FN Archimer Export Format
PT J
TI Phosphorus limitation affects the molecular composition of Thalassiosira weissflogii leading to increased biogenic silica dissolution and high degradation rates of cellular carbohydrates
BT 
AF Panagiotopoulos, Christos
   Goutx, Madeleine
   Suroy, Maxime
   Moriceau, Brivaela
AS 1:1;2:1;3:1;4:2;
FF 1:;2:;3:;4:;
C1 Aix Marseille Univ., Université de Toulon, CNRS, IRD, Mediterranean Institute of Oceanography (MIO) UM 110, 13288, Marseille, France
   Université de Brest, Institut Universitaire Européen de la Mer (IUEM), CNRS, Laboratoire des Sciences de l’Environnement Marin, UMR 6539 CNRS/UBO/IFREMER/IRD, 29280 Plouzané, France
C2 UNIV AIX MARSEILLE, FRANCE
   CNRS, FRANCE
UM LEMAR
IN WOS Cotutelle UMR
   copubli-france
   copubli-univ-france
IF 3.607
TC 5
UR https://archimer.ifremer.fr/doc/00636/74781/74978.pdf
LA English
DT Article
DE ;Bacterial biodegradation;Thalassiosira weissflogii;P-stress;POC;PON;Carbohydrates;Biogenic silica
AB Diatoms in general, and Thalassiosira weissflogii (T. weissflogii) in particular, are among the most ubiquitous phytoplanktonic species while, phosphorus (P) is an essential nutrient that limits productivity in many oceanic regimes. To investigate how T. weissflogii cultures grown under different P regimes are chemically altered before and during their prokaryotic degradation, T. weissflogii cells were cultivated under two contrasting P conditions, “P-stress” and “P-replete”. Biodegradation experiments were conducted in natural sea water comprising a natural prokaryotic community. The particulate fraction was monitored for 3 weeks for organic carbon (POC), nitrogen (PON), biogenic silica (bSiO2), total carbohydrates (PCHO) and individual monosaccharides, including prokaryotic counting. Our results indicated that P-stress induced changes in the chemical composition of the T. weissflogii cells, causing a decrease to the Si/N (1.1 to 0.46) and Si/C (0.17 to 0.08) ratios. The “P-stress T. weissflogii” cells were characterized by high amounts of galactose (23% of PCHO), xylose (21%), and glucose (19%) compared to the “P-replete T. weissflogii” cells, which were dominated by ribose (20% of PCHO), further indicating the exhaustion of ribose-rich molecules (e.g., ATP) in T. weissflogii under “P-stress” conditions. The degradation experiments showed that bSiO2 produced under “P-stress” conditions dissolved more rapidly than bSiO2 formed under “P-replete” conditions, whereas POC and PON exhibited higher degradation rate constants in the “P-replete T. weissflogii” than in the “P-stress T. weissflogii” experiment. Overall, these observations show that T. weissflogii submitted to P-limitation, results in changes in its initial biochemical composition, increases frustule dissolution rate, and decreases the degradation of T. weissflogii-organic matter by marine prokaryotes. 
PY 2020
PD OCT
SO Organic Geochemistry
SN 0146-6380
PU Elsevier BV
VL 148
UT 000574905400001
DI 10.1016/j.orggeochem.2020.104068
ID 74781
ER

EF