Ectoenzymatic ratios in relation to particulate organic matter distribution (Ross Sea, Antarctica)
The results of a study on ectoenzymatic activity (the enzyme activity bound to particles larger than 0.2 μm) and its relation to organic particle concentration are reported here. The sampling was carried out during the 1994 Antarctic spring, at a fixed station (Station 11) in the polynya of the Ross...
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Online Access: | http://hdl.handle.net/11567/244422 https://doi.org/10.1007/s00248-002-2017-9 |
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ftunivgenova:oai:iris.unige.it:11567/244422 2024-04-14T08:02:23+00:00 Ectoenzymatic ratios in relation to particulate organic matter distribution (Ross Sea, Antarctica) MISIC, CRISTINA POVERO, PAOLO FABIANO, MAURO Misic, Cristina Povero, Paolo Fabiano, Mauro 2002 STAMPA http://hdl.handle.net/11567/244422 https://doi.org/10.1007/s00248-002-2017-9 eng eng Springer-Verlag New York Incorporated:175 Fifth Avenue:New York, NY 10010:(212)460-1500, EMAIL: orders@springer-ny.com, INTERNET: http://www.springer-ny.com, Fax: (212)533-3503 info:eu-repo/semantics/altIdentifier/wos/WOS:000179056700004 volume:44(3) firstpage:224 lastpage:234 numberofpages:11 journal:MICROBIAL ECOLOGY http://hdl.handle.net/11567/244422 doi:10.1007/s00248-002-2017-9 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-0036779947 info:eu-repo/semantics/article 2002 ftunivgenova https://doi.org/10.1007/s00248-002-2017-9 2024-03-21T02:22:27Z The results of a study on ectoenzymatic activity (the enzyme activity bound to particles larger than 0.2 μm) and its relation to organic particle concentration are reported here. The sampling was carried out during the 1994 Antarctic spring, at a fixed station (Station 11) in the polynya of the Ross Sea, an area characterised by quick changes in sea ice cover. The sampling was repeated 4 times over a 20-day time period. The particulate organic matter distribution followed the physical structure of the water column, which depends on ice dynamics and is mainly determined by salinity. In the mixed-water surface layer (0-50 m) the concentrations were higher (on average 65.6 μgC/l), than in the deeper water layer (50 m-bottom), (on average 19.1 μgC/l). This distribution and quality, expressed by the protein:carbohydrate ratio, linked the particulate organic matter to the phytoplanktonic bloom which was in progress in the area. We determined the kinetic parameters of the glycolytic and proteolytic ectoenzymes and also the total activity for the proteolytic enzyme, in order to evaluate the contribution of the particle-bound activity. We observed higher values in the surface layer than in the deeper layer. -glucosidase activity ranged between 0.03 and 0.92 nmol l-1h-1, -N-acetylglucosaminidase activity was in the range of 0.04-0.58 nmol l-1h-1. The total proteolytic activity (leucine aminopeptidase) ranged between 0.85 and 33.71 nmol l-1h-1. The ectoproteolytic activity was about 35% – 60 % of the total. The Km values were slightly higher for the proteolytic activity (on average 0.43 μM for ectoproteolytic activity and 0.58 μM for total proteolytic activity) than for the -glucosidase (on average 0.36 μM) and -N-acetylglucosaminidase (on average 0.17 μM), showing no remarkable variations in the water column. The ectoenzymatic ratios and their relationship with particulate organic substrates confirm the close link between organic substrate availability and degradation system response. The significant and positive ... Article in Journal/Newspaper Antarc* Antarctic Antarctica Ross Sea Sea ice Università degli Studi di Genova: CINECA IRIS Antarctic Ross Sea Microbial Ecology 44 3 224 234 |
institution |
Open Polar |
collection |
Università degli Studi di Genova: CINECA IRIS |
op_collection_id |
ftunivgenova |
language |
English |
description |
