Evaluation of Arthrobacter aurescens Strain TC1 as Bioaugmentation Bacterium in Soils Contaminated with the Herbicidal Substance Terbuthylazine

PLoS One. 2015 Dec 14;10(12):e0144978. doi: 10.1371/journal.pone.0144978. eCollection 2015.

Abstract

In the last years the chloro-s-triazine active substance terbuthylazine has been increasingly used as an herbicide and may leave residues in the environment which can be of concern. The present study aimed at developing a bioaugmentation tool based on the soil bacterium Arthrobacter aurescens strain TC1 for the remediation of terbuthylazine contaminated soils and at examining its efficacy for both soil and aquatic compartments. First, the feasibility of growing the bioaugmentation bacterium inocula on simple sole nitrogen sources (ammonium and nitrate) instead of atrazine, while still maintaining its efficiency to biodegrade terbuthylazine was shown. In sequence, the successful and quick (3 days) bioremediation efficacy of ammonium-grown A. aurescens TC1 cells was proven in a natural soil freshly spiked or four-months aged with commercial terbuthylazine at a dose 10× higher than the recommended in corn cultivation, to mimic spill situations. Ecotoxicity assessment of the soil eluates towards a freshwater microalga supported the effectiveness of the bioaugmentation tool. Obtained results highlight the potential to decontaminate soil while minimizing terbuthylazine from reaching aquatic compartments via the soil-water pathway. The usefulness of this bioaugmentation tool to provide rapid environment decontamination is particularly relevant in the event of accidental high herbicide contamination. Its limitations and advantages are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arthrobacter / growth & development*
  • Arthrobacter / metabolism
  • Biodegradation, Environmental
  • Herbicides / chemistry
  • Herbicides / metabolism*
  • Herbicides / toxicity
  • Microalgae / drug effects
  • Nitrogen / metabolism
  • Soil Microbiology*
  • Soil Pollutants / chemistry
  • Soil Pollutants / metabolism*
  • Soil Pollutants / toxicity
  • Triazines / metabolism*
  • Triazines / toxicity

Substances

  • Herbicides
  • Soil Pollutants
  • Triazines
  • terbutylazine
  • Nitrogen

Grants and funding

This work was supported by funding received by iBB-Institute for Bioengineering and Biosciences (UID/BIO/04565/2013) and other funding (Contracts PTDC/AAC-AMB/111317/2009, Pest-OE/EQB/LA0023/2011) from European Funds for Economic and Regional Development - FEDER- through the Competitiveness Factors Operational Programme - COMPETE and National Funds through the Portuguese Foundation of Science and Technology (FCT). M Moreira-Santos thanks to FCT for a postdoctoral fellowship (reference SFRH/BPD/99800/2014), funded by Programa Operacional Potencial Humano of QREN Portugal (2014–2020) and by the Portuguese budget through the Ministry of Education and Science. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.