Structural and functional patterns of active bacterial communities during aging of harpacticoid copepod fecal pellets
Cnudde, C.; Sanchez Clavano, C.J.; Moens, T.; Willems, A.; De Troch, M. (2013). Structural and functional patterns of active bacterial communities during aging of harpacticoid copepod fecal pellets, in: Cnudde, C. Trophic ecology of intertidal harpacticoid copepods, with emphasis on their interactions with bacteria = Trofische ecologie van intertidale harpacticoide copepoden, met de nadruk op hun interacties met bacteriën. pp. 107-126
In: Cnudde, C. (2013). Trophic ecology of intertidal harpacticoid copepods, with emphasis on their interactions with bacteria = Trofische ecologie van intertidale harpacticoide copepoden, met de nadruk op hun interacties met bacteriën. PhD Thesis. Ghent University (UGent): Gent. ISBN 9789090278285. 209 pp., more
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| Author keywords |
Copepod fecal pellet; Fecal pellet degradation; Active bacterial communities; Harpacticoid copepods; 16S rRNA; DGGE; Biolog EcoPlateTM |
| Abstract |
Copepod fecal pellet (fp) dissolved organic matter is consumed by free-living bacteria, while particulate matter is degraded by bacteria packed inside the fp (‘internal’) or attached to the fp surface after colonization from the environment (external). This study analyzed the contribution of ‘internal’ and external fp bacteria to the active bacterial community associated with the fp from two copepod species, Paramphiascella fulvofasciata and Platychelipus littoralis, during 60 h of fp aging in seawater. Despite early colonization (within 20-40 h), fp enrichment by seawater bacteria as deduced from RNA-based DGGE after 60 h was limited. In contrast, ‘internal’ bacteria showed high phylotype richness. The majority of ‘internal’ bacterial phylotypes persisted on aged fp and together represented half of the active bacterial community. Food source strongly impacted ‘internal’ bacterial diversity, though the exact origin of fp ‘internal’ bacteria, as either undigested food-associated bacteria or as copepod gut bacteria, could not be unambiguously determined. ‘Internal’ bacteria of fresh fp showed a high functional diversity (based on Biolog assays) to which Vibrio sp. contributed significantly. In terms of bacterial diversity and functional potential, degradation of copepod fp by ‘internal’ bacteria is equally important as by bacteria which colonize fp from the outside. |
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