Degradation of Mangrove-Derived Organic Matter in Mangrove Associated Sponges

Abstract

Degradation of mangrove-derived organic matter in mangrove associated spongesHunting, E.R.; de Goeij, J.M.; Asselman, M.; van Soest, R.W.M.; van der Geest, H.G. General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. ABSTRACTSponge communities found in Caribbean mangroves are typical to this habitat: partly endemic and very distinct from sponge communities on nearby reefs. A tradeoff between resistance to competitors and predators appears to influence success of individual sponge species in mangrove habitats. We speculate that differences in the symbiotic microbial communities may partly be responsible for these differences, as partial degradation of recalcitrant compounds by tannin-degrading microorganisms may enhance palatability and facilitate dissolved organic matter (DOM) assimilation in the presence of high concentrations of tannins, thereby improving their competitive capabilities. We tested tannase activity and ability to degrade mangrove-derived DOM in a random set of sponge species collected from mangrove roots in Curaçao and adjacent reefs. Our results suggest that sponges commonly associated with mangrove roots contain bacteria that are capable of degrading mangrove-derived DOM, while bacterial communities associated with sponges that are more typical to reef environments appear less proficient in degrading mangrove-derived DOM. Host specificity of bacterial endobionts capable of degrading mangrove-derived DOM and the presence of high concentrations of recalcitrant organic compounds may lead to ecological separation between mangrove and reef sponge communities.

Substrate as a driver of sponge distributions in mangrove ecosystems

“…Bacterial endosymbionts of the sponge specimens were extracted from subsamples of sponge tissue (0.1 cm 3 ) in a Precellys 24 lysis/homogenizer (Bertin Technologies) using ∅ = 0.1-and 0.5-mm beads. Subsequent centrifugation was performed for 30 s at 11 000 × g (Hunting et al 2010a). We assessed bacterial metabolic diversity by community level physiological profiling using Biolog GN microplates containing 95 unique single substrates (Garland & Mills 1991, Garland 1997.…”

“…However, mangrove-derived dissolved organic matter (DOM) consists mainly of tannins and polyphenolic compounds (Maie & Jaffe 2006), which are structurally complex and recalcitrant to biodegradation (Field & Lettinga 1992, Koch et al 2005, Kristensen et al 2008. Increasing evidence suggests that only a limited number of bacterial and fungal species are able to degrade complex polyphenols and tannins (Bhat et al 1998) and it has indeed been demonstrated that sponges commonly associated with mangrove roots contain bacteria that are capable of degrading mangrove-derived DOM, while bacterial communities associated with sponges that are typical to reef environments appear less proficient in degrading mangrove-derived DOM (Hunting et al 2010a). It is therefore hypothesized that the presence of bacterial endosymbionts that are capable of degrading mangrove-derived DOM may explain the observed differences in species composition between mangrove and reef sponge communities.…”

Contribution of bacteria to redox potential (E h) measurements in sediments

“…Bacterial activity was analyzed by dehydrogenase enzyme activity via the reduction of 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride (INT) to formazan (INTF), since INT reduction proved an accurate assay of electron transfer system activities (ETSA) under both anaerobic and aerobic conditions (Smith and Mcfeters 1997;Hunting et al 2010). Bacterial cells were simultaneously sampled alongside the platinum electrodes (400 lL porewater sample).…”

Predictability of bacterial activity and denitrification in aquatic sediments with continuous measurements of redox potential

“…It should be noted, however, this approach is used to address the predictive potential of Eh and accurate estimations of denitrifications rates were beyond the scope of this study, provided that the approach is very likely to overestimate the actual process (Seitzinger, 1988). Overall respiratory capacity of th e bacter ial commun ity was approximated by dehydrogenase enzyme activity via th e reduction of 2-(p-iodoph en yl)-3-(p- Porewater probe Bacteria probe impermeable HDPE accurate assay of Electron transfer system activities (ETSA) under both anaerobic and aerobic conditions (Smith and Mcfeters, 1997;Bhupathiraju et al, 1999;Rozzi and Remigi, 2004;Hunting et al, 2010). Bacterial cells were simultaneously sampled alongside the platinum electrodes (400 µL porewater sample).…”