Improved detection of Ochratoxin A by marine bioluminescent bacteria V. harveyi BA

Abstract

We applicate the bioluminescent assay system for evaluating the toxicity of Ochratoxin A (OTA). The optimum conditions for the growth and bioluminescence of V. harveyi BA were investigated, including NaCl concentration and pH in the medium, incubation temperature, and OTA action time. The growth and luminescence reached the perfect phase with the NaCl concentration in the range of 1% to 2%, pH 8–9, incubation temperature 25–30°C, and OTA acting for1 hour. Based on these optimum conditions for bioluminescence, the inhibitory effect of OTA on luminosity was pursued. When OTA concentration fell into the range of 0.1–1.0 µg/l, bioluminescence inhibition followed a linear pattern with a good correlation coefficient (R² = 0.944). The calculated recovery percentages fell into the range of 81–102% within the spiking range of 20–200 µg/kg. This system provided a screening method for the measurement of toxic OTA by monitoring the changes in luminescence.