Measurement Report: Effects on viability, culturability, and cells fragmentation of two bioaerosol generators during aerosolization of <i>E. coli</i> bacteria

Abstract. Bioaerosol is a significant element of Particulate Matter (PM) and comprises various components, with bacterial species ranking as some of the most important. Reliable and consistent bioaerosol generators are essential for the investigation of bioaerosol in laboratory environments. Aerosol generators are utilized to evaluate the performance of bioaerosol collectors, explore the transport and deposition of biological particles, and study the health impacts and exposure to airborne microorganisms. The main goal of the bacteria experiments is to have an aerosol generator able to aerosolize the maximum number of viable and culturable cells at elevated particle concentrations. This study performs a comparative investigation of two bioaerosol generators: the Sparging Liquid Aerosol Generator (SLAG) by CH Technologies and the 1520 Flow Focusing Monodisperse Aerosol Generator (FMAG) by TSI. The analysis concentrated on the vitality, culturability, fragmentation, and nebulization efficiency of E. coli cells. The results indicated increased fragmentation using the SLAG nebulizer, and the size distribution varied according to the concentration of the injection fluid for FMAG. Both nebulizers imposed significant stress on bacteria during nebulization, halving their viability. Ultimately, the nebulization efficiency of FMAG is twenty times higher than that of SLAG.