Evaluation of Water-Borne Toxicity Using Bioluminescent Bacteria

Abstract

We investigated the toxicity of field waters using a multi-channel continuous monitoring system in Berlin, Germany. This system uses genetically engineered bioluminescent bacteria for the assessment of the toxicity of soluble chemicals. It showed easy and long-term monitoring without any system shut down due to pollution overloading. We used the bioluminescent bacterial strains DPD2794, DPD2540, TV1061 and GC2, which respond respectively to DNA-, cell membrane-, protein- and general cellular-damaging agents. The bioluminescent levels either increase for DPD2794, DPD2540 and TV1061 strains, or decrease for the GC2 strain after being mixed with toxic samples. We monitored the toxicity over a period of two to three weeks at three different sites: the Ruhleben wastewater treatment plant discharge flow, and river flows at the Teltowkanal and Fischereiamt in Berlin. At all sites the DPD2540 and TV1061 strains showed a significant increase of bioluminescence while bioluminescence decreased for the GC2 strain. This result demonstrates the occurrence of chemicals that affect the integrity of the cellular membrane; leading to either protein denaturation and inhibiting cellular metabolism or to cell death. Therefore, our findings suggest that the bioluminescent bacteria array may serve as a novel water toxicity monitoring system in outdoor fields.