Quenching and enhancement effects of ATP extractants, cleansers, and sanitizers on the detection of the ATP bioluminescence signal

Abstract

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 problem in the use of these ATP bioluminescence techniques due to the degradation of the firefly luciferin-luciferase substrate-enzyme system by these cleaning chemicals. The objectives of this study were the evaluation of the quenching and enhancement effects on the detection of the 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 aureus, and Pseudomonas fragi. Extractants evaluated were benzalkonium chloride, Triton X-100, benzethonium chloride, cetylpyridinium chloride, and trichloroacetic acid. Cleansers evaluated were an alkaline foam and an acid foam. Also evaluated were a quaternary ammonium sanitizer, a D-limolene sanitizer, commercial sodium hypochlorite, and household bleach (sodium hypochlorite). The extractant cetylpyridinium chloride (0.0125%) did not have a statistically significant effect on the detection of the ATP bioluminescence signal at a 95% confidence level. A transition from enhancement to quenching as a concentration-dependent phenomenon was observed for the alkaline foam, acid foam, commercial sodium hypochlorite, D-limolene, and household bleach. An enhancement effect that did not appear to be concentration-dependent was observed for the quaternary ammonium sanitizer, Antimicrobial disc assays demonstrated that in some cases the cleanser or sanitizer concentration was not effective against the bacteria, but enhanced or quenched the detection of the bioluminescence signal, leading to false-positive or false-negative results respectively.