Application of a bioluminescence method for the beer industry:: Sensitivity of MicroStar™-RMDS for detecting beer-spoilage bacteria

We set up the original operating conditions of the MicroStar(TM)-Rapid Microbe Detection System (RMDS) to suppress false positives, which have kept this system from practical. The detection limit of our system was between 6.3 x 10(-16) mol and 3.1 x 10(-16) mol in terms of the amount of ATP, which is approximately equal to the ATP content of one yeast cell or 50 lactic acid bacteria cells. The detection time and the detection count were compared between the RMD method and the conventional plate count method (C.P.C. method) using 23 test samples of beer-spoilage Lactobacillus brevis. Judging from the detection time and detection count, 16-24 hours of cultivation for the RMD method corresponded to 40-96 hours of cultivation for the C.P.C. method. The RMD method reached a useful level for our practical use at the point of sensitivity.