Linkages between Dissolved Organic Matter Composition and Bacterial Community Structure

Foreman, Christine M.; Covert, Joseph S.

doi:10.1016/b978-012256371-3/50015-9

Cited by 23 publications

(13 citation statements)

References 65 publications

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“…The RAPD analyses separated spring water from Wappinger Creek samples amended with tannic acid, implying either differences in genetic potential in the two water types or, more likely, a difference in ''selective pressure'' exerted by tannic acid when added to low-DOC spring water versus higher DOC stream water. Selection of bacterial guilds by availability of labile versus refractory carbon has been documented in previous carbon amendments (Foreman and Covert 2003;Sinsabaugh and Foreman 2003).…”

Section: Discussionmentioning

confidence: 99%

Metabolic and structural response of hyporheic microbial communities to variations in supply of dissolved organic matter

Findlay

Sinsabaugh

Sobczak

et al. 2003

Limnology & Oceanography

205

124

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Hyporheic sediment bacterial communities were exposed to dissolved organic matter (DOM) from a variety of sources to assess the interdependence of bacterial metabolism and community composition. Experiments ranged from small-scale core perfusions with defined compounds (glucose, bovine serum albumin) to mesocosms receiving natural leaf leachate or water from different streams. Response variables included bacterial production, oxygen consumption, extracellular enzyme activity, and community similarity as manifest by changes in banding patterns of randomly amplified polymorphic DNA (RAPD). All DOM manipulations generated responses in at least one metabolic variable. Additions of both labile and recalcitrant materials increased either oxygen consumption, production, or both depending on background DOM. Enzyme activities were affected by both types of carbon addition with largest effects from the labile mixture. Cluster analysis of RAPD data showed strong divergence of communities exposed to labile versus recalcitrant DOM. Additions of leaf leachate to mesocosms representing hyporheic flowpaths caused increases in oxygen consumption and some enzyme activities with weaker effects on production. Community structure was strongly affected; samples from the leachate-amended mesocosms clustered separately from the control samples. In mesocosms receiving water from streams ranging in DOC (0.5-4.5 mg L Ϫ1 ), there were significant differences in bacterial growth, oxygen consumption, and enzyme activities. RAPD analysis showed strongest clustering of samples by stream type with more subtle effects of position along the flowpaths. Responses in community metabolism were always accompanied by shifts in community composition, suggesting carbon supply affects both functional and structural attributes of hyporheic bacterial communities.

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Section: Discussionmentioning

confidence: 99%

Metabolic and structural response of hyporheic microbial communities to variations in supply of dissolved organic matter

Findlay

Sinsabaugh

Sobczak

et al. 2003

Limnology & Oceanography

205

124

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“…Recent studies have begun to explore relationships between bacterial community structure (Chapter 3) and organic matter fluxes in the oceans (Foreman and Covert 2003;Kirchman 2003). There is no a priori reason to expect a tight link between 16S rRNA genes (phylogenetic lineage) and phenotypic traits involved in organic matter cycling (e.g., extracellular enzyme activity), because functional genes (particularly non-essential genes) may be easily transferred across different lineages (lateral gene transfer), as suggested for chitinase genes .…”

Section: Bacterial Community Structure and Utilization Of Organic Mattermentioning

confidence: 99%

Organic Matter–Bacteria Interactions in Seawater

Nagata

2008

Microbial Ecology of the Oceans

117

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“…DOM is an important carbon source for microbial communities (Voelker et al 1997;Tranvik and Kokalj 1998;Moran et al, 1999;Foreman and Covert 2003) and plays a critical role in the cycling of global carbon (Amon and Benner 1994;Hedges et al 1997;Dittmar and Kattner 2003). Organic matter concentrations in Arctic rivers are generally among the highest reported in the world's rivers, with dissolved organic carbon (DOC) levels between 230 and 1000 lM C (e.g., Lara et al 1998;Opsahl et al 1999;Kohler et al 2003), which typically exceed particulate organic carbon levels (Lobbes et al 2000).…”

Section: Introductionmentioning

confidence: 97%

Hydroxyl Radical Production from Irradiated Arctic Dissolved Organic Matter

et al. 2006

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The hydroxyl radical (OHAE) plays an important role in the environmental chemistry and biogeochemistry of surface waters. OHAE acts as a strong oxidant within the irradiated water column, and affects the bioavailability, cycling, and mineralization of dissolved organic matter (DOM), the speciation and redox state of important trace metals e.g., iron and copper, and the fate of persistent organic pollutants (POPs). The generation of this species from irradiated DOM may be especially important in Arctic surface waters during the boreal summer, which contains high levels of DOM and experiences continual solar irradiance. Here, we investigate the OHAE produced from laser irradiated Arctic DOM isolated from Toolik Lake, AK (68°38¢ N, 149°43¢ W). We measured the wavelength dependence of OHAE production for aqueous solutions of DOM and report that the greatest OHAE production occurs at wavelengths less than 360 nm. OHAE production rates ranged from 1.7 (±0.1) · 10 À7 M h À1 to 6.4 (±0.2) · 10 À7 M h À1 , with the rate depending on both irradiation wavelength and to a lesser degree the method used to isolate the DOM matrix. These findings lead to a better understanding of the potentially important photo-oxidation processes that may impact DOM cycling in the Arctic.

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Linkages between Dissolved Organic Matter Composition and Bacterial Community Structure

Cited by 23 publications

References 65 publications

Metabolic and structural response of hyporheic microbial communities to variations in supply of dissolved organic matter

Metabolic and structural response of hyporheic microbial communities to variations in supply of dissolved organic matter

Organic Matter–Bacteria Interactions in Seawater

Hydroxyl Radical Production from Irradiated Arctic Dissolved Organic Matter

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