AME 67:59-76 (2012)  -  DOI: https://doi.org/10.3354/ame01582

ABSTRACT: The goals of this 18 mo field study were to examine temporal changes in viral community composition in a temperate eutrophic freshwater lake (Lake Matoaka) and to identify potential drivers of seasonal changes in microbial community composition. We show that analyses of aquatic viral community composition can be streamlined by concentrating viruses from small water samples without compromising the resolution of the community profile data. The use of small-volume viral concentrates paired with randomly amplified polymorphic DNA (RAPD) polmerase chain reaction (PCR) generated significantly richer and more complex banding patterns than the use of pulsed-field gel electrophoresis (PFGE) and the large-volume concentrates that PFGE requires. Thus, the small-volume RAPD-PCR approach was used in the subsequent analyses. Viral and bacterial communities in Lake Matoaka were highly dynamic, exhibiting strong seasonal shifts. However, repeating annual patterns were not detected among the bacterial or viral communities. Temperature was the most important factor explaining changes in viral and bacterial abundance. Viral and bacterial abundance were also significantly correlated to each other. Multivariate analysis indicated weak relationships between temperature and bacterial community composition and between temperature and viral community composition. Mantel tests revealed a strong and significant correlation between viral and bacterial community composition. Taken together with the correlation between viral and bacterial abundance, these data suggest that phages dominate the virioplankton of Lake Matoaka and indicate tightly linked phage–host dynamics.

KEY WORDS: Virioplankton · Bacterioplankton · RAPD-PCR · tRFLP · Eutrophic lake · Community dynamics