engleski

Characterization of an atrazine-degrading community enriched from agrochemical factory soil

An atrazine degrading bacterial community was enriched from agrochemical factory soil exposed to repeated spills of effluent from atrazine synthesis. The community consisted of at least four strains, possessing catabolic activities and mineralized 78.4% of (14C-ring) atrazine as well as 35.6% of (ethyl-14C) atrazine within 6 days batch cultivation in mineral salts medium. Atrazine-degrading genetic potential of the community estimated by PCR revealed the presence of trzN, atzB, atzC and trzD genes. Based on partial 16S rDNA sequencing, two strains (ATZ1 and ATZ2) showed close phylogenic relationships to Arthrobacter crystallopoietes (99%) and Arthrobacter keyseri (98%), respectively. Further study of catabolic activities showed that strains ATZ1 and ATZ2 were capable of dechlorinating atrazine and contained the trzN. The strain ATZ2 continued to degrade hydroxyatrazine to cyanuric acid and contained atzB and atzC, while the strain ATZ1 accumulated hydroxyatrazine and contained atzC. Two other community members, tentatively identified as Achromobacter species, contained trzD known to be responsible for cyanuric acid degradation, which suggested their important role in completing atrazine degradation. The obtained results also suggested that in addition to the combined metabolic activities a different type of interactions may exist between community members during atrazine mineralization.

atrazine; biodegradation

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