Isolation and characterization of atrazine-degrading strain Shewanella sp. YJY4 from cornfield soil.

Abstract

Atrazine has been used worldwide for over 50years as a chemical herbicide. A strain of bacteria, YJY4 which utilizes atrazine as its sole nitrogen source for growth was isolated from agricultural black soil in northeastern China. 16S rDNA sequencing identified YJY4 as a Shewanella sp. PCR analysis and sequencing confirmed that YJY4 contained atrazine-degrading atzA, atzB and atzC genes. These genes revealed high similarity with those in Pseudomonas sp. ADP and Arthrobacter sp. TC1. The strain YJY4 was observed to degrade atrazine (100mgl(-1) ) to cyanuric acid completely after 36h. To the best of our knowledge, YJY4 was the first reported Shewanella sp. to grow in pure culture with atrazine serving as a sole source of nitrogen. Therefore, YJY4 may help with atrazine biodegradation and may become an abundant resource of atrazine degradation strains. A new isolated strain, YJY4 showed high atrazine-degrading ability, being able to degrade 100mgl(-1) atrazine completely in 36h. Strain YJY4 was identified as Shewanella sp. and contained atrazine-degrading atzA, atzB and atzC genes. This study examined the degradation mechanism and metabolic ability of this strain and for the bioremediation of contaminated environments, provides more strain selection and determines the strain of atrazine bioremediation potential.