Distribution of virus-like-particles in desert and East Tennessee forest soils. (6183)
Authors:
M. Radosevich* - University of Tennessee J. Janowitz - University of Tennessee K.E. Williamson - University of Delaware K.E. Wommack - University of Delaware W.C. Lindemann - New Mexico State University
Abstract:
Viruses are the most numerically abundant biological entities in natural environments, yet very little is known regarding their distribution and ecological role in soils. As a first step towards determining the importance of viruses in terrestrial environments, an epiflourescence direct counting method of Williamson et al. (2003, Appl. Environ. Microbiol. 69:6628-6633) was used to enumerate virus-like particles (VLP) in agricultural (Tennessee) and desert (Jornada basin, New Mexico and Antarctica) soils. VLP counts were highest in agricultural soils ranging from 5.1 to 8.3 x 109 VLPs g soil-1. These estimates were comparable to previously reported counts in soils from Delaware (Williamson et al., 2003). Non-encapsulated DNA had little effect on these estimates since the counts declined only slightly after samples were treated with Dnase. VLP counts in agricultural soil were independent of the eluent (k-citrate or Na-pyrophosphate) used to extract the samples. In contrast, estimates of VLPs in desert soils were variable and strongly influenced by non-ecapsulated DNA, the extracting solution, and other unidentified interfering substances. VLP in a soil sample from Jornada Basin, New Mexico was estimated to contain 4.0 x 109 VLPs g soil-1. These results indicate that viruses are abundant members of geographically diverse soil environments.
Speaker Information: Mark Radosevich, University of Tennessee, Biosystems Engineering and Environmental Science 2506 E.J. Chapman Dr., Knoxville, TN 37996; Phone: 865-974-7454; E-mail:
Session Information: Tuesday, November 2, 2004, 8:00 AM-10:00 AM Presentation Start: 8:00 AM (Poster Board Number: 2612)
Keywords: soil; virus; enumeration; microscopy