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Titolo:
Profiles of ectoenzymes in the Indian Ocean: phenomena of phosphatase activity in the mesopelagic zone
Autore:
Hoppe, HG; Ullrich, S;
Indirizzi:
Univ Kiel, Inst Marine Sci, D-24105 Kiel, Germany Univ Kiel Kiel GermanyD-24105 l, Inst Marine Sci, D-24105 Kiel, Germany
Titolo Testata:
AQUATIC MICROBIAL ECOLOGY
fascicolo: 2, volume: 19, anno: 1999,
pagine: 139 - 148
SICI:
0948-3055(19991001)19:2<139:POEITI>2.0.ZU;2-2
Fonte:
ISI
Lingua:
ENG
Soggetto:
DEEP-SEA SEDIMENTS; ENZYME-ACTIVITIES; BACTERIAL-POPULATIONS; PROTEOLYTIC ACTIVITY; MARINE-BACTERIA; ORGANIC-MATTER; PHOSPHORUS; GROWTH; BACTERIOPLANKTON; WATERS;
Keywords:
ectoenzymes; phosphatase; aminopeptidase; glucosidase; bacteria; Indian Ocean; Arabian Sea; mesopelagic zone; deep sea;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
48
Recensione:
Indirizzi per estratti:
Indirizzo: Hoppe, HG Univ Kiel, Inst Marine Sci, Dusternbrooker Weg 20, D-24105 Kiel,Germany Univ Kiel Dusternbrooker Weg 20 Kiel Germany D-24105 l, Germany
Citazione:
H.G. Hoppe e S. Ullrich, "Profiles of ectoenzymes in the Indian Ocean: phenomena of phosphatase activity in the mesopelagic zone", AQUAT MIC E, 19(2), 1999, pp. 139-148

Abstract

Phosphatase (P-ase) activity was determined together with other extracellular enzyme activities, bacterial abundance and production rates during the 2 SW Monsoon process studies of the German JGOFS Arabian Sea Program. Watersamples were collected along the cruise tracks from the equator to the upwelling region at the shelf edge off Oman. Depth profiles of P-ase activity were strikingly different from those of the other enzymes. While values of aminopeptidase and beta-glucosidase generally decreased below the euphotic zone, P-ase increased by factors of 1 to 7. The relation between peptidase-and P-ase activity was from 4 to 21 at the surface and from 3 to 5 at 800 m depth. Because P-ase production (dissolved and cell-bound) in deep watersis mainly dependent on bacteria, P-ase activities per bacterial cell were calculated: these were, on average, 37 times higher at 800 m than at the surface. We also observed a positive correlation of P-ase activity with phosphate concentrations in the depth profiles below the euphotic zone, while this relationship was much more variable in the mixed surface layer. These observations suggest that C-limited bacteria in the deep strata did not primarily focus on the phosphate generated by their P-ase activity but on the organic C compounds which were simultaneously produced and which could probably not be taken up prior to the hydrolytic detachment of phosphate. It is hypothesised that a considerable part of the measured P-ase activity was dissolved (though it might have originated from bacteria). These enzymes may be important for the slow, but steady regeneration of phosphate and organic C in mesopelagic waters.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 02/12/20 alle ore 14:34:30