The role of a groundwater bacterial community in the degradation of  the herbicide terbuthylazine

Abstract

A bacterial community in an aquifer contaminated by s-triazines was studied. Groundwater microcosms were treated with terbuthylazine at a concentration of 100 microg L(-1) and degradation of the herbicide was assessed. The bacterial community structure (abundance and phylogenetic composition) and function (carbon production and cell viability) were analysed. The bacterial community was able to degrade the terbuthylazine; in particular, Betaproteobacteria were involved in the herbicide biotransformation. Identification of some bacterial isolates by PCR amplification of the 16S rRNA gene revealed the presence of two Betaproteobacteria species able to degrade the herbicide: Advenella incenata and Janthinobacterium lividum. PCR detection of the genes encoding s-triazine-degrading enzymes indicated the presence of the atzA and atzB genes in A. incenata and the atzB and atzC genes in J. lividum. The nucleotide sequences of the PCR fragments of the atz genes from these strains were 100% identical to the homologous genes of the Pseudomonas sp. strain ADP. In conclusion, the results show the potential for the use of a natural attenuation strategy in the treatment of aquifers polluted with the terbuthylazine. The two bacteria isolated could facilitate the implementation of effective bioremediation protocols, especially in the case of the significant amounts of herbicide that can be found in groundwater as a result of accidental spills.

Altered Protozoan and Bacterial Communities and Survival of Escherichia coli O157:H7 in Monensin-Treated Wastewater from a Dairy Lagoon

“…An unintended consequence of using monensin to inhibit protozoa resulted in enrichment of an uncultured Advenella species known to degrade a chloro- s -triazine herbicide, terbuthylazine, when present in ground water [57]. The enrichment of Advenella, representing one-third of all characterized sequences, indicated that this organism likely used monensin for growth.…”

Pesticide residues in vineyard soils from Spain: Spatial and temporal distributions

“…Among s-triazines, terbuthylazine is the most persistent in surface environments (Barra Caracciolo et al, 2010) and, in general, the presence of this herbicide and its metabolites DET and HT occurs at the same time, with their concentrations commonly being higher than those of the parent compound.…”

Targeted metagenomics demonstrates the ecological role of IS1071in bacterial community adaptation to pesticide degradation

“…linuron in case of L SM A, and linuron and MCPA/2,4-D in case of BPS Kortrijk. Atrazine has been banned for use since many years but atzA can be linked to terbuthylzamine, another triazine compound with structure highly similar to atrazine, present in the wastewater (Caracciolo et al, 2010). Several other catabolic gene functions were recovered, including amidohydrolases and dioxygenases, which are likely involved in, but could not be directly linked to the degradation of a particular xenobiotic substrates.…”