Observations on the use of membrane filtration and liquid impingement to collect airborne microorganisms in various atmospheric environments
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 m, one on a mountain top at an altitude of ~3,000.0 m, one at ~1.0 m altitude in Tallahassee, Florida, and one at ~1.0 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) <3.0 colony-forming units (CFU) m−3. At the Florida and subterranean sites, the lowest average count noted was 3.5 bacteria CFU m−3, and the highest averaged 140.4 total CFU m−3. 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.
KeywordsBacteria Fungi Methods Membrane filtration Liquid impingement Aeromicrobiology Microbiology
Appreciation is extended to Dr. Dan Jaffe of University of Washington at Bothell for support at Mount Bachelor Observatory and Dale Pate and Paul Burger of the U.S. National Park Service for assistance at Carlsbad Caverns National Park. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
- Buttner, M. P., Willeke, K., & Grinshpun, S. A. (1997). Sampling and analysis of airborne microorganisms. In C. J. Hurst, G. R. Knudsen, M. J. McInerney, L. D. Stetzenbach, & M. V. Walter (Eds.), Manual of environmental microbiology (pp. 629–640). Washington, DC: American Society for Microbiology Press.Google Scholar
- Dowd, S. E., & Maier, R. M. (2000). Aeromicrobiology. San Diego: Academic Press.Google Scholar
- Dytham, C. (1999). Choosing and using statistics, a biologist’s guide. Oxford: Blackwell Science.Google Scholar
- Gregory, P. H. (1961). The microbiology of the atmosphere. London: Leonard Hill Books Ltd.Google Scholar
- Honrath, R. E., Owen, R. C., Marti’n, M. V., Reid, J. S., Lapina, K., Fialho, P., et al. (2004). Regional and hemispheric impacts of anthropogenic and biomass burning emissions on summertime CO2 and O3 in the North Atlantic lower free troposphere. Journal of Geophysical Research, 109. doi: 10.1029/2004JD005147.
- Jensen, P. A., Lighthart, B., Mohr, A. J., & Shaffer, B. T. (1994). Instrumentation used with microbial bioaerosol. In B. Lighthart & A. J. Mohr (Eds.), Atmospheric microbial aerosols: theory and applications (pp. 226–284). New York, NY: Chapman and Hall.Google Scholar
- Keleman, P. B., Kikawa, E., Miller, D. J., Abe, N., Bach, W., Carlson, R. L., et al. (2004). Leg 209 summary. In Proceedings of the Ocean Drilling Program, Initial Reports—Leg 209. College Station, TX: Ocean Drilling Program, pp. 1–139.Google Scholar
- Lin, X., Willeke, K., Ulevicius, V., & Grinshpun, S. (1997). Effect of sampling time on the collection efficiency of all-glass impingers. American Industrial Hygiene Association Journal, 58, 480–488.Google Scholar
- McFeters, G. A., Cameron, S. C., & LeChevallier, M. W. (1982). Influence of diluents, media, and membrane filter on detection of injured waterborne coliform bacteria. Applied and Environmental Microbiology, 43, 97–103.Google Scholar
- Mohr, A. J. (1997). Fate and transport of microorganisms in air. Washington: ASM Press.Google Scholar
- Pasteur, L. (1861) Memoire sur les corpuscles organises qui existent dans l’atmosphere. Examen de la doctrine des generations spontanees. Annales des Sciences Naturelles—Zoologie et Biologie Animale 4 e ser., 16, 5–98.Google Scholar
- Prospero, J. M., Blades, E., Mathison, G., & Naidu, R. (2005). Interhemispheric transport of viable fungi and bacteria from Africa to the Caribbean with soil dust. Aerobiologia, 21, 1–19.Google Scholar
- Reasoner, D. J., & Geldreich, E. E. (1985). A new medium for the enumeration and subculture of bacteria from potable water. Applied and Environmental Microbiology, 49, 1–7.Google Scholar
- Terzieva, S., Donnelly, J., Ulevicius, V., Grinshpun, S. A., Willeke, K., Stelma, G. N., et al. (1996). Comparison of methods for detection and enumeration of airborne microorganisms collected by liquid impingement. Applied and Environmental Microbiology, 62, 2264–2272.Google Scholar
- Tobin, R. S., Lomax, P., & Kushner, D. J. (1980). Comparison of nine brands of membrane filter and the most-probable-number methods for total coliform enumeration in sewage-contaminated drinking water. Applied and Environmental Microbiology, 40, 186–191.Google Scholar
- Tyndall, J. (1882). Essays on the floating-matter of the air in relation to putrefaction and infection. New York and London: Johnson Reprint Corporation.Google Scholar
- Yu, L., Wen, S., Li, J., Yang, W., Wang, J., Li, N., et al. (2009). Effects of different sampling solutions on the survival of bacteriophages in bubbling aeration. Aerobiologia. Online first: doi 10.1007/s10453-10009-19144-10454.