Atrazine degradation by a simple consortium of Klebsiella sp A1 and Comamonas sp A2 in nitrogen enriched medium

A simple consortium consisted of two members of Klebsiella sp. A1 and Comamonas sp. A2 was isolated from the sewage of a pesticide mill in China. One member of Klebsiella sp. A1 is a novel strain that could use atrazine as the sole carbon and nitrogen source. The consortium showed high atrazine-mineralizing efficiency and about 83.3% of 5 g l(-1) atrazine could be mineralized after 24 h degradation. Contrary to many other reported microorganisms, the consortium was insensitive to some nitrogenous fertilizers commonly used, not only in presence of 200 mg l(-1) atrazine but also in 5 g l(-1) atrazine mediums. After 24 h incubation, 200 mg l(-1) atrazine was completely mineralized despite of the presence of urea, (NH4)(2)CO3 and (NH4)(2)HPO4 in the medium. Very minor influence was observed when NH4Cl was added as additional nitrogen source. Advantages of the simple consortium, high mineralizing efficiency and insensitivity to most of exogenous nitrogen sources, all suggested application potential of the consortium for the bioremediation of atrazine-contaminated soils and waters.