Particle-associated extracellular enzyme activity and bacterial community composition across the Canadian Arctic Ocean.
FEMS Microbiol Ecol
; 89(2): 360-75, 2014 Aug.
Article
en En
| MEDLINE
| ID: mdl-24666253
ABSTRACT
Microbial enzymatic hydrolysis of marine-derived particulate organic carbon (POC) can be a dominant mechanism for attenuating carbon flux in cold Arctic waters during spring and summer. Whether this mechanism depends on composition of associated microbial communities and extends into other seasons is not known. Bacterial community composition (BCC) and extracellular enzyme activity (EEA, for leucine aminopeptidases, glucosidases and chitobiases) were measured on small suspended particles and potentially sinking aggregates collected during fall from waters of the biologically productive North Water and river-impacted Beaufort Sea. Although other environmental variables appeared influential, both BCC and EEA varied along a marine productivity gradient in the two regions. Aggregates harbored the most distinctive bacterial communities, with a small number of taxa driving differences between particle-size classes (1.0-60 and > 60 µm) and free-living bacteria (0.2-1.0 µm). Significant relationships between patterns in particle-associated BCC and EEA suggest strong links between these two variables. Calculations indicated that up to 80% of POC in the euphotic zone of the North Water, and 20% in the Beaufort Sea, may be hydrolyzed enzymatically, underscoring the importance of this mechanism in attenuating carbon fluxes in Arctic waters even as winter approaches.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Agua de Mar
/
Bacterias
/
Proteínas Bacterianas
/
Microbiología del Agua
Tipo de estudio:
Risk_factors_studies
País/Región como asunto:
America do norte
Idioma:
En
Revista:
FEMS Microbiol Ecol
Año:
2014
Tipo del documento:
Article
País de afiliación:
Estados Unidos