FN Archimer Export Format
PT J
TI Exoproteolytic activity in an Atlantic pond (France): estimates of in situ activity
BT 
AF CROTTEREAU, C
   DELMAS, Daniel
AS 1:1,2;2:1,2;
FF 1:;2:;
C1 IFREMER, CNRS, Ctr Rech Ecol & Aquaculture LHoumeau, F-17137 Lhoumeau, France.
   CNRS, IFREMER, Ctr Rech Ecol & Aquaculture LHoumeau, F-17137 Lhoumeau, France.
C2 IFREMER, FRANCE
   CNRS, FRANCE
IN WOS Ifremer jusqu'en 2018
IF 2.19
TC 13
UR https://archimer.ifremer.fr/doc/00446/55803/62288.pdf
LA English
DT Article
DE ;bacterioplankton;in situ exoproteolytic hydrolysis rate;kinetic parameters;DCAA;marine pond
AB In order to estimate in situ bacterial exoproteolysis and its contribution to bacterial secondary production (BSP), we studied microbial activities (BSP and kinetics of exoproteolytic activity) in relation to dissolved combined amino acids (DCAA) during the survey of an Atlantic marine pond. In this pond, high concentrations of DCAA (mean = 4.27 mu M), probably generated by zooplankton grazing, allowed large bacterial biomass development and high production (max = 10(11) cells l(-1) and 18.8 x 10(9) cells l(-1) d(-1) respectively). Exoproteolytic enzyme activity (mean V-m = 55.9 mu M d(-1)) was tightly cou pled to bacterial production, suggesting that protein utilization was essential for bacterial growth. Calculation, according to the Michaelis-Menten equation, of the dissolved protein in situ hydrolysis rates using the kinetic parameters (V-m and K-m) and the ambient concentration of DCAA proved to be a better estimation of the actual rate of hydrolytic activity than the potential activity based on V-m only. The rates found with this calculation agreed with those obtained from different environments with other methods (DCAA and labelled proteins uptake). Furthermore, our estimates of in situ proteolysis were consistent with BSP (nitrogen fluxes originating from dissolved protein hydrolysis averaging 56% of the N bacterial production), and as a result, these estimates seem to provide a realistic estimation of the actual dissolved protein hydrolysis rates. 
PY 1998
PD AUG
SO Aquatic Microbial Ecology
SN 0948-3055
PU Inter-research
VL 15
IS 3
UT 000075783800002
BP 217
EP 224
DI 10.3354/ame015217
ID 55803
ER

EF