A systematic comparison of four bioaerosol generators: Affect on culturability and cell membrane integrity when aerosolizing Escherichia coli bacteria

Bioaerosol research requires stable and reliable aerosol generators that can produce high particle concentrations with minimal damage to microorganisms. This study compared Collison nebulizer, Liquid Sparging Aerosolizer (LSA), C-Flow nebulizer, and a newly designed Single-Pass Aerosolizer with respect to their physical performance, and ability to preserve the culturability and structural integrity of bacteria. Escherichia coli bacteria were aerosolized at different air pressures, collected by a BioSampler and their Cell Membrane Damage Index (ID), expressed as the fraction of 16S rRNA gene copies in the supernatant liquid versus the amount of 16S rRNA gene copies in the total sample (cell pellet plus supernatant), was determined. The ID of E. coli aerosolized by the Collison and C-Flow nebulizers at 40psi compared to aerosolization at 5 and 15psi was significantly higher (p