@article{fdi:010066987,
  title = {{S}uccession within the prokaryotic communities during the {VAHINE} mesocosms experiment in the {N}ew {C}aledonia lagoon},
  author = {{P}freundt, {U}. and {V}an {W}ambeke, {F}. and {C}affin, {M}. and {B}onnet, {S}ophie and {H}ess, {W}. {R}.},
  editor = {},
  language = {{ENG}},
  abstract = {{N}-2 fixation fuels similar to 50% of new primary production in the oligotrophic {S}outh {P}acific {O}cean. {T}he {VAHINE} experiment has been designed to track the fate of diazotroph-derived nitrogen ({DDN}) and carbon within a coastal lagoon ecosystem in a comprehensive way. {F}or this, large-volume (similar to 50 m(3)) mesocosms were deployed in the {N}ew {C}aledonian lagoon and were intentionally fertilized with dissolved inorganic phosphorus ({DIP}) to stimulate {N}-2 fixation. {T}his study examined the temporal dynamics of the prokaryotic community together with the evolution of biogeochemical parameters for 23 consecutive days in one of these mesocosms ({M}1) and in the {N}oumea lagoon using {M}i{S}eq 16{S} r{RNA} gene sequencing and flow cytometry. {C}ombining these methods allowed for inference of absolute cell numbers from 16{S} data. {W}e observed clear successions within {M}1, some of which were not mirrored in the lagoon. {T}he dominating classes in {M}1 were {A}lpha-and {G}ammaproteobacteria, {C}yanobacteria, eukaryotic microalgae, {M}arine {G}roup {II} {E}uryarchaeota, {F}lavobacteriia, and {A}cidimicrobia. {E}nclosure led to significant changes in the {M}1 microbial community, probably initiated by the early decay of {S}ynechococcus and diatoms. {H}owever, we did not detect a pronounced bottle effect with a copiotroph-dominated community. {T}he fertilization with similar to 0.8 mu {M} {DIP} on day 4 did not have directly observable effects on the overall community within {M}1, as the data samples obtained from before and 4 days after fertilization clustered together, but likely influenced the development of individual populations later on, like {D}efluviicoccus-related bacteria and {UCYN}-{C}-type diazotrophic cyanobacteria ({C}yanothece). {G}rowth of {UCYN}-{C} led to among the highest {N}-2-fixation rates ever measured in this region and enhanced growth of nearly all abundant heterotrophic groups in {M}1. {W}e further show that different {R}hodobacteraceae were the most efficient heterotrophs in the investigated system and we observed niche partitioning within the {SAR}86 clade. {W}hereas the location in-or outside the mesocosm had a significant effect on community composition, the temporal effect was significantly stronger and similar in both locations, suggesting that overarching abiotic factors were more influential than the enclosure. {W}hile temporal community changes were evident, prokaryotic diversity ({S}hannon index) only declined slightly from similar to 6.5 to 5.7 or 6.05 in the lagoon and {M}1, respectively, throughout the experiment, highlighting the importance of multiple and varying sources of organic matter maintaining competition.},
  keywords = {{NOUVELLE} {CALEDONIE} ; {PACIFIQUE} {SUD} {OUEST} ; {NOUMEA} {LAGON}},
  booktitle = {},
  journal = {{B}iogeosciences},
  volume = {13},
  numero = {8},
  pages = {2319--2337},
  ISSN = {1726-4170},
  year = {2016},
  DOI = {10.5194/bg-13-2319-2016},
  URL = {https://www.documentation.ird.fr/hor/fdi:010066987},
}