Production and fate of extracellular polymeric substances produced by benthic diatoms and bacteria: A laboratory study

Lundkvist, Morten; Gangelhof, Uffe; Lunding, Jens; Flindt, Mogens

doi:10.1016/j.ecss.2007.04.034

Cited by 28 publications

(17 citation statements)

References 32 publications

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“…Synergistic effects between autotrophic and heterotrophic microorganisms have already been demonstrated in terms of EPS secretion and especially the contribution of proteins (Gerbersdorf et al, 2009;Lubarsky et al, 2010). Our summer results suggest such synergistic effects between bacteria, microalgae and EPS (van Duyl et al, 2000;Gerbersdorf et al 2009, Lubarsky et al, 2010Lundkvist et al, 2007), since bacteria and diatoms were positively correlated in summer. Such positive association between MPB and bacteria was not detected in winter, along with the absence of proteins in EPS.…”

Section: The Diversity Of Colloidal and Bound Eps Functionssupporting

confidence: 69%

Tidal and seasonal effects on the short-term temporal patterns of bacteria, microphytobenthos and exopolymers in natural intertidal biofilms (Brouage, France)

Orvain

Crignis

Guizien

et al. 2014

Journal of Sea Research

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International audienceRelationships between bacteria, microphytobenthos and extracellular polymeric substances (EPS) that makeup microbial biofilms over bare mudflats were investigated at an hourly frequency during two 14-day spring–neap cycles in winter and summer 2008. Bacterial abundance and total chl a concentration were lower in summer(0.78 × 108 ± SD 0.39 × 108 cell.m−2 and 59.0 ± SD 10.42 mgchla.m−2) than in winter (3.7 × 108 ± SD1.9 × 108 cell.m−2 and 106.64 ± SD 11.29 mgchla.m−2), coinciding with a high abundance of the gastropodPeringia ulvae in summer, which subsequently impacted 1st-cm chl a concentration by intense grazing. Boundand colloidal EPS carbohydrate temporal patterns were similar in winter (5.71 ± SD 3.95 and 4.67 ± SD3.45 μg.g−1, respectively) butwere different in summer (14.9±SD 4.05 and 5.60±SD 4.50 μg.g−1, respectively).Carbohydrate colloidal EPS appeared to be related to light and salinity, while 1st-mm chl a concentration wasnegatively affected by strong salinities and predation pressure by P. ulvae. The fluctuations of colloidal carbohydrateswere remarkably similar in the two seasons with peaks just after spring tideswhen the highest irradiancewas received by microphytobenthic cells. Apparently, colloidal EPS carbohydrates can protect cells against thehigh salinity values ranging from 32.3 to 50.4 PSU. The presence of bound EPS carbohydrates may be linked tosediment colonization and resistance of biofilm activity. Proteins in EPS were absent in winter and representeda small proportion in summer (10%), but they appeared to be a good indicator of potential synergistic effects betweenMPB and bacteria in summer. Conversely, bound EPS carbohydrates reached high levels in winter, whilethe number of bacteria decreased simultaneously, suggesting a negative effect on bacterial growth in the absenceof proteins in EPS. There was a lower proportion (31%) of low molecular weight EPS in summer than in winter(83%), possibly in relation to desiccation

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Section: The Diversity Of Colloidal and Bound Eps Functionssupporting

confidence: 69%

Tidal and seasonal effects on the short-term temporal patterns of bacteria, microphytobenthos and exopolymers in natural intertidal biofilms (Brouage, France)

Orvain

Crignis

Guizien

et al. 2014

Journal of Sea Research

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“…Cohesive sediments free of fauna generally experience high surface stability due to undisturbed growth of microphytobenthos films and the associated high EPS production that binds sediment particles (Austen et al, 1999;Paterson et al, 2000;Whitehouse et al, 2000;Lundkvist et al, 2007a). The almost doubled erosion threshold (u c ) during the 5 days between erosion cycles in our defaunated sediment emphasizes that the development of biostabilization through microphytobenthic EPS production is rapid and efficient.…”

