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Titolo:
STORM-STIMULATED ENZYMATIC DECOMPOSITION OF ORGANIC-MATTER IN BENTHICPELAGIC COASTAL MESOCOSMS
Autore:
CHROST RJ; RIEMANN B;
Indirizzi:
UNIV WARSAW,DEPT MICROBIAL ECOL,UI KAROWA 18 PL-00927 WARSAW POLAND WATER QUAL RES INST,INT AGCY C DETERMINAT DK-2970 HORSHOLM DENMARK
Titolo Testata:
Marine ecology. Progress series
fascicolo: 1-2, volume: 108, anno: 1994,
pagine: 185 - 192
SICI:
0171-8630(1994)108:1-2<185:SEDOOI>2.0.ZU;2-X
Fonte:
ISI
Lingua:
ENG
Soggetto:
HETEROTROPHIC ACTIVITY; NUTRIENT REGENERATION; AQUATIC ENVIRONMENTS; BACTERIAL PRODUCTION; MARINE-SEDIMENTS; WATER; ESTUARINE; ZONE; SEA;
Keywords:
ORGANIC MATTER; ENZYMES; DECOMPOSITION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
37
Recensione:
Indirizzi per estratti:
Citazione:
R.J. Chrost e B. Riemann, "STORM-STIMULATED ENZYMATIC DECOMPOSITION OF ORGANIC-MATTER IN BENTHICPELAGIC COASTAL MESOCOSMS", Marine ecology. Progress series, 108(1-2), 1994, pp. 185-192

Abstract

Sediment resuspension caused by simulated storms led to a dramatic short-term increase of aminopeptidase (AMPase) and beta-glucosidase (GLCase) activities and bacterial secondary production in coastal waters during a mesocosm experiment in Knebel Vig, Denmark. Perturbation of sediments strongly affected the kinetic parameters of AMPase and GLCase in the water column of the enclosures. V(max) values of AMPase and GLCase determined 4 h after a simulated storm event were 24 % and 43 % higher, respectively, than those assayed during the calm period. Sediment resuspension in enclosures ('storm enclosures') had the most pronounced effect on GLCase apparent k(m) (Michaelis constant) values, which increased 2.6 times (163 %) after sediment resuspension. AMPase Km values were approximately 1.6 times higher after sediment resuspension than before sediment resuspension. Changes in of the V(max) and K(m) values of GLCase and AMPase in storm enclosures were accompanied by longer turnover times for enzymatic hydrolysis of substrates. GLCase and AMPase after sediment resuspension had noticeably higher specific activities than before the storm event. GLCase and AMPase specific activities produced by an 'average' single bacterium were 2.4 and 2.1 times higher, respectively, after the storm event. Sediment in the water causeda situation in which most GLCase activity (68 %) was associated with the particle size fraction > 10 pm. AMPase activity after a storm event also shifted towards the > 10 mum size fractions. Activities of freeAMPase and GLCase dissolved in the water were low and contributed 8 %and 14-16 %, respectively, to the total activity of these enzymes. Results of simultaneously radiolabeling size-fractionated samples with [H-3]thymidine and [C-14]protein hydrolysate showed that the water column of storm enclosures was inhabited by metabolically different bacterial populations before and after sediment resuspension. The response of the suspended microbial assemblages to the storm event was very rapid but short-term; enzymatic activity levels returned to pre-storm levels within 24 h. Our mesocosm experiments demonstrated that sediment resuspension caused by simulated storms had a pronounced stimulatory effect on the rates of microbial enzymatic degradation of organic matter in a coastal ecosystem.

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Documento generato il 15/01/21 alle ore 23:19:47