A NOVEL BIOLUMINESCENT CYCLING ASSAY FOR ATP AND AMP USING PYRUVATE ORTHOPHOSPHATE DIKINASE

摘要

In any food-processing environment, food residues can encourage and facilitate the survival and growth of microorganism by providing a nutritious medium for growth and protection from disinfectants. In order to prevent contamination of the product, it is important to keep food contact surfaces clean. Several hygiene monitoring systems for determining the cleanliness of surfaces were developed. Above all, the adenosine triphosphate (ATP) method is recommended due to ATP being widely found in food residues and microorganisms. However, in some food residues the ATP method shows insufficient sensitivity, especially processed foods. In order to improve the sensitivity, we have developed a novel bioluminescent enzymatic cycling system using pyruvate orthophosphate dikinase (PPDK) (ATP-PPDK method) (Fig. 1). PPDK catalyses the formation of ATP from AMP, pyrophosphate (PPi), and phosphoenolpyruvate (PEP). This system enables the detection of the combined total ATP and AMP with a high degree of consistency and higher bioluminescence when compared to existing ATP methods. We have applied this system to hygiene monitoring and have developed a novel hygiene monitoring device "LuciPac W" and photodiode luminometer "Lumitester PD-10".