PARENT SESSION
Posters P5D Emerging techniques and systems. Abstracts (731-741)

LuminoTox : a tool for toxicity management based on isolated stabilized photosynthetic enzyme complexes. Nathalie Boucher^*,1, Marie-Eve Rouette¹, Nancy Déziel², Olivier Parent¹, Lucie Lorrain¹, Élisabeth Perron¹, François Bellemare¹, ¹ Lab_Bell inc., Shawinigan, Québec, Canada² CNETE, Shawinigan, Québec, Canada

ABSTRACT- Toxicity control is a major driving force in the efforts to comply urban and industrial wastewater treatment directives. Until now there has not been a fast and reliable test for measuring the toxicity and evaluating the efficiency of the wastewater effluent treatments. Since several toxic molecules inhibit the electron transport chain, Lab_-Bell has developed the LuminoTox test, a fast and useful fluorescence biosensor for toxicity detection in water. The LuminoTox test comprises a hand-hold fluorescence apparatus designed to measure the relative photochemical yield of photosystem II and also includes biological material: photosynthetic enzyme complexes (PECs). To improve the stability of their biological functions at 22^oC for their use in field investigations, PECs have been stabilized by vacuum evaporation. Since the LuminoTox can be used in complex effluents, a study was conducted to evaluate the influence of different chemical and physical properties on the LuminoTox. The results, expressed by the stability of the IC₂₀ and IC₅₀ toxicity parameters, reveal that the LuminoTox can be operated in a wide range of environmental conditions. The efficiency of this biosensor in toxicity detection has been demonstrated in real urban and industrial effluents. In all effluents tested, toxicity can be measured in 15 minutes, while sensitivity detection can be increased by lengthening the incubation time. Toxicity reduction after effluent treatment can also be confirmed by the LuminoTox test. The potential of individual substance detection by the LuminoTox was also determined by evaluating the threshold of many toxic molecules. The results show that molecules inhibiting the electron transport chain downstream from the photosystem II can be detected at elevated concentrations. To improve sensitivity detection of these molecules, modifications have been made on the LuminoTox apparatus to allow fluorescence kinetic measurements. The preliminary results of this study are shown and discussed.

KEY WORDS: fluorescence, toxicity, biosensor, environment