Temporal changes of major bacterial groups and bacterial heterotrophic activity during a Phaeocystis globosa bloom in the eastern English Channel

A new virus that infects the harmful algal bloom-forming microalga Phaeocystis globosa was isolated from surface water in the English Channel off the coast of Plymouth, UK, in May 2001. Phylogenetic analysis of the DNA polymerase gene revealed the virus isolate, designated PgV-102P, belongs to the family Phycodnaviridae, a group of large double-stranded DNA viruses known to infect algae. Basic characterization of PgV-102P revealed it was a lytic virus with a relatively slow culture lysis period of 10-days. The genome size (176 kbp) and capsid diameter (98 nm) of PgV-102P fall at the bottom end of the range expected for phycodnaviruses. Interestingly, PgV-102P did not cluster with other P. globosa viruses; instead, it was more closely related to other prymnesioviruses that infect the marine prymnesiophyte Chrysochromulina brevifilum. We discuss the effectiveness of DNA polymerase as a diagnostic marker. Although it is ideal for determining what family or even genus an algal virus belongs to, it is clear that the DNA polymerase gene does not have sufficient resolution when looking for relationships within algal virus genera.

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Temporal changes in the dominance of major planktonic bacterial groups in an alpine lake: discrepancy with their contribution to bacterial production

Aquatic Microbial Ecology ◽

10.3354/ame01505 ◽

2011 ◽

Vol 63 (2) ◽

pp. 161-170 ◽

Cited By ~ 17

Author(s):

MT Pérez ◽

R Sommaruga

Keyword(s):

Bacterial Production ◽

Temporal Changes ◽

Alpine Lake ◽

Bacterial Groups

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Spatio-temporal changes of the near-bottom mesozooplankton from the English Channel

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315404009543h ◽

2004 ◽

Vol 84 (3) ◽

pp. 539-546 ◽

Cited By ~ 7

Author(s):

Carole Vallet ◽

Jean-Claude Dauvin

Keyword(s):

Bottom Layer ◽

Temporal Changes ◽

English Channel ◽

Taxa Richness ◽

Significant Difference ◽

Spatio Temporal ◽

Calanus Helgolandicus

The near-bottom mesozooplankton was caught by a four net suprabenthic sledge on six sites in the English Channel during both spring and autumn. Taxa richness showed no significant difference between seasons, nevertheless diversity (H′), evenness (J) and normalized rarefaction number of taxa E(S91) were higher in autumn than in spring at each site except at Site 2 offshore Plymouth, where Calanus helgolandicus dominated at both seasons. Copepods dominated in abundance at each site in spring while crustacean larvae were dominant in autumn except at Site 2 offshore Plymouth, where copepods remained dominant and, at Site 6 in the Dover Strait, where no significant difference occurred between copepod and crustacean larvae abundances. Four assemblages were distinguished depending on the season. Abundance was higher during the day than at night as a result of a mesozooplankton concentration in the near-bottom layer during the daytime. Moreover, three vertical patterns of suprabenthic mesozooplankton were identified according to their distribution above the near-bottom layer: taxa distributed homogeneously in the four nets; taxa concentrated in nets 2 and 4, and taxa concentrated in the three upper nets.

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