QUENCHING AND ENHANCEMENT EFFECTS OF ATP EXTRACTANTS, CLEANSERS, AND SANITIZERS ON THE DETECTION OF THE ATP BIOLUMINESCENCE SIGNAL

Techniques for measuring ATP bioluminescence are being used widely as rapid methods for the assessment of the cleanliness of food-processing plants. Sanitizer or cleanser residues could present a potential prob lem in the use of these ATP bioluminescence techniques due to the degr adation of the firefly luciferin-luciferase substrate-enzyme system by these cleaning chemicals. The objectives of this' study were the eval uation of the quenching and enhancement effects on the detection of th e ATP bioluminescence signal using various ATP extractants, commercial cleansers, and sanitizers, and the determination of the antimicrobial properties of different concentrations of cleansers and sanitizers on Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aure us, and Pseudomonas fragi. Extractants evaluated were benzalkonium chl oride, Triton X-100, benzethonium chloride, cetylpyridinium chloride, and trichloroacetic acid. Cleansers evaluated were an alkaline foam an d an acid foam. Also evaluated were a quaternary ammonium sanitizer, a D-limolene sanitizer, commercial sodium hypochlorite, and household b leach (sodium hypochlorite). The extractant cetylpyridinium chloride ( 0.0125%) did not have a statistically significant effect on the detect ion of the ATP bioluminescence signal at a 95% confidence level. A tra nsition from enhancement to quenching as a concentration-dependent phe nomenon was observed for the alkaline foam, acid foam, commercial sodi um hypochlorite, D-limolene, and household bleach. An enhancement effe ct that did not appear to be concentration-dependent was observed for the quaternary ammonium sanitizer. Antimicrobial disc assays demonstra ted that in some cases the cleanser or sanitizer concentration was not effective against the bacteria, but enhanced or quenched the detectio n of the bioluminescence signal, leading to false-positive or false-ne gative results respectively.