Section: Discussionmentioning

confidence: 91%

“…A 12 light/12 dark cycle was maintained by tube lamps (Philips TL-D 36W/54-765) placed 0.5 m above the water surface. The light intensity was monitored continuously using a LI-COR Data Logger (LI-1000) to assure an intensity of at least 100 mmol photons m À2 s À1 at the sediment surface, which was considered optimal for the microphytobenthos (Lundkvist et al, 2007a). Three separate experimental series were carried out; one for each animal species (Exp HU with Hydrobia ulvae, Exp ND with Nereis diversicolor and Exp SP with Scrobicularia plana).…”

Section: Methodsmentioning

confidence: 99%

Influence of benthic macroinvertebrates on the erodability of estuarine cohesive sediments: Density- and biomass-specific responses

Kristensen

Neto

Lundkvist

et al. 2013

Estuarine, Coastal and Shelf Science

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Regional index term: Portugal Mondego EstuaryKeywords: erosion threshold erosion rate behaviour macrofauna feeding microphytobenthos biostabilization a b s t r a c tThe impact of three dominating benthic invertebrates on sediment stability and erosion conditions of cohesive sediments in the Mondego Estuary, Portugal, was examined in laboratory annular flume experiments. The purpose was to test how the life habits and body size of the three involved species (Hydrobia ulvae, Nereis diversicolor and Scrobicularia plana) in terms of density or biomass influence sediment erosion. All three species decreased the free-stream erosion threshold (u c ) and increased erosion rate (E), since their feeding activities diminished the surface stabilizing effect of extracellular polymeric substances (EPS) produced by microphytobenthos. S. plana had the highest and H. ulvae the lowest impact when related to density (factor of 29 for u c and factor of 19 for E), while H. ulvae was more important than S. plana when related to biomass (factor of 4 for u c and factor of 6 for E). N. diversicolor had intermediate density-specific (4e6 times higher than H. ulvae) and lowest biomass-specific (2e3 times lower than S. plana) effects on erosion. It appears that faunal erosion impacts preferably should be reported in biomass units for comparative purposes because individual behavioural effects of a smallbodied species like H. ulvae functionally can be relatively more important than those of a 100 times heavier S. plana individual. This is clearly evidenced from the strongly diminished response in suspended Chlorophyll-a content in the presence of the former than the latter species, which is caused by an efficient microphytobenthos grazing by H. ulvae. It is also important to emphasize that the total faunal impact on erosion threshold in a certain area is dictated by combination of contributions from individual species. The total outcome is unpredictable and controlled by synergistic and antagonistic speciesspecific effects, species interactions as well as environmental and sediment conditions.

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“…Indeed, not only diatoms are well known contributors to EPS in soft-bottom environments, but also their EPS are mainly composed of carbohydrates (Hoagland et al, 1993;Underwood et al, 2004). Other possible contributors to EPS secretion in our experiment were bacteria (Decho, 1990;Lundkvist et al, 2007) and also H. diversicolor, which produces mucus helping their locomotion and feeding behaviours (Scaps, 2002;Stabili et al, 2011). Yet, bacterial EPS are mainly made of proteins (Bhaskar et al, 2005;Lubarsky et al, 2010), as well as mucus of annelids (Stabili et al, 2011).…”

Section: Enhanced Sediment Adhesives Capacity In Presence Of Both Diamentioning

confidence: 93%

Surface adhesion of microphytobenthic biofilms is enhanced under Hediste diversicolor (O.F. Müller) trophic pressure

Passarelli

Hubas

Segui

et al. 2012

Journal of Experimental Marine Biology and Ecology

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Production and fate of extracellular polymeric substances produced by benthic diatoms and bacteria: A laboratory study

Cited by 28 publications

References 32 publications

Tidal and seasonal effects on the short-term temporal patterns of bacteria, microphytobenthos and exopolymers in natural intertidal biofilms (Brouage, France)

Tidal and seasonal effects on the short-term temporal patterns of bacteria, microphytobenthos and exopolymers in natural intertidal biofilms (Brouage, France)

Influence of benthic macroinvertebrates on the erodability of estuarine cohesive sediments: Density- and biomass-specific responses

Surface adhesion of microphytobenthic biofilms is enhanced under Hediste diversicolor (O.F. Müller) trophic pressure

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