Application of an Ultra-Weak Bioluminescence Measurement System for Escherichia coli Detection in Sanitary Control

Detection and measurement of ultra-weak photon emission (UWPE) from biological samples is a promising tool with potential use in several fields such as agriculture, environmental science, food science and biomedicine. A measurement system especially designed to detect UWPE, and an application in sanitary control of natural water resources is presented here. The system was implemented based on a dark-chamber with a photomultiplier module (PMT) cooled with a microprocessor controlled thermoelectric device coupled. The PMT detects the UWPE from the biological sample under measurement. The performance evaluation of the measuring system in terms of dark-noise and bacteria detection was performed in order to assure that it is able to realize UWPE measurements for the proposed application. The samples under test were comprised of a series of 3 control cultures of standard Escherichia coli strain, used as control, and other 3 water samples collected from a river close to a metropolitan area in Brazil. The comparison between the control and test samples has shown that the proposed application is feasible for Escherichia coli detection tests in water samples from natural water resources to assure the evaluation of their microbiologic quality.