@article{fdi:010066165, title = {{H}eterotrophic bacteria show weak competition for nitrogen in {M}editerranean coastal waters ({T}hau {L}agoon) in autumn}, author = {{T}rottet, {A}urore and {L}eboulanger, {C}hristophe and {V}idussi, {F}. and {P}ete, {R}. and {B}ouvy, {M}arc and {F}ouilland, {E}.}, editor = {}, language = {{ENG}}, abstract = {{T}he importance of heterotrophic bacteria relative to phytoplankton in the uptake of ammonium and nitrate was studied in {M}editerranean coastal waters ({T}hau {L}agoon) during autumn, when the {M}editerranean {S}ea received the greatest allochthonous nutrient loads. {S}pecific inhibitors and size-fractionation methods were used in combination with isotopic {N}-15 tracers. {NO}3 (-) and {NH}4 (+) uptake was dominated by phytoplankton (60 % on average) during the study period, which included a flood event. {D}espite lower biomass specific {NH}4 (+) and {NO}3 uptake rates, free-living heterotrophic bacteria contributed significantly (> 30 %) to total microbial {NH}4 (+) and {NO}3 (-) uptake rates in low chlorophyll waters. {U}nder these conditions, heterotrophic bacteria may be responsible for more than 50 % of primary production, using very little freshly produced phytoplankton exudates. {I}n low chlorophyll coastal waters as reported during the present 3-month study, the heterotrophic bacteria seemed to depend to a greater extent on allochthonous {N} and {C} substrates than on autochthonous substrates derived from phytoplankton.}, keywords = {{B}acteria ; {P}hytoplankton ; {I}nhibitors ; {S}ize fractionation ; {N}itrogen uptake ; {D}issolved inorganic nitrogen ; {FRANCE} ; {MEDITERRANEE} ; {ZONE} {MEDITERRANEENNE}}, booktitle = {}, journal = {{M}icrobial {E}cology}, volume = {71}, numero = {2}, pages = {304--314}, ISSN = {0095-3628}, year = {2016}, DOI = {10.1007/s00248-015-0658-8}, URL = {https://www.documentation.ird.fr/hor/fdi:010066165}, }