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Home Journal Highlights Atrazine-Eating Pseudomonas Uses Pyrimidine Receptor for Chemoattraction
Atrazine-Eating Pseudomonas Uses Pyrimidine Receptor for Chemoattraction Print E-mail

 

Atrazine is a human-made herbicide used worldwide to control broadleaf and grassy weeds that was first synthesized about half a century ago. In the United States, concentrations in agricultural runoff can exceed the EPA's maximum allowable level by several orders of magnitude. Recent studies show that atrazine causes sexual abnormalities in frogs, reduced testosterone in rats, and elevated prostate cancer in workers in an atrazine manufacturing facility. Pseudomonas sp. strain ADP uses atrazine as its sole nitrogen source. Xianxian Liu and Rebecca E. Parales of the University of California, Davis show that strain ADP orients towards atrazine, and related s-triazines, and that this chemoattraction probably results from atrazine's similarity to pyrimidines, the closest natural structural analogs, rather than due to evolution that might have taken place since the herbicide's invention. The supporting evidence includes that an Escherichia coli mutant that lacks response to pyrimidines is unable to respond to certain triazines that the wild-type recognizes. Additionally, saturating Pseudomonas strain ADP with pyrimidines blocks attraction to atrazine, and vice versa, suggesting that one receptor is responsible for both responses, says Parales. (The relevant receptor in Pseudomonas is unknown.) The research could lead to improved strategies for bioremediation of atrazine, says Parales.

(X. Liu and R. E. Parales. 2009. Bacterial chemotaxis to atrazine and related s-triazines. Appl. Environ. Microbiol. 75:5481-5488.)