Taylor, JD and McKew, BA and Kuhl, A and McGenity, TJ and Underwood, GJC (2013) Microphytobenthic extracellular polymeric substances (EPS) in intertidal sediments fuel both generalist and specialist EPS-degrading bacteria. Limnology and Oceanography, 58 (4). pp. 1463-1480. DOI https://doi.org/10.4319/lo.2013.58.4.1463
Taylor, JD and McKew, BA and Kuhl, A and McGenity, TJ and Underwood, GJC (2013) Microphytobenthic extracellular polymeric substances (EPS) in intertidal sediments fuel both generalist and specialist EPS-degrading bacteria. Limnology and Oceanography, 58 (4). pp. 1463-1480. DOI https://doi.org/10.4319/lo.2013.58.4.1463
Taylor, JD and McKew, BA and Kuhl, A and McGenity, TJ and Underwood, GJC (2013) Microphytobenthic extracellular polymeric substances (EPS) in intertidal sediments fuel both generalist and specialist EPS-degrading bacteria. Limnology and Oceanography, 58 (4). pp. 1463-1480. DOI https://doi.org/10.4319/lo.2013.58.4.1463
Abstract
Microphytobenthic biofilms contain high concentrations of carbohydrate-rich extracellular polymeric substances (EPS) that are important in sediment carbon cycling. Field measurements at two locations in the Colne Estuary, U.K., showed that a significant curvilinear relationship explained 50% of the variability in chlorophyll a and EPS content. Estimates of EPS production, based on field data and published rates of production by diatoms, revealed that EPS turnover of 52% to 369% over the tidal cycle was required to account for field standing stocks. We investigated EPS degradation in sediment slurries using purified 13C-EPS produced by the diatom Nitzschia tubicola. Although EPS constituted only 5% of the sediment dissolved organic carbon (DOC) pool, 100% of the added EPS was utilized within 30 h, before decreases in other sediment-carbohydrate fractions and DOC concentrations. A general 13C enrichment of phospholipid fatty acids (PLFAs), representative of Gram-positive and Gram-negative bacteria, occurred within 6 h, with the PLFAs a15:0, i15:0, and 18:1?7c being highly enriched. The diatom PLFA 20:5?3 had relatively low but significant 13C enrichment. Stable isotope probing of 16S ribosomal ribonucleic acid (RNA-SIP) at 30 h revealed 13C-enriched sequences from the diatom genus Navicula; further evidence that diatoms assimilated the EPS, or EPS-breakdown products, from other diatom taxa. RNA-SIP also demonstrated a diverse range of highly 13C-enriched bacterial taxa, including a distinct subset (Alphaproteobacteria and Gammaproteobacteria) found only in the heavily labeled microbial assemblages. Thus, cycling of diatom EPS is rapid, and involves a wide range of microbial taxa, including some apparent specialists.
Item Type: | Article |
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Subjects: | Q Science > QH Natural history > QH301 Biology |
Divisions: | Faculty of Science and Health Faculty of Science and Health > Life Sciences, School of |
SWORD Depositor: | Unnamed user with email elements@essex.ac.uk |
Depositing User: | Unnamed user with email elements@essex.ac.uk |
Date Deposited: | 11 Jun 2013 21:03 |
Last Modified: | 16 May 2024 16:42 |
URI: | http://repository.essex.ac.uk/id/eprint/6890 |
Available files
Filename: 1463.pdf