A multi-channel continuous toxicity monitoring system using recombinant bioluminescent bacteria for classification of toxicity

A multi-channel system for continuous toxicity monitoring and classificatio n of toxicity was developed based upon a previously developed two-stage min ibioreactor system. The multi-channel system consists of a series of a two- stage minibioreactor systems connected by a fiber optic probe to a luminome ter. Each channel was used for cultivating different recombinant bacterial strains, such as TV1061 (grpE::luxCDABE), DPD2794 (recA::luxCDABE), and DPD 2540 (fabA::luxCDABE), which are induced by protein-, DNA-, and cell membra ne damaging-agents, respectively. GC2 (lac::luxCDABE) is a bacterium expres sing bioluminescence constitutively, which shows a reduction in its light l evel as cellular toxicity increases. Artificial wastewater samples were mad e by combining toxic chemicals, including Mitomycin C (a representative DNA damaging agent), phenol (a representative protein damaging agent), and cer ulenin (a representative cell membrane damaging agent), and injecting this sample into each channel in order to simulate the detection of toxicity for mixed chemical samples. Each channel showed a specific bioluminescent resp onse due to the toxic chemicals contained in the sample wastewater, while G C2 showed a general response to cellular toxicity. By using this multi-chan nel continuous toxicity monitoring system, classification of toxicity in fi eld samples was found to be possible. (C) 2001 Elsevier Science B.V. All ri ghts reserved.