaware have created inexpensive biosensors that rapidly detect a key toxin in poultry feed, as well as broad classes of other environmental contaminants, including herbicides and metals.

"Our glowing bacteria should make it easier to pre-screen for potential contaminants, including aflatoxin B1, a known carcinogen that can be toxic for chickens," DuPont Co. researcher Tina K. Van Dyk will report March 21 during the American Chemical Society meeting.*

Aflatoxin B1 is produced by molds found in poultry feed, and it "can be of concern for human foods, too," says Van Dyk, a UD graduate who worked with Robin W. Morgan, a professor of animal and food sciences at UD.

The research is fundamental, Van Dyk says, but it should be compatible with a simple, hand-held device for spotting contaminants on farms or in other real-world settings. "A light detector could be used to measure the bioluminescent response of these genetically engineered bacteria to various chemicals," she explains.

To make the glowing biosensors, Van Dyk and Morgan combined genetic material from Photorhabdus luminescens--a bioluminescent bacterium--with part of the common bacterium, Escherichia coli, or E. coli. Specifically, the researchers fused "glow-making" genes from the luxCDABE group to various E. coli promoters, which respond to damaging environmental threats by triggering the production of new proteins.

The result, Van Dyk says, is that "any stress activates bioluminescence in the resulting cells. The engineered cells emit light in response to protein damage, acidification, exposure to antibiotics and other forms of stress."

So far, the DuPont/UD research team has subjected a panel of six E. coli biosensor strains to nine chemicals. Some of the chemicals, such as the herbicide, 2,4-dichlorophenoxyacetic acid (2-4D), can be found in the environment. In response to each chemical, the biosensors produced a "characteristic stress fingerprint," Van Dyk says.

The biosensors detect general classes of contaminants, rather than specific chemicals. Van Dyk says she views the technology "mainly as a pre-screening method."

The DuPont Co. holds patents on stress responsive gene fusions to the "glow-making" luxCDABE genes, Van Dyk says. Other DuPont researchers working with Van Dyk included Dana R. Smulski, David A. Elsemore and Robert A. LaRossa.
*NOTE TO REPORTERS: This research will be described during the ACS presentation, "A Panel of Bioluminescent Biosensors for the Characterization of Chemically Induced Bacterial Stress Responses," to take place Sunday, March 21, at 3:50 p.m. Pacific Time in the WestCoast Hotel, Palm West room, Anaheim, Calif.

University of Delaware

Related Stress Articles from Brightsurf:

Stress-free gel
Researchers at The University of Tokyo studied a new mechanism of gelation using colloidal particles.

Early life stress is associated with youth-onset depression for some types of stress but not others
Examining the association between eight different types of early life stress (ELS) and youth-onset depression, a study in JAACAP, published by Elsevier, reports that individuals exposed to ELS were more likely to develop a major depressive disorder (MDD) in childhood or adolescence than individuals who had not been exposed to ELS.

Red light for stress
Researchers from the Institute of Industrial Science at The University of Tokyo have created a biphasic luminescent material that changes color when exposed to mechanical stress.

How do our cells respond to stress?
Molecular biologists reverse-engineer a complex cellular structure that is associated with neurodegenerative diseases such as ALS

How stress remodels the brain
Stress restructures the brain by halting the production of crucial ion channel proteins, according to research in mice recently published in JNeurosci.

Why stress doesn't always cause depression
Rats susceptible to anhedonia, a core symptom of depression, possess more serotonin neurons after being exposed to chronic stress, but the effect can be reversed through amygdala activation, according to new research in JNeurosci.

How plants handle stress
Plants get stressed too. Drought or too much salt disrupt their physiology.

Stress in the powerhouse of the cell
University of Freiburg researchers discover a new principle -- how cells protect themselves from mitochondrial defects.

Measuring stress around cells
Tissues and organs in the human body are shaped through forces generated by cells, that push and pull, to ''sculpt'' biological structures.

Cellular stress at the movies
For the first time, biological imaging experts have used a custom fluorescence microscope and a novel antibody tagging tool to watch living cells undergoing stress.

Read More: Stress News and Stress Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to