ATP BIOLUMINESCENCE PROCEDURE FOR VIABILITY TESTING OF POTENTIAL BEERSPOILAGE MICROORGANISMS

A procedure is outlined whereby adenosine 5'-triphosphate (ATP) biolum inescence is used to evaluate the potential for an unknown species of microorganism to survive and/or proliferate in a finished product. Usi ng ATP internal standardization and commercially available test kits, precise amounts of ATP can be calculated in beer at specific times. Th ese ATP values can be plotted so that the viability trend of the poten tial beer spoilage microorganism can be assessed with high resolution. The use of internal standardization ensures that low values of relati ve light units are real and not false negatives associated with enzyme instability. Using test strains of Lactobacillus and Pediococcus spec ies, trends were consistent for ATP and colony-forming units (cfu), an d several orders of magnitude of growth or death were easily detected when between 10(6) and 10(7) cfu were inoculated into a finished produ ct at the start of the analysis. This procedure offers significant val ue in assessing the potential of a microorganism to spoil beer.