Prokaryotic extracellular enzymatic activity in relation to biomass production and respiration in the meso- and bathypelagic waters of the (sub)tropical Atlantic

Environ Microbiol. 2009 Aug;11(8):1998-2014. doi: 10.1111/j.1462-2920.2009.01922.x. Epub 2009 Mar 26.


Prokaryotic extracellular enzymatic activity, abundance, heterotrophic production and respiration were determined in the meso- and bathypelagic (sub)tropical North Atlantic. While prokaryotic heterotrophic production (PHP) decreased from the lower euphotic layer to the bathypelagic waters by two orders of magnitude, prokaryotic abundance and cell-specific PHP decreased only by one order of magnitude. In contrast to cell-specific PHP, cell-specific extracellular enzymatic activity (alpha- and beta-glucosidase, leucine aminopeptidase, alkaline phosphatase) increased with depth as did cell-specific respiration rates. Cell-specific alkaline phosphatase activity increased from the intermediate water masses to the deep waters up to fivefold. Phosphate concentrations, however, varied only by a factor of two between the different water masses, indicating that phosphatase activity is not related to phosphate availability in the deep waters. Generally, cell-specific extracellular enzymatic activities were inversely related to cell-specific prokaryotic leucine incorporation. Thus, it is apparent that the utilization of deep ocean organic matter is linked to higher cell-specific extracellular enzymatic activity and respiration and lower cell-specific PHP than in surface waters.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaline Phosphatase / analysis
  • Archaea / enzymology*
  • Atlantic Ocean
  • Bacteria / enzymology*
  • Biomass
  • Environmental Monitoring
  • Extracellular Space / enzymology
  • Heterotrophic Processes
  • Kinetics
  • Leucyl Aminopeptidase / analysis
  • Phosphates / analysis
  • Plankton / enzymology*
  • Seawater / chemistry
  • Seawater / microbiology*
  • alpha-Glucosidases / metabolism
  • beta-Glucosidase / metabolism


  • Phosphates
  • Alkaline Phosphatase
  • alpha-Glucosidases
  • beta-Glucosidase
  • Leucyl Aminopeptidase