FN Archimer Export Format
PT J
TI Diversity of cultivated and metabolically active aerobic anoxygenic phototrophic bacteria along an oligotrophic gradient in the Mediterranean Sea
BT 
AF JEANTHON, C.
   BOEUF, D.
   DAHAN, O.
   LE GALL, F.
   GARCZAREK, L.
   BENDIF, El Mahdi
   LEHOURS, A. -C.
AS 1:1,2;2:1,2;3:1,2;4:1,2;5:1,2;6:1,2;7:3;
FF 1:;2:;3:;4:;5:;6:;7:;
C1 Observ Oceanol Roscoff, Grp Plancton Ocean, INSU CNRS, UMR7144, F-29680 Roscoff, France.
   Univ Paris 06, Stn Biol Roscoff, UMR7144, F-29680 Roscoff, France.
   Univ Clermont Ferrand, CNRS, UMR6023, F-63177 Aubiere, France.
C2 CNRS, FRANCE
   UNIV PARIS 06, FRANCE
   UNIV CLERMONT FERRAND, FRANCE
IF 3.859
TC 17
TU Centre national de la recherche scientifique
   Université Blaise Pascal
   Université Pierre et Marie Curie
   Université d'Auvergne
UR https://archimer.ifremer.fr/doc/00133/24391/22419.pdf
LA English
DT Article
CR BOUM
BO L'Atalante
AB Aerobic anoxygenic phototrophic (AAP) bacteria play significant roles in the bacterioplankton productivity and biogeochemical cycles of the surface ocean. In this study, we applied both cultivation and mRNA-based molecular methods to explore the diversity of AAP bacteria along an oligotrophic gradient in the Mediterranean Sea in early summer 2008. Colony-forming units obtained on three different agar media were screened for the production of bacteriochlorophyll-a ( BChl-a), the light-harvesting pigment of AAP bacteria. BChl-a-containing colonies represented a low part of the cultivable fraction. In total, 54 AAP strains were isolated and the phylogenetic analyses based on their 16S rRNA and pufM genes showed that they were all affiliated to the Alphaproteobacteria. The most frequently isolated strains belonged to Citromicrobium bathyomarinum, and Erythrobacter and Roseovarius species. Most other isolates were related to species not reported to produce BChl-a and/or may represent novel taxa. Direct extraction of RNA from seawater samples enabled the analysis of the expression of pufM, the gene coding for the M subunit of the reaction centre complex of aerobic anoxygenic photosynthesis. Clone libraries of pufM gene transcripts revealed that most phylotypes were highly similar to sequences previously recovered from the Mediterranean Sea and a large majority ( similar to 94%) was affiliated to the Gammaproteobacteria. The most abundantly detected phylotypes occurred in the western and eastern Mediterranean basins. However, some were exclusively detected in the eastern basin, reflecting the highest diversity of pufM transcripts observed in this ultra-oligotrophic region. To our knowledge, this is the first study to document extensively the diversity of AAP isolates and to unveil the active AAP community in an oligotrophic marine environment. By pointing out the discrepancies between culture-based and molecular methods, this study highlights the existing gaps in the understanding of the AAP bacteria ecology, especially in the Mediterranean Sea and likely globally.
PY 2011
SO Biogeosciences
SN 1726-4170
PU Copernicus Gesellschaft Mbh
VL 8
IS 7
UT 000294153700014
BP 1955
EP 1970
DI 10.5194/bg-8-1955-2011
ID 24391
ER

EF