Rapid and practical microbial detection method for brewery hygiene management using the EZ-Fluo system

The early detection of microorganisms in the brewery environment is crucial for taking quick corrective actions and minimizing the risk of microbial contamination. However, hygiene tests using traditional culture methods for visual detection have poor turnaround times. In this study, we optimized the test conditions for the EZ-Fluo Rapid Detection System for brewery hygiene management. In this system, microorganisms are trapped on a membrane filter, cultured on agar, and detected after brief incubation using fluorescence-based technology with a dedicated detector. Among several alternatives, the EZ-Fluo system was chosen for its cost-effectiveness. We determined the appropriate test conditions, including the incubation temperature, fluorescent reagent, and temperature for the fluorescence reaction, using two slow growing environmental indicator species, Acetobacter pasteurianus and Pseudomonas fluorescens. Using the EZ-Fluo system under our optimized detection conditions (hereafter referred to as the EZF-ODC method), nine indicator species common to breweries were detected at a recovery rate of 54.0-117.2 % after only 30 h of incubation. No significant difference was found in colony-forming units among the analysts (p > 0.05). In brewery hygiene tests, the EZF-ODC method (30-h incubation) and the traditional culture method (72-h incubation) yielded comparable detection profiles, with positive or negative results matching in 94.6 % of the 222 samples. The EZF-ODC method can provide results by the following day, representing a significant improvement over the 3 days needed for traditional methods and enabling the rapid implementation of hygiene control measures to maintain a clean brewery environment and possibly expedite production planning.