Comparison of Luminol Chemiluminescence With Atp Bioluminescence for the Estimation of Total Bacterial Load in Pure Cultures

Abstract

A rapid chemiluminescent assay of total bacterial load that is based on the oxidation of luminol (5‐amino‐2,3‐dihydro‐1,4‐phthalazinedione) as catalyzed by bacterial iron protoporphyrins is described and compared to the ATP bioluminescent assay of microbial biomass. An assay format that elicits linear light output response to a range of analyte concentrations of model compounds such as hematin and various heme‐containing enzymes within the dynamic range of a BioOrbit 1251 luminometer is presented. When the assay was applied to eight pure bacterial cultures, the sensitivity was typically in the range of 104‐105 cfu/ml, and was comparable to that obtained by the ATP assay. Similar levels of sensitivity can be derived from estimates of average values of 2.8 × 10‐18 mole of heme/cfu and 1 × 10‐19 mole of ATP/cfu. The potential of the luminal assay as an alternative rapid test for the estimation of total bacterial count in food and environmental samples is discussed.

POTENTIAL FOR RAPID IN VITRO ASSAYS TO MEASURE FOODBORNE SALMONELLA VIRULENCE IN FOODS – A REVIEW

“…Bioluminescence techniques have been used in food microbiology for a variety of applications (Baker et al. 1992; Pietrzak and Denes 1996). Bioluminescence methods have been specifically used to detect and model S. Typhimurium thermal inactivation (Duffy et al.…”