The results of a study on ectoenzymatic activity (the enzyme activity bound to particles larger than 0.2 μm) and its relation to organic particle concentration are reported here. The sampling was carried out during the 1994 Antarctic spring, at a fixed station (Station 11) in the polynya of the Ross Sea, an area characterised by quick changes in sea ice cover. The sampling was repeated 4 times over a 20-day time period. The particulate organic matter distribution followed the physical structure of the water column, which depends on ice dynamics and is mainly determined by salinity. In the mixed-water surface layer (0-50 m) the concentrations were higher (on average 65.6 μgC/l), than in the deeper water layer (50 m-bottom), (on average 19.1 μgC/l). This distribution and quality, expressed by the protein:carbohydrate ratio, linked the particulate organic matter to the phytoplanktonic bloom which was in progress in the area. We determined the kinetic parameters of the glycolytic and proteolytic ectoenzymes and also the total activity for the proteolytic enzyme, in order to evaluate the contribution of the particle-bound activity. We observed higher values in the surface layer than in the deeper layer. -glucosidase activity ranged between 0.03 and 0.92 nmol l-1h-1, -N-acetylglucosaminidase activity was in the range of 0.04-0.58 nmol l-1h-1. The total proteolytic activity (leucine aminopeptidase) ranged between 0.85 and 33.71 nmol l-1h-1. The ectoproteolytic activity was about 35% – 60 % of the total. The Km values were slightly higher for the proteolytic activity (on average 0.43 μM for ectoproteolytic activity and 0.58 μM for total proteolytic activity) than for the -glucosidase (on average 0.36 μM) and -N-acetylglucosaminidase (on average 0.17 μM), showing no remarkable variations in the water column. The ectoenzymatic ratios and their relationship with particulate organic substrates confirm the close link between organic substrate availability and degradation system response. The significant and positive ... |
author2 |
Misic, Cristina Povero, Paolo Fabiano, Mauro |
format |
Article in Journal/Newspaper |
author |
MISIC, CRISTINA POVERO, PAOLO FABIANO, MAURO |
spellingShingle |
MISIC, CRISTINA POVERO, PAOLO FABIANO, MAURO Ectoenzymatic ratios in relation to particulate organic matter distribution (Ross Sea, Antarctica) |
author_facet |
MISIC, CRISTINA POVERO, PAOLO FABIANO, MAURO |
author_sort |
MISIC, CRISTINA |
title |
Ectoenzymatic ratios in relation to particulate organic matter distribution (Ross Sea, Antarctica) |
title_short |
Ectoenzymatic ratios in relation to particulate organic matter distribution (Ross Sea, Antarctica) |
title_full |
Ectoenzymatic ratios in relation to particulate organic matter distribution (Ross Sea, Antarctica) |
title_fullStr |
Ectoenzymatic ratios in relation to particulate organic matter distribution (Ross Sea, Antarctica) |
title_full_unstemmed |
Ectoenzymatic ratios in relation to particulate organic matter distribution (Ross Sea, Antarctica) |
title_sort |
ectoenzymatic ratios in relation to particulate organic matter distribution (ross sea, antarctica) |
publisher |
Springer-Verlag New York Incorporated:175 Fifth Avenue:New York, NY 10010:(212)460-1500, EMAIL: orders@springer-ny.com, INTERNET: http://www.springer-ny.com, Fax: (212)533-3503 |
publishDate |
2002 |
url |
http://hdl.handle.net/11567/244422 https://doi.org/10.1007/s00248-002-2017-9 |
geographic |
Antarctic Ross Sea |
geographic_facet |
Antarctic Ross Sea |
genre |
Antarc* Antarctic Antarctica Ross Sea Sea ice |
genre_facet |
Antarc* Antarctic Antarctica Ross Sea Sea ice |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000179056700004 volume:44(3) firstpage:224 lastpage:234 numberofpages:11 journal:MICROBIAL ECOLOGY http://hdl.handle.net/11567/244422 doi:10.1007/s00248-002-2017-9 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-0036779947 |
op_doi |
https://doi.org/10.1007/s00248-002-2017-9 |
container_title |
Microbial Ecology |
container_volume |
44 |
container_issue |
3 |
container_start_page |
224 |
op_container_end_page |
234 |
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1796314542032027648 |