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Seasonal viral loop dynamics in two ultraoligotrophic Antarctic freshwater lakes

Säwström, Christin LU ; Anesio, Alexandre Magno LU ; Granéli, Wilhelm LU and Laybourn-Parry, Johanna (2007) In Microbial Ecology 53(1). p.1-11
Abstract
The effect of viruses on the microbial loop, with particular emphasis on bacteria, was investigated over an annual cycle in 2003–2004 in Lake Druzhby and Crooked Lake, two large ultraoligotrophic freshwater lakes in the Vestfold Hills, Eastern Antarctica. Viral abundance ranged from 0.16 to 1.56 × 109 particles L-1;1 and bacterial abundances ranged from 0.10 to 0.24 × 109 cells L-1;1, with the lowest bacterial abundances noted in the winter months. Virus-to-bacteria ratios (VBR) were consistently low in both lakes throughout the season, ranging from 1.2 to 8.4. lysogenic bacteria, determined by induction with mitomycin C, were detected on three sampling occasions out of 10 in both lakes. In Lake Druzhby and Crooked Lake, lysogenic bacteria... (More)
The effect of viruses on the microbial loop, with particular emphasis on bacteria, was investigated over an annual cycle in 2003–2004 in Lake Druzhby and Crooked Lake, two large ultraoligotrophic freshwater lakes in the Vestfold Hills, Eastern Antarctica. Viral abundance ranged from 0.16 to 1.56 × 109 particles L-1;1 and bacterial abundances ranged from 0.10 to 0.24 × 109 cells L-1;1, with the lowest bacterial abundances noted in the winter months. Virus-to-bacteria ratios (VBR) were consistently low in both lakes throughout the season, ranging from 1.2 to 8.4. lysogenic bacteria, determined by induction with mitomycin C, were detected on three sampling occasions out of 10 in both lakes. In Lake Druzhby and Crooked Lake, lysogenic bacteria made up between 18% and 73% of the total bacteria population during the lysogenic events. Bacterial production ranged from 8.2 to 304.9 × 106 cells L-1;1 day-1;1 and lytic viral production ranged from 47.5 to 718.4 × 106 viruslike particles L-1;1 day-1;1. When only considering primary production, heterotrophic nanoflagellate (HNF) grazing and viral lysis as the major contributors to the DOC pool (i.e., autochthonous sources), we estimated a high contribution from viruses during the winter months when >60% of the carbon supplied to the DOC pool originated from viral lysis. In contrast, during the summer <20% originated from viral lysis. Our study shows that viral process in ultraoligotrophic Antarctic lakes may be of quantitative significance with respect to carbon flow especially during the dark winter period. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
bacteria, antarctic, virus, lake
in
Microbial Ecology
volume
53
issue
1
pages
1 - 11
publisher
Springer
external identifiers
  • wos:000243908700001
  • scopus:33846686780
ISSN
1432-184X
DOI
10.1007/s00248-006-9146-5
language
English
LU publication?
yes
id
ae2d8f03-932c-4236-80a5-58edf51fb352 (old id 698229)
date added to LUP
2007-12-05 16:08:56
date last changed
2017-05-21 03:29:22
@article{ae2d8f03-932c-4236-80a5-58edf51fb352,
  abstract     = {The effect of viruses on the microbial loop, with particular emphasis on bacteria, was investigated over an annual cycle in 2003–2004 in Lake Druzhby and Crooked Lake, two large ultraoligotrophic freshwater lakes in the Vestfold Hills, Eastern Antarctica. Viral abundance ranged from 0.16 to 1.56 × 109 particles L-1;1 and bacterial abundances ranged from 0.10 to 0.24 × 109 cells L-1;1, with the lowest bacterial abundances noted in the winter months. Virus-to-bacteria ratios (VBR) were consistently low in both lakes throughout the season, ranging from 1.2 to 8.4. lysogenic bacteria, determined by induction with mitomycin C, were detected on three sampling occasions out of 10 in both lakes. In Lake Druzhby and Crooked Lake, lysogenic bacteria made up between 18% and 73% of the total bacteria population during the lysogenic events. Bacterial production ranged from 8.2 to 304.9 × 106 cells L-1;1 day-1;1 and lytic viral production ranged from 47.5 to 718.4 × 106 viruslike particles L-1;1 day-1;1. When only considering primary production, heterotrophic nanoflagellate (HNF) grazing and viral lysis as the major contributors to the DOC pool (i.e., autochthonous sources), we estimated a high contribution from viruses during the winter months when &gt;60% of the carbon supplied to the DOC pool originated from viral lysis. In contrast, during the summer &lt;20% originated from viral lysis. Our study shows that viral process in ultraoligotrophic Antarctic lakes may be of quantitative significance with respect to carbon flow especially during the dark winter period.},
  author       = {Säwström, Christin and Anesio, Alexandre Magno and Granéli, Wilhelm and Laybourn-Parry, Johanna},
  issn         = {1432-184X},
  keyword      = {bacteria,antarctic,virus,lake},
  language     = {eng},
  number       = {1},
  pages        = {1--11},
  publisher    = {Springer},
  series       = {Microbial Ecology},
  title        = {Seasonal viral loop dynamics in two ultraoligotrophic Antarctic freshwater lakes},
  url          = {http://dx.doi.org/10.1007/s00248-006-9146-5},
  volume       = {53},
  year         = {2007},
}