VIDAL, Luciana O.; ABRIL, Gwenaël; ARTIGAS, Luiz F.; MELO, Michaela L.; BERNARDES, Marcelo C.; LOBÃO, Lúcia M.; REIS, Mariana C.; MOREIRA-TURCQ, Patrícia; BENEDETTI, Marc; TORNISIELO, Valdemar L.; ROLAND, Fabio

doi:10.3389/fmicb.2015.01054

Environnements et Paléoenvironnements OCéaniques [EPOC]

ARTIGAS, Luiz F.

Langue

Article de revue

Ce document a été publié dans

Frontiers in Microbiology. 2015-09-30, vol. 6

Résumé en anglais

We evaluated in situ rates of bacterial carbon processing in Amazonian floodplain lakes and mainstems, during both high water (HW) and low water (LW) phases (p < 0.05). Our results showed that bacterial production (BP) was lower and more variable than bacterial respiration, determined as total respiration. Bacterial carbon demand was mostly accounted by BR and presented the same pattern that BR in both water phases. Bacterial growth efficiency (BGE) showed a wide range (0.2-23%) and low mean value of 3 and 6%, (in HW and LW, respectively) suggesting that dissolved organic carbon was mostly allocated to catabolic metabolism. However, BGE was regulated by BP in LW phase. Consequently, changes in BGE showed the same pattern that BP. In addition, the hydrological pulse effects on mainstems and floodplains lakes connectivity were found for BP and BGE in LW. Multiple correlation analyses revealed that indexes of organic matter (OM) quality (chlorophyll-a, N stable isotopes and C/N ratios) were the strongest seasonal drivers of bacterial carbon metabolism. Our work indicated that: (i) the bacterial metabolism was mostly driven by respiration in Amazonian aquatic ecosystems resulting in low BGE in either high or LW phase; (ii) the hydrological pulse regulated the bacterial heterotrophic metabolism between Amazonian mainstems and floodplain lakes mostly driven by OM quality.< Réduire

Mots clés en anglais

bacterialproduction

bacterialrespiration

bacterialcarbondemand

bacterialgrowthefficiency

hydrologicalpulse

Amazonianfreshwaterecosystems

URI

https://oskar-bordeaux.fr/handle/20.500.12278/200539

DOI

http://dx.doi.org/10.3389/fmicb.2015.01054

Project ANR

CARBon biogeochemistry and atmospheric exchanges in the AMAzon river system - ANR-08-BLAN-0221

Unités de recherche

EPOC : Environnements et Paléoenvironnements Océaniques et Continentaux - UMR 5805

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Hydrological pulse regulating the bacterial heterotrophic metabolism between Amazonian mainstems and floodplain lakes