Effect of a reactive oxygen species-generating system for control of airborne microorganisms in a meat-processing environment

The effectiveness of reactive oxygen species (ROS)-generating AirOcare equipment on the reduction of airborne bacteria in a meat-processing environment was determined. Serratia marcescens and lactic acid bacteria (Lactococcus lactis subsp. lactis and Lactobacillus plantarum) were used to artificially contaminate the air via a six-jet Collison nebulizer. Air in the meat-processing room was sampled immediately after aerosol generation and at various predetermined times at multiple locations by using a Staplex 6 stage air sampler. Approximately a 4-log reduction of the aerial S. marcescens population was observed within 2 h of treatment (P < 0.05) compared to a 1-log reduction in control samples. The S. marcescens populations reduced further by approximately 4.5 log after 24 h of exposure to ROS treatment. Approximately 3-log CFU/m3 reductions in lactic acid bacteria were observed following 2-h ROS exposure. Further ROS exposure reduced lactic acid bacteria in the air; however, the difference in their survival after 24 h of exposure was not significantly different from that observed with the control treatment. S. marcescens bacteria were more sensitive to ROS treatment than the lactic acid bacteria. These findings reveal that ROS treatment using the AirOcare unit significantly reduces airborne S. marcescens and lactic acid bacteria in meat-processing environments within 2 h.