title: Exponential ATP amplification through simultaneous regeneration from AMP and pyrophosphate for luminescence detection of bacteria.
abstract: Bacteria monitoring is essential for many industrial manufacturing processes, particularly those involving in food, biopharmaceuticals, and semiconductor production. Firefly luciferase ATP luminescence assay is a rapid and simple bacteria detection method. However, the detection limit of this assay for Escherichia coli is approximately 10(4) colony-forming units (CFU), which is insufficient for many applications. This study aims to improve the assay sensitivity by simultaneous conversion of PP(i) and AMP, two products of the luciferase reaction, back to ATP to form two chain-reaction loops. Because each consumed ATP continuously produces two new ATP molecules, this approach can achieve exponential amplification of ATP. Two consecutive enzyme reactions were employed to regenerate AMP into ATP: adenylate kinase converting AMP into ADP using UTP as the energy source, and acetate kinase catalyzing acetyl phosphate and ADP into ATP. The PP(i)-recycling loop was completed using ATP sulfurylase and adenosine 5' phosphosulfate. The modification maintains good quantification linearity in the ATP luminescence assay and greatly increases its bacteria detection sensitivity. This improved method can detect bacteria concentrations of fewer than 10 CFU. This exponential ATP amplification assay will benefit bacteria monitoring in public health and manufacturing processes that require high-quality water.
authors.affiliation: Department of Biological Science and Technology, National Chiao Tung University, Hsin Chu 30010, Taiwan.
authors.forename: Hui-Ju
authors.initials: HJ
authors.lastname: Lee
authors.forename: Min-Rong
authors.initials: MR
authors.lastname: Ho
authors.forename: Chih-Sian
authors.initials: CS
authors.lastname: Tseng
authors.forename: Ching-Yi
authors.initials: CY
authors.lastname: Hsu
authors.forename: Meng-Shun
authors.initials: MS
authors.lastname: Huang
authors.forename: Hwei-Ling
authors.initials: HL
authors.lastname: Peng
authors.forename: Hwan-You
authors.initials: HY
authors.lastname: Chang
mesh_terms: D000249:Adenosine Monophosphate / Q000737:chemistry / Q000378:metabolism*; D000250:Adenosine Phosphosulfate / Q000737:chemistry / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism*; D001409:Bacillus cereus / Q000378:metabolism; D001419:Bacteria / Q000302:isolation & purification*; D015169:Colony Count, Microbial; D011756:Diphosphates / Q000737:chemistry / Q000378:metabolism*; D049449:Luminescence; D008163:Luminescent Measurements / Q000379:methods; D011550:Pseudomonas aeruginosa / Q000378:metabolism; D012680:Sensitivity and Specificity; D013430:Sulfate Adenylyltransferase / Q000737:chemistry / Q000378:metabolism
chemical_list: D011756:Diphosphates; D000249:Adenosine Monophosphate; D000250:Adenosine Phosphosulfate; D000255:Adenosine Triphosphate; D013430:Sulfate Adenylyltransferase