Microbe polishes off pollutant.
Studies had established that the soil-dwelling bacterium Pseudomonas pavonaceae breaks down a pesticide residue called 3-chloroacrylic acid. Richard V. Wolfenden and Christopher M. Horvat of the University of North Carolina at Chapel Hill wanted to determine how long this residue would remain in. the environment if the bacterium didn't digest it.
By measuring the residue's decomposition rate at various temperatures, the researchers found that spontaneous decomposition would take a whopping 10,000 years to cut the residue's abundance in half--a persistence comparable to that of plutonium 239.
In contrast, an enzyme in the microbe can clear soil of 3-chloroacrylic acid in a matter of seconds.
Absent the microbe, the residue would "stick around for cons," building up in the soil and contaminating groundwater, says Wolfenden. He adds that the residue-busting activity appears to be a happy accident. The enzyme "doesn't seem to be designed with [the residue] in mind," he says.--A.C.
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||Pseudomonas pavonaceae|
|Article Type:||Brief Article|
|Date:||Dec 17, 2005|
|Previous Article:||Changes in the air: variations in atmospheric oxygen have affected evolution in big ways.|
|Next Article:||Dark shadows.|