Detection and organization of atrazine-degrading genetic potential of seventeen bacterial isolates belonging to divergent taxa indicate a recent common origin of their catabolic functions

Abstract

A collection of 17 atrazine-degrading bacteria isolated from soils was studied to determine the composition of the atrazine-degrading genetic potential (i.e. trzN, trzD and atz) and the presence of IS1071. The characterization of seven new atrazine-degrading bacteria revealed for the first time the trzN-atzBC gene composition in Gram-negative bacteria such as Sinorhizobium sp. or Polaromonas sp. Three main atrazine-degrading gene combinations (i) trzN-atzBC, (ii) atzABC-trzD and (iii) atzABCDEF were observed. The atz and trz genes were often located on plasmids, suggesting that plasmid conjugation could play an important role in their dispersion. In addition, the observation of these genes (i) on the chromosome, (ii) on the same DNA fragment but on different plasmids and (iii) on DNA fragments also hybridizing with IS1071 suggests that transposition may also contribute to disperse the atrazine-degrading genes.

Thermostable Cyanuric Acid Hydrolase from Moorella thermoacetica ATCC 39073

“…Immediately before inoculation, 10 ml of a reducing solution, containing 0.36 g of Na 2 S ⅐ 9H 2 O and 0.36 g of cysteine HCl, was added. The pH of all media was adjusted to 6.6 prior to the addition of 2 g/liter NaHCO 3 Cloning and expression. Total genomic DNA was extracted from cell pellets of M. thermoacetica ATCC 39073, Pseudomonas sp.…”

“…Microbial enzymatic degradation of cyanuric acid has been studied previously (3,4,8,18). Two distinct but homologous enzymes, AtzD from Pseudomonas sp.…”

Simultaneous degradation of atrazine and simazine by a binary culture of Stenotrophomonas maltophilia and Arthrobacter sp. in a two‐stage biofilm reactor

“…34 Thus, the organization of atrazine-catabolic genes seems highly variable among Arthrobacter strains, suggesting that transposition may contribute to disperse the genes coding for enzymes of the atrazine-degradation pathway. 35 In the case of the Arthrobacter strain used in this work, the genes atzA, atzB and atzC have been previously identified, 18 and their presence was corroborated by PCR amplification of Arthrobacter DNA (Fig. 2(A)), using the primers shown in Table 1.…”

Applied Microbial Ecology and Bioremediation

“…Although trzN is contributing to the transformation of atrazine in hydroxyatrazine, it is significantly differing from atzA and trzA, which suggest a different origin. This gene has since been isolated in many bacterial strains and detected in many agricultural soils cropped with corn and regularly treated with atrazine (Devers et al 2007b).…”