US 5,672,470 AGranted

Microbial process for detection of toxic substances

OwnerWolfgang Hengstenberg, Roman Kolar +1inventors

InventorsWolfgang Hengstenberg, Roman Kolar, Marko Scholz

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Abstract

A microbial process for detection of toxic substances. The bacterial luminescence test so far used to detect toxic substances is extremely fast in its performance and reacts with very high sensitivity to heavy metals such as mercury and lead. However, that is not the case for other toxicologically relevant heavy metals such as cadmium and chromium. The inhibitory effect of toxic substances on the phosphotransferase system of bacteria, in particular, the E. coli mutant 1219 bgl+, is set forth as proof for the presence of toxic substances in samples. This test method responds with high sensitivity to the presence of the heavy metals cadmium and chromium. The test process constitutes a complement to the bacterial luminescence test and makes it possible to quickly exclude the presence of toxicologically relevant concentrations of cadmium and chromium in such cases where only a slight or no effect at all is indicated on the phosphotransferase system.

Claims14

Dependent claims

A process for detection of toxic substances wherein said process involves determining the inhibition effect of such toxic substances, contained in a sample, on microorganism metabolism, wherein the inhibition effects of the toxic substances on carbohydrate transport into the microorganism, as effected by the microorganism phosphotransferase systems, are determined and serve as evidence of toxic substances being present in the sample, wherein said process comprises:

producing a suspension of bacterium cells having said phosphotransferase system along with the sample to be examined, in a buffer system;
adding a substrate analog for a carbohydrate, wherein the substrate analog is transported into the bacterium cells by means of the phosphotransferase systems, which is dependent on a phosphoenol pyruvate, under phosphorylation, wherein the substrate analog, after its phosphorylation, is hydrolyzed by a bacteria specific enzyme of the phosphotransferase system thereby releasing a substance susceptible to analysis;
determining the released substance concentration after a defined reaction time;
and
comparing the determined concentration of the released substance with a value obtained from a comparative batch of a suspension without a sample additive.

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