Assessing extracellular enzymatic activities of biofilms on natural and standardized organic substrata immersed in a stream

2019 ◽  
Vol 83 (2) ◽  
pp. 161-166 ◽  
Author(s):  
M Joly ◽  
C Mallet ◽  
J Artigas
Keyword(s):  
Enzymatic Activities ◽  
Extracellular Enzymatic Activities

Brief communication: Extracellular enzymatic activities of dermatophytes

1985 ◽  
Vol 92 (1) ◽  
pp. 19-22 ◽  
Author(s):  
Ma. A. Calvo ◽  
T. Bruguera ◽  
F. J. Caba�es ◽  
R. Ma. Calvo ◽  
J. Trape ◽  
...  
Keyword(s):  
Enzymatic Activities ◽  
Extracellular Enzymatic Activities

Identification of three inducible and extracellular enzymatic activities working on sucrose in Bacillus subtilis NCIMB 11871 and 11872 supernatant

2002 ◽  
Vol 31 (1-2) ◽  
pp. 44-52 ◽  
Author(s):  
Karine Le Gorrec ◽  
Cristelle Connes ◽  
Alain Guibert ◽  
Jean-Louis Uribelarrea ◽  
Didier Combes
Keyword(s):  
Bacillus Subtilis ◽  
Enzymatic Activities ◽  
Extracellular Enzymatic Activities

scholarly journals Temporal variations in microbial activities and carbon turnover in subtidal sandy sediments

2009 ◽  
Vol 6 (7) ◽  
pp. 1149-1165 ◽  
Author(s):  
S. I. Böer ◽  
C. Arnosti ◽  
J. E. E. van Beusekom ◽  
A. Boetius
Keyword(s):  
Temporal Dynamics ◽  
Temporal Variations ◽  
Enzymatic Activities ◽  
Community Respiration ◽  
Organic Carbon Content ◽  
Seasonal Temperature ◽  
Carbon Production ◽  
Carbon Demand ◽  
Extracellular Enzymatic Activities ◽  
Sandy Sediments

Abstract. Temporal dynamics and vertical patterns in bacterial abundances and activities were studied in a shallow subtidal sand flat in the Sylt-Rømø Basin (North Frisian Wadden Sea, Germany). Extracellular enzymatic activities, bacterial carbon production and community respiration showed strong (factor of 4–5) temporal variations that were mostly related to seasonal temperature change and to changes in substrate availability. These temporal patterns in enzymatic activity were barely reflected in bacterial (200–400 mmol C m−2) and microphytobenthic biomass (800–1500 mmol C m−2) or the sedimentary carbohydrate inventory (1300–2900 mmol C m−2), suggesting that grazing controls the standing stocks of the microphytobenthic and bacterial assemblages. Despite their exposure to strong hydrodynamic forces such as tidal currents and wind-induced wave surge, the subtidal sandy sediments showed persistent vertical gradients in bacterial abundances, carbon production and extracellular enzymatic activities at all times. The vertical distribution of these parameters was tightly coupled to that of the microphytobenthos, dominated by diatoms. Despite the low organic carbon content typical for surge-exposed sandy sediments, high extracellular enzymatic activities and bacterial carbon production rates indicate a very active heterotrophic bacterial community, with a gross secondary productivity of 30–180 mmol C m−2, and a biomass turnover time of 2–18 days. Our data suggest that this high activity is supported by the rapid flux of carbohydrates from microphytobenthic primary productivity. Accordingly, the potential activities of enzymes hydrolyzing carbohydrates cover most of the total bacterial carbon demand during all seasons.

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