Atrazine toxicity in marine algae Chlorella vulgaris and in E. coli lux and gfp biosensor tests

Abstract

Atrazine (ATR) is a widely used chlorinated herbicide from the s-triazine group. Due to the widespread use of ATR, it leaks into the environment and is detected in drinking water, exceeding the WHO-acceptable concentration of atrazine in drinking water, which is 2 μg/L. The aim of our study was to determine toxicity, protein degradation and genotoxicity of ATR at concentrations of 10; 1; 0.1; 0.01 mg/L on Chlorella vulgaris and with the application of E. coli bioluminescent biosensor strains. We measured the content of chlorophyll a, b, carotenoids in Chlorella vulgaris and the inhibition of this algae culture growth. E. coli RFM443 strains with gene constructs grpE:luxCDABE, lac:luxCDABE, recA:luxCDABE and E. coli strain MM294 trc:luxCDABE were used to determine toxicity, degradation of cellular proteins and genotoxicity. On the base of the obtained results, we concluded that ATR in the tested concentrations shows a toxic effect in relation to Chlorella vulgaris. ATR is toxic and genotoxic in E. coli RFM443 strains with grpE, lac, recA promoters and causes degradation of cellular proteins. Moreover, we have detected ATR toxicity toward the GFP protein in E. coli strain MM294-GFP. Taking into account the toxicity and genotoxicity of ATR documented in our research and in the experiments of other authors, we conclude that the presence of this herbicide in surface waters and drinking water is a serious threat to living organisms.

Keywords

• ecotoxicology
• atrazine
• chlorella vulgaris
• bioluminescent biosensors
• water contamination