Re-examining the relationship between virus and microbial cell abundances in the global oceans

Abstract

abundances were related in a predictable way it would be possible to infer the rate of contact, and potentially the relative importance of virus-induced cell lysis, from estimates of microbial abundance alone.Virus ecology underwent a transformation in the late 1980s with the recognition that virus abundances, as estimated using culture-independent methods, were orders of magnitude higher than estimates via culture-based methods [4]. Soon thereafter, researchers began to report the "virus to bacterium ratio" (VBR) as a statistical proxy for the strength of the relationship between viruses and their potential hosts in both freshwater and marine systems [31]. This ratio is more appropriately termed the "virus-to-prokaryote ratio" (VPR) -a convention which Typeset by REVT E X

Bacteriophage Distributions and Temporal Variability in the Ocean’s Interior

“…Different theories exist to explain the ecologic factors that may influence the proportion of lytic versus lysogenic phages. For example, the “piggy-back the winner” hypothesis predicts that lysogeny should be more prevalent at higher host cell densities ( 28 ) and has been based on cell- and virus-like particle abundance patterns ( 9 , 28 , 29 ). Our metagenomic data do not directly support these results, since we found evidence for more lysogens in deeper waters that have lower cell densities (cell abundance data available at http://hahana.soest.hawaii.edu/hot/hot-dogs/ ), consistent with earlier results from mitomycin C phage induction studies ( 30 ).…”

Double-stranded DNA virioplankton dynamics and reproductive strategies in the oligotrophic open ocean water column

“…Viruses represent dynamic reservoirs of unexplored genetic diversity. On average an order of magnitude more abundant than cellular organisms [1], viruses occur at~10 7 /mL in the surface layer of open oceans covering~40% of Earth [2]. In this environment, dsDNA bacteriophages infect key microbial groups, including oxygenic photoautotrophs such as Prochlorococcus and Synechococcus (e.g., [3,4]) and common bacterial heterotrophs such as Pelagibacter (SAR11), Puniceispirillum (SAR116), Roseobacter, and Alteromonas (e.g., [5][6][7][8]).…”

A viral reckoning: viruses emerge as essential manipulators of global ecosystems

“…Viruses are integral components and critical regulators of microbial ecosystems. In terms of numbers alone, virus‐like particles seemingly outnumber microbial cells in every ecosystem (Weinbauer and Rassoulzadegan, ), with a virus‐to‐microbe ratio typically ranging from 1 to 100 (Wigington et al ., ). While challenging to assess, profound ecological and evolutionary impacts of virus‐host interactions have nonetheless been uncovered across a broad range of ecosystems, from the bottom of the oceans to bubbling acidic hot springs, coral reefs and thawing permafrost (Suttle, ; Rohwer and Vega Thurber, ; Dell'Anno et al ., ; Williamson et al ., ; Emerson et al ., ).…”