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Bacterivorous nematodes stimulate microbial growth and exopolymer production in marine sediment microcosms

TitreBacterivorous nematodes stimulate microbial growth and exopolymer production in marine sediment microcosms
Type de publicationJournal Article
Year of Publication2010
AuteursHubas, C, Sachidhanandam, C, Rybarczyk, H, Lubarsky, HV, Rigaux, A, Moens, T, Paterson, DM
JournalMarine Ecology-Progress Series
Volume419
Pagination85–94
ISSN0171-8630
Mots-clésbacteria, Benthic diatoms, EPS, Extracellular polymeric substances, Free living nematodes, Intertidal, Marine sediment
Résumé

The cohesive strength of intertidal soft sediments depends on a large range of physicochemical parameters, but the production of exopolymers by the inhabiting organisms is increasingly recognized as a major stabilizing factor. It is likely that the vast majority of these polymers are produced by microorganisms but very few studies have addressed the impact of benthic meiofauna on this microbial production. The major aim of this study was thus to estimate the impact of nematodes (often the main contributor to meiofauna abundance and biomass in temperate intertidal habitats) on the EPS (extracellular polymeric substances) production of marine sediments. Bacterivorous nematodes Diplolaimelloides meyli Timm, 1961 and D. oschei Meyl, 1954, bacteria and diatoms were grown in laboratory experiments both separately and together to estimate their respective influence. Our experiment revealed a positive impact of bacterivorous nematodes on microbial density and EPS production. Surprisingly, the biofilm structure (in terms of microbial abundance/biomass and EPS content) was better explained by the complexity (i.e. the number of trophic levels) of the assemblages rather than by any specific types of organisms involved in the experiment.

DOI10.3354/meps08851