Efficiency of bioaerosol samplers: A comparison study

Bioaerosols, including bacteria and fungi, are ubiquitous and have been shown to impact various organisms as well as biogeochemical cycles and human health. However, sample collection poses a challenge for aeromicrobiologists and can determine the success of a study. Establishing a standard collection procedure for bioaerosol sampling could help advance the field. We tested the efficiency (number of organisms collected and DNA yield per unit time) of three sampling devices: a membrane filtration device, a liquid impinger, and a portable electrostatic precipitator bioaerosol collector. We compared the efficiency of these three devices for both culture-dependent studies, by enumerating colony forming units (CFUs), and culture-independent studies, by extracting and quantifying total DNA. Our results show that the electrostatic precipitator collected microorganisms significantly more efficiently than the membrane filtration and liquid impingement in both types of studies over the same time interval. This is due to the high flow rate of the device. This work is important and timely because aeromicrobiology is currently restricted by long sampling times and  risk of evaporation, desiccation, or freezing during sample, which increases with sampling times.  Fieldwork convenience and portability of instruments are an additional challenge for sampling. Using a sampler that can overcome these technical hurdles can accelerate the advancement of the field, and the use of a lightweight, battery-powered, inexpensive, and portable bioaerosol collection device could address these limitations.