Name: Katherine Sides

Email: ksides@utk.edu

Author: Katherine Sides1, Krishnakali Roy1, Velusamy Srinivasan1, Dhritiman Ghosh1, Susan Pfiffner2, K. Eric Wommack3, and Mark Radosevich1

Author affiliation: 1. Biosystems Engineering and Soil Science, University of Tennessee, Knoxville, TN, USA 2. Center for Environmental Biotechnology, University of Tennessee, Knoxville, TN, USA 3. Department of Plant and Soil Sciences, University of Delaware, Newark, DE, USA

Abstract title: Prevalence of lysogeny in forested and agricultural soil bacteria as a function of host colony formation rate.

Absstract:

Researchers have only recently begun to assess temperate phage-host interactions in soils. A collection of 740 bacteria isolated from the Kellogg Biological Station Long-Term Ecological Research Site in Hickory Corners, MI using a variety of media, incubation times and land management systems were classified using partial 16S rRNA sequences. Ecocollections were established by incubating initial spread plates for 80+ days and randomly selecting colonies as they appeared within four time periods. Of the 14 bacterial orders cultivated the Actinomycetales, Rhizobiales, and Burkholderiales, were represented in all sampling times, media substrates and land management systems comprising 24, 33, and 19% of the total collection respectively. The 143 Burkholderiales isolates were chosen for phage induction assays. We hypothesized that hosts with slower colony formation rates (isolated at time points 3 and 4) would be more likely to possess inducible prophage compared to faster colony forming hosts (from time points 1 and 2). Mitomycin-C (mitC) and Acyl homoserine lactones (AHL) were used as inducing agents. Approximately 50% of the isolates produced phage upon exposure to mitC, while only 20% of the Burkholderiales isolates from the earliest time period were inducible. None of the isolates tested to date were inducible with AHL. This work will also be presented at the 109th ASM General Meeting.