Prokaryotic extracellular enzymatic activity in relation to biomass production and respiration in the meso- and bathypelagic waters of the (sub)tropical Atlantic
17 pages, 9 figures 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 bathypelag...
| Published in: | Environmental Microbiology |
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| Main Authors: | , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Blackwell Publishing
2009
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| Subjects: | |
| Online Access: | http://hdl.handle.net/10261/19755 https://doi.org/10.1111/j.1462-2920.2009.01922.x |
| Summary: | 17 pages, 9 figures 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. This research was supported by a predoctoral Fellowship of the Spanish Ministry of Education and Science (AP2005-3932) to F.B., a grant of the Spanish Ministry of Education and Science to J.A. [Remolinos Oceánicos y Deposiciones Atmosféricas (RODA) project; CTM 2004–06842-C03/MAR], and a grant of the Earth and Life Science Division of the Dutch Science Foundation (ALW-NWO; ARCHIMEDES project, 835.20.023) to G.J.H. Peer reviewed |
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