C. Gonzalez N. Teigell Terry Petrosky D.E. Northup M. Lyles Dale W. Griffin 2011 <p><span>The influence of sample-collection-time on the recovery of culturable airborne microorganisms using a low-flow-rate membrane-filtration unit and a high-flow-rate liquid impinger were investigated. Differences in recoveries were investigated in four different atmospheric environments, one mid-oceanic at an altitude of ~10.0&nbsp;m, one on a mountain top at an altitude of ~3,000.0&nbsp;m, one at ~1.0&nbsp;m altitude in Tallahassee, Florida, and one at ~1.0&nbsp;m above ground in a subterranean-cave. Regarding use of membrane filtration, a common trend was observed: the shorter the collection period, the higher the recovery of culturable bacteria and fungi. These data also demonstrated that lower culturable counts were common in the more remote mid-oceanic and mountain-top atmospheric environments with bacteria, fungi, and total numbers averaging (by sample time or method categories) &lt;3.0 colony-forming units (CFU) m</span>⁻³<span>. At the Florida and subterranean sites, the lowest average count noted was 3.5 bacteria CFU&nbsp;m</span>⁻³<span>, and the highest averaged 140.4 total CFU&nbsp;m</span>⁻³<span>. When atmospheric temperature allowed use, the high-volume liquid impinger utilized in this study resulted in much higher recoveries, as much as 10× greater in a number of the categories (bacterial, fungal, and total CFU). Together, these data illustrated that (1) the high-volume liquid impinger is clearly superior to membrane filtration for aeromicrobiology studies if start-up costs are not an issue and temperature permits use; (2) although membrane filtration is more cost friendly and has a ‘typically’ wider operational range, its limits include loss of cell viability with increased sample time and issues with effectively extracting nucleic acids for community-based analyses; (3) the ability to recover culturable microorganisms is limited in ‘extreme’ atmospheric environments and thus the use of a ‘limited’ methodology in these environments must be taken into account; and (4) the atmosphere culls, i.e., everything is not everywhere.</span></p> application/pdf 10.1007/s10453-010-9173-z en Springer Link Observations on the use of membrane filtration and liquid impingement to collect airborne microorganisms in various atmospheric environments article