Advertisement

Aquatic Sciences

, Volume 61, Issue 4, pp 279–292 | Cite as

Proteolytic and glycolytic activities in size-fractionated surface water samples from an oligotrophic reservoir in relation to plankton communities

  • Mathilde Richardot
  • Didier Debroas
  • Antoine Thouvenot
  • Jean Claude Romagoux
  • Jean Louis Berthon
  • Jean Devaux

Abstract:

From February to August 1996, the following parameters were determined in surface water samples from an oligotrophic reservoir: concentrations of dissolved combined amino acids (DCAA), monosaccharides (DFCHO) and polysaccharides (DCCHO); activities of glycolytic and proteolytic enzymes associated with three size fractions (0-0.2 μm, 0.2-2 μm, and 2-100 μm); densities and biomass of free-living and attached bacteria, nanoflagellates, and metazoan zooplankton. The mean concentrations of DCAA, DFCHO and DCCHO were 2.7, 0.5 and 1.4 mg C l-1 respectively. Both βGlcA and αGlcA showed a high substrate affinity. The enzyme activities associated with all size fractions fluctuated throughout the year. Highest activities were generally associated with the 2-100 μm fraction; the mean percentages of leucine-aminopeptidase (LeuA), β-glucosidase (βGlcA), α-glucosidase (αGlcA) and β-N-acetylglucosaminidase (βGlcNAcA) activities were 58%, 62%, 76%, and 59%, respectively. Activities of αGlcA and βGlcNAcA in the 0.2-2 μm fraction were correlated with the abundance of free-living picobacteria (bacteria <2 μm). The biomass-specific activity of attached bacteria was 18 to 64 fold higher for attached compared to free-living bacteria. The abundances of autotrophic and mixotrophic nanoflagellates (ANF) were correlated with LeuA (r = 0.59, P < 0.05) and the βGlcA (r = 0.64, P < 0.05) activities in the 2-100 μm fraction.

Key words: Proteolytic activity, glycolytic activities, bacteria, organic matter, reservoir. 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Birkhäuser Verlag, 1999

Authors and Affiliations

  • Mathilde Richardot
    • 1
  • Didier Debroas
    • 1
  • Antoine Thouvenot
    • 1
  • Jean Claude Romagoux
    • 1
  • Jean Louis Berthon
    • 2
  • Jean Devaux
    • 1
  1. 1.Université Blaise Pascal, Laboratoire de biologie des protistes, Unité Associée CNRS 6023, 63177 Aubière Cedex, France FR
  2. 2.Laboratoire de biologie, Université de St-Etienne, 43023 St-Etienne Cedex 2, France FR

Personalised recommendations