Evolution of atrazine-degrading capabilities in the environment

Abstract

Since their first introduction in the mid 1950s, man-made s-triazine herbicides such as atrazine have extensively been used in agriculture to control broadleaf weed growth in different crops, and thus contributed to improving crop yield and quality. Atrazine is the most widely used s-triazine herbicide for the control of weeds in crops such as corn and sorghum. Although atrazine was initially found to be slowly and partially biodegradable, predominantly by nonspecific P450 monoxygenases which do not sustain microbial growth, microorganisms gradually evolved as a result of repeated exposure, started using it as a growth substrate and eventually succeeded in mineralizing it. Within three decades, an entirely new hydrolase-dependent pathway for atrazine mineralization emerged and rapidly spread worldwide among genetically different bacteria. This review focuses on the enzymes involved in atrazine mineralization and their evolutionary histories, the genetic composition of microbial populations involved in atrazine degradation and the biotechnologies that have been developed, based on these systems, for the bioremediation of atrazine contamination in the environment.

An unexpected vestigial protein complex reveals the evolutionary origins of an s-triazine catabolic enzyme

“…One of the most well studied examples of an evolutionary response by bacterial to the presence of synthetic xenobiotics is that of the s-triazines (2). This family of compounds includes fertilizers (e.g., atrazine and ametryn), resins and plastics (e.g., melamine), explosives (e.g., RDX) and disinfectants (e.g.…”

Evolutionary Expansion of the Amidohydrolase Superfamily in Bacteria in Response to the Synthetic Compounds Molinate and Diuron

“…Triazine hydrolases (subtype IX) catalyze hydrolytic dechlorinations from s-triazine rings, a reaction similar to the hydrolytic deaminations from diazine ring systems that deaminases (subtype III enzymes) catalyze. Evidence of the evolution of triazine hydrolase from deaminases has now been established, which again explains their lack of separation in both the phylogenetic and SSN representations of the AHS (25,26). It is therefore of note that subtypes VIII and I group together in the SSN and are closely associated in the phylogenetic tree.…”

“…For example, subtype I phosphotriesterases break down organophosphate nerve agents and pesticides and have been shown to have evolved from subtype II lactonases (5,23,24). Subtype IX triazine hydrolases break down the herbicide atrazine and have been shown to evolve from subtype III deaminases (25,26).…”

Inkjet-printed microtiter plates for portable electrochemical immunoassays

“…Therefore, significant amounts can be still detected, as classical wastewater treatment plants do not eliminate efficiently ATR, because advanced oxidation processes would be required [8][9][10][11][12]. Despite the fact that recent studies presented the evolution of ATR-degrading capabilities in the environment [13], the maximum residue level of ATR in water defined by the WHO (i.e. 0.1 μg/L) requires sensitive analytical tools such as immunoassay strategies for its fast and reliable detection [14][15][16].